essay on perception

Psychology Discussion

Essay on perception | psychology.

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After reading this essay you will learn about:- 1. Introduction to Perception 2. Phenomenological and Gestalt View on Perception 3. Perceptual Organisation 4. Transactional Approach 5. Depth Perception 6. Constancy 7. Perception of Movement 8. Development 9. Errors 10. Studies.

• Essay on the Studies on Perception

Essay # 1. Introduction to Perception:

Perception involves arriving at meanings often leading to action. In addition to the nature of the stimuli, and past knowledge, perception is influenced by many other factors. In this article, an attempt is made to present to the student a discussion of the various factors involved in attention and perception.

How exactly are we able to relate to discrete sensory experiences in order to see them as meaningful? In other words, how exactly does perception occur? At any time we are attending to a number of stimuli. For example even when we are listening to the teacher we are conscious of his voice, his movement, his appearance etc., but at the same time we respond to him as a single person. This shows that our response is integrated and organised to become meaningful. This process of organising and integrating discrete stimuli and responding to them meaningfully is known as perception.

In the early part of this century the structuralist view of perception was dominant. It held that just as consciousness could be neatly dissected into its component parts, so also could perceptual experiences. Thus, the phenomenon of perception was, for the structuralists, the sum of mere sensations and the meaning associated with it through experience.

Without the benefits of experience there can be no meaning attached to stimuli or to sensations, and thus, there can be no ‘perception’. The infant, therefore, is able only to receive sensory input; it is not able to ‘perceive’ anything meaningful. William James described the infant’s perceptual world as a “booming, buzzing confusion.”

However, what does this actually mean in terms of the process of perception? It means that the infant has to learn to differentiate between different sensory experiences. It has to learn to construct perceptual categories through which it can perceive the differences between various sights, sounds, smells and feelings.

The infant’s visual world is formless, shapeless and chaotic. The real physical categories that exist in the world like forms, sounds and colours have to be repeated a sufficient number of times to be perceived as distinct and separate impressions by the infant. In this way the infant learns to perceive forms and objects and associates them with various meanings in their context.

Essay # 2. Phenomenological and Gestalt View on Perception :

A view totally different from the one given above emerged from the writings of phenomenologists. Even in the earlier days, German writers and philosophers had differed on the concept of perception as resulting from a combination of discrete sensory stimulations compounded by experience. They had tended to take the view that perception is a total act not necessarily bearing total resemblance to external stimulus characteristics.

The process of perception is not totally logical but it is, to a large extent, phenomenological. The German philosophers made a distinction between physical reality and experienced reality or phenomenal reality. One’ fact of experience is that perceived objects are always perceived as one and not as assemblages or discrete pieces of sensory information.

The phenomenological writers tended to lay emphasis on the inner processes rather than just experience and stimulus characteristics. The phenomenological view gained popularity through the writings of Husserel Brentano and Carl Stumpf. The real landmark in phenomenology was the work of Ehrenfels on tonal qualities.

He emphasised the totality of experience in melodies. The total experience is something more than some of the individual elements and he gave the name Gestalt Qualitat to this. An example of the phenomenological process in perception can be clearly seen in our experience of illusions. This line of explanation and experimentation was further developed by gestalt psychologists.

The ‘gestalt psychologists’ experiments on animals and birds showed that even at birth there are certain perceptual categories and abilities already present. Riesen showed that chicks brought up in total darkness could immediately distinguish the shape of a grain on the floor when brought into the light.

More recently, experiments by Lipsitt and Siquel have shown that even- a few hours old human infants can distinguish between the sound of a buzzer and that of a bell. Thus the infant’s world is neither a confusion nor a chaos as it was earlier made out to be.

Of course, the infant cannot perceive all objects with the same depth of meaning and understanding as adults can. But certain fundamental perceptual and discriminatory abilities – called perceptual organisations-are built into animals and human beings from birth.

Furthermore, the gestaltists challenged the view that perceptions can be divided into component elements. According to the structuralists, perceiving a chair means dissecting it into the elements of shape, size and angles of the parts of the chair, bound together by meanings from previous experience.

To the gestaltists, this molecular view of the subject destroyed one’s understanding of the phenomenon of perception as a whole. They demonstrated how perceptual phenomena often could not be reduced to elements. The experience of watching a movie on a screen cannot be explained by analysing the series of still pictures that go to make it up.

Listening to a tune- or a particular tune- in one key still gives the experience of the same tune when listening to it in another key, although the elements in both cases are entirely different. This lead to their famous dictum that the whole is greater than the sum of its parts – Gestalt Qualitat. – a unique quality of wholeness.

Essay # 3. Perceptual Organisation :

Animals and human beings are endowed with the capacity to organise and group stimuli which are ambiguous, confusing and novel, thus making them meaningful or sensible. Gestalt psychologists have demonstrated the principles which affect and direct the organisation in order to make the stimulus a meaningful whole within the perceptual field.

Some of the well recognised principles which contribute to perceptual organisation are as follows:

Figure and Ground Relationship :

The basic principle behind perceptual organisation is known as figure and ground organisation. This phenomenon was originally demonstrated by Rubin. One of the most fundamental principles of organisation in the field of perception is distinguishing between the figure and the ground, i.e. the figure which appears against a background.

Gestalt psychologists claim that even in the simplest form of perception, the figure and ground factor operates. For instance, when one is reading these sentences the black letters are perceived against the white background. A flying aero plane, for example, stands out as a figure against the sky or the clouds around it which form its background.

Stimuli which are outstanding and striking in terms of colour, shape etc. come to the foreground to form the figure and the less important or less significant ones recede to the background. However, when there are several objects in the general field of awareness which have equally balancing qualities there may be a conflict and two or more figures may be formed. In such a case there will be a shifting of ground and figure. One part may become the figure at one moment and at the next moment the same may become the ground (see Fig.7.1).

Essay # 4. Transactional Approach to Perception:

The traditional watertight distinctions among different kinds of behaviour like learning perception, motivation are also being given up resulting in a tendency to look at human actions as involving an entire organism totally integrated and directed towards adjusting or adopting to certain environmental requirements.

This emerging view has led to a perspective called the transactional perspective or transactional approach. One of the pioneers in promoting this approach was Ames whose experiments on perception and perceptual illusions are well known.

The transactional approach to perception basically holds that any act of perception at any time is influenced by the past learning experience of the individual and looks at any perception as a transaction or an act of dealing with the environment and other stimulus situations and tries to structure one’s perception in a manner that is maximally approximate to the world of reality.

Some of the basic postulates of the transactional approach to perception are:

(A) Basically those who support this view hold that perception involves an active interaction between the perceiver and the environment, and in this, the past experience and learning of the individual plays a crucial role. Further they also hold that every new perception results in new learning.

(B) The final perception results from a process of active interaction, in which the individual operates on the environment. Thus interaction serves our adaptive function and in view of this they often use the term transactional functionalism.

(C) Such interactions are often unconscious and unknown to the individual resulting in sudden and spontaneous inferences – the role of the conscious process being insignificant.

(D) Transactions not only reflect the past and help us in drawing inferences about the past of the persons, but are also future orientations and the overall life orientations of people. Thus, it may be seen that the past .influence and the present, both are integrated and oriented towards the future.

Ames says that people perceive things, objects, persons and the environment not always as the latter are, but in such a way as to make them compatible with one’s own assumptions and beliefs already acquired, thus very often necessitating distortion of objective reality.

Ames designed a number of experiments using a variety of perceptual situations designed by him like the well-known rotating trapezoid and also what are well known as Ames room experiments. Some of the other postulates of this approach are, that perception follows a certain trend of development during childhood.

It is further claimed that perceptual illusions can be overcome through learning. Though far from being advocates of the typical learning theory approach, those who support the transactional view express the view that even space perception and depth perception are very much products of learning. Thus, they do not support a mechanical view.

What happens in perception is a projection of the perceiver’s own constructs about the stimulus situation with the intention of achieving one’s purpose in action. Thus there is a give and take relationship between perceiver and the perceived situation involving a compromise with the actual reality and one’s own propensity or desire to keep certain assumptions and beliefs constant. The transactional approach is still a loosely formulated approach on the basis of a variety of experiments carried out by different investigators.

One can clearly see the impact of other earlier views on human behaviour like psychodynamics, influences of past experiences, tendency to maintain equilibrium and constancy (dynamic-homeostasis) and phenomenology. The transactional approach in a way makes use of all these assumptions and integrates them. One may not call it a theory, but it certainly is an approach.

Essay # 5. Depth Perception:

One important aspect in perception is the perception of depth, the third dimension or distance we are able to perceive objects as being near or far off. The basic psychological mechanism cannot explain this. The question has been a perplexing one. One view holds that this ability is innate while the other holds that this is an acquired ability. We perceive one rupee coin as one with a depth. This is called the third dimension.

Empiricistic and Nativistic Views :

To have a better understanding of the phenomenon of depth one ought to consider the philosophies of empiricism and nativism. Their views emerged as a consequence of the certainties and uncertainties about human nature. Their key concepts regarding the mind contradict each other and yet remain as the supporting pillars of these views to this day. Empiricism claims that the mind at birth is like a ‘blank slate’ while nativism claims that it is like a ‘veined marble’.

John Locke was the first philosopher who suggested that the mind was initially a ‘tabula rasa’,i.e. it is like a smooth wax table upon which impressions of external events print themselves. This is the crux of empiricism.

Processes like perception and thought reflect the particular structure and dynamics of the world in which we happen to live. However, the basic mechanism through which printing or imprinting operates is by the principles of association, similarity, contiguity, etc. According to the empiricists impressions arrange and rearrange themselves to form the core of our perceptions.

We can see that this idea has shaped many modem systems of psychology. Wundt’s theory of introspectionism is bolstered by empiricism. Pavlov’s work on conditioning, Guthrie’s theory of contiguity, and Broadbent’s account of mental functioning in terms of information processing are all built on the philosophy of empiricism.

Other theorists like Leibnitz proclaimed that the mind is like a slab of marble with veins or streaks. His theory of knowledge was aimed against sensualism and empiricism. To Locke’s postulate “there is nothing in the mind which has not been in the senses” Leibnitz added except the intellect itself.

According to him intellect is present at birth and only gets shaped by experiences. It becomes obvious that nativism as a doctrine boldly proclaims the importance of innate factors in the development of an organism rather than the environmental or experiential ones. A lot of research findings of recent years are heading towards nativism.

Andrey’s books “The African Genesis” “The Territorial Imperative” have popularized a nativistic interpretation of man’s aggression and of his alleged tendency to defend his territory. Audrey believes that many of the modem man’s aggressive tendencies can be traced back to his meat-eating, weapon using ancestors.

Jung’s concept of archetypes leans heavily on nativism. Ethnologists like Lorenz and Tinbergen have shown a strong evidence for innate determination of species-specific behaviour. Another piece of nativistic evidence comes from the field of perception. T.G.R. Bower has found a striking evidence that form constancy, through the visual cliff experiment, is innate in human infants.

A circle seen at an angle is responded to as a circle and not as an ellipse. Gibson and others have provided evidence indicating that depth perception is innate in many species. Immense support to this doctrine is lent from oriental philosophy which has recently been invading the western scientific world. The oriental philosophers support nativism to the core. In the following discussion we see a clear swing towards nativism.

In Gibson’s experiment, the visual cliff consists of a wide sheet of transparent glass placed over a drop on the floor. Gibson and Walk showed that by the time infants could crawl, they would not crawl over the deep side of a visual cliff under any circumstances (see Fig.7.7). This is also true of most new-born animals, which refuse to cross over the cliff.

By the time they start crawling, however, human infants have had ample time to learn depth cues. White tested infant perception of depth prior to the crawling stage by noting eye-blink responses to a falling object in a transparent cylinder positioned over the infant’s face.

If the infants blinked it was assumed that they were responding to the change in distance rather than just the change in retinal size of the falling object which did not otherwise elicit a blink. White also observed that the eye-blink response and, therefore, distance perception-occurred only after eight weeks in the human infant.

Bower put even younger infants in an upright position in a chair and found that infants even as young as two-week old adopted defensive behaviour when seeing an object approach their faces. Eye-blinking, which in this case would not have served to protect them, did not occur, but there was clear eye widening, head retraction and the interposition of the hands between the face and the object.

Bower, thus, demonstrated a clear functional response to visual cues of distance alone, which, in a one-week old infant can be assumed to be unlearned.

Feature Analysis :

Our analysis of the perceptual process has indicated that in any instance the act of perception is influenced by two types of processes. On the one hand we have high level central and also psychological factors like expectations and motivations which do not originate from lower order sense impressions, even though they may be triggered off by them.This type of involvement of high level process is known as top-down processing.

On the other hand processes which originate from lower level physiological and stimulation information are known as bottom-up processing. In this context, psychologists refer to a term called ‘feature analysis’, explaining how these two types of processes operate.

Some psychologists hold the view that perceptual recognition is made possible because a particular set of neurons in the brain are activated, as and when they find an appropriate matter in the field of perception. This is like the phenomenon where only one tuning fork from among a row goes into vibration, when its corroborating match is set in motion.

This is the hierarchical feature detection model. But the difficulty with this model is that this would require a specific set of neurons or feature detection in our brain .Every corresponding sound or light stimulus should have such detectors.

Though it is now known that there are specific set of neurons for certain specific stimulus characteristics, the possibility of having an endless number of specific detectors is yet to be proved. Thus the correctness of this view depends on further achievements in neurology regarding the neuronal functions.

A different and perhaps more widely accepted view is that there occurs what may be called feature analysis. According to this view, the specific detection neurons are of such a type that they can operate in different combinations. For example, they may be recognised as a pair of vertical lines which are parallel with a horizontal line connecting the two in the middle.

Feature analysis involves the brain analysing experiences or perceptual contents into such sets and whenever such set or combination, is available for retrieval from neurons, then recognition occurs. This concept of feature analysis explains how people recognise stimuli and in addition, also provides a clue as to how different stimuli can be given a common interpretation.

For example, when we see different flowers, though we see them as different, we see them all as flowers. But what happens when a. combination of such detections stored in memory do not match with what is actually present? For example, it is very difficult for us or at least some of us to recognise cauliflower as a flower, though many stimulus characteristics resemble that of many other flowers.

It is here that the concept of feature analysis cannot explain, what happens, when the stimuli are ambiguous and are both similar and dissimilar to stored up combinations. It is here that one sees the limitations of bottom up processing theory. It is in this context that the top down processing comes into operation.

Top down processing is influenced by the context of stimuli which creates certain expectations or “expectancies.” We expect certain things to occur, under certain situations or contexts. These expectations based on past experiences and contextual factors, set in motion certain perceptual sets.

The role of expectancy in perceptual recognition was clearly demonstrated in an experiment by Palmer. Palmer showed his subject a scene of a kitchen. Then they were given a very brief exposure to two objects, one resembling a loaf of bread (context relevant) and another a mail box (context irrelevant). The two objects were of the same size and shape. But the subject recognised the loaf of bread more than the mail box, thus showing the influence of centrally aroused expectancy.

Motivation is another factor. The importance of needs in influencing process of perceptions has already been examined. The classical experiments of Brownes and others have already demonstrated the role of motivational factors and needs in the process of perception.

Normally in most acts of perception both top down and bottom up processes work together, each supplementing and complementing the other. Top down processing plays a more crucial role where the stimulus situations are ambiguous, or relatively unfamiliar.

The importance of top down processing will become clearer to the reader later when we discuss the role of “personality factors in perception”. A number of experiments have shown that our perception is very much influenced by the totality of our personality, and personalities have been classified even on the basis of perceptual styles or modes.

Essay # 6. Constancy in Perception:

When we think about perceptual experiences they seem to be incredibly paradoxical. We realise that we see mobility in stationary objects, immobility in moving objects, and see things which are incomplete as complete. The cues which are said to facilitate perception of distance can, at times, corrupt and distort the same.

Similarly, we are able to respond to a stimulus appropriately even with a distorted, wrong or absent retinal image. This contradicts the view that the retinal image is a true reproduction of the object being sensed and considered as a basic mechanism which provokes an appropriate action or reaction. All these make us wonder if we are in a world of illusions or whether perception, by itself, is a big illusion.

One such paradoxical phenomenon discussed here is perceptual constancy. The phenomenon of constancy refers to our perceptual experiences wherein perception remains constant, in spite of the fact that stimulating conditions stipulate a change. Thus, the human being is perceived to be of the same height whether he is seen from a distance of two feet, five feet or fifteen feet.

The phenomenon of constancy is seen in relation to several attributes of the objects like shape and size. To a certain extent the phenomenon of constancy also results in errors of perception, though its advantages far outweigh its disadvantages.

If we accept that the infant does not have to learn entirely to distinguish between forms, shapes and sounds in his environment, but possesses a congenital capacity to do so, there is yet another problem which has aroused a lot of controversy. When we talk of visual perception in particular, how do infants – or even adults – actually make sense of visual objects? The obvious answer seems to be that objects in the external world appear as images on the retina and the individual then responds to these images as objects.

However, the answer is not quite so simple. The retina receives images which vary drastically depending on the particular lighting conditions, the viewing angle and the distance of the object at any given time. If one were to perceive objects merely on the basis of retinal images, one would see a different object at each angle and at each distance from which the same object was viewed. This obviously, does not happen.

When we see a plate at an angle its retinal image is an ellipse. If we see it head on then the retinal image is a complete circle. Yet, we know that both the greatly differing images are of the same object. When we see a chair from a foot away, the retinal image we receive is much larger than that received when the chair is two yards away from us. Yet we know that it is the same object. How do we come to know this?

The controversy that has surrounded the answer to this question has been again one of the opposition between the view that the child is born with the complete ability to see the world as the adult sees it, and the view that the child has to learn to see stable objects. For a long time the latter view held sway-namely, that the individual has to learn to compensate for the differences in angle, colour and distance presented by the same objects.

Recently, however, this view has been challenged and it has been shown that infants of six to eight weeks possess the ability to compensate for changes in the size and shape of retinal images. T.G.S. Bower’s experiments suggest that this ability is innate. Very young infants were conditioned to a cube of a certain size shown at a distance of one metre. Different-size cubes were then shown at a distance of three metres from the infant.

The conditioned response was always given, not to the larger cube which would have presented the same size of retinal image as did the correct cube at one metre, but to the correct cube despite its smaller retinal image size. Size constancy, however, does not occur in the absence of information or cues regarding the distance of the object. Holway and Boring showed that the judged size of cardboard disks became more and more inaccurate as more distance cues were eliminated.

Similar constancies occur regarding colour. A familiar object is always perceived as having the same colour even under different lighting conditions. For example, a piece of white paper is perceived as white whether seen under the yellowish glow of candle light, the stark whiteness of a tube light or under any other coloured lights.

Perceptual constancy, then, seems to be partly due to some innate mechanism and partly due to the influence of past experience and knowledge. The role of past experience in perception and the human being’s tendency to perceive on the basis of assumptions constructed from this past experience was clearly brought out by Ames.

In his famous ‘distorted room’ experiment Ames presented to his subjects an apparent perceptual contradiction between a specially constructed room (which looked normal from the subjects viewing angle when the room alone was seen) and known normal-sized objects seen in windows of the room.

Ames showed that whether the room or the object was suddenly seen as distorted, depended on the subject’s assumptions, i.e. whether the subject ‘assumed’ the room to be truly rectangular. He believed that our perceptions of the objects and people in our environment are subjective. In other words, they are based upon the assumptions we have built up about various objects and people. The organism, therefore, creates its phenomenal world.

Essay # 7. Perception of Movement :

Perception of movement is essential not only to human beings but also to animals. Movement is closely linked to the instinct of self-preservation because moving objects sometimes mean danger. However, the perception of movement involves both the visual messages from the eye as an image moves across the retina and the kinesthetic messages from the muscles around the eye as they shift the eye to follow a moving object.

But at times our perceptual processes play tricks on us and we think we perceive movement when the objects we are looking at are actually not moving at all. Thus, perceived movements can be divided into two types: real movement and illusory movement.

Real movement means the actual physical displacement of an object from one position to another. When we see a car being driven we perceive only the car in motion and the other things around it like trees, buildings etc. are stationary.

Illusory movement is that when an individual perceives objects as moving although they are stationary as is shown in Fig.7.12. One perceives this figure as moving black waves. Another example to illustrate this phenomena is an experience that you must have often felt while sitting in a stationary train; if another train moves by you feel that your own train is moving.

Another form of illusory movement is stroboscopic motion-the apparent motion created by a rapid movement of a series of images of stationary objects. A motion picture, for example, is not actually in motion at all. The film consists of a series of still pictures each one showing persons or objects in slightly different positions.

When these separate images are projected in a sequence on to the screen at a specified speed, the persons or objects seem to be moving because of the rapid change from one still picture to the next. The same illusion occurs when two lights are set apart at a suitable distance from each other and when they are switched on and off at an interval of one sixteenth of a second.

As a consequence the perceptual effect created is that of one light moving back and forth. This phenomenon of apparent motion is called the phi-phenomenon. Wertheiner’s experiments on phi- phenomenon formed the foundation for gestalt psychology.

Essay # 8. Development of Perception :

The infant’s perceptual world is different from the adult’s. Perception develops gradually as the individual grows and develops. It has also been shown that it is influenced to a great extent by the biological needs, maturation, learning, culture etc. Thus, qualitative and quantitative changes in perception take place in the course of an individual’s development.

The experiments of Gibson and Bowers show that depth and object perceptions are inborn, i.e. they are not dependent on learning, although they develop and shape at different rates. Goldstein emphasised the gradual development of perception from concrete to abstract.

However, Goldstein does not make a direct reference to perception but refers to it as the development of thinking or attitude. Witkin emphasises that perception which in the early years is field dependent gradually transforms itself into field independent.

Thus, stability and abstraction become possible as the individual develops. Von Senden presented a very interesting data regarding the patients who were born blind but have gained their vision as the result of operations. Their perceptual processes were studied carefully because their situation was considered analogous to a new-born infant’s who sees the world for the first time. Von Senden found that these patients did not experience normal perception immediately after they gained vision.

When an object was shown to them they could see something against a background but could not identify it, its shape and its distance from them. Colour discriminations were learned immediately. However learning to identify forms and objects in different contexts was a long and difficult process.

One patient learned to identify an egg, a potato and sugar in normal light on a table after many repetitions although he failed to recognise the same objects in colour light or when they were suspended by a thread with a change of background.

He could point correctly to the source of a sound but could not say from which direction it was coming. One can know from the above studies that perception does not develop overnight; perceptual capacity may be inborn but the ability develops gradually along with the development of other processes.

Essay # 9. Errors of Perception:

The perceptual processes enable an individual to perceive things around him accurately and facilitate his smooth functioning. However, some errors creep into this process, under certain circumstances, leading to wrong or impaired perceptions.

Two well-documented errors of perceptions are illusions and hallucinations:

1. Illusions :

A mistaken perception or distortion in perception is called an illusion. Generally perception involves the integration of sensory experiences and present psychological and organismic conditions. When the interpretation of a particular stimulus goes wrong, it gives rise to a wrong perception. For example, a rope in the dark is perceived as a snake; a dry leaf moving along the ground in the dark is perceived as a moving insect. Similarly, in the phi-phenomenon, although there is no physical movement of the lights, they are still perceived as moving.

Some illusions which occur commonly in the perception of geometrical figures are discussed in this article. These illusions are popularly known as ‘geometrical optical illusions’ a term coined by Oppel, a German scientist. He used this term to explain the over-estimation of an interrupted spatial extent compared to an uninterrupted one. Later, the term was used for any illusion seen in line drawings.

a. Mueller – Lyer Illusion:

In Figure 7.13 one line is bounded by ‘arrowheads’ and the other by ‘shaft heads’. Though these two lines are equal in length, invariably the line with closed heads is perceived as shorter than the line with open heads. Similarly, lines bounded by closed curves or brackets and circles are underestimated with respect to their length and vice versa.

b. Horizontal-Vertical Illusion:

In Fig.7.14 one line is horizontal and the other is vertical. Though both are equal in length, the vertical line is perceived as longer than the horizontal line. To test this you can make someone stand straight stretching both arms out to their full length.

Ask your friend whether the height of this person is the same as the length of his arms, i.e. the length from the right fingertips to the left fingertips. If your friend is not aware that these two lengths are equal, then he will invariably report that the height is greater than the length of the arms.

c. Poggendorff’s Illusion:

In Fig.7.15 a straight line appears to become slightly displaced as it passes through two parallel rectangles. Poggendorffs’ illusion is demonstrated in this figure.

d. Zollner’s Illusion:

In Fig.7.16 when two parallel lines are intersected by numerous short diagonal lines slanting in the opposite direction then the parallel lines are perceived as diverging, i, e. slanting backwards slightly instead of being straight.

The Mueller-Lyer Illusion, the Poggendorff’s Illusion and the Zollner’s Illusion are named after the scientists who discovered these phenomena. Illusions are not totally caused by subjective conditions. Sometimes the environment or the context within which a particular stimulus is perceived is responsible for illusions. For instance, the perception of a rope as a snake or a leaf as an insect, may have occurred due to darkness which is an environmental condition.

It has been suggested by scientists that geometrical illusions like the ones mentioned above are the natural outcome of a certain kind of nerve structure, functioning under a given set of physical conditions. The reader may raise the question as to why only visual illusions are elaborated in this article.

This is because so far scientists have been attracted by the problem of vision and consequently the maximum amount of research has been done in this particular area. However, researchers today are busy exploring and experimenting with illusions arising out of other sensory experiences like audition, gustation and so on.

2. Hallucinations :

Hallucinations are identified as one of the major errors of perception. While an illusion is considered as an inaccuracy, a distorted perception of existing stimuli, hallucinations are considered as false perceptions. Hallucinations are sensory perceptions in the absence of any corresponding external sensory stimuli.

For example, if a person claims that he has seen a ghost or a goddess when there is practically no stimulus either in the form of a human skeleton or a live human figure or at least anything resembling it, this will be conceived by scientific minds as a hallucination.

Strictly speaking, dreams are hallucinations since the persons and things perceived while one is asleep have no factual basis. But for all practical purposes the use of the term hallucination is restricted to imaginary perceptions experienced in the waking state. Thus, when a person hallucinates he hears, sees and feels non-existent objects or stimuli.

Like illusions, hallucinations sometimes depend on needs, mental states like fear, anxiety, culture, etc. Hallucinations are not necessarily indicative of abnormality. For example, normal individuals reared in certain cultures are encouraged to hallucinate as part of their religious experiences. They may claim to have seen or heard from their deity and this is considered a normal phenomenon.

Similarly, in our present society, it is not an uncommon sight, if a lover waiting anxiously says he heard the telephone ringing or a knock on the door and other such experiences in the absence of stimuli. These experiences which occur specially in moments of anxiety or fear or keen expectation are taken as natural and normal phenomena.

However, hallucinations verge on abnormality when they become chronic, intense and problematic to the perceiver and others around him and begin to hamper the normal and smooth functioning of his day-to-day activities.

Auditory Hallucination :

Mr. S, an agricultural worker, around 30 years of age, complained to his psychiatrist that voices bother him day and night. He can hear them cursing his mother and father Sometimes they command him to hit himself; sometimes they say obscene things. These voices are feminine and sometimes masculine; at times he hears his own voice commanding him.

Hallucinations are caused by psychological factors like conflict, guilt, fear, anxiety etc. They can also occur due to cerebral injuries, intake of alcohol, drugs like L.S.D. or heroin and the presence of certain toxic substances in the body.

Figural After – Effects :

The term figural after-effect is used to denote certain phenomena observed by Gibson in a series of interesting experiments. In one of his experiments subjects saw a distorted line passing through a prism. After 10 minutes, the apparent ‘curvature’ of the line was perceived as very much decreased.

The line tended to straighten out and when the prism was removed, the line was perceived as being curved in the opposite direction. In another experiment, by Kohler & Wallach, one figure (known as l or inspection figure) is observed for several minutes with total fixation.

Then this figure is replaced by a Test stimuls card T1 and the subjects are required to report its characteristics. It may be seen that objectively the two figures, the one inside T1 and T2 are identical in size, brightness and the distance from P. But both are smaller than the 1 square.

The square T1 falls in line with the contours of the inspection square and a little nearer its right hand contours. The phenomenal reports indicated that T1 was perceived as smaller and more distant from point P and further, its margins appeared paler. It is not necessary that all these characteristics should appear in the case of a given person at any time.

Kohler & Wallach offer an explanation for this, based on certain electrical field processes in the brain. According to them, there are some unspecified regions, of the central visual area through which current keeps on flowing. The currents flow according to the principle of least resistance.

When the 1 figure is presented, this flow is interrupted and the current flow is set up along the contours of this figure. The flow of the current however, increases the resistance in the tissues, thus forcing the current to flow into the neighbouring regions which in turn results in a gradient of resistance satiation about the contour of fig. Satiation present after the – removal of the 1 figure, lead to distortions in the T figures. There has been a lot of criticism against this view, particularly from the neurophysiological angle. It is also argued that the phenomenon of figural after-effect can be explained without having to take recourse to ‘electrical fields.’

Essay # 10. Studies on Perception:

Findings arrived at by studies of perception are not as dramatic as the findings of experiments in learning. Nevertheless their value has been recognised increasingly to serve mankind in many significant ways. An understanding of the subtleties and complexities of perception as a process gives an impression that human behaviour can be reduced to an interplay of the perceptions of self, the world, people, objects and events. As a matter of fact, various activities like science, art, religion etc., are nothing more than the outcome of human perceptions.

Turning to more concrete contributions, one of the major areas of investigation is in the field of colour perception. This brought out interesting findings as to why and how certain psychological factors determine colour perception. The impact of these findings can be seen on the walls of living rooms, bedrooms, showrooms, in the market for selling automobiles, textiles and even fruits and flowers.

Colour technologists involved in manufacturing dyes, textiles, and those who are involved in agencies of mass media like the cinema, television, magazines, photography and interior decorators invest large amounts of money to find out, create, and impress human perception, captivate their interests, moods and money through colours. They try to demonstrate how different and pleasant it is living and working with certain colours around you, rather than being in colourless, or lifeless surroundings.

Another area in which the findings of perception studies are being used is communication. Communication devices ranging from satellites to telephones are devised to facilitate the audio-visual perceptions of human beings. The utmost care has to be taken in designing transmission devices and equipping them to counter­balance phenomena like illusions, constancies etc. which arise in perception especially regarding sounds and figures.

They take care to make the communication of the speaker and the listener clear and intelligible, eliminate non-essential stimuli and aim at presenting synchronized and simultaneous transmission. Transport system such as airways, seaways and roadways have realised the importance of perception because the individuals who steer these vehicles make use of processes like sensation, attention and perception to the maximum extent.

If these processes fail or do not function adequately for one reason or the other, the consequence is human error or accident. Scientists working in the area of prevention of accidents, especially on highways, realised that accidents occur due to certain visual and auditory illusions.

Over-estimation or under-estimation of curves, distortion of cues due to excess of light, fog, or snow, and illusions of sound created by moving stimuli, all these sometimes can produce disasters. Thus, measures are being taken to provide information, instructions and clues which are specially devised and placed at convenient heights, angles and directions so that the driver can perceive from his fast-moving vehicle and avert disasters. The importance of such findings can be well understood by this illustration.

On December 4, 1965, a TWA Boeing 707 and an Eastern Airline Lockheed 1049 were enroute to John F. Kennedy International Airport and to Newark Airport, respectively. Both were converging on the New York area, the Boeing 707 at its assigned altitude of 11,000 feet and the Lockheed at its assigned altitude of 10,000 feet.

At the time, the area was overcast and the cloud tops protruded above a height of 10,000 feet. The clouds were generally higher in the north than in the south and seemed to form an upward, sloping bar of white against the blue background of the sky. Within a few moments of each other, the crew of both the aircraft perceived what appeared to be an imminent collision between the two planes.

They rapidly began evasive manoeuvres. The Lockheed aircraft pulled up and the Boeing rolled first to the right then to the left. The two aircrafts collided at approximately 11,000 feet. The structural damage to the Lockheed was sufficient to force it to land in an open field, where it was destroyed by impact and friction.

There were four fatalities and forty-nine non-fatal injuries. The U.S. Civil Aeronautics Board attributed the collision to misjudgment of altitude separation by the crew of the Lockheed aircraft because of an ‘optical illusion’ created by the upward sloping contours of the cloud tops.

Four persons died and 49 were injured through the operation of the simple effect that we mimic on paper with simple lines and call the ‘Poggendorff illusion’. Perhaps, the idea that visual illusions are interesting but relatively unimportant oddities of perceptions itself is merely another illusion, which can prove costly.

Similar precautions are being taken in certain accident-prone heavy industries, like mining and manufacturing of volatile substances like explosives, chemicals and “so on where individuals have to attend to and comprehend several stimuli accurately within a short time.

Contributions to clinical psychology of the findings on hallucinations are immense. It has become one of the most important tools in diagnosing psychotic disorders. The seriousness of a psychosis is determined to a great extent by the degree, intensity and number of hallucinations experienced by the individual.

Researchers working on the problem of subliminal perception are trying to contribute their share of findings through work done on advertisements, unconscious processes etc. The advertising agencies are realising that they can capture their audience and customers by making their messages less obvious and more subtle. This is one way to induce curiosity and attract them to their products and thus, increase their sales.

The role of the unconscious in the area of subliminal perception is quite significant. Unconscious processes and their allied phenomena, for all practical purposes, can be considered synonymous with subliminal perceptions, because they operate from a level of consciousness which is less than normal.

One may wonder whether findings on ESP have any value to the present computer world which is capable of anything right from brushing one’s teeth to singing a lullaby. But ESP seems to offer so much that the world is beginning to develop an impression that parapsychology is no more a mere intellectual adventure. If individuals could be taught and made to develop this capacity we could go to the moon and other planets, eat and live comfortably and chat with friends across the seas and continents for hours together.

Imagine, all this could be done without spending a paisa and then money would lose its importance. However, to achieve this stage, sciences have to travel a long and difficult way like Christian in ‘A Pilgrim’s Progress’. Today, such fantastic activities may appear to be distant probabilities but we may soon see them as distinct possibilities.

The one area where research findings on perception and the perceptual processes have been found extremely useful is in advertising. Very innovative advertisements are designed today based on their knowledge of the perceptual processes.

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What Is Perception?

Recognizing Environmental Stimuli Through the Five Senses

Types of Perception

• How It Works

Perception Process

• Influential Factors
• Improvement Tips
• Potential Pitfalls

History of Perception

Perception refers to our sensory experience of the world. It is the process of using our senses to become aware of objects, relationships, and events. It is through this experience that we gain information about the environment around us.

Perception relies on the cognitive functions we use to process information, such as utilizing memory to recognize the face of a friend or detect a familiar scent. Through the perception process, we are able to both identify and respond to environmental stimuli.

Perception includes the five senses: touch, sight, sound, smell , and taste . It also includes what is known as proprioception , which is a set of senses that enable us to detect changes in body position and movement.

Many stimuli surround us at any given moment. Perception acts as a filter that allows us to exist within and interpret the world without becoming overwhelmed by this abundance of stimuli.

The different senses often separate the types of perception. These include visual, scent, touch, sound, and taste perception. We perceive our environment using each of these, often simultaneously.

There are also different types of perception in psychology, including:

• Person perception refers to the ability to identify and use social cues about people and relationships.
• Social perception is how we perceive certain societies and can be affected by things such as stereotypes and generalizations.

Another type of perception is selective perception. This involves paying attention to some parts of our environment while ignoring others.

The different types of perception allow us to experience our environment and interact with it in ways that are both appropriate and meaningful.

How Perception Works

Through perception, we become more aware of (and can respond to) our environment. We use perception in communication to identify how our loved ones may feel. We use perception in behavior to decide what we think about individuals and groups.

We perceive things continuously, even though we don't typically spend a great deal of time thinking about them. For example, the light that falls on our eye's retinas transforms into a visual image unconsciously and automatically. Subtle changes in pressure against our skin, allowing us to feel objects, also occur without a single thought.

Mindful Moment

Need a breather? Take this free 9-minute meditation focused on awakening your senses —or choose from our guided meditation library to find another one that will help you feel your best.

To better understand how we become aware of and respond to stimuli in the world around us, it can be helpful to look at the perception process. This varies somewhat for every sense.

In regard to our sense of sight, the perception process looks like this:

• Environmental stimulus: The world is full of stimuli that can attract attention. Environmental stimulus is everything in our surroundings that has the potential to be perceived.
• Attended stimulus: The attended stimulus is the specific object in the environment on which our attention is focused.
• Image on the retina: This part of the perception process involves light passing through the cornea and pupil onto the lens of the eye. The cornea helps focus the light as it enters, and the iris controls the size of the pupils to determine how much light to let in. The cornea and lens act together to project an inverted image onto the retina.
• Transduction: The image on the retina is then transformed into electrical signals through a process known as transduction. This allows the visual messages to be transmitted to the brain to be interpreted.
• Neural processing: After transduction, the electrical signals undergo neural processing. The path followed by a particular signal depends on what type of signal it is (for example, an auditory signal or a visual signal).
• Perception: In this step of the perception process, you perceive the stimulus object in the environment. It is at this point that you become consciously aware of the stimulus.
• Recognition: Perception doesn't just involve becoming consciously aware of the stimuli. It is also necessary for the brain to categorize and interpret what you are sensing. This next step, known as recognition, is the ability to interpret and give meaning to the object.
• Action: The action phase of the perception process involves some type of motor activity that occurs in response to the perceived stimulus. This might involve a significant action, like running toward a person in distress. It can also include doing something as subtle as blinking your eyes in response to a puff of dust blowing through the air.

Think of all the things you perceive on a daily basis. At any given moment, you might see familiar objects, feel a person's touch against your skin, smell the aroma of a home-cooked meal, or hear the sound of music playing in your neighbor's apartment. All of these help make up your conscious experience and allow you to interact with the people and objects around you.

Recap of the Perception Process

• Environmental stimulus
• Attended stimulus
• Image on the retina
• Transduction
• Neural processing
• Recognition

Factors Influencing Perception

What makes perception somewhat complex is that we don't all perceive things the same way. One person may perceive a dog jumping on them as a threat, while another person may perceive this action as the pup just being excited to see them.

Our perceptions of people and things are shaped by our prior experiences, our interests, and how carefully we process information. This can cause one person to perceive the exact same person or situation differently than someone else.

Perception can also be affected by our personality. For instance, research has found that four of the Big 5 personality traits —openness, conscientiousness, extraversion, and neuroticism—can impact our perception of organizational justice.

Conversely, our perceptions can also affect our personality. If you perceive that your boss is treating you unfairly, for example, you may show traits related to anger or frustration. If you perceive your spouse to be loving and caring, you may show similar traits in return.

Are Perception and Attitude the Same?

While they are similar, perception and attitude are two different things. Perception is how we interpret the world around us, while our attitudes (our emotions, beliefs, and behaviors) can impact these perceptions.

Tips to Improve Perception

If you want to improve your perception skills, there are some things that you can do. Actions you can take that may help you perceive more in the world around you—or at least focus on the things that are important—include:

• Pay attention. Actively notice the world around you, using all your senses. What do you see, hear, taste, smell, or touch? Using your sense of proprioception, notice the movements of your arms and legs or your changes in body position.
• Make meaning of what you perceive. The recognition stage of the perception process is essential since it allows you to make sense of the world around you. You place objects in meaningful categories so you can understand and react appropriately.
• Take action. The final step of the perception process involves taking some sort of action in response to your environmental stimulus. This could involve a variety of actions, such as stopping to smell the flower you see on the side of the road and incorporating more of your senses into your experiences.

Potential Pitfalls of Perception

The perception process does not always go smoothly, and there are a number of things that may interfere with our ability to interpret and respond to our environment. One is having a disorder that impacts perception.

Perceptual disorders are cognitive conditions marked by an impaired ability to perceive objects or concepts. Some disorders that may affect perception include:

• Spatial neglect syndromes , which involve not attending to stimuli on one side of the body
• Prosopagnosia , also called face blindness, is a disorder that makes it difficult to recognize faces
• Aphantasia , a condition characterized by an inability to visualize things in your mind
• Schizophrenia , a mental health condition that is marked by abnormal perceptions of reality

Some of these conditions may be influenced by genetics, while others result from stroke or brain injury.

Certain factors can also negatively affect perception. For instance, one study found that when people viewed images of others, they perceived individuals with nasal deformities as having less satisfactory personality traits. So, factors such as this can potentially affect personality perception in others.

Interest in perception dates back to ancient Greek philosophers who were interested in how people know the world and gain understanding. As psychology emerged as a science separate from philosophy, researchers became interested in understanding how different aspects of perception worked—particularly the perception of color.

In addition to understanding basic physiological processes, psychologists were also interested in understanding how the mind interprets and organizes these perceptions.

Gestalt psychologists proposed a holistic approach, suggesting that the whole is greater than the sum of its parts.  Cognitive psychologists have also worked to understand how motivations and expectations can play a role in the process of perception.

As time progresses, researchers continue to investigate perception on the neural level. They also look at how injury, conditions, and substances might affect perception.

American Psychological Association. Perception .

University of Minnesota. 3.4 Perception . Organizational Behavior .

Jhangiani R, Tarry H. 5.4 Individual differences in person perception . Principles of Social Psychology - 1st International H5P Edition . Published online January 26, 2022.

Aggarwal A, Nobi K, Mittal A, Rastogi S. Does personality affect the individual's perceptions of organizational justice? The mediating role of organizational politics . Benchmark Int J . 2022;29(3):997-1026. doi:10.1108/BIJ-08-2020-0414

Saylor Academy. Human relations: Perception's effect . Human Relations .

ICFAI Business School. Perception and attitude (ethics) . Personal Effectiveness Management Course .

King DJ, Hodgekins J, Chouinard PA, Chouinard VA, Sperandio I. A review of abnormalities in the perception of visual illusions in schizophrenia .  Psychon Bull Rev . 2017;24(3):734‐751. doi:10.3758/s13423-016-1168-5

van Schijndel O, Tasman AJ, Listschel R. The nose influences visual and personality perception . Facial Plast Surg . 2015;31(05):439-445. doi:10.1055/s-0035-1565009

Goldstein E. Sensation and Perception . Thomson Wadsworth; 2010.

Yantis S. Sensation and Perception . Worth Publishers; 2014.

By Kendra Cherry, MSEd Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

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perception , in humans , the process whereby sensory stimulation is translated into organized experience. That experience, or percept, is the joint product of the stimulation and of the process itself. Relations found between various types of stimulation (e.g., light waves and sound waves) and their associated percepts suggest inferences that can be made about the properties of the perceptual process; theories of perceiving then can be developed on the basis of these inferences. Because the perceptual process is not itself public or directly observable (except to the perceiver himself, whose percepts are given directly in experience), the validity of perceptual theories can be checked only indirectly. That is, predictions derived from theory are compared with appropriate empirical data, quite often through experimental research.

Historically, systematic thought about perceiving was the province of philosophy . Indeed, perceiving remains of interest to philosophers, and many issues about the process that were originally raised by philosophers are still of current concern. As a scientific enterprise, however, the investigation of perception has especially developed as part of the larger discipline of psychology .

Philosophical interest in perception stems largely from questions about the sources and validity of what is called human knowledge (see epistemology ). Epistemologists ask whether a real, physical world exists independently of human experience and, if so, how its properties can be learned and how the truth or accuracy of that experience can be determined. They also ask whether there are innate ideas or whether all experience originates through contact with the physical world, mediated by the sense organs . For the most part, psychology bypasses such questions in favour of problems that can be handled by its special methods. The remnants of such philosophical questions, however, do remain; researchers are still concerned, for example, with the relative contributions of innate and learned factors to the perceptual process.

Such fundamental philosophical assertions as the existence of a physical world, however, are taken for granted among most of those who study perception from a scientific perspective. Typically, researchers in perception simply accept the apparent physical world particularly as it is described in those branches of physics concerned with electromagnetic energy , optics, and mechanics. The problems they consider relate to the process whereby percepts are formed from the interaction of physical energy (for example, light) with the perceiving organism. Of further interest is the degree of correspondence between percepts and the physical objects to which they ordinarily relate. How accurately, for example, does the visually perceived size of an object match its physical size as measured (e.g., with a yardstick)?

Questions of the latter sort imply that perceptual experiences typically have external referents and that they are meaningfully organized, most often as objects. Meaningful objects, such as trees, faces, books, tables, and dogs, are normally seen rather than separately perceived as the dots, lines, colours, and other elements of which they are composed. In the language of Gestalt psychologists, immediate human experience is of organized wholes ( Gestalten ), not of collections of elements.

A major goal of Gestalt theory in the 20th century was to specify the brain processes that might account for the organization of perception. Gestalt theorists, chief among them the German-U.S. psychologist and philosopher, the founder of Gestalt theory, Max Wertheimer and the German-U.S. psychologists Kurt Koffka and Wolfgang Köhler , rejected the earlier assumption that perceptual organization was the product of learned relationships ( associations ), the constituent elements of which were called simple sensations . Although Gestaltists agreed that simple sensations logically could be understood to comprise organized percepts, they argued that percepts themselves were basic to experience. One does not perceive so many discrete dots (as simple sensations), for example; the percept is that of a dotted line.

Without denying that learning can play some role in perception, many theorists took the position that perceptual organization reflects innate properties of the brain itself. Indeed, perception and brain functions were held by Gestaltists to be formally identical (or isomorphic), so much so that to study perception is to study the brain. Much contemporary research in perception is directed toward inferring specific features of brain function from such behaviour as the reports ( introspections ) people give of their sensory experiences. More and more such inferences are gratifyingly being matched with physiological observations of the brain itself.

Many investigators relied heavily on introspective reports, treating them as though they were objective descriptions of public events. Serious doubts were raised in the 1920s about this use of introspection by the U.S. psychologist John B. Watson and others, who argued that it yielded only subjective accounts and that percepts are inevitably private experiences and lack the objectivity commonly required of scientific disciplines . In response to objections about subjectivism, there arose an approach known as behaviourism that restricts its data to objective descriptions or measurements of the overt behaviour of organisms other than the experimenter himself. Verbal reports are not excluded from consideration as long as they are treated strictly as public (objective) behaviour and are not interpreted as literal, reliable descriptions of the speaker’s private (subjective, introspective) experience. The behaviouristic approach does not rule out the scientific investigation of perception; instead, it modestly relegates perceptual events to the status of inferences. Percepts of others manifestly cannot be observed, though their properties can be inferred from observable behaviour (verbal and nonverbal).

One legacy of behaviourism in contemporary research on perception is a heavy reliance on very simple responses (often nonverbal), such as the pressing of a button or a lever. One advantage of this Spartan approach is that it can be applied to organisms other than man and to human infants (who also cannot give verbal reports). This restriction does not, however, cut off the researcher from the rich supply of hypotheses about perception that derive from his own introspections. Behaviourism does not proscribe sources of hypotheses; it simply specifies that only objective data are to be used in testing those hypotheses.

Behaviouristic methods for studying perception are apt to call minimally on the complex, subjective, so-called higher mental processes that seem characteristic of adult human beings; they thus tend to dehumanize perceptual theory and research. Thus, when attention is limited to objective stimuli and responses, parallels can readily be drawn between perceiving (by living organisms) and information processing (by such devices as electronic computers). Indeed, it is from this information-processing approach that some of the more intriguing theoretical contributions (e.g., abstract models of perception) are currently being made. It is expected that such practical applications as the development of artificial “eyes” for the blind may emerge from these man–machine analogies . Computer-based machines that can discriminate among visual patterns already have been constructed, such as those that “read” the code numbers on bank checks.

Essay on Perception In Life

Students are often asked to write an essay on Perception In Life in their schools and colleges. And if you’re also looking for the same, we have created 100-word, 250-word, and 500-word essays on the topic.

Let’s take a look…

100 Words Essay on Perception In Life

Understanding perception.

Perception is the way we see and understand things around us. It’s like wearing glasses that can change how the world looks to us. Everyone has their own set of glasses, so what one person sees might be different from what another sees. This is why two people can look at the same thing but have different ideas about it.

Perception Shapes Thoughts

Our thoughts are often based on our perceptions. If we see a dark cloud, we might think it will rain. This shows that what we see can influence what we think or expect. Our mind uses what we see to make guesses about what will happen next.

Perception Influences Actions

What we do is also affected by how we see things. For example, if we see a dog and think it is friendly, we might want to pet it. But if we see it as scary, we would probably stay away. So, our actions can change based on our perception.

Changing Perceptions

Sometimes, we can change how we see things. If we learn more about something or hear what others think, our view can change. This is important because it helps us understand others better and learn new things.

250 Words Essay on Perception In Life

What is perception, why perception matters.

Our perception is important because it affects what we think and how we feel. If you see a glass with water up to the middle, you might think it’s half full or half empty. Your answer can show if you see things in a hopeful way or maybe a less hopeful way. This can influence your mood and how you deal with problems.

Perception Shapes Our World

The way we see things can shape our world. For example, if you believe you’re good at drawing, you’ll feel happy when you have a pencil and paper. But if you think you’re bad at it, you might feel sad or not want to draw at all. Our beliefs can encourage us to try new things or stop us from trying.

Perception Can Change

The good news is that our perception can change. If you learn more about something or see it from a different angle, you might start to see it in a new light. It’s like getting a new lens for your mind’s camera. With a new lens, you can take better pictures and understand the world in a better way.

In conclusion, perception is a powerful part of life. It’s the set of glasses we wear to look at the world. By knowing this, we can try to see things in a brighter, kinder way and make our lives and the lives of others better.

500 Words Essay on Perception In Life

Perception is the way we see and understand things around us. It is like having a set of glasses through which we look at the world. These glasses can change the way everything looks to us. For example, if you wear pink glasses, everything seems pink. In life, our experiences, feelings, and thoughts are like these glasses, they shape how we see our surroundings.

Perception and Communication

When we talk to others, our perception plays a big role. If you believe someone is kind, you might listen to them more carefully. On the other hand, if you think someone is not nice, you might not listen to them at all. This can lead to misunderstandings. It’s like if you’re playing a game of telephone; what you hear can be very different from what the first person said.

Perception and Learning

In school, perception is a big deal. If you see math as fun, you might do better at it because you enjoy practicing. But if you see math as hard, you might not want to try. Teachers try to make subjects interesting so students can have a positive view of learning. This can make school more fun and help students do better.

Changing Our Perception

Perception and happiness.

Finally, how we see things can affect our happiness. If we focus on the good in our lives, we tend to feel happier. It’s like when you find a $5 bill on the ground, you feel lucky and happy. But if you only think about the $5 you lost last week, you might feel sad. By looking for the good, we can feel better about our lives.

In conclusion, perception is like a pair of glasses that colors everything in our lives. It shapes how we see people, how we learn, and even how happy we are. By understanding that we can change our perception, we can improve our communication, learn better, and find more joy in life. It’s important to remember that our view is not the only one and that being open to new ideas can make our world a brighter place.

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Perceiving Is Believing

How naive realism influences our perception of everything..

Posted January 23, 2021 | Reviewed by Ekua Hagan

The only true voyage of discovery...would be not to visit strange lands, but to possess other eyes, to behold the universe through the eyes of another, of a hundred others, to behold the hundred universes that each of them beholds, that each of them is. — Marcel Proust

Perception is everything—and it is flawed. Most of us navigate our daily lives believing we see the world as it is. Our brains are perceiving an objective reality, right? Well, not quite. Everything we bring in through our senses is interpreted through the filter of our past experiences.

Understanding Sensation and Perception

Sensation is physical energy detection by our sensory organs. Our eyes, mouth, tongue, nose, and skin relay raw data via a process of transduction, which is akin to the translation of physical energy—such as sound waves—into the electrochemical energy the brain understands. At this point, the information is the same from person to person—it is unbiased.

To understand human perception, you must first understand that all information in and of itself is meaningless. — Beau Lotto

While Dr. Lotto's statement is bold, from the perspective of neuroscience , it is true. Meaning is applied to everything, from the simplest to the most complex sensory input. Our brain's interpretation of the raw sensory information is known as perception. Everything from our senses is filtered through our unique system of past experiences in the world. Usually, the meaning we apply is functional and adequate—if not fully accurate, but sometimes our inaccurate perceptions create real-world difficulty.

Perceptual Illusions

There are numerous optical illusions that distinctly convey how easily our perception can lead us to incorrect conclusions. Psychologist Roger Shepard (1990) illustrated that our perceptions can be inaccurate with his famous table-top demonstration (see video below), which clearly establishes that our brains may fool us into perceiving an erroneous view of reality regarding even the simplest of visual perceptual questions.

Countless illusion examples may be found in psychology textbooks or via internet searches, but this captivating video unmistakably illustrates how our past experiences in the world interfere with our accurate perception regarding a simple line length comparison.

How does our brain get deceived ? We trust that our perceptual system constructs accurate representations of the surrounding world. However, our assumptions regarding perception are unsupported by evidence. The deficient understanding of how we perceive the world was originally termed naive realism by Lee Ross and his colleagues in the 1990s. Naive realism is thought to be the theoretical foundation for many cognitive biases , such as the fundamental attribution error , the false consensus effect, and the bias blind spot.

Perceptual illusions are endlessly fascinating and provide a microcosm of potentially faulty human perception. When we encounter these illusions, we initially believe we are seeing an accurate representation of reality only to be surprised by how easily our brains mislead us.

Inter-Group Conflict and Naive Realism

What happens when we extrapolate our perceptual shortcomings to large-scale human interaction? Too often, humans get stuck believing their view of the world is an objective reality. This, of course, leads to conflict with other humans who disagree, especially those we perceive to be part of an out-group . Naive realism leads us to reason that we see the world objectively—and that others do as well. When we encounter people who disagree with us on important matters, we tend to think they are uninformed, irrational, or biased.

Why does this happen? It is challenging and uncomfortable to confront our own understanding of the world, especially if we are unaware of our tendency for faulty interpretations of reality. Most people have likely not considered that their opinions about the world are filtered through their unique perceptual lens, which is fundamentally biased and based on past experiences.

How we perceive the world and important issues, from parenting to the political, is based on our perception. When we begin to understand that other people's experiences in the world vary greatly and influence how they interpret complex issues, we can begin to have a greater understanding of other points of view.

However, we tend to become more entrenched in our beliefs about our representations of reality when interacting with people in a different "tribe." Instead of seeking common ground—which can be an effective method to initiate belief change, we instead become more tribal and refute any information from our rival group.

What Can We Do?

The polarization in our modern world is widespread and appears to be increasing. Determining how to find commonalities between groups can feel impossible due to naive realism. Fascinatingly, researchers have uncovered a simple intervention that may promote greater understanding between members of rival groups.

Dr. Meytal Nasir (2014) and her colleagues set out to empirically investigate whether people could be more open to narratives of their adversaries (out-group) following an intervention that raises awareness regarding the concept of naive realism and the implications in the real world.

The researchers conducted their study within the context of the Israeli-Palestinian conflict, an exemplar of a well-known intractable struggle. Their focus was to raise awareness of naive realism as a universal cognitive psychological bias that fuels adversaries to adhere to a collective narrative of the ingroup and reject the out-group narrative during conflict.

Results from the research indicated that the intervention—a short text describing naive realism and its implications—did produce an increased openness to adversary's narratives by raising the experimental group members' awareness of cognitive limitations. Fascinatingly, the intervention made no mention of the rival group or the specific conflict, yet still brought about positive change.

The Nasie research aligns with Dr. Lotto's commentary about how we can overcome our perceptual deficiencies.

By becoming aware of the principles by which your perceptual brain works, you can become an active participant in your own perceptions and in this way change them in the future. — Beau Lotto

Final Thoughts

A metacognitive strategy aimed at our perceptual system is a promising intervention for intractable disagreements between groups. While tribalism was certainly evolutionarily adaptive for humans thousands of years ago, current trends suggest it is detrimental and leading to deleterious consequences across the globe.

With knowledge regarding naive realism, we need to look beyond our own experiences and attempt to see the world with the eyes of others—especially those we perceive to be in out-groups. The insight uncovered with this new viewpoint may or may not move our positions on various issues, but as we navigate an ever-polarizing world of divisiveness—fueled by social media , it may be our only hope (sorry Obi-Wan).

Jessica Koehler, Ph.D., is an Associate Faculty Member in the University of Arizona Global Campus Psychology Department.

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Perception, the process through which individuals interpret sensory information to understand their environment, is a multidisciplinary topic explored within psychology, philosophy, neuroscience, and other fields. Essays on perception might delve into how it’s processed, the psychological and neurological mechanisms involved, and how perception varies among different individuals or across species. Discussions could also explore the implications of perception in everyday life, including social interactions, decision-making, and the perception of self. We’ve gathered an extensive assortment of free essay samples on the topic of Perception you can find at Papersowl. You can use our samples for inspiration to write your own essay, research paper, or just to explore a new topic for yourself.

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The Perception Process Stages – Psychology Essay

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Introduction

Stages of the perception process.

Perception refers to the process of organizing, identifying, and interpreting sensory information in an effort to understand and make sense of the environment (Blake and Sekuler, 2006, p.35). Perception involves the transmission of sensory information in the form of stimuli to the nervous system. Sensory information arises from the stimulation of different human senses by physical agents.

For example, an individual is able to perceive visual stimuli whenever light lands on a certain part of the eye that perceives light. In humans, processes of learning, expectation, and memory affect perception significantly. Perception is controlled by the proper functioning of the nervous system (Blake and Sekuler, 2006, p.36). However, since it is not a conscious human act, it is effortless and automatic. The human brain plays an important role in the perception process. It comprises different parts that process different types of sensory information. Most of these parts are interconnected and complement each other.

The perception process involves three main stages namely selection, organization and interpretation (Blake and Sekuler, 2006, p.39). The perception process involves three distinct steps that occur continuously. The process is facilitated by the five senses that include sight, smell, sound, taste, and touch.

Selection is the first stage of the perception process. It refers to a process by which an individual chooses which stimuli to attend to and which to disregard (Goldstein, 2010, p.53). Stimuli to be attended to are selected with the aid of touch, smell, sound, sight, and taste. Stimuli and motives are two main factors that influence the selection process. Stimulus is defined as anything that makes any of the five sense organs to function or respond to sensory information (Goldstein, 2010, p.54).

Intense stimuli such as bright light, strong scents, loud sound and hot surfaces usually make sense organs that are associated with the respective stimuli to respond and become active. On the other hand, a motive is defined as an impulse or an incentive that motivates an individual to behave in a certain way (Goldstein, 2010, p.54). Motives usually influence the process of selection significantly. There are three main types of selection. They include selective perception, selective exposure, and selective retention. In all these types, an individual sees, hears, retains, and exposes himself to stimuli that are in line with personal values and beliefs.

Organization

Organization is the second stage of the perception process. It involves the mental arrangement of sensory information in order to make sense of the happenings that take place in the environment (Jackson, 1998, p.63). The stimuli that an individual chooses to attend to is arranged into patterns that are meaningful and easy to understand.

Types of communication organization include punctuation, similarity, closure, perceptual schemes, stereotyping, and proximity. Perceptual schemes refer to the different systems that individuals use to organize impressions. Different ways to organize impressions include appearance, social roles, interaction style, and psychological traits such as nervousness and confidence (Jackson, 1998, p.66). After an individual chooses a certain scheme to describe and group people, perceptions are then organized in different ways. These ways include stereotyping, punctuation, closure, similarity, and proximity.

Interpretation

Interpretation is the third and final stage of the perception process. It involves the attachment of meaning to certain stimuli. Interpretation of sensory information is determined by personal values, experiences, beliefs, needs, involvement and other personal factors (Goldstein, 2010, p.56). These factors make the interpretation stage subjective. As such, people exhibit different methods of perception. After sensory information is interpreted, it is then expressed either verbally or physically. Interpretation of sensory information is highly influenced by factors such as memories and prejudices.

Psychologists have shown that interpretation occurs under different contexts and the outcome varies in different individuals. The mind interprets sensory information by forming connections and correlations between different stimuli (Jackson, 1998, p.68). Examples of the outcome of interpretation include smiling, being choked or withdrawing one’s hand from a hot object. People interpret information differently. Some interpret information based on negative emotions while others interpret it based on positive emotions. Factors such as intensity, repetition, and contrast make some stimuli more striking than others.

Perception is defined as the process through which individuals decode information from their everyday experiences to make sense of the environment that they live in. People have different ways of perception. Also, their actions that result from interpreting stimuli are different. However, the process of perception takes the same pathway for all people despite the outcomes. Perception involves three main stages, namely selection, organization, and interpretation.

Selection involves choosing the type of stimuli to respond to while the organization involves arranging sensory information in a way that is understandable. Individuals choose the stimuli that they wish to attend to, organize the received information in a way that makes sense, and finally interpret and express the stimuli. The processes of learning, expectation, and memory can affect perception in humans significantly. The process of perception is directed and governed by the proper functioning of the nervous system.

Blake, R., and Sekuler, R. (2006). Perception . New York: McGraw-Hill.

Goldstein, E. (2010). Sensation and Perception . New York: Cengage Learning.

Jackson, F. (1998). Perception: A Representative Theory . New York: CUP Archive.

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The Problem of Perception

The Problem of Perception is a pervasive and traditional problem about our ordinary conception of perceptual experience. The problem is created by the phenomena of perceptual illusion and hallucination: if these kinds of error are possible, how can perceptual experience be what we ordinarily understand it to be: something that enables direct perception of the world? These possibilities of error challenge the intelligibility of our ordinary conception of perceptual experience; the major theories of experience are responses to this challenge.

1.1 Starting Points

1.2 ordinary objects, 1.3 presentation, 1.4 direct realism, 1.5 the character of experience, 1.6 the common kind claim, 2.1 the argument from illusion.

• 2.2 The Argument from Hallucination

3.1.1 The Sense-Datum Theory in Outline

3.1.2 the sense-datum theory and the problem of perception.

• 3.1.3 The Sense-Datum Theory and our Ordinary Conception of Perceptual Experience

3.1.4 The Sense-Datum Theory and Perception of the World

3.1.5 objections to the sense-datum theory, 3.2.1 adverbialism in outline.

• 3.2.2 The Adverbialism and Qualia

3.2.3 Objections to Adverbialism

3.2.4 adverbialism and the problem of perception.

• 3.2.5 Adverbialism and Our Ordinary Conception of Perceptual Experience

3.2.6 Adverbialism and Perception of the World

3.3.1 intentionalism in outline, 3.3.2 sources of intentionalism, 3.3.3 the intentional content of perceptual experience, 3.3.4 intentionalism and the problem of perception, 3.3.5 intentionalism and perception of the world, 3.3.6 intentionalism and our ordinary conception of perceptual experience, 3.4.1 naive realism in outline, 3.4.2 naive realism and the problem of perception, 3.4.3 the development of naive realist disjunctivism.

• 3.4.4 Naive Realism Disjunctivism and our Ordinary Conception of Perceptual Experience

4. Conclusion

Further reading, other internet resources, related entries, 1. our ordinary conception of perceptual experience.

A.D. Smith claims that what most authors have in mind in talking about the Problem of Perception is the “question of whether we can ever directly perceive the physical world”, where “the physical world” is understood in a realist way: as having “an existence that is not in any way dependent upon its being... perceived or thought about” (2002: 1). The arguments at the heart of the Problem of Perception challenge this direct realist perspective on perceptual experience. But since this perspective is embedded within our ordinary conception of perceptual experience, the problem gets to the heart of our ordinary ways of thinking.

So, what is our ordinary conception of perceptual experience? And how does it embed a direct realist perspective?

We conceive of perceptual experiences as occurrences with phenomenal character. The phenomenal character of an experience is what it is like for a subject to undergo it (Nagel (1974)). Our ordinary conception of perceptual experience emerges from first-personal reflection on its character, rather than from scientific investigation; it is a conception of experience from a “purely phenomenological point of view” (Broad 1952: 3–4). We’ll present this conception by outlining what phenomenological reflection suggests first about the objects ( §1.2 ), structure ( §1.3 ), and character ( §1.5 ) of experience, and then about the relation between veridical, illusory, and hallucinatory experiences, and in particular whether these cases form a common kind ( §1.6 ).

Let’s begin with P.F. Strawson’s idea that “mature sensible experience (in general) presents itself as, in Kantian phrase, an immediate consciousness of the existence of things outside us” (1979: 97), and similarly McDowell’s idea that perceptual experience appears to be an “openness to the world” (1994: 111), conceived of as openness to mind-independent reality (1994: 25–26).

These ideas reflect the basic phenomenological observation that perceptual experiences have objects, and more specifically direct objects: objects that are simply perceived or experienced, but not in virtue of the perception or experience of distinct, more “immediate”, objects.

Various authors appeal to a notion of directness in outlining our ordinary conception of perceptual experience, and the Problem of Perception. A dissenting voice is Austin (1962), and for recent critical discussion see Martin (2017). For further discussion of how to understand notions of direct and indirect perception, see Jackson (1977), Snowdon (1992), Foster (2000), Smith (2002), and Martin (2005).

This starting point gives rise to the following questions (cf. Martin 1998: 176):

• The Objects Question: what is the nature of the direct objects of experience?
• The Structure Question: in what sense are experiences directly of their objects?

Let’s turn to the answers to these questions suggested by Strawson and McDowell’s remarks (for a more critical stance on these remarks see Mackie (2020)).

Strawson begins his argument by asking how someone might typically respond to a request for a description of their current visual experience. He says that it is natural to give the following kind of answer: “I see the red light of the setting sun filtering through the black and thickly clustered branches of the elms; I see the dappled deer grazing in groups on the vivid green grass…” (1979: 97). There are two ideas implicit in this answer. First, the description talks about objects which are things distinct from experience. Second, the description is “rich”, describing the nature of the experience not merely in terms of simple shapes and colours; but in terms of the familiar things we encounter in the “lived world” in all their complexity (see also Heidegger (1977: 156)).

So, we can highlight the following answer to the Objects Question:

• Ordinary Objects : perceptual experiences are directly of ordinary mind-independent objects .

There are three things to clarify about this. First, it incorporates realism in that it appeals to the notion of a mind-independent object of experience: one that doesn’t depend for its existence upon experience. Second, it concerns familiar or ordinary objects, things that we admit as part of common-sense ontology. Third, “object of experience” is understood broadly to encompass perceptible entities in mind-independent reality including ordinary material objects, but also features and other entities (e.g., events, quantities of stuff). When we talk of “ordinary objects”, “the world” etc, we take this as shorthand for: familiar or ordinary mind-independent perceptible entities.

Some writers have defended a thesis known as the transparency of experience (see Harman (1990); Speaks (2009); Tye (1992, 1995, 2000); Thau (2002); and for critical discussions, Martin (2002a), Smith (2008), Stoljar (2004) and Soteriou (2013)). Transparency is normally defined as the thesis that introspecting what it is like for a subject to have an experience does not reveal awareness of experiences themselves, but only of their mind-independent objects. There are two claims here: (i) introspection reveals the mind-independent objects of experience, and (ii) introspection does not reveal any features of anything else.

Transparency is similar to Ordinary Objects . The latter claim does involve something like (i). But it does not involve (ii). And it is not obvious that (ii) is part of our ordinary conception of perceptual experience. After all, we readily admit that an ordinary scene (e.g., a snow-covered churchyard) can look very different when one removes one’s glasses: one’s visual experience then becomes blurred. But this phenomenal difference does not seem to derive from any apparent difference in the objects of experience. Rather, it seems to be a difference in the way in which those objects are experienced. (See Tye (2000) and Gow (2019) for different responses. For further discussion, see Crane (2000), Smith (2008), Allen (2013), and French (2014). For a different challenge to (ii) and its ilk see Richardson (2010) and Soteriou (2013: Chapter 5), and French (2018)).

What, then, about the Structure Question? Strawson speaks of the manner in which we directly experience objects as a matter of “immediate consciousness”, and McDowell talks of our “openness” to objects. Other notions commonly invoked here include the idea that we are directly “acquainted” with objects, we directly “apprehend” them, they are “given” to us, or directly “present to the mind”. What these notions all aim to capture is the intuitive idea that perceptual experience of an object involves a special intimate perceptual relation to an object, a relation which differentiates perceptual experiences from non-perceptual states of mind which are similarly directed on the world (e.g., non-sensory, non-perceptual thoughts).

One function of this relation is to make objects present in such a way that they can shape or mould the character of one’s experience. In virtue of this, perceptions of the world are unlike (non-perceptual) thoughts about the world: they are constrained by the objects actually given. One’s perception of a snow-covered churchyard is responsive to how the churchyard is now, as one is perceiving it. But one’s (non-perceptual) thought need not be: in the middle of winter, one can imagine the churchyard as it is in spring, and one can think of it in all sorts of ways which are not the ways it presently is.

In what follows we will use the notion of perceptual presentation to capture this perceptual relation. We can thus highlight the following answer to the structure question:

• Presentation : perceptual experiences are direct perceptual presentations of their objects.

In what follows, we use “direct presentation” for short.

Putting the pieces together, our ordinary conception of perceptual experience involves:

• Direct Realist Presentation : perceptual experiences are direct perceptual presentations of ordinary objects .

If direct perceptual presentation of an ordinary object is a way of directly perceiving it, then this gives us:

• Direct Realism : we can directly perceive ordinary objects.

We can now shed light on the phenomenal character of perceptual experience. Consider, then, the following question:

• The Character Question: what determines the phenomenal character of experience?

We began with the basic phenomenological observation that perceptual experiences are directly of things. A similarly basic observation is that what it is like for us to experience is at least partly a matter of such things appearing certain ways to us. When we reflect upon what determines what it is like to have an experience, we naturally begin with what is presented to us, and how it is presented. This is why it is so natural for Strawson to describe his experience in terms of what he perceives, and for Martin to say that “our awareness of what an experience is like is inextricably bound up with knowledge of what is presented to one in having such experience” (1998: 173).

Further, when we reflect upon what determines what it is like for us to experience, we naturally begin with the ordinary objects that are presented to us, and how they are presented or appear. This is why it is so natural for Strawson to describe his experience in terms of such objects, and why many find (at least component (i) of) Transparency intuitive.

So, we can highlight the following answer to the Character Question:

• Direct Realist Character: the phenomenal character of experience is determined, at least partly, by the direct presentation of ordinary objects.

Perceptual experiences are not just veridical experiences: there are illusions and hallucinations too. What does phenomenological reflection say about how these cases relate to each other? More specifically:

• The Common Kind Question: are veridical, illusory, and hallucinatory experiences fundamentally the same, do they form of a common kind ?

In the context of the Problem of Perception, these cases are usually distinguished as follows: a veridical experience is an experience in which an ordinary object is perceived, and where the object appears as it is; an illusory experience is an experience in which an ordinary object is perceived, and where the object appears other than it is; a hallucination is an experience which seems to the subject exactly like a veridical perception of an ordinary object but where there is no such perceived or presented object. (For illusions and hallucinations which don’t fit these forms, see Johnston (2011), and Batty and Macpherson (2016)).

Clearly, there are differences between these categories, but from a phenomenological point of view, these experiences seem the same in at least this sense: for any veridical perception of an ordinary object, we can imagine a corresponding illusion or hallucination which cannot be told apart or distinguished, by introspection, from the veridical perception. This suggests the following answer to the Common Kind Question:

• Common Kind Claim: veridical, illusory, and hallucinatory experiences (as) of an F are fundamentally the same; they form a common kind .

Thus, a veridical, illusory, and hallucinatory experience, all alike in being experiences (as) of a churchyard covered in white snow, are not merely superficially similar, they are fundamentally the same: these experiences have the same nature, fundamentally the same kind of experiential event is occurring in each case. Any differences between them are external to their nature as experiences (e.g., to do with how they are caused).

2. The Problem of Perception

The Problem of Perception is that if illusions and hallucinations are possible, then perceptual experience, as we ordinarily understand it, is impossible. The Problem is animated by two central arguments: the argument from illusion (§2.1) and the argument from hallucination (§2.2). (A similar problem arises with reference to other perceptual phenomena such as perspectival variation or conflicting appearances: see Burnyeat (1979) and the entry on sense-data). For some classic readings on these arguments, see Moore (1905, 1910); Russell (1912); Price (1932); Broad (1965); and Ayer (1940), see Swartz (1965) for a good collection of readings. And for more recent expositions see Snowdon (1992), Valberg (1992), Robinson (1994: Chapter 2), Smith (2002: Chapters 1 and 7), Martin (2006), Fish (2009: Chapter 2), Brewer (2011: Chapter 1) and Pautz (2021).

The two central arguments have a similar structure which we can capture as follows:

• In an illusory/hallucinatory experience, a subject is not directly presented with an ordinary object.
• The same account of experience must apply to veridical experiences as applies to illusory/hallucinatory experiences.
• Subjects are never directly presented with ordinary objects.

(C) contradicts Direct Realist Presentation, and thus our ordinary conception of perceptual experience. And since Direct Realism seems to follow from Direct Realist Presentation, the argument challenges Direct Realism too (for more on this see §3.2.6 ).

Representing the arguments in this basic form enables us to highlight their two major movements; what Paul Snowdon calls the base case, and the spreading step (1992, 2005). In the base case a conclusion about just illusory/hallucinatory experiences is sought: (A). In the spreading step, (B), this result is generalised so as to get (C). This generalising move works on these background assumptions: (a1) that (B) yields the claim that one is not directly presented with ordinary objects in veridical experiences (given (A)), and (a2) if one is not directly presented with such objects in even veridical experiences, one never is.

We’ll look at more complex versions of the argument shortly. As we’ll see, the main burden on the arguer from illusion is in supporting the relevant version of (A), whereas the main burden on the arguer from hallucination is in defending the relevant version of (B).

Now, the argument here is purely negative. But many philosophers have moved from this to the further conclusion that since we are always directly presented with something in perceptual experience, what we are presented with is a “non-ordinary” object (see §3.1.2 ).

Applying the above structure, the argument from illusion is:

• In illusory experiences, we are not directly presented with ordinary objects.
• The same account of experience must apply to veridical experiences as applies to illusory experiences.
• We are never directly presented with ordinary objects.

Moving beyond the simple formulation, the argument is typically presented as involving these steps, for an arbitrary subject S:

• In an illusion, it seems to S that something has a sensible quality, F, which the ordinary object supposedly being perceived does not have.
• When it seems to S that something has a sensible quality, F, then there is something directly presented to S which does have this quality.
• Since the ordinary object in question is, by hypothesis, not-F, then it follows that in an illusion, S is not directly presented with the ordinary object supposedly being perceived.
• The same account of experience must apply to both veridical and illusory experiences.
• In veridical experience, S is not directly presented with the ordinary object supposedly being perceived.
• If S is not directly presented with the ordinary object supposedly being perceived in veridical experience, S is never directly presented with an ordinary object.

The most controversial premise here is premise (ii). The others reflect intuitive ways of thinking about perceptual experience, or plausible assumptions. This is clear enough with (i) and (iv). Premise (i) articulates the operative conception of illusions. An example to illustrate is a case where a white wall looks yellow to you, in peculiar lighting (Smith (2002: 25)). And premise (vi) reflects the intuitive idea that if we aren’t directly presented with the ordinary objects we seem to perceive in veridical experiences, then we aren’t directly presented with ordinary objects at all. For it would be implausible to relinquish the idea that we are directly presented with the ordinary objects we seem to perceive in veridical experience, yet maintain that we can still somehow else be directly presented with ordinary objects, e.g., with the idea that hallucinations are direct presentations of ordinary objects, or with the idea that veridical experiences are direct presentations of ordinary objects just not those we seem to perceive.

But what about (iv)? On one way of interpreting this, it reflects the Common Kind Claim applied to veridical experiences and illusions. Furthermore, various authors hold that (iv) is supported by the continuity between veridical experiences and illusory experience (Price (1932: 32), Ayer (1940: 8–9), Broad (1952: 9), Robinson (1994: 57), Smith (2002: 26–28): the fact that they may form a “continuous series” in which they “shade into one another” (Ayer (1940: 8–9)). This, it is held, supports the idea that experiential differences between illusions and veridical perceptions are differences of “degree and not of kind” (Ayer (1940: 8)).

Premise (ii) is a version of what Robinson calls the Phenomenal Principle:

If there sensibly appears to a subject to be something which possesses a particular sensible quality then there is something of which the subject is aware which does possess that sensible quality (1994: 32).

C.D. Broad motivates this principle on explanatory grounds. In cases of perceptual experience things appear some ways rather than others to us. We need to explain this. Why does the penny look elliptical to you as opposed to some other shape? One answer is that there is something directly presented to you which is in fact elliptical. Thus, as Broad says “If, in fact, nothing elliptical is before my mind, it is very hard to understand why the penny should seem elliptical rather than of any other shape.” (1923: 240). Other philosophers have simply taken the principle to be obvious. H.H. Price, for example, says that “When I say ‘this table appears brown to me’ it is quite plain that I am acquainted with an actual instance of brownness” (1932: 63).

So much for the argument’s main premises. How is it supposed to work? Here we find the suggestion that it hinges on an application of Leibniz’s Law of the Indiscernibility of Identicals (Robinson (1994: 32); Smith (2002: 25)). The point is that (i) and (ii) tell us that in an illusory experience you are directly presented with an F thing, but the ordinary object supposedly being perceived is not F, thus the F thing and the ordinary object are not identical, by Leibniz’s Law. On these grounds, the conclusion of the base case is supposed to follow. And then the ultimate conclusion of the argument can be derived from its further premises.

But as French and Walters (2018) argue, this is invalid. (i), (ii) and Leibniz’s Law entail that in an illusory experience you are directly presented with an F thing which is non-identical to the ordinary object supposedly being perceived. However, this doesn’t entail that in the illusion you are not directly presented with the ordinary object. You might be directly presented with the ordinary object as well as the F thing. We should be careful to distinguish not being directly presented with the ordinary object from being directly presented with something which is not the ordinary object (e.g., between not being directly presented with the white wall, and being directly presented with something that is not the white wall, e.g., a yellow entity). The argument is invalid in conflating these two ideas.

One option for fixing the argument is to introduce what French and Walters call the Exclusion Assumption (cf., Snowdon (1992: 74)): If in an illusion of an ordinary object as F, a subject is directly presented with an F thing non-identical to the ordinary object, then they are not also directly presented with the ordinary object.

This assumption bridges the gap between the conclusion actually achieved: namely, in an illusory experience S is directly presented with an F thing non-identical to the ordinary object, and the desired conclusion (iii). But whether this assumption is defensible remains to be seen. We leave this and the issue of validity aside and consider responses from different theories of experience below.

2.2 The Argument From Hallucination

The argument from hallucination relies on the possibility of hallucinations as understood above. Such hallucinations are not like real drug-induced hallucinations or hallucinations suffered by those with certain mental disorders. They are rather supposed to be merely possible events. For example, suppose you are now having a veridical perception of a snow-covered churchyard. The assumption that hallucinations are possible means that you could have an experience which is subjectively indistinguishable—that is, indistinguishable by you, “from the inside”—from a veridical perception of a snow-covered churchyard, but where there is in fact no churchyard presented or there to be perceived. The claim that such hallucinations are possible is widely accepted but not indisputable (see Austin (1962) and Masrour (2020)). For more on hallucinations, see Macpherson and Platchias (2013).

The argument from hallucination runs as follows:

• In hallucinatory experiences, we are not directly presented with ordinary objects
• The same account of experience must apply to veridical experiences as applies to hallucinatory experiences.

Unlike with the argument from illusion, the base case doesn’t rely on the Phenomenal Principle: (A) simply falls out of what hallucinations are supposed to be.

The spreading step can be interpreted in terms of the Common Kind Claim , applied to veridical experiences and hallucinations. Accepting (B) understood in this way puts a constraint on what can be said about the nature of veridical experience: whatever can be said had better be able to apply to hallucinations too. The argument is that, given (A), this then rules out an account of veridical experiences as direct presentations of ordinary objects. But then (C) follows (given that if we are not directly presented with ordinary objects in veridical experience, we never are).

With the argument understood in this way, we can see the power of the Problem of Perception. (A) is intuitive, and (B) is part of our ordinary conception of perceptual experience, yet what follows, (C), contradicts another aspect of our ordinary conception ( Direct Realist Presentation ). Thus, the very intelligibility of our ordinary conception of perceptual experience is threatened.

Now it might be argued that the Common Kind Claim applied to veridical perceptions and hallucinations is not as plausible as it is when applied to veridical perceptions and illusions. For veridical and illusory experiences are more naturally grouped together anyway, unlike veridical perceptions and hallucinations. For, at least before we encounter the argument from illusion, veridical perceptions and illusions are both naturally thought of as direct presentations of ordinary objects (it’s just that in illusory cases the presented objects appear other than they are). However, as noted above, from a phenomenological point of view, hallucinations too seem as though they are direct presentations of ordinary objects: from the subject’s perspective a hallucination as of an F cannot be distinguished from a veridical experience of an F. This is why it seems so plausible to think of them as fundamentally the same.

Even so, the Common Kind Claim applied to veridical perceptions and hallucinations is controversial, and rejecting it is central to the disjunctivist response to the Problem of Perception that we will consider later ( §3.4 ).

3. Theories of Experience

A number of philosophical theories of experience have emerged as responses to the Problem of Perception, or in relation to such responses. Here we consider the sense-datum theory ( §3.1 ), adverbialism ( §3.2 ), intentionalism ( §3.3 ), and naive realist disjunctivism ( §3.4 ). In this exposition we do not consider much the possibility of hybrid views. The way these positions relate to the Problem of Perception is mapped most clearly in Martin (1995, 1998, 2000).

We present these theories as operating on two levels. On Level 1, they tell us about the nature of experience. With the exception of adverbialism (for reasons that will emerge shortly), this can be investigated by considering the stance of each theory on the nature of the objects of experience, and the structure of our experience of objects. On Level 2, they tell us how what is said at the first level bears on the explanation of the character of experience. We also consider how each theory addresses the common kind question.

In what follows, we’ll work with the example of a visual experience of a snow-covered churchyard. To simplify, we will discuss the character of this experience in terms of one aspect of it: things looking white to a subject. The question at Level 1 is: what is the nature of such an experience? Does it involve the direct presentation of objects, or not? If so, what sorts of objects? If not, how are we to understand the nature of this experience? The question at Level 2 is: what is it about the nature of this experience that explains why things look any way at all to someone, and why they look, specifically, white?

3.1 The Sense-Datum Theory

What does the sense-datum theorist say at Level 1? On this theory, whenever a subject has a sensory experience, there is something which is presented to them. This relational conception of experience is sometimes called an “act-object” conception, since it posits a distinction between the mental act of being presented with something, and the object presented. More precisely, the sense-datum theorist holds that an experience in which something appears F to S, where F is a sensible quality (e.g., whiteness), consists in S being directly presented with something which actually is F (e.g. a white thing). They thus endorse the aforementioned Phenomenal Principle . The sense-datum theorist calls these objects of perception “sense-data”.

Understood in this way, a sense-datum is just whatever it is that you are directly presented with that instantiates the sensible qualities which characterise the character of your experience. This involves no further claim about the nature of sense-data, though as we’ll see shortly, sense-datum theorists do go on to make further claims about the nature of sense-data.

What about Level 2? With respect to our example, the sense-datum theorist claims that things appearing any way at all to you consists in the fact that you are directly presented with a sense-datum, and things appearing white to you consists in the fact that you are directly presented with a white sense-datum. The character of your experience is explained by an actual instance of whiteness manifesting itself in experience.

The sense-datum theorist endorses the Common Kind Claim . So, a veridical experience in which something appears white to you consists in your being directly presented with a white sense-datum; but so do corresponding illusory and hallucinatory experiences. These experiences have the same nature.

The sense-datum theorist endorses the following negative claim:

They accept this on the basis of the arguments from illusion and hallucination. However, the intended contrast with Direct Realist Presentation usually involves a stronger claim:

• We are only ever directly presented with sense-data , which are non-ordinary objects.

This involves a positive claim about what we are directly presented with, given that we are never directly presented with ordinary objects. And it embeds a claim about the nature of sense-data that goes beyond that outlined above: now sense-data are understood as non-ordinary objects.

Sense-datum theorists divide over exactly how to understand sense-data insofar as they are non-ordinary. Some early sense-datum theorists (such as Moore) initially took sense-data to be mind-independent, but peculiar non-physical objects. Later theorists treat sense-data as mind-dependent entities (Robinson (1994)). This is how the theory tends to be understood in literature from second half of the 20th century on.

Sense-datum theorists have developed more positive Problem of Perception style reasoning to support these additional ideas. For instance, Macpherson (2013: 12–13) outlines a more complicated version of the argument from hallucination than that above which concludes that “All perceptual experience, hallucinatory and non-hallucinatory, involves awareness of a mind-dependent, nonphysical object—a sense-datum”. And some sense-datum theorists have attempted to support non-ordinary sense-data outside of the context of the Problem of Perception (see Jackson (1977) and Lowe (1992)).

From now on when we speak of “sense-data” we will mean non-ordinary sense-data, and when we speak of the “sense-datum theory” we have in mind a theory that endorses not just (1) but (2).

3.1.3 The Sense-Datum Theory and Our Ordinary Conception of Perceptual Experience

The sense-datum theorist agrees with some aspects of our ordinary conception of perceptual experience. They endorse the Common Kind Claim . They also endorse Presentation – the idea that the direct objects of experience are perceptually presented to us. It’s just that they don’t agree that the direct objects of experience are ordinary objects – they are non-ordinary sense-data. They thus reject Ordinary Objects , and hence Direct Realist Presentation , and Direct Realist Character .

Is the sense-datum theory a theory on which we completely lose contact with the world, a theory on which we cannot perceive the world?

Though it is possible for a sense-datum theorist to accept this, a more popular position has been one on which we still have some form of perception of the world, just not direct perception. That is, the sense-datum theorist can say that we indirectly perceive ordinary objects: we perceive them by being directly presented with sense-data. A sense-datum theorist who says this is known as an indirect realist or representative realist (see the entry on epistemological problems of perception ). The task for such a sense-datum theorist is to spell out how the direct presentation of sense-data can lead to indirect perception of ordinary objects. This is something early sense-datum theorists pursued by asking how sense-data are related to ordinary objects. A theorist who denies that we perceive mind-independent objects at all, directly or indirectly, but only sense-data construed as mental entities, is known as a phenomenalist or an idealist (see Foster (2000), see Crane and Farkas (2004: Section 2) for an introduction to the subject; and the entry on idealism ).

The sense-datum theory was widely rejected in the second half of the 20th century, though it still had its occasional champions (e.g., Jackson (1977), O’Shaughnessy (2000, 2003), Lowe (1992), Robinson (1994), Foster (2000)). A number of objections have been made to the theory. Some of these are objections specifically to the indirect realist version: for example, the claim that the theory gives rise to an unacceptable “veil of perception” between mind and world. The idea is that sense-data “interpose” themselves between perceivers and ordinary objects, and therefore problematise our perceptual, cognitive, and epistemic access to the world. In response, the indirect realist can say that sense-data are the medium by which we perceive ordinary objects, and no more create a “veil of perception” than the fact that we use words to talk about things creates a “veil of words” between us and what we talk about. (For recent discussion see Silins (2011)).

A common objection is to attack the Phenomenal Principle (see Barnes (1944–5); Anscombe (1965)). The objection is that the Phenomenal Principle is fallacious. It is not built into the meaning of “something appears F to one” that “one is directly presented with an F thing”. Defenders of the sense-datum theory can respond that the Phenomenal Principle is not supposed to be a purely logical inference; it is not supposed to be true simply because of the logical form or semantic structure of “appears” and similar locutions. Rather, it is true because of specific phenomenological facts about perceptual experience. But this just means that theorists who reject the Phenomenal Principle are not disagreeing about whether the Phenomenal Principle involves a fallacy or about some semantic issue, but rather about the nature of experience itself.

Another influential objection to sense-data comes from the prevailing naturalism of contemporary philosophy. Naturalism (or physicalism) says that the world is entirely physical in its nature: everything there is supervenes on the physical, and is governed by physical law. Many sense-datum theorists are committed to the claim that non-ordinary sense-data are mind-dependent: objects whose existence depends on the existence of states of mind. Is this consistent with naturalism? If so, the challenge is to explain how an object can be brought into existence by the existence of an experience, and how this is supposed to be governed by physical law.

Many contemporary sense-datum theorists, however, will not be moved by this challenge, since they are happy to accept the rejection of naturalism as a consequence of their theory (Robinson (1994), Foster (2000)). On the other hand, one might think that there is no conflict here with naturalism, as long as experiences themselves are part of the natural order. But if sense-data are non-ordinary in being mind-independent but non-physical , then it is much less clear how naturalism can be maintained (cf., what Martin (2004, 2006) calls “experiential naturalism” which serves as a constraint on theories of experience and rules out some but not all forms of the sense-datum theory).

For other objections to the sense-datum theory, including the worry that it must admit “indeterminate” sense-data (e.g., on the basis of seeing a speckled hen, which appears to have a number of speckles but no definite number), see the entry on sense-data .

3.2 Adverbialism

Part of the point of adverbialism, as defended by Ducasse (1942) and Chisholm (1957) is to do justice to the phenomenology of experience whilst avoiding the dubious metaphysical commitments of the sense-datum theory. The only entities which the adverbialist needs to acknowledge are subjects of experience, experiences themselves, and ways these experiences are modified. Let us explain.

At Level 1, the adverbialist rejects the Phenomenal Principle and the whole idea that experience consists in being directly presented with perceptible entities. For the adverbialist, when someone has an experience of something white, something like whiteness is instantiated, but in the experience itself, not a presented thing. This is not to say that the experience is white, but rather that the experience is modified in a certain way , the way we can call “perceiving whitely”. The canonical descriptions of perceptual experiences, then, employ adverbial modifications of the perceptual verbs: instead of describing an experience as someone’s “visually sensing a white sphere”, the theory says that they are “visually sensing whitely and spherely”. This is why this theory is called the “adverbial theory”; but it is important to emphasize that it is more a theory about the nature of experience itself than it is a semantic analysis of sentences describing experience.

It is also intended as a theory of the character of experience (Level 2). The adverbialist claims that things appearing white to you consists in you sensing whitely . It is because you are sensing in some way that explains why things appear a certain way to you at all, and it is the fact that you are sensing whitely that explains why things appear white to you, rather than some other way. The character of your experience is explained by the specific “white” way in which your experience is modified.

The adverbialist endorses the Common Kind Claim . So, a veridical experience in which something appears white to you, consists in you sensing whitely, but so do corresponding illusory and hallucinatory experiences: these experiences have the same nature.

3.2.2 Adverbialism and Qualia

When used in a broad way, “qualia” picks out whatever qualities a state of mind has which constitute the state of mind’s having the phenomenal character it has. In this broad sense, any phenomenally conscious state of mind has qualia. (This is the way the term is used in, e.g., Chalmers (1996)). Used in a narrow way, however, qualia are non-intentional, intrinsic properties of experience: properties which have no intentional or representational aspects whatsoever. To use Gilbert Harman’s apt metaphor, qualia in this sense are “mental paint” properties (1990). Harman rejects mental paint, but the idea of experience as involving mental paint is defended by Block (2004)).

It is relatively uncontroversial to say that there are qualia in the broad sense. It can be misleading, however, to use the term in this way, since it can give rise to the illusion that the existence of qualia is a substantial philosophical thesis when in fact it is something which will be accepted by anyone who believes in phenomenal character. (Hence Dennett’s (1991) denial of qualia can seem bewildering if “qualia” is taken in the broad sense). It is controversial to say that there are qualia in the narrow sense, though, and those who have asserted their existence have therefore provided arguments and thought-experiments to defend this assertion (see Block (1997), Peacocke (1983: Chapter 1), Shoemaker (1990)). In what follows, “qualia” will be used exclusively in the narrow sense.

As noted, adverbialism is committed to the view that experiencing something white, for example, involves your experience being modified in a certain way: experiencing whitely. A natural way to understand this is in terms of the idea that the experience is an event, and the modification of it is a property of that event. Since this property is both intrinsic (as opposed to relational or representational) and phenomenal then this way of understanding adverbialism is committed to the existence of qualia.

An important objection to adverbialism is the “Many Property Problem” proposed by Frank Jackson (1975). Consider someone who senses a brown square and a green triangle simultaneously. The adverbialist will characterize this state of mind as “sensing brownly and squarely and greenly and triangularly”. But how can they distinguish the state of mind they are describing in this way from that of sensing a brown triangle and a green square? The characterization fits that state of mind equally well. Obviously, what is wanted is a description according to which the brownness “goes with” the squareness, and the greenness “goes with” the triangularity. But how is the adverbialist to do this without introducing objects of experience—the things which are brown and green respectively—or a visual field with a spatial structure? The challenge is whether the adverbialist can properly account for the spatial structure and complexity in what is given in visual experience. See Tye (1984), Breckenridge (2018: Chapter 10), and D’Ambrosio (2019) for adverbialist responses to this challenge. For a helpful overview, see Fish (2010: Chapter 3).

A further challenge is that adverbialism is “incapable of doing justice to the most obvious and indeed essential phenomenological fact about perceptual consciousness… namely… its object-directness” (Butchvarov (1980: 272)). Recall here the basic phenomenological observation we began with: perceptual experiences are directly of things.

As we’ve seen, at Level 1, the adverbialist denies that perceptual experiences are direct presentations of objects. And at Level 2, in explaining character, the adverbialist assigns no role to the direct presentation of things, just ways of sensing. But then if it is an aspect of the phenomenology of experience that our experiences have direct objects, then it is not clear that the adverbialist has the resources to capture this. For the adverbialist, to capture your experience of a snow-covered churchyard we invoke seeing whitely not seeing a white thin g. How, then, can we explain why phenomenologically , your experience is directly of a white thing – or even why it seems to be object-directed in this way? Butchvarov’s charge is that the adverbialist doesn’t have the resources to answer these questions. (See D’Ambrosio (2019) for a recent adverbialist attempt to capture something like object-directness).

The argument from illusion relies on the Phenomenal Principle . In rejecting this, the adverbialist thus rejects the argument. But what about the argument from hallucination? This does not rely on the Phenomenal Principle. The adverbialist accepts (A). And they also accept (B) in the form of the Common Kind Claim . (C) follows (given assumptions (a1) and (a2)). For this reason, the adverbialist must reject Direct Realist Presentation . So, like the sense-datum theorist, the adverbialist must admit that we are never directly presented with ordinary objects, not even in veridical experience.

3.2.5 Adverbialism and our Ordinary Conception of Perceptual Experience

Like the sense-datum theorist, though the adverbialist accepts some of our ordinary conception of perceptual experience (the Common Kind Claim ), they reject other aspects of it. The argument from hallucination forces them to reject Direct Realist Presentation (and therefore Direct Realist Character ). Underlying this is the adverbialist’s rejection of Presentation , and arguably Ordinary Objects too. They reject Presentation in denying that experiences have a relational structure. And given our discussion of Butchvarov’s challenge, it seems as though they must reject (or at least don’t have the resources to accept) Ordinary Objects . For it is unclear how they can validate the phenomenological claim that experiences are of objects, let alone directly of ordinary objects.

So, even though adverbialism arises as a response to the sense-datum theory, given its almost wholesale rejection of our ordinary conception of perceptual experience, it is unclear how much of an improvement the approach is in the broader dialectic of the Problem of Perception.

One response to this is that we should not suppose that the only way to articulate direct realism is through the claim we’ve labelled Direct Realist Presentation . There is another way to articulate it which, it might be suggested, enables the adverbialist to account for direct perception of the world. Consider, then:

• Direct Realist Presentation : perceptual experiences are direct perceptual presentations of ordinary objects.

This entails Direct Realism – that we can directly perceive ordinary objects – on the assumption that being directly perceptually presented with an ordinary object is a way of directly perceiving it. On this way of thinking, direct perception of an ordinary object is built into perceptual experience itself. However, one might reject this claim about experience (as adverbialists do), and still hold that we can have direct perception of an ordinary object. How?

Instead of thinking of direct perception of the world as built into experience, we can think of direct perception of the world as built out of experience together with the satisfaction of other conditions. This idea is usually developed through a causal theory of perception (Grice 1961): where perception of an object is analysed in terms of (i) experience of an ordinary object (conceived as something which is not sufficient for perception), and (ii) the satisfaction of a causal condition which requires that the experience be caused by the object (in a non-deviant way). This is a causal theory of direct perception on the assumption that the account doesn’t involve any perceptual intermediaries.

The adverbialist might suggest that they can embrace this: by combining their theory of experience with a causal analysis of direct perception. Thus, they can hold that when you have an experience of a snow-covered churchyard, if this experience is appropriately caused by an ordinary white thing (e.g., some snow), this is what directly perceiving such an object amounts to (given that no perceptual intermediaries are involved).

However, whether the adverbialist is entitled to this way of making sense of direct perceptual contact with the world hinges on whether they can make sense of the idea of an experience of an ordinary object . But as we have seen in considering Butchvarov’s challenge, it is unclear whether the adverbialist can do this. It is thus unclear whether the adverbialist can really make sense of clause (i).

In response, the adverbialist might offer a causal analysis of experiences being of objects. They might thus attempt to fall back on the idea that an experience in which you sense whitely is an experience “of” a white thing insofar as it is causally related to a white thing (or, insofar as it is of a type, instances of which are typically caused by white things). However, as Butchvarov argues, the fact that “x is causally related to S’s sensing in a certain way can no more reasonably be described as S’s being conscious of [i.e. having a conscious experience of] x than the fact that the presence of carbon monoxide in the air is causally related to S’s having a headache can be described as S’s being conscious of [having a conscious experience of] carbon monoxide” (1980: 273).

Even if the adverbialist is able to sustain such a causal form of direct realism, it is very different from the phenomenological form of direct realism embedded in our ordinary conception of perceptual experience. It is thus unlikely to satisfy a direct realist sensitive to the phenomenological concerns which give rise to our ordinary conception of perceptual experience.

3.3 Intentionalism

The intentionalist holds that we directly experience ordinary objects. The distinguishing feature of the view is a specific conception of the manner in which experiences are directly of ordinary objects: here the intentionalist appeals to intentionality conceived of as a form of mental representation (hence it is also sometimes called the representationalist theory of experience). “Intentionality” is a term with its origins in scholastic philosophy (see Crane (1998b)), but its current use derives from Brentano (1874), who introduced the term “intentional inexistence” for the “mind’s direction upon its objects”. Intentional inexistence, or intentionality, is sometimes explained as the “aboutness” of mental states (see the entries on Franz Brentano , representational theories of consciousness and intentionality ).

At Level 1, then, the intentionalist holds that to experience a snow-covered churchyard is to directly perceptually represent such an object (i.e. to represent such an object but not in virtue of representing another more “immediate” object). At Level 2, this is put to work in explaining phenomenal character. In relation to our example, why is this a case of things appearing any way at all to you, and why is it a case of things appearing white to you? Here the intentionalist appeals to the experience’s directly representing things in a certain way, and specifically to experience’s directly representing whiteness in the environment, to account for this. The character of your experience is explained by the specific way in which your experience directly represents the world.

Critics of intentionalism have argued that it does not adequately distinguish perceptual experience from other forms of intentionality, and therefore does not manage to capture what is distinctive about experience (Robinson (1994: 164)). One objection of this kind is that the aforementioned intentionalist explanation of character is inadequate. The worry is that believing that something is the case, for example, or hoping that something is the case, are both forms of mental representation, but neither state of mind has any “feel” or phenomenal character to call its own. (Words or images may come to mind when mentally representing something in this way, but it is not obvious that these are essential to the states of mind themselves.) So, the challenge is that if there is nothing about representation as such which explains the character of an experience, how is experience supposed to be distinguished from mere thought?

There are a number of ways an intentionalist can respond. One is simply to take it as a basic fact about perceptual intentionality that it has phenomenal character (see Kriegel (2013)). After all, even those who believe in qualia have to accept that some states of mind have qualia and some do not, and that at some point the distinction between mental states which are phenomenally conscious, and those which are not, just has to be accepted as a brute fact. Another response is to say that in order to fully explain the phenomenal character of perceptual experience, we need to treat experience as involving non-intentional qualia as well as intentionality (see Peacocke (1983: Chapter 1); Shoemaker (1996); Block (1997)). There is, accordingly, a dispute between these intentionalists who accept qualia (like Block and Shoemaker) and those who don’t (like Harman (1990) or Tye (1992)). (For more on this see the entries on qualia and inverted qualia . Additional readings are: Block (2005) (2010), Egan (2006), Hilbert and Kalderon (2000), Marcus (2006), Shoemaker (1990), Speaks (2015), Spener (2003), and Tye (2000)).

Intentionalists endorse the Common Kind Claim . So, a veridical experience of churchyard covered in white snow, consists in direct representation of such a scene, but so do corresponding illusory and hallucinatory experiences: these experiences have the same nature.

Like adverbialists, the intentionalist has no need to postulate non-ordinary perceptible entities in the cases of illusion and hallucination. It is not generally true that when a representation represents something (as being F), there has to actually be something (which is F). Thus, for the intentionalist, experience is representational in a way that contrasts with it being relational/presentational. Experience does not genuinely have an act-object structure. This is in keeping with a standard tradition in the theory of intentionality which treats it as non-relational (the tradition derives from Husserl (1900/1901); for discussion see Zahavi (2003: 13–27). So, for the intentionalist, since it is not of the essence of experience or its character that it is relational, it is not of its essence that it is a relation to a sense-datum.

Some of the most influential (at least partial) intentional theories are Anscombe (1965), Armstrong (1968), Pitcher (1970), Peacocke (1983), Harman (1990), Tye (1992, 1995), Dretske (1995), Lycan (1996); for more recent accounts, see Byrne (2001), Siegel (2010), Pautz (2010) and the entry on the contents of perception .

Within analytic philosophy, intentionalism is a generalisation of an idea presented by G.E.M. Anscombe (1965), and the “belief theories” of D.M. Armstrong (1968) and George Pitcher (1970). (Within the phenomenological tradition intentionality and perception had always been discussed together: see the entry on phenomenology. ) Anscombe had drawn attention to the fact that perceptual verbs satisfy the tests for non-extensionality or intensionality (see the entry on intensional transitive verbs ). For example, just as ‘Vladimir is thinking about Pegasus’ is an intensional context, so ‘Vladimir has an experience as of a pink elephant in the room’ is an intensional context. In neither case can we infer that there exists something Vladimir is thinking about, or that there is exists something he is experiencing. This is the typical manifestation of intensionality. Anscombe regarded the error of sense-datum and naive realist theories as the failure to recognise this intensionality. (Her own example was the alleged intensionality of ‘see’, but this is controversial.)

Armstrong and Pitcher argued that perception is a form of belief. (More precisely, they argued that it is the acquisition of a belief, since an acquisition is a conscious event, as perceiving is; rather than a state or condition, as belief is.) Belief is an intentional state in the sense that it represents the world to be a certain way, and the way it represents the world to be is said to be its intentional content. Perception, it was argued, is similarly a representation of the world, and the way it represents the world to be is likewise its intentional content. The fact that someone can have a perceptual experience of something as F, without there being any thing which is F was taken as a reason for saying that perception is just a form of belief-acquisition.

Certain cases put pressure on this. For instance, consider the famous Müller-Lyer illusion in which two lines of equal length look unequal. You can experience this even if you know (and therefore believe) that the lines are the same length. If perception were simply the acquisition of belief, then this would be a case of explicitly contradictory beliefs: you believe that the lines are the same length and that they are different lengths. But this is surely not the right way to describe this situation. (Armstrong recognized this, and re-described perception as a “potential belief”; this marks a significant retreat from the original claim).

The belief theory (and related theories, like the judgement theory of Craig (1976)) is a specific version of the intentional theory. But it is not the most widely accepted version (though see Glüer (2009) for a recent defence; and Byrne (forthcoming)). Intentionalism is, however, not committed to the view that perceptual experience is belief; experience can be a sui generis kind of intentional state or event (Martin (1993)).

Intentionalists hold that what is in common between veridical experiences and indistinguishable hallucinations/illusions is their intentional content : roughly speaking, how the world is represented as being by the experiences. Many intentionalists hold that the sameness of phenomenal character in perception and hallucination/illusion is exhausted or constituted by this sameness in content (see Tye (2000), Byrne (2001)). But this latter claim is not essential to intentionalism (see the discussion of intentionalism and qualia above). What is essential is that the intentional content of perception explains (whether wholly or partly) its phenomenal character.

The intentional content of perceptual experience is sometimes called “perceptual content” (see the entry on the contents of perception ). What is perceptual content? A standard approach to intentionality treats all intentional states as propositional attitudes: states which are ascribed by sentences of the form “S ___ that p” where ‘S’ is to be replaced by a term for a subject, ‘p’ with a sentence, and the ‘___’ with a psychological verb. The distinguishing feature of the propositional attitudes is that their content—how they represent the world to be—is something which is assessable as true or false. Hence the canonical form of ascriptions of perceptual experiences is: “S perceives/experiences that p”. Perceptual experience, on this kind of intentionalist view, is a propositional attitude (see Byrne (2001), Siegel (2010)).

But intentionalism is not committed to the view that experience is a propositional attitude. For one thing, it is controversial whether all intentional states are propositional attitudes (see Crane (2001: Chapter 4)). Among the intentional phenomena there are relations like love and hate which do not have propositional content; and there are also non-relational states expressed by the so-called “intensional transitive” verbs like seek, fear, expect (see the entry on intensional transitive verbs ). All these states of mind have contents which are not, on the face of it, assessable as true or false. If I am seeking a bottle of inexpensive Burgundy, what I am seeking—the intentional content of my seeking, or the intentional object under a certain mode of presentation—is not something true or false. Some argue that these intentional relations and intentional transitives are analysable or reducible to propositional formulations (see Larson (2003) for an attempt to defend this view of intensional transitives; and Sainsbury (2010) for a less radical defence). But the matter is controversial; and it is especially controversial where experience is concerned. For we have many ways of talking about experience which do not characterize its content in propositional terms: for example, “Vladimir sees a snail on the grass”, or “Vladimir is watching a snail on the grass” can be distinguished from the propositional formulation “Vladimir sees that there is a snail on the grass” (for discussion of watching, see Crowther 2009).

There are those who follow Dretske (1969) in claiming that these semantical distinctions express an important distinction between “epistemic” and “non-epistemic” seeing. However, the view that perceptual content is non-propositional is not the same as the view that it is “non-epistemic” in Dretske’s sense. For ascriptions of non-epistemic seeing are intended to be fully extensional in their object positions, but not all non-propositional descriptions of perception need be (for example, some have argued that “Macbeth saw a dagger before him” does not entail “there is a dagger which Macbeth saw”: cf. Anscombe (1965)). The question of whether perceptual experience has a propositional content is far from being settled, even for those who think it has intentional content (see McDowell (2008); Crane (2009)).

Another debate about the content of perceptual experience is whether it is object-dependent, or object-independent (see Soteriou (2000) and Schellenberg (2018: Part II); and for a more general discussion, see Chalmers (2006)). An object-dependent content is a content which concerns a particular object, and is such that it cannot be the content of a state of mind unless that object exists (McDowell (1987) and Brewer (1999)). An object-independent content is one whose ability to be the content of any intentional state is not dependent on the existence of any particular object (Davies (1992) and McGinn (1989)).

The intentionalist holds that the content that is common to veridical experiences and subjectively indistinguishable hallucinations is object-independent: since such hallucinations occur in the absence of objects for such content to depend upon. However, as Martin (2002b) argues, drawing on (Burge 1991), the intentionalist can still appeal to the idea that particular veridical experiences have particular object-dependent contents in addition to the object-independent contents they share with subjectively indistinguishable hallucinations.

The objects of intentional states are sometimes called “intentional objects” (Crane (2001: Chapter 1)). What are the intentional objects of perceptual experience, according to intentionalists? In the case of veridical perception, the answer is simple: ordinary objects like the churchyard, the snow etc. But what should be said about the hallucinatory case? Since this case is by definition one in which there is no ordinary object being perceived, how can we even talk about something being an “object of experience” here? As noted above, intentionalists say that experiences are representations; and one can represent what does not exist (see Harman (1990), Tye (1992)). This is certainly true; but isn’t there any more to be said? For how does a representation of a non-existent churchyard differ from a representation of a non-existent cat, say, when one of those is hallucinated? The states seem to have different objects; but neither of these objects exist (see the entry nonexistent-objects ).

One proposal is that the objects of hallucinatory experience are the properties which the hallucinated object is presented as having (Johnston (2004)). Another answer is to say that these hallucinatory states of mind have intentional objects which do not exist (Smith (2002: Chapter 9)). Intentional objects in this sense are not supposed to be entities or things of any kind. When we talk about perception and its “objects” in this context, we mean the word in the way it occurs in the phrase “object of thought” or “object of attention” and not as it occurs in the phrase “physical object”. An intentional object is always an object for a subject, and this is not a way of classifying things in reality. An intentionalist need not be committed to intentional objects in this sense; but if they are not, then they owe an account of the content of hallucinatory experiences.

How does the content of perceptual experience differ from the content of other intentional states? According to some intentionalists, one main difference is that perception has “non-conceptual” content. The basic idea is that experience involves a form of mental representation which is in certain ways less sophisticated than the representation involved in (say) belief. For example, having the belief that the churchyard is covered in snow requires that you have the concept of a churchyard. This is what it means to say that belief has conceptual content: to have the belief with the content that a is F requires that you possess the concept a and the concept F. So, to say that experience has non-conceptual content is to say the following: for you to have an experience with the content that a is F does not require that you have the concept of a and the concept F. The idea is that your perceptual experience can represent the world as being a certain way—the “a is F” way—even if you do not have the concepts that would be involved in believing that a is F. (For a more detailed version of this definition, see Crane (1998a) and Cussins (1990); for a different way of understanding the idea of non-conceptual content, see Heck (2000) and Speaks (2005). The idea of non-conceptual content derives from Evans (1982); there are some similar ideas in Dretske (1981); see Gunther (2002) for a collection of articles on this subject. Other support for non-conceptual content can be found in Bermúdez (1997); Peacocke (1992); Crowther (2006); for opposition see Brewer (1999) and McDowell (1994)).

The intentionalist rejects the argument from illusion as it hinges on the Phenomenal Principle which they reject. For the intentionalist, an illusory experience in which you see a white wall as yellow is not a case in which you are directly presented with a yellow sense-datum, but a case in which a white wall is directly represented as being yellow.

However, the intentionalist must accept the argument from hallucination. They accept (A), and they also accept (B) in the form of the Common Kind Claim . (C) follows (given (a1) and (a2)). Thus, like sense-datum theorists and adverbialists, intentionalists reject Direct Realist Presentation , and admit that we are not ever directly presented with ordinary objects, not even in veridical experience.

In response to this, the intentionalist can suggest that although they reject Direct Realist Presentation , they do not reject Direct Realism . They can suggest that the former is not the only way to understand the latter. As we saw above, another way to understand Direct Realism is with a causal understanding of direct perception.

As we noted above, it is unclear whether the adverbialist is entitled to this, since it is unclear how the adverbialist can make sense of the object-directedness of experience. But the intentionalist doesn’t face this problem. The object-directedness of experience is at the heart of their approach. Even though intentionalism denies that experiences involve the direct presentation of ordinary objects, it (a) respects and is motivated by the phenomenological observation that experiences are directly of ordinary objects, and (b) offers an alternative account of the manner in which experiences are directly of ordinary objects. As we’ve seen, instead of presentation, the intentionalist appeals to representation.

Thus, the intentionalist can maintain that when you see a snow-covered churchyard for what it is you do directly perceive a snow-covered churchyard. This is not because your experience itself directly presents you with a snow-covered churchyard. It doesn’t. After all, your experience is of such a kind that it could occur in a hallucination, where it wouldn’t directly present any ordinary object. It is rather because your experience directly perceptually represents the presence of a snow-covered churchyard and is non-deviantly caused by the churchyard in question. This is what direct perception amounts to for the intentionalist

A concern about adverbialism that we raised above, from the perspective of one who wants to uphold our ordinary conception of perceptual experience, is that (a) it rejects our ordinary conception of perceptual experience almost wholesale , and (b) adverbialist causal direct realism, even if it could be made to work, doesn’t seem to compensate for that: it isn’t sensitive enough to the phenomenological concerns that motivate our ordinary conception of perceptual experience. In contrast, intentionalism seems to fare better on both scores.

First, strictly speaking, the intentionalist must reject our ordinary conception of perceptual experience. Even though they accept the Common Kind Claim , they reject Direct Realist Presentation . Underlying this is not rejection of Ordinary Objects but of Presentation . But even here, their rejection of Presentation is not too radical. For intentionalists can say that experiences are quasi -presentational. The appeal to representation enables this. For when you directly perceptually represent the snow-covered churchyard, it certainly seems to you as if a churchyard is directly present to you, even if it is not (as you are, say, hallucinating). As we noted above, it is not clear from the resources the adverbialist offers how they can account for how it even seems as if an object is present to you. How does perceiving whitely make it seem as if a white thing is present to you?

Similarly, though strictly speaking the intentionalist must reject Direct Realist Character , the departure from this is not too radical. For instead, the intentionalist holds that the character of experience is determined, at least partly, by the direct perceptual representation of ordinary objects. It is not as if ordinary objects and their apparent presence drops out of the picture on the intentionalist account of phenomenal character. The account is similar to Direct Realist Character , just stripped of the genuine relationality.

Finally, the causal direct realist story that the intentionalist offers is intelligible in the way that it arguably isn’t for the adverbialist. And although it invokes causal notions, this is not to the exclusion of a core phenomenological understanding of direct experience of an object, which the intentionalist accounts for with the notion of direct perceptual representation.

Intentionalism, then, is a Direct Realist theory which upholds some of our ordinary conception of perceptual experience, and insofar as it rejects aspects of our ordinary conception, it does so in a non-radical way, sensitive to the phenomenological concerns that motivate this conception in the first place.

3.4 Naive Realist Disjunctivism

Consider the veridical experiences involved in cases where you genuinely perceive objects as they actually are. At Level 1, naive realists hold that such experiences are, at least in part, direct presentations of ordinary objects. At Level 2, the naive realist holds that things appear a certain way to you because you are directly presented with aspects of the world, and – in the case we are focusing on – things appear white to you, because you are directly presented with some white snow. The character of your experience is explained by an actual instance of whiteness manifesting itself in experience.

Naive realists thus assign an important explanatory role to the world itself in explaining the character of veridical experiences. But this doesn’t mean that they are committed to the idea that such character is fully explained or exhausted by the presented world. Naive realists admit that even holding fixed presented aspects of the world there can be variation in the character of experience. This is worked out in different (but compatible) ways by different theorists. One approach is to note how variations in the perceiver can make for variations in the character of experience (Logue (2012a)). Another is to highlight a third-relatum (of the relation of presentation) which encapsulates various conditions of perception such as one’s spatiotemporal perspective and the operative perceptual modality, where variation in such conditions can make for variation in phenomenal character (Campbell (2009), Brewer (2011)). Finally, some suggest that there can be variation in the way or manner in which one is related to perceived objects which makes a difference to phenomenal character (Soteriou (2013), Campbell (2014), French and Phillips (2020)). For further discussion see French (2018).

For the naive realist, insofar as experience and experiential character is constituted by a direct perceptual relation to aspects of the world, it is not constituted by the representation of such aspects of the world. This is why many naive realists describe the relation at the heart of their view as a non-representational relation. This doesn’t mean that experiences must lack intentional content, but it means that (a) insofar as appeal is made to presentation to explain character, no appeal is made to intentional content for that purpose, and (b) what is fundamental to experience is something which itself cannot be explained in terms of representing the world: a primitive relation of presentation. (For further discussion of naive realism as a non-representational view, see the articles in Part Three of Brogaard (2014)).

The other theories we have considered all endorse the Common Kind Claim . We’ve noted that naive realism applies to the veridical experiences involved in genuine perception, but does it apply more widely? Though naive realists may extend their approach to illusions, they typically deny that it applies to hallucinations and so reject the Common Kind Claim . Naive realists who deny the Common Kind Claim are disjunctivists . We call such a position naive realist disjunctivism . Let’s explore these ideas now.

There are various different naive realist approaches to illusion (see e.g., Fish (2009: Chapter 6), Brewer (2008, 2011: Chapter 5), Kalderon (2011), Genone (2014), French and Phillips (2020)). When it comes to the argument from illusion, the naive realist (like the intentionalist) rejects the Phenomenal Principle . So how does naive realism differ from intentionalism about illusions? In two respects: first, naive realists can maintain that illusory experiences are fundamentally direct presentations of the world. Second, the naive realist can explain the character of such illusory experiences without appeal to intentional content, but instead by appealing to the direct presentation of ordinary objects. Consider, for example, the approach developed by Brewer:

visually relevant similarities are those that ground and explain the ways that the particular physical objects that we are acquainted with in perception look. That is to say, visually relevant similarities are similarities by the lights of visual processing of various kinds... very crudely, visually relevant similarities are identities in such things as the way in which light is reflected and transmitted from the objects in question, and the way in which the stimuli are handled by the visual system, given its evolutionary history and our shared training during development (2011: 103)... in a case of visual illusion in which a mind-independent physical object, o, looks F, although o is not actually F, o is the direct object of visual perception from a spatiotemporal point of view and in circumstances of perception relative to which o has visually relevant similarities with paradigm exemplars of F although it is not actually an instance of F (2011: 105).

So though o may not itself be F, it can exist in certain conditions, C, such that it has visually relevant similarities to paradigm F things and in that sense it will objectively look F, or look like an F thing—that is, it will itself have a property, a look or an appearance, independently of anyone actually seeing it (see also Martin (2010), Kalderon (2011), Antony (2011), and Genone (2014) on objective looks). If o is then seen in C, o itself will look F to you in perception. Brewer spells this all out in more detail, and with various examples. One is seeing a white piece of chalk as red. The chalk is seen in abnormal illumination conditions such that the white piece of chalk itself looks like a paradigm red piece of chalk—it has “visually relevant similarities with a paradigm piece of chalk, of just that size and shape” (2011: 106). Given that it is seen in those conditions, it looks red to you, even though it is not in fact red. Here, then, we have an account of illusions in which we appeal to objects and the ways those objects are, not the ways they are represented to be, in explaining character.

What about the argument from hallucination? The naive realist thinks that at least veridical experiences are direct presentations of ordinary objects. They thus reject the conclusion (C) of the argument. But typically, naive realists accept (A). They therefore block the argument by rejecting the spreading step (B), understood in terms of the Common Kind Claim applied to veridical and hallucinatory experiences.

Such a naive realist reasons as follows: suppose that when you see a snow-covered churchyard for what it is, you have an experience which is in its nature a relation between you and ordinary objects. But a subjectively indistinguishable hallucinatory experience does not have such a nature. For such a hallucination could occur in the absence of any relevant worldly items (e.g., in the lab of a scientist manipulating your brain, in a world with no white things). Instead of taking (B) and these facts about hallucination to ground the rejection of naive realism, the naive realist instead rejects (B): even though the hallucination as of a snow-covered churchyard is subjectively indistinguishable from a veridical experience of such a scene, it is not of the same fundamental kind. (For a more nuanced formulation of the naive realist reasoning here, see Martin (2004), (2006). Raleigh (2014) and Ali (2018) advocate a naïve realist position which keeps the Common Kind Claim but rejects (A) and hence the understanding of hallucinations we are operating with here. See also Masrour (2020) who argues that it is an open question whether hallucinations are possible.).

In blocking the argument from hallucination in this way the naive realist endorses disjunctivism . This theory was first proposed by Hinton (1973) and was later developed by P.F. Snowdon (1979, 1990), John McDowell (1982, 1987) and M.G.F. Martin (2002, 2004, 2006). Disjunctivism is not best construed as it is by one of its proponents, as the view “that there is nothing literally in common” in veridical perception and hallucination, “no identical quality” (Putnam (1999: 152)). For both the veridical perception of an F and a subjectively indistinguishable hallucination of an F are experiences which are subjectively indistinguishable from a veridical perception of an F. What disjunctivists deny is that what makes it true that these two experiences are describable in this way is the presence of the same fundamental kind of mental state. Disjunctivists reject what J.M. Hinton calls “the doctrine of the ‘experience’ as the common element in a given perception” and an indistinguishable hallucination (Hinton (1973: 71)). The most fundamental common description of both states, then, is a merely disjunctive one: the experience is either a genuine perception of an F or a mere hallucination as of an F. Hence the theory’s name.

The disjunctivist rejects the Common Kind Claim . Underlying this is a rejection of what Martin (2004, 2006) calls the “common kind assumption”, namely:

• (CKA) whatever fundamental kind of mental event occurs when you veridically perceive, the very same kind of event could occur were you undergoing a subjectively indistinguishable hallucination.

But is the disjunctivist’s rejection of (CKA) plausible? The disjunctivist can note how the fact that a hallucination is subjectively indistinguishable from a veridical experience does not entail that they are of the same fundamental kind, even if it does suggest this.

However, some argue that even if such an appeal to subjective indistinguishability is not enough to establish (CKA) , it is nonetheless well supported by a causal argument (Robinson (1985)). We can suppose that when you see the snow-covered churchyard for what it is, there is some proximal cause of this experience: the experience is preceded by a certain sort of brain state B. But now we can imagine a situation in which we bring about B thus producing an experience in you, yet where B is not brought about through any interaction between you and a snow-covered churchyard—e.g., in laboratory conditions. In this scenario you have an hallucinatory experience as of a snow-covered churchyard. It is plausible to suppose that these experiences are of the very same kind given that they have the same proximal cause.

The point here is that (CKA) looks like a plausible principle for causally matching veridical and hallucinatory experiences – veridical and hallucinatory experiences with the same proximal cause. This way of motivating (CKA) appeals to a same-cause, same-effect principle:

• Causal Principle 1: an event e1 is of the same kind as an event e2 if event e1 is produced by the same kind of proximate causal condition as e2 (Nudds 2009: 336).

Is this the end of the road for the naive realist disjunctivist, then? Not quite, since as Martin argues, the naive realist should reject this principle:

On [the naive realist] conception of experience, when one is veridically perceiving the objects of perception are constituents of the experiential episode. The given event could not have occurred without these entities existing and being constituents of it; in turn, one could not have had such a kind of event without there being relevant candidate objects of perception to be apprehended. So, even if those objects are implicated in the causes of the experience, they also figure non-causally as essential constituents of it... Mere presence of a candidate object will not be sufficient for the perceiving of it, that is true, but its absence is sufficient for the non-occurrence of such an event. The connection here is [one] of a constitutive or essential condition of a kind of event. (2004: 56–57).

Martin’s point is that the naive realist may well admit the possibility of veridical experiences and causally matching hallucinations, but they will resist the idea that sameness of proximal cause implies sameness of the kind of experience involved. This is because there are non-causal constitutive condition s for the occurrence of the veridical experience which are not satisfied in the hallucinatory case.

However, Martin suggests that the arguer from hallucination can develop their case against naive realism further. This development involves an argument with two stages. First, a modified causal argument: the reverse causal argument , and second the screening-off problem.

The modified causal argument involves a modified causal principle:

• Causal Principle 2: an event e1 is of the same kind K as an event e2 if event e1 is produced by the same kind of proximate causal condition as e2 in circumstances that do not differ in any non-causal conditions necessary for the occurrence of an event of kind K (Nudds 2009: 337).

(Martin’s own modified causal principle is more complicated than this in allowing for indeterministic causation. We gloss over this important complication here). Take N to be the fundamental kind which characterizes a veridical experience of a snow-covered churchyard, according to the naive realist. Does Causal Principle 2 allow us to say that N is present in the causally matching hallucinatory case, as (CKA) predicts? No. For the hallucination is produced in circumstances that differ in non-causal conditions necessary for the occurrence of N given how the naive realist understands N : in the circumstances in which the hallucination occurs there is no appropriate object of perception, but the presence of such an object is necessary for the occurrence of N.

So how does Causal Principle 2 help the arguer from hallucination? We have to run an argument in “the reverse direction, from what must be true of cases of causally matching hallucinations, to what must thereby be true of the veridical perceptions they match” (Martin 2006: 368). That is, take a hallucination as of a snow-covered churchyard h, and suppose that h is of some fundamental kind H. Now we can apply Causal Principle 2 to show that H is present in a causally matching veridical experience of a snow-covered churchyard, v. For now v is produced by the same kind of proximal cause in circumstances where there is no difference in the non-causal conditions necessary for the occurrence of an event of kind H. This is because all that is necessary for an occurrence of H is some brain condition, which is present in the circumstances in which v is brought about. This reverse causal argument does not show that v is not of fundamental kind N. What it does show, however, is that whatever fundamental kind is present in a hallucinatory case will also be present in a causally matching veridical case. So even if v is fundamentally N it is also H. That is, we have the Reverse Common Kind Assumption:

• (RCKA) Whatever fundamental kind of event occurs when you hallucinate, the very same kind of event also occurs in a causally matching veridical experience.

But now we run into the screening-off problem . There is something it is like for you to have an hallucinatory experience as of a snow-covered churchyard, and the experience seems to relate you to a snow-covered churchyard. This fact about the hallucinatory experience is grounded in its being of kind H. But now if an experience of that kind is present in the veridical case, it is difficult to see how what the naive realist says is fundamental to that case, N, is doing anything by way of explaining what it is like for a subject to have the experience. The presence of H in the veridical case seems to make N explanatorily redundant, or “screen off” N’s explanatory role, contra the ambitions of naive realism. (For more detailed expositions of this two-stage argument see Martin (2004), Byrne and Logue, (2008), Hellie (2013) and Soteriou (2014: Chapter 6)).

The most widely discussed naive realist response to this argument is that of Martin (2004, 2006). Though there are now a range of different naive realist responses available, some of which integrate critical discussion of Martin’s own approach (see Allen (2015), Logue (2012b, 2013), Fish (2009: Chapter 4), Hellie (2013), Moran (2019), Sethi (2020)).

Martin argues that the screening-off stage of the argument is only problematic if we accept a positive, non-derivative account of causally matching hallucinations. On such an account, hallucinations have a positive nature which doesn’t derive from that of veridical perception: a nature that can be specified independently of any reference to veridical perception. For instance, hallucinations are direct presentations of sense-data, or representations of ordinary objects. Instead, Martin suggests, the disjunctivist should conceive of causally matching hallucinations in a purely negative epistemic way: such a hallucination as of an F is a state of mind which is not introspectively knowably not a veridical perception of an F. What makes it the case that your hallucinatory experience is as of a snow-covered churchyard, with a certain sort of phenomenal character, is just that it is an occurrence which cannot be discriminated, by introspection alone, from a veridical perception of a snow-covered churchyard. The particular subjective perspective that a hallucinator has in a causally matching hallucination as of a snow-covered churchyard is explained just by the obtaining of this negative epistemic condition, not by anything more positive such as a relation to a white sense-datum or the representation of white snow (c.f., Dancy (1995: 425)). On such a view, causally matching hallucinations are derivative: specifying their nature requires essential reference to the basic case of veridical perception.

If we accept Martin’s account of causally matching hallucinations, then we can see how H can be present in both the hallucinatory and the veridical case: since trivially a veridical experience of a snow-covered churchyard is indiscriminable from a veridical experience of a snow-covered churchyard. But what about screening off? Does H have a nature which means that the presence of H in the veridical case threatens the explanatory power of N? It doesn’t, Martin argues, since H’s explanatory force is derivative or dependent: it is parasitic on that of N. As Martin notes with his own example:

But if that is so [if H screens off the explanatory role of N], then the property of being a veridical perception of a tree [i.e. N] never has an explanatory role, since it is never instantiated without the property of being indiscriminable from such a perception being instantiated as well. But if the property of being a veridical perception lacks any explanatory role, then we can no longer show that being indiscriminable from a veridical perception has the explanatory properties which would screen off the property of being a veridical perception (2004: 69).

Here, then, is a summary of this complex dialectic: the argument from hallucination seems to disprove naive realism, but the naive realist appeals to disjunctivism in response. However, the causal argument puts pressure on disjunctivism, by supporting the common kind assumption . In response, the naive realist rejects the key principle of this argument (Causal Principle 1). But then a two-stage argument consisting of the reverse causal argument and the screening-off problem attempts to show that: (1) the fundamental kind of experience present in hallucination is also present in causally matching veridical experience, and (2) this undermines the naive realist idea that the character of veridical experience is shaped by the directly presented world. In response, Martin accepts a form of naive realism which embraces disjunctivism (in the form of the claim that causally matching veridical and hallucinatory experiences are fundamentally different). But which also accepts (as per the reverse causal argument) that there is a common element across the cases, for the hallucinatory kind is present in veridical cases too. But since he conceives of this common element in a derivative, and purely negative epistemic way, he blocks the argument at the second stage, rejecting screening off.

Naturally, then, much subsequent critical discussion has focused on Martin’s negative epistemic conception of hallucination. Further discussion and development of Martin’s approach is to be found in Nudds (2009, 2013) and Soteriou (2014: Chapter 6). For criticism of Martin’s approach see Hawthorne and Kovakovich (2006), Farkas (2006), Sturgeon (2008), Siegel (2004, 2008), and Robinson (2013). See Burge (2005) for a general and polemical attack on disjunctivism. For more on disjunctivism, see Haddock and Macpherson (eds.) (2008), Byrne and Logue (eds.) (2009), Macpherson and Platchias (eds.) (2013) and the entry on the disjunctive theory of perception .

3.4.4 Naive Realist Disjunctivism and Our Ordinary Conception of Perceptual Experience

According to naive realist disjunctivists, at least veridical experiences are directly of ordinary objects ( Ordinary Objects ), and are direct presentations of their objects ( Presentation ). Naive realist disjunctivists thus maintain Direct Realist Presentation , and hence Direct Realism for at least veridical experiences – indeed they maintain Direct Realism without the need for any appeal to a causal theory of direct perception. Further, naive realist disjunctivists hold that the phenomenal character of such experiences is determined, at least in part, by the direct presentation of ordinary objects ( Direct Realist Character ). The only aspect of our ordinary conception of perceptual experience which naive realist disjunctivists reject outright is the Common Kind Claim .

Sense-datum theorists and adverbialists depart substantially from our ordinary conception of perceptual experience. Advocates of each view will argue, in their different ways, that this is a consequence of responding adequately to the Problem of Perception.

Intentionalists and naive realist disjunctivists disagree, and argue, in different ways, that we can respond to the Problem of Perception without departing substantially from our ordinary conception of perceptual experience: by maintaining Direct Realism in some form, and maintaining or at least being sensitive to many of the specific phenomenological components of our ordinary conception of perceptual experience. Whilst the debate between sense-datum theorists and adverbialists (and between these and other theories) is not as prominent as it once was, the debate between intentionalists and naive realist disjunctivists is a significant ongoing debate in the philosophy of perception: a legacy of the Problem of Perception that is arguably “the greatest chasm” in the philosophy of perception (Crane (2006)). The question, now, is not so much whether to be a direct realist, but how to be one.

• Allen, Keith, 2015, “Hallucination and Imagination”, Australasian Journal of Philosophy , 93: 287–302.
• Ali, Rami, 2018, “Does Hallucinating Involve Perceiving”, Philosophical Studies , 175: 601–627.
• Anscombe, G.E.M., 1965, “The Intentionality of Sensation: a Grammatical Feature”, in R.J. Butler (ed.), Analytical Philosophy: First Series , 143–58, Oxford: Blackwell. [Reprinted in her Metaphysics and the Philosophy of Mind: Collected Papers, Vol. II . Oxford: Blackwell; also in Noë and Thompson (eds.) 2002].
• Antony, Louise, 2011, “The Openness of Illusions”, Philosophical Issues , 21: 25–44.
• Armstrong, D.M., 1968, A Materialist Theory of the Mind , London: Routledge and Kegan Paul.
• Austin, J.L., 1962, Sense and Sensibilia , Oxford: Oxford University Press.
• Barnes, W.H.F., 1944–45, “The Myth of Sense-Data”, Proceedings of the Aristotelian Society , 45: 89–117.
• Batty, Clare, 2011, “Smelling Lessons”, Philosophical Studies , 153: 171–164.
• Batty, Clare, and Macpherson, Fiona, (2016), “Redefining Illusion and Hallucination in Light of New Cases”, Philosophical Issues , 26: 263–296.
• Block, Ned, 1997, “Inverted Earth”, in Ned Block, Owen Flanagan and Güven Güzeldere (eds.), The Nature of Consciousness , 677–94, Cambridge, MA: MIT Press.
• –––, 2004, “Mental Paint”, in Martin Hahn and Bjørn Ramberg (eds.) Reflections and Replies: 10 Essays on the Philosophy of Tyler Burge , 165–201, Cambridge, MA: MIT Press.
• –––, 2007, “Wittgenstein and Qualia”, Philosophical Perspectives , 21: 73–115.
• –––, 2010, “Attention and Mental Paint”, Philosophical Issues , 20: 23–63.
• Breckenridge, Wylie, 2018, Visual Experience: A Semantic Approach , Oxford: Oxford University Press.
• Brewer, Bill, 2000, Perception and Reason , Oxford: Oxford University Press.
• –––, 2008, “How to Account for Illusion”, in Haddock and Macpherson (eds.) 2008.
• –––, 2011, Perception and its Objects , Oxford: Oxford University Press.
• Broad, C. D., 1923, Scientific Thought , London: Kegan Paul, Trench, Trubner & Co.
• –––, 1952, “Some Elementary Reflexions on Sense-Perception”, Philosophy , 27: 3–17.
• –––, 1965, “The Theory of Sensa”, in Swartz (ed.) 1965, 85–129 [edited selection from Broad 1923].
• Brogaard, Berit (ed.), 2014, Does Perception Have Content? , New York: Oxford University Press.
• Burge, Tyler, 1991, “Vision and Intentional Content”, in E. LePore and R. Van Gulick (eds.) John Searle and his Critics , 195–214, Oxford: Blackwell.
• –––, 2005, “Disjunctivism and Perceptual Psychology”, Philosophical Topics , 33: 1–78.
• Burnyeat, Myles, 1979, “Conflicting Appearances”, Proceedings of the British Academy , 65: 69–111.
• Butchvarov, Panayot, 1980, “Adverbial Theories of Consciousness”, Midwest Studies in Philosophy , 5: 261–80.
• Byrne, Alex 2001, “Intentionalism Defended”, Philosophical Review , 110: 199–240.
• –––, forthcoming, “Concepts, Beliefs and Perception”, in C. Demmerling & D. Schröder (eds.), Concepts in Thought, Action, and Emotion: New Essays , New York: Routledge.
• Byrne, Alex, and Logue, Heather, 2008, “Either/Or”, in Haddock and Macpherson (eds.), 57–94.
• ––– (eds.), 2009, Disjunctivism , Cambridge, MA: MIT Press.
• Campbell, John, 2002, Reference and Consciousness , Oxford: Oxford University Press.
• –––, 2009, “Consciousness and Reference”, in McLaughlin et al (eds.) 2009.
• –––, 2014, Berkeley’s Puzzle (with Quassim Cassam), Oxford: Oxford University Press.
• Chalmers, David, 1996, The Conscious Mind , Oxford: Oxford University Press.
• –––, 2006, “Perception and the Fall from Eden”, in Gendler and Hawthorne (eds.) 2006, 49–125.
• Chisholm, R, 1957, Perceiving: A Philosophical Study , Ithaca: Cornell University Press.
• Craig, E.J., 1976, “Sensory Experience and the Foundations of Knowledge”, Synthese , 33.
• Crane, Tim 1998a, “Content, Non-Conceptual”, in E.J. Craig (ed.), Routledge Encyclopedia of Philosophy , London: Routledge.
• –––, 1998b, “Intentionality”, in E.J. Craig (ed.), Routledge Encyclopedia of Philosophy , London: Routledge.
• –––, 2000, “Introspection, Intentionality, and the Transparency of Experience”, Philosophical Topics , 28: 49–67.
• –––, 2001, Elements of Mind , Oxford: Oxford University Press.
• –––, 2006, “Is there a Perceptual Relation?”, in Gendler and Hawthorne (eds.) 2006, 126–46.
• –––, 2009, “Is Perception a Propositional Attitude?”, Philosophical Quarterly , 59: 452–69.
• –––, (ed.) 1992, The Contents of Experience , Cambridge: Cambridge University Press.
• Crane, Tim and Sarah Patterson (eds.) 2000, History of the Mind-Body Problem , London: Routledge.
• Crane, Tim and Katalin Farkas (eds.) 2004, Metaphysics: a Guide and Anthology , Oxford: Oxford University Press.
• Crowther, Tom, 2006, “Two Conceptions of Conceptualism and Nonconceptualism”, Erkenntnis , 65: 245–276.
• –––, 2009, “Watching, Sight, and the Temporal Shape of Perceptual Activity”, Philosophical Review , 118: 1–27.
• Cussins, Adrian, 1990, “The Connectionist Construction of Concepts”, in M. Boden (ed.) The Philosophy of Artificial Intelligence , 368–440, Oxford: Oxford University Press.
• D’Ambrosio, Justin, 2019, “A New Perceptual Adverbialism”, The Journal of Philosophy , 116: 413–446.
• Dancy, Jonathan (ed.) 1988, Perceptual Knowledge , Oxford: Oxford University Press.
• –––, 1995, “Arguments from Illusion”, The Philosophical Quarterly , 45: 421–38.
• Davies, M. 1992 “Perceptual Content and Local Supervenience”, Proceedings of the Aristotelian Society 92: 21–45.
• Dennett, Daniel, 1991, Consciousness Explained , New York: Little, Brown.
• Dretske, Fred, 1969, Seeing and Knowing , Chicago: University of Chicago Press.
• –––, 1981, Knowledge and the Flow of Information , Oxford: Blackwell.
• –––, 1995, Naturalizing the Mind Cambridge, MA: MIT Press.
• Ducasse, C.J., 1942. “Moore’s Refutation of Idealism”, in P.Schilpp (ed.) The Philosophy of G.E. Moore , 223–52, Chicago: Northwestern University Press.
• Egan, Andy, 2006, “Appearance Properties?”, Noüs , 40 3:495–521.
• Evans, Gareth, 1982, The Varieties of Reference , Oxford: Clarendon Press
• Farkas, Katalin, 2006, “Indiscriminability and the Sameness of Appearance”, Proceedings of the Aristotelian Society 106: 39–59.
• Fish, William, 2009, Perception, Hallucination, and Illusion , New York: Oxford University Press.
• –––, 2010, Philosophy of Perception: A Contemporary Introduction , New York: Routledge.
• Foster, John, 2000, The Nature of Perception , Oxford: Oxford University Press.
• French, Craig, 2014, “Naive Realist Perspectives on Seeing Blurrily”, Ratio , 27: 393–413.
• –––, 2018, “Naïve Realism and Diaphaneity”, Proceedings of the Aristotelian Society , 118: 149–175.
• French, Craig, and Walters, Lee, 2018, “The Invalidity of the Argument from Illusion”, American Philosophical Quarterly , 54: 357–364.
• French, Craig, and Phillips, Ian, 2020, “Austerity and Illusion”, Philosophers’ Imprint , 20(15): 1–19.
• Fulkerson, Matthew, 2014, The First Sense: A Philosophical Study of Human Touch Cambridge, MA: MIT Press.
• Gendler, Tamar Szabó and John Hawthorne, eds., 2006, Perceptual Experience , Oxford: Oxford University Press.
• Genone, James, 2014, “Appearance and Illusion”, Mind , 123: 339–376.
• Glüer, Kathrin, 2009, “In Defence of a Doxastic Account of Experience”, Mind and Language, 24: 297–327.
• Gow, Laura, 2019, “Everything is Clear: All Perceptual Experiences are Transparent”, European Journal of Philosophy , 27: 412–425.
• Grice, H.P., 1961, “The Causal Theory of Perception”, Proceedings of the Aristotelian Society Supplementary Volume 35: 121–52. Selection reprinted in Dancy 1988.
• Gunther, York (ed.), 2002, Essays on Non-Conceptual Content , Cambridge, MA: MIT Press.
• Guttenplan, Samuel (ed.), 1995, A Companion to the Philosophy of Mind , Oxford: Blackwell.
• Haddock, Adrian and Macpherson, Fiona, (eds.) 2008, Disjunctivism: Perception, Action, Knowledge , Oxford University Press.
• Harman, Gilbert, 1990, “The Intrinsic Quality of Experience”, in J. Tomberlin ed. Philosophical Perspectives , 31–52, 4 Atascadero: Ridgeview 1990, reprinted in Ned Block, Owen Flanagan and Guven Güzeldere eds. The Nature of Consciousness , 663–76, Cambridge, Mass.: MIT Press 1997.
• Heck, Richard, 2000, “Non-conceptual Content and the Space of Reasons”, Philosophical Review , 109: 483–523.
• Heidegger, Martin, “The Origin of the Work of Art”, translated by David Farrell Krell, in Martin Heidegger: Basic Writings , New York: Harper and Row 1977.
• Hellie, Benj, 2013, “The Mulitdisjunctive Conception of Hallucination”, in Macpherson and Platchias (eds.) 2013.
• Hilbert, David R. and Mark Eli Kalderon, 2000, “Color and the Inverted Spectrum”, in S. Davis (ed.) Color Perception: Philosophical, Psychological, Artistic and Computational Perspectives , Vancouver Studies in Cognitive Science Volume 9 New York and Oxford: Oxford University Press.
• Hinton, J.M., 1973, Experiences , Oxford: Clarendon Press.
• Husserl, Edmund, 1900–01, Logical Investigations translated by J.N. Findlay, 2 volumes, revised edition by D. Moran, London: Routledge 2001.
• Jackson, Frank, 1975, “On the Adverbial Analysis of Visual Experience”, Metaphilosophy , 6: 127–135.
• –––, 1977, Perception: A Representative Theory . Cambridge: Cambridge University Press.
• Jackson, F. and Smith, M, 2005, The Oxford Handbook of Contemporary Philosophy . Oxford: Oxford University Press.
• Johnston, Mark, 2004, “The Obscure Object of Hallucination”, Philosophical Studies , 103: 113–83.
• –––, 2011, “On a Neglected Epistemic Virtue”, Philosophical Issues , 21: 165–218.
• Kalderon, Mark, 2011, “Color Illusion”, Noûs , 45: 751–775.
• Kim, Jaegwon, 1993, Supervenience and Mind , Cambridge: Cambridge University Press.
• Kriegel, Uriah, 2013, Phenomenal Intentionality , New York: Oxford University Press.
• Lewis, C.I., 1929, Mind and the World Order , London: Constable.
• Logue, Heather, 2012a, “Why Naive Realism?”, Proceedings of the Aristotelian Society , 112: 211–237.
• –––, 2012b, “What Should the Naive Realist Say About Total Hallucinations?”, Philosophical Perspectives , 26: 173–199.
• –––, 2013, “Good News for the Disjunctivist about (one of) the Bad Cases”, Philosophy and Phenomenological Research , 86: 105–133.
• Loar, Brian, 2002, “Transparent Experience”, in A. Jokic and Q.Smith eds. Consciousness: New Philosophical Perspectives , 77–96, Oxford: Oxford University Press.
• Lycan, W.G., 1996, Consciousness and Experience Cambridge, Mass.: MIT Press.
• –––, 1999, Mind and Cognition , Second Edition. Oxford: Blackwell.
• Mackie, Penelope, 2020, “Perception, Mind-Independence, and Berkeley”, Australasian Journal of Philosophy , 98(3): 449–464.
• Macpherson, Fiona, 2011, “Individuating the Senses”, in Macpherson (ed.) 2011a.
• ––– (ed.), 2011a, The Senses: Classical and Contemporary Readings , Oxford University Press.
• –––, 2013, “The Philosophy and Psychology of Hallucination: An Introduction”, in F. Macpherson and D. Platchias 2013, 1–38.
• Macpherson, Fiona and Dimitris Platchias, (eds.) 2013, Hallucination , Cambridge, MA: MIT Press.
• Marcus, Eric 2006. “Intentionalism and the Imaginability of the Inverted Spectrum”, Philosophical Quarterly 56: 321–339
• Martin, M.G.F., 1992, “Sight and Touch”, in Crane (ed.) 1992, 196–215.
• –––, 1993, “The Rational Role of Experience”, Proceedings of the Aristotelian Society, 93: 71–88.
• –––, 1995, “Perceptual Content”, in Guttenplan (ed.) 1995, 459–62.
• –––, 1998, “Setting Things Before the Mind”, in A. O’Hear (ed.) Contemporary Issues in the Philosophy of Mind , 157–80, Cambridge: Cambridge University Press.
• –––, 2000, “Beyond Dispute: Sense-Data, Intentionality and the Mind-Body Problem”, in Crane and Patterson (eds.) 2000, 195–231.
• –––, 2002a, “The Transparency of Experience”, Mind and Language , 17: 376–425.
• –––, 2002b, “Particular Thoughts and Singular Thought”, in A. O’Hear (ed.), Logic, Thought, and Language , Cambridge: Cambridge University Press, 173–214.
• –––, 2004, “The Limits of Self-Awareness”, Philosophical Studies , 120: 37–89.
• –––, 2005, “Perception” in Jackson and Smith (eds.) 2005, 701–738.
• –––, 2006, “On Being Alienated”, in Gendler and Hawthorne (eds.) 2006, 354–410.
• –––, 2010, “What’s in a Look?”, in B. Nanay (ed.) 2010, 160–225.
• –––, 2017, “Elusive Objects”, Topoi , 36: 247–271.
• Masrour, Farid, 2020, “On the Possibility of Hallucinations”, Mind , 129: 737–768.
• Matilal, Bimal Krishna, 1986, Perception: An Essay on Classical Indian Theories of Knowledge , Oxford: Clarendon Press.
• McCulloch, Greg, 2003, The Life of the Mind , London: Routledge.
• McDowell, John, 1982, “Criteria, Defeasibility & Knowledge”, Proceedings of the British Academy 1982 , 455–79. Reprinted in Dancy (ed.) 1988.
• –––, 1987, “Singular Thought and the Extent of Inner Space”, in McDowell and Pettit (eds.) 1987. Reprinted in McDowell 1998.
• –––, 1994, Mind and World , Cambridge, MA: Harvard University Press.
• –––, 1998, Meaning, Knowledge and Reality , Cambridge, MA: Harvard University Press.
• –––, 2008, “Avoiding the Myth of the Given”, in Jakob Lindgaard (ed.), John McDowell: Experience, Norm, and Nature, 1–14, Oxford: Blackwell.
• McGinn, Colin, 1989, Mental Content , Oxford: Blackwell.
• McLaughlin, Brian, A. Beckermann and S. Walter (eds.), 2009, Oxford Handbook to the Philosophy of Mind , Oxford: Oxford University Press.
• Merleau-Ponty, Maurice, 1945, The Phenomenology of Perception , translated by Colin Smith, London: Routledge 2002.
• Millikan, Ruth Garrett, 1987, Language, Thought and Other Biological Categories , Cambridge, Mass.: MIT Press.
• Moore, G.E., 1905, “The Refutation of Idealism”, in Philosophical Studies . London: Routledge & Kegan Paul. Reprinted in Moore 1993, 23–44.
• –––, 1910, “Sense Data”, Reprinted in Moore 1993, 45–58.
• –––, 1993, Selected Writings , edited by Thomas Baldwin London: Routledge.
• Moran, Alex, 2019, “Naïve Realism, Hallucination, and Causation: A New Response to the Screening Off Problem”, Australasian Journal of Philosophy , 97: 368–382.
• Nagel, Thomas, 1974, “What is it Like to be a Bat?”, Philosophical Review , 83: 435–50.
• Nanay, Bence (ed.), 2010, Perceiving the World . New York: Oxford University Press.
• Noë, Alva and Evan Thompson (eds.), 2002, Vision and Mind: Selected Readings in the Philosophy of Perception Cambridge, Mass.: MIT Press.
• Nudds, Matthew, 2001, “Experiencing the Production of Sounds” , European Journal of Philosophy , 9: 210–29.
• –––, 2003, “The significance of the senses”, Proceedings of the Aristotelian Society , 104: 31–51.
• –––, 2009, “Recent Work in Perception: Naïve Realism and its Opponents”, Analysis , 69: 334–6.
• –––, 2013, “Naive Realism and Hallucinations”, in Macpherson and Platchias (eds.) 2013.
• Nudds, Matthew and O’Callaghan Casey, (eds.) 2009, Sounds and Perception, Oxford: Oxford University Press.
• O’Callaghan, Casey, 2007, Sounds: a Philosophical Theory , Oxford: Oxford University Press.
• –––, 2019, A Multisensory Philosophy of Perception , Oxford: Oxford University Press.
• O’Shaughnessy, Brian, 1980, The Will: A Dual Aspect Theory , Cambridge: Cambridge University Press.
• –––, 1989, “The Sense of Touch”, Australasian Journal of Philosophy , 67: 37–58.
• –––, 2000, Consciousness and the World Oxford: Oxford University Press.
• –––, 2003, “Sense Data”, in Barry Smith (ed.) John Searle Cambridge: Cambridge University Press.
• Pautz, Adam, 2010, “Why Explain Experience in Terms of Content?”, in Nanay (ed.) 2010.
• –––, 2021, Perception , London: Routledge.
• Peacocke, Christopher, 1983, Sense and Content , Oxford: Oxford University Press.
• –––, 1992, A Study of Concepts Cambridge, MA: MIT Press.
• Perkins, Moreland, 1983, Sensing the World , Indianapolis: Hackett.
• Pessin, Andrew and Sanford Goldberg, (eds.), 1996, The Twin Earth Chronicles , New York: M.E. Sharpe.
• Pettit, Philip and John McDowell (eds.), 1986, Subject, Thought and Context , Oxford: Clarendon Press.
• Pitcher, George, 1970, A Theory of Perception , Princeton: Princeton University Press.
• Price, H.H., 1932, Perception . London: Methuen.
• Putnam, Hilary, 1999, The Threefold Cord , New York: Columbia University Press.
• Raleigh, Thomas, 2014, “A New Approach to ‘Perfect’ Hallucination”, Journal of Consciousness Studies , 21: 81–110.
• Richardson, Louise, 2010, “Seeing Empty Space”, European Journal of Philosophy , 18: 227–243.
• –––, 2013a, “Sniffing and Smelling”, Philosophical Studies , 162: 401–419.
• –––, 2013b, “Flavour, Taste and Smell”, Mind and Language , 28: 322–341.
• Robinson, Howard, 1985, “The General Form of the Argument for Berkeleian Idealism”, in Essays on Berkeley: A Tercentennial Celebration , edited by J. Foster and H. Robinson, 163–86. Oxford: Clarendon Press.
• –––, 1994, Perception , London: Routledge
• –––, 2013, “The Failure of Disjunctivism to Deal with ”Philosophers’ Hallucinations“”, in Macpherson and Platchias (eds) 2013.
• Russell, Bertrand. 1912, The Problems of Philosophy Oxford: Oxford University Press.
• Sainsbury, Mark, 2010, “Intentionality without Exotica”, in Robin Jeshion, (ed.), Singular Thought: New Essays, 300–18, Oxford: Oxford University Press.
• Schellenberg, Susanna, 2018, The Unity of Perception: Content, Consciousness, Evidence . Oxford: Oxford University Press.
• Searle, John, 1983, Intentionality , Cambridge: Cambridge University Press.
• Segal, Gabriel, 1989, “Seeing What is Not There”, Philosophical Review , 98: 189–214.
• Sethi, Umrao, 2020, “Sensible Overdetermination”, Philosophical Quarterly , 70(280): 588–616.
• Shoemaker, Sydney, 1990 “Qualities and Qualia: What’s in the Mind?”, Philosophy and Phenomenological Research 50 (Supplement): 109–31.
• –––, 1996, “Color, Subjective Reactions, and Qualia”, in Enrique Villanueva (ed.), Philosophical Issues, 55–66, Atascadero: Ridgeview.
• Siegel, Susanna, 2004, “Indiscriminability and the Phenomenal”, Philosophical Studies , 120: 91–112.
• –––, 2008, “The Epistemic Conception of Hallucination”, in Haddock and Macpherson (eds.) 2008.
• –––, 2010, The Contents of Visual Experience New York: Oxford University Press.
• Silins, Nico, 2011, “Seeing Through the ‘Veil of Perception’ ”, Mind , 120: 329–367.
• Smith, A.D., 2002, The Problem of Perception , Cambridge, Mass.: Harvard University Press
• –––, 2008, “Translucent Experiences”, Philosophical Studies , 140: 197–212.
• Smith, Barry, C, 2015, “The Chemical Senses”, in Mohan Matthen (ed.), The Oxford Handbook of the Philosophy of Perception , 314–352, Oxford: Oxford University Press.
• Snowdon, P.F., 1979–80, “Perception, Vision and Causation”, Proceedings of the Aristotelian Society , 81: 175–92.
• –––, 1990, “The Objects of Perceptual Experience”, Proceedings of the Aristotelian Society Supplementary Volume , 64: 121–150.
• –––, 1992, “How to Interpret ‘Direct Perception’”, in Crane 1992, 48–78.
• –––, 2005, “Some Reflections on an Argument from Hallucination”, Philosophical Topics 33.1: 285–305.
• Soteriou, Matthew, 2000, “The Particularity of Visual Experience”, European Journal of Philosophy , 8: 173–89.
• –––, 2013, The Mind’s Construction: The Ontology of Mind and Mental Action , Oxford: Oxford University Press.
• –––, 2014, Disjunctivism , London: Routledge.
• Speaks, Jeff, 2005, “Is there a problem about non-conceptual content?”, Philosophical Review , 114: 359–98.
• –––, 2009, “Transparency, Intentionalism, and the Nature of Perceptual Content”, Philosophy and Phenomenological Research 79: 539–573.
• –––, 2015, The Phenomenal and the Representational , Oxford: Oxford University Press.
• Spener, Maja, 2003, Gilding or Staining the Mind: Phenomenology and the Metaphysics of Visual Experience , PhD thesis, University of London.
• Stokes, Dustin, Matthen, Mohan, and Briggs, Stephen (eds.), 2015, Perception and Its Modalities , New York: Oxford University Press.
• Strawson, P.F., 1979, “Perception and its Objects”, in G. Macdonald (ed.) Perception and Identity: Essays Presented to A.J. Ayer with His Replies , London: Macmillan; reprinted in Noë and Thompson (eds.) 2002. Page references to reprint.
• Stoljar, Daniel, 2004, “The Argument from Diaphanousness”, in M. Ezcurdia, R. Stainton and C. Viger (eds.) New Essays in the Philosophy of Language and Mind , Canadian Journal of Philosophy (Supplementary Volume), 341–90, Calgary: University of Calgary Press.
• Sturgeon, Scott, 2008, “Disjunctivism about Visual Experience”, in Haddock and Macpherson (eds.) 2008.
• Swartz, R.J. 1965, Perceiving, Sensing and Knowing , Los Angeles and Berkeley: University of California Press.
• Thau, Michael, 2002, Consciousness and Cognition , Oxford: Oxford University Press.
• Tye, Michael, 1984, “The Adverbial Theory of Visual Experience”, Philosophical Review , 93: 195–225.
• –––, 1992, “Visual Qualia and Visual Content”, in Crane (ed.) 1992, 158–76.
• –––, 1995, Ten Problems of Consciousness , Cambridge, MA: MIT Press.
• –––, 2000, Consciousness, Color and Content , Cambridge, MA: MIT Press.
• Valberg, J.J., 1992, The Puzzle of Experience . Oxford: Clarendon Press.
• Zahavi, Dan, 2003, Husserl’s Phenomenology Stanford: Stanford University Press.

Any serious attempt to master the literature on the problem of perception should include a reading of Anscombe (1965), Armstrong (1968: Chapter 10), Dretske (1969), Jackson (1977), Martin (2002), Moore (1905), Peacocke (1983: Chapter 1), Robinson (1994), Russell (1912), Smith (2002), Snowdon (1992), Strawson (1979), Tye (1992), and Valberg (1992a). Useful collections: Swartz (1965), Dancy (1988), Noë and Thompson (2002), Gendler and Hawthorne (2006), Haddock and Macpherson (2008), Byrne and Logue (2009), Nanay (2010), and Brogaard (2014). Matilal (1986) explores how issues around the Problem of Perception and theories of experience play out in Classical Indian philosophy.

For discussion of how the problem of perception, somewhat differently construed, arises in the senses other than vision, see Perkins (1983). There is much literature on non-visual perception, not all of it addressing the problem of perception, but much of it will be relevant to considering the problem of perception in non-visual modalities: on sounds, see Nudds (2001), O’Callaghan (2007), Nudds and O’Callaghan (2009); on smell, see Batty (2011), Richardson (2013a, 2013b); on touch, see O’Shaughnessy (1989), Martin (1992) and Fulkerson (2014); for the senses in general, see Nudds (2003), Macpherson (2011, 2011a) and Stokes, Matthen, and Briggs (2015)). On multisensory perception, see O’Callaghan (2019).

How to cite this entry . Preview the PDF version of this entry at the Friends of the SEP Society . Look up topics and thinkers related to this entry at the Internet Philosophy Ontology Project (InPhO). Enhanced bibliography for this entry at PhilPapers , with links to its database.

• The Illusions Index maintained by Fiona Macpherson (University of Glasgow, Centre for the Study of Perceptual Experience), designed by Keith Wilson and Mucky Puddle.
• Akiyoshi’s Illusion Pages: The Latest Works , maintained by Akiyoshi Kitaoka (Ritsumeikan University).
• Edward Adelson’s illusion pages , by Edward Adelson, MIT.

Brentano, Franz | color | consciousness | consciousness: and intentionality | consciousness: representational theories of | intensional transitive verbs | intentionality | mental representation | perception: epistemological problems of | perception: the contents of | perception: the disjunctive theory of | phenomenology | qualia | qualia: inverted | sense data

Acknowledgments

We are very grateful to Tim Bayne, David Chalmers, Katalin Farkas, Mike Martin and Susanna Siegel for their comments on previous versions of this entry. For discussion thanks to Arif Ahmed, Joshua Gert, Anil Gomes, Penelope Mackie, and Lee Walters.

Copyright © 2021 by Tim Crane < timcrane @ ceu . edu > Craig French < Craig . French @ nottingham . ac . uk >

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Home — Essay Samples — Psychology — Cognitive Psychology — Perception

Essays on Perception

Brief description of perception.

Perception refers to the way individuals interpret and understand the world around them. It encompasses sensory experiences, cognitive processes, and cultural influences, shaping how people make sense of their environment. Understanding perception is crucial for comprehending human behavior, decision-making, and communication.

Importance of Writing Essays on This Topic

Essays on perception provide a platform for critical thinking and analysis of how individuals perceive and interpret the world. They offer opportunities for personal reflection and exploration of diverse viewpoints, contributing to a deeper understanding of human cognition and behavior. Academic essays on perception also contribute to the advancement of knowledge in psychology, philosophy, and other related fields.

Tips on Choosing a Good Topic

• Consider current debates or controversies in the field of perception, such as the nature vs. nurture debate or the role of technology in shaping perception.
• Explore personal experiences or observations related to perception, such as the impact of cultural differences on interpretation or the influence of media on perception.
• Look for interdisciplinary connections, such as the intersection of perception and art, literature, or neuroscience, to develop a unique and engaging essay topic.

Essay Topics

• The role of perception in decision-making processes
• The impact of social media on body image perception
• The influence of cultural background on perception of time
• The relationship between language and perception
• How technology shapes our perception of reality
• The role of perception in the formation of stereotypes
• The connection between perception and memory
• The impact of sensory impairment on perception
• The role of perception in understanding works of art
• The influence of emotions on perception

Concluding Thought

Exploring perception through essay writing provides a unique opportunity for critical engagement with the complexities of human cognition and behavior. By delving into this topic, individuals can gain a deeper understanding of themselves and the world around them, fostering personal growth and intellectual curiosity.

The Subjectivity of Perception

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How People Perceive Their Sight

Sensation and perception: autism, our senses detect physical stimuli, and our brains process perception, the way temple grandin saw the world, the construction of a perfect plot, the role of the sense of touch, perceptions of self leading to early sexual debut among adolescents, variation in colour perception in normal individual, attribution theory and perceptual errors, difference between types of explanation, the art of active listening, analysis of henri bergson’s theory of time, my perceptions based on indirect observation and readings, audience perception and influence: marxism approach, similarities and differences in perceptions between englishmen and americans, "space invaders" analysis, the theories of preferred reading & oppositional reading, avertising and percepttion, an analysis of hermann ebbinghaus’s introduction to cognitive psychology, sound and fury analysis, relevant topics.

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Chapter 4: Sensation and Perception

Sensation and perception.

Sensation and perception are two separate processes that are very closely related. Sensation is input about the physical world obtained by our sensory receptors, and perception is the process by which the brain selects, organizes, and interprets these sensations. In other words, senses are the physiological basis of perception. Perception of the same senses may vary from one person to another because each person’s brain interprets stimuli differently based on that individual’s learning, memory, emotions, and expectations.

Video 1. Sensation and Perception explains the differences between these two processes.

What does it mean to sense something? Sensory receptors are specialized neurons that respond to specific types of stimuli. When sensory information is detected by a sensory receptor, sensation has occurred. For example, light that enters the eye causes chemical changes in cells that line the back of the eye. These cells relay messages, in the form of action potentials (as you learned when studying biopsychology), to the central nervous system. The conversion from sensory stimulus energy to action potential is known as transduction .

You have probably known since elementary school that we have five senses: vision, hearing (audition), smell (olfaction), taste (gustation), and touch (somatosensation). It turns out that this notion of five senses is oversimplified. We also have sensory systems that provide information about balance (the vestibular sense), body position and movement (proprioception and kinesthesia), pain (nociception), and temperature (thermoception).

The sensitivity of a given sensory system to the relevant stimuli can be expressed as an absolute threshold. Absolute threshold refers to the minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time. Another way to think about this is by asking how dim can a light be or how soft can a sound be and still be detected half of the time. The sensitivity of our sensory receptors can be quite amazing. It has been estimated that on a clear night, the most sensitive sensory cells in the back of the eye can detect a candle flame 30 miles away (Okawa & Sampath, 2007). Under quiet conditions, the hair cells (the receptor cells of the inner ear) can detect the tick of a clock 20 feet away (Galanter, 1962).

Video 2.  Absolute Threshold of Sensation

It is also possible for us to get messages that are presented below the threshold for conscious awareness—these are called subliminal messages . A stimulus reaches a physiological threshold when it is strong enough to excite sensory receptors and send nerve impulses to the brain: this is an absolute threshold. A message below that threshold is said to be subliminal: we receive it, but we are not consciously aware of it. Therefore, the message is sensed, but for whatever reason, it has not been selected for processing in working or short-term memory. Over the years there has been a great deal of speculation about the use of subliminal messages in advertising, rock music, and self-help audio programs. Research evidence shows that in laboratory settings, people can process and respond to information outside of awareness. But this does not mean that we obey these messages like zombies; in fact, hidden messages have little effect on behavior outside the laboratory (Kunst-Wilson & Zajonc, 1980; Rensink, 2004; Nelson, 2008; Radel, Sarrazin, Legrain, & Gobancé, 2009; Loersch, Durso, & Petty, 2013).

Dig Deeper: Unconscious Perception

Figure 2 . Priming can be used to improve intellectual test performance. Research subjects primed with the stereotype of a professor – a sort of intellectual role model – outperformed those primed with an anti-intellectual stereotype. [Photo: Jeremy Wilburn]

Absolute thresholds are generally measured under incredibly controlled conditions in situations that are optimal for sensitivity. Sometimes, we are more interested in how much difference in stimuli is required to detect a difference between them. This is known as the just noticeable difference (jnd) or difference threshold . Unlike the absolute threshold, the difference threshold changes depending on the stimulus intensity. As an example, imagine yourself in a very dark movie theater. If an audience member were to receive a text message on her cell phone which caused her screen to light up, chances are that many people would notice the change in illumination in the theater. However, if the same thing happened in a brightly lit arena during a basketball game, very few people would notice. The cell phone brightness does not change, but its ability to be detected as a change in illumination varies dramatically between the two contexts. Ernst Weber proposed this theory of change in difference threshold in the 1830s, and it has become known as Weber’s law : The difference threshold is a constant fraction of the original stimulus, as the example illustrates. It is the idea that bigger stimuli require larger differences to be noticed. For example, it will be much harder for your friend to reliably tell the difference between 10 and 11 lbs. (or 5 versus 5.5 kg) than it is for 1 and 2 lbs.

Video 3.  Weber’s Law and Thresholds 

While our sensory receptors are constantly collecting information from the environment, it is ultimately how we interpret that information that affects how we interact with the world. Perception refers to the way sensory information is organized, interpreted, and consciously experienced. Perception involves both bottom-up and top-down processing. Bottom-up processing refers to the fact that perceptions are built from sensory input. On the other hand, how we interpret those sensations is influenced by our available knowledge, our experiences, and our thoughts. This is called top-down processing .

Video 4.  Bottom-up versus Top-down Processing.

Look at the shape in Figure 3 below. Seen alone, your brain engages in bottom-up processing. There are two thick vertical lines and three thin horizontal lines. There is no context to give it a specific meaning, so there is no top-down processing involved.

Figure 3 . What is this image? Without any context, you must use bottom-up processing.

Now, look at the same shape in two different contexts. Surrounded by sequential letters, your brain expects the shape to be a letter and to complete the sequence. In that context, you perceive the lines to form the shape of the letter “B.”

Figure 4 . With top-down processing, you use context to give meaning to this image.

Surrounded by numbers, the same shape now looks like the number “13.”

Figure 5 . With top-down processing, you use context to give meaning to this image.

When given a context, your perception is driven by your cognitive expectations. Now you are processing the shape in a top-down fashion.

One way to think of this concept is that sensation is a physical process, whereas perception is psychological. For example, upon walking into a kitchen and smelling the scent of baking cinnamon rolls, the sensation is the scent receptors detecting the odor of cinnamon, but the perception may be “Mmm, this smells like the bread Grandma used to bake when the family gathered for holidays.”

Although our perceptions are built from sensations, not all sensations result in perception. In fact, we often don’t perceive stimuli that remain relatively constant over prolonged periods of time. This is known as sensory adaptation . Imagine entering a classroom with an old analog clock. Upon first entering the room, you can hear the ticking of the clock; as you begin to engage in conversation with classmates or listen to your professor greet the class, you are no longer aware of the ticking. The clock is still ticking, and that information is still affecting sensory receptors of the auditory system. The fact that you no longer perceive the sound demonstrates sensory adaptation and shows that while closely associated, sensation and perception are different.

Attention and Perception

There is another factor that affects sensation and perception: attention. Attention plays a significant role in determining what is sensed versus what is perceived. Imagine you are at a party full of music, chatter, and laughter. You get involved in an interesting conversation with a friend, and you tune out all the background noise. If someone interrupted you to ask what song had just finished playing, you would probably be unable to answer that question.

One experiment that demonstrates this phenomenon of inattentional blindness  asked participants to observe images moving across a computer screen. They were instructed to focus on either white or black objects, disregarding the other color. When a red cross passed across the screen, about one-third of subjects did not notice it (Most, Simons, Scholl, & Chabris, 2000).

Link to Learning

Video 5.  Test your perceptual abilities.

Figure 6 . Nearly one third of participants in a study did not notice that a red cross passed on the screen because their attention was focused on the black or white figures. (credit: Cory Zanker)

Motivations, Expectations, and Perception

Motivation can also affect perception. Have you ever been expecting a really important phone call and, while taking a shower, you think you hear the phone ringing, only to discover that it is not? If so, then you have experienced how motivation to detect a meaningful stimulus can shift our ability to discriminate between a true sensory stimulus and background noise. The ability to identify a stimulus when it is embedded in a distracting background is called signal detection theory . This might also explain why a mother is awakened by a quiet murmur from her baby but not by other sounds that occur while she is asleep. Signal detection theory has practical applications, such as increasing air traffic controller accuracy. Controllers need to be able to detect planes among many signals (blips) that appear on the radar screen and follow those planes as they move through the sky. In fact, the original work of the researcher who developed signal detection theory was focused on improving the sensitivity of air traffic controllers to plane blips (Swets, 1964).

Video 6.   Signal Detection Theory. 

Our perceptions can also be affected by our beliefs, values, prejudices, expectations, and life experiences. As you will see later in this module, individuals who are deprived of the experience of binocular vision during critical periods of development have trouble perceiving depth (Fawcett, Wang, & Birch, 2005). The shared experiences of people within a given cultural context can have pronounced effects on perception. For example, Marshall Segall, Donald Campbell, and Melville Herskovits (1963) published the results of a multinational study in which they demonstrated that individuals from Western cultures were more prone to experience certain types of visual illusions than individuals from non-Western cultures, and vice versa. One such illusion that Westerners were more likely to experience was the Müller-Lyer illusion: the lines appear to be different lengths, but they are actually the same length.

Figure 7 . In the Müller-Lyer illusion, lines appear to be different lengths although they are identical. (a) Arrows at the ends of lines may make the line on the right appear longer, although the lines are the same length. (b) When applied to a three-dimensional image, the line on the right again may appear longer although both black lines are the same length.

These perceptual differences were consistent with differences in the types of environmental features experienced on a regular basis by people in a given cultural context. People in Western cultures, for example, have a perceptual context of buildings with straight lines, what Segall’s study called a carpentered world (Segall et al., 1966). In contrast, people from certain non-Western cultures with an uncarpentered view, such as the Zulu of South Africa, whose villages are made up of round huts arranged in circles, are less susceptible to this illusion (Segall et al., 1999). It is not just vision that is affected by cultural factors. Indeed, research has demonstrated that the ability to identify an odor and rate its pleasantness and its intensity, varies cross-culturally (Ayabe-Kanamura, Saito, Distel, Martínez-Gómez, & Hudson, 1998).

Children described as thrill-seekers are more likely to show taste preferences for intense sour flavors (Liem, Westerbeek, Wolterink, Kok, & de Graaf, 2004), which suggests that basic aspects of personality might affect perception. Furthermore, individuals who hold positive attitudes toward reduced-fat foods are more likely to rate foods labeled as reduced-fat as tasting better than people who have less positive attitudes about these products (Aaron, Mela, & Evans, 1994).

Think It Over

Think about a time when you failed to notice something around you because your attention was focused elsewhere. If someone pointed it out, were you surprised that you hadn’t noticed it right away?

• North, A & Hargreaves, David & McKendrick, Jennifer. (1999). The Influence of In-Store Music on Wine Selections. Journal of Applied Psychology. 84. 271-276. 10.1037/0021-9010.84.2.271. ↵
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Visual Perception Theory In Psychology

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On This Page:

What is Visual Perception?

To receive information from the environment, we are equipped with sense organs, e.g., the eye, ear, and nose.  Each sense organ is part of a sensory system that receives sensory inputs and transmits sensory information to the brain.

A particular problem for psychologists is explaining how the physical energy received by sense organs forms the basis of perceptual experience. Sensory inputs are somehow converted into perceptions of desks and computers, flowers and buildings, cars and planes, into sights, sounds, smells, tastes, and touch experiences.

A major theoretical issue on which psychologists are divided is the extent to which perception relies directly on the information present in the environment.  Some argue that perceptual processes are not direct but depend on the perceiver’s expectations and previous knowledge as well as the information available in the stimulus itself.

This controversy is discussed with respect to Gibson (1966), who has proposed a direct theory of perception which is a “bottom-up” theory, and Gregory (1970), who has proposed a constructivist (indirect) theory of perception which is a “top-down” theory.

Psychologists distinguish between two types of processes in perception: bottom-up processing and top-down processing .

Bottom-up processing is also known as data-driven processing because perception begins with the stimulus itself. Processing is carried out in one direction from the retina to the visual cortex, with each successive stage in the visual pathway carrying out an ever more complex analysis of the input.

Top-down processing refers to the use of contextual information in pattern recognition. For example, understanding difficult handwriting is easier when reading complete sentences than reading single and isolated words. This is because the meaning of the surrounding words provides a context to aid understanding.

Gregory (1970) and Top-Down Processing Theory

Psychologist Richard Gregory (1970) argued that perception is a constructive process that relies on top-down processing.

Stimulus information from our environment is frequently ambiguous, so to interpret it, we require higher cognitive information either from past experiences or stored knowledge in order to make inferences about what we perceive. Helmholtz called it the ‘likelihood principle’.

For Gregory, perception is a hypothesis which is based on prior knowledge. In this way, we are actively constructing our perception of reality based on our environment and stored information.

• A lot of information reaches the eye, but much is lost by the time it reaches the brain (Gregory estimates about 90% is lost).
• Therefore, the brain has to guess what a person sees based on past experiences. We actively construct our perception of reality.
• Richard Gregory proposed that perception involves a lot of hypothesis testing to make sense of the information presented to the sense organs.
• Our perceptions of the world are hypotheses based on past experiences and stored information.
• Sensory receptors receive information from the environment, which is then combined with previously stored information about the world which we have built up as a result of experience.
• The formation of incorrect hypotheses will lead to errors of perception (e.g., visual illusions like the Necker cube).

Supporting Evidence

There seems to be an overwhelming need to reconstruct the face, similar to Helmholtz’s description of “unconscious inference.” An assumption based on past experience.

Perceptions can be ambiguous

The Necker cube is a good example of this. When you stare at the crosses on the cube, the orientation can suddenly change or “flip.”

It becomes unstable, and a single physical pattern can produce two perceptions.

Gregory argued that this object appears to flip between orientations because the brain develops two equally plausible hypotheses and is unable to decide between them.

When the perception changes though there is no change in the sensory input, the change of appearance cannot be due to bottom-up processing. It must be set downwards by the prevailing perceptual hypothesis of what is near and what is far.

Perception allows behavior to be generally appropriate to non-sensed object characteristics.

Critical Evaluation of Gregory’s Theory

1. the nature of perceptual hypotheses.

If perceptions make use of hypothesis testing, the question can be asked, “what kind of hypotheses are they?” Scientists modify a hypothesis according to the support they find for it, so are we, as perceivers, also able to modify our hypotheses? In some cases, it would seem the answer is yes.  For example, look at the figure below:

This probably looks like a random arrangement of black shapes. In fact, there is a hidden face in there; can you see it? The face is looking straight ahead and is in the top half of the picture in the center.  Now can you see it?  The figure is strongly lit from the side and has long hair and a beard.

Once the face is discovered, very rapid perceptual learning takes place and the ambiguous picture now obviously contains a face each time we look at it. We have learned to perceive the stimulus in a different way.

Although in some cases, as in the ambiguous face picture, there is a direct relationship between modifying hypotheses and perception, in other cases, this is not so evident.  For example, illusions persist even when we have full knowledge of them (e.g., the inverted face, Gregory 1974).

One would expect that the knowledge we have learned (from, say, touching the face and confirming that it is not “normal”) would modify our hypotheses in an adaptive manner. The current hypothesis testing theories cannot explain this lack of a relationship between learning and perception.

2. Perceptual Development

A perplexing question for the constructivists who propose perception is essentially top-down in nature is “how can the neonate ever perceive?”  If we all have to construct our own worlds based on past experiences, why are our perceptions so similar, even across cultures?  Relying on individual constructs for making sense of the world makes perception a very individual and chancy process.

The constructivist approach stresses the role of knowledge in perception and therefore is against the nativist approach to perceptual development.

However, a substantial body of evidence has been accrued favoring the nativist approach. For example, Newborn infants show shape constancy (Slater & Morison, 1985); they prefer their mother’s voice to other voices (De Casper & Fifer, 1980); and it has been established that they prefer normal features to scrambled features as early as 5 minutes after birth.

3. Sensory Evidence

Perhaps the major criticism of the constructivists is that they have underestimated the richness of sensory evidence available to perceivers in the real world (as opposed to the laboratory, where much of the constructivists” evidence has come from).

Constructivists like Gregory frequently use the example of size constancy to support their explanations. That is, we correctly perceive the size of an object even though the retinal image of an object shrinks as the object recedes. They propose that sensory evidence from other sources must be available for us to be able to do this.

However, in the real world, retinal images are rarely seen in isolation (as is possible in the laboratory). There is a rich array of sensory information, including other objects, background, the distant horizon, and movement. This rich source of sensory information is important to the second approach to explaining perception that we will examine, namely the direct approach to perception as proposed by Gibson.

Gibson argues strongly against the idea that perception involves top-down processing and criticizes Gregory’s discussion of visual illusions on the grounds that they are artificial examples and not images found in our normal visual environments.

This is crucial because Gregory accepts that misperceptions are the exception rather than the norm. Illusions may be interesting phenomena, but they might not be that information about the debate.

Gibson (1966) and Bottom-Up Processing

Gibson’s bottom-up theory suggests that perception involves innate mechanisms forged by evolution and that no learning is required. This suggests that perception is necessary for survival – without perception, we would live in a very dangerous environment.

Our ancestors would have needed perception to escape from harmful predators, suggesting perception is evolutionary.

James Gibson (1966) argues that perception is direct and not subject to hypothesis testing, as Gregory proposed. There is enough information in our environment to make sense of the world in a direct way.

His theory is sometimes known as the ‘Ecological Theory’ because of the claim that perception can be explained solely in terms of the environment.

For Gibson: the sensation is perception: what you see is what you get.  There is no need for processing (interpretation) as the information we receive about size, shape, distance, etc., is sufficiently detailed for us to interact directly with the environment.

Gibson (1972) argued that perception is a bottom-up process, which means that sensory information is analyzed in one direction: from simple analysis of raw sensory data to the ever-increasing complexity of analysis through the visual system.

Features of Gibson’s Theory

The optic array.

Perception involves ‘picking up’ the rich information provided by the optic array in a direct way with little/no processing involved.

Because of movement and different intensities of light shining in different directions, it is an ever-changing source of sensory information. Therefore, if you move, the structure of the optic array changes.

According to Gibson, we have the mechanisms to interpret this unstable sensory input, meaning we experience a stable and meaningful view of the world.

Changes in the flow of the optic array contain important information about what type of movement is taking place. The flow of the optic array will either move from or towards a particular point.

If the flow appears to be coming from the point, it means you are moving towards it. If the optic array is moving towards the point, you are moving away from it.

Invariant Features

the optic array contains invariant information that remains constant as the observer moves. Invariants are aspects of the environment that don’t change. They supply us with crucial information.

Two good examples of invariants are texture and linear perspective.

Another invariant is the horizon-ratio relation. The ratio above and below the horizon is constant for objects of the same size standing on the same ground.

OPTICAL ARRAY : The patterns of light that reach the eye from the environment.

RELATIVE BRIGHTNESS : Objects with brighter, clearer images are perceived as closer

TEXTURE GRADIENT : The grain of texture gets smaller as the object recedes. Gives the impression of surfaces receding into the distance.

RELATIVE SIZE : When an object moves further away from the eye, the image gets smaller. Objects with smaller images are seen as more distant.

SUPERIMPOSITION : If the image of one object blocks the image of another, the first object is seen as closer.

HEIGHT IN THE VISUAL FIELD : Objects further away are generally higher in the visual field

Evaluation of Gibson’s (1966) Direct Theory of Perception

Gibson’s theory is a highly ecologically valid theory as it puts perception back into the real world.

A large number of applications can be applied in terms of his theory, e.g., training pilots, runway markings, and road markings.

It’s an excellent explanation for perception when viewing conditions are clear. Gibson’s theory also highlights the richness of information in an optic array and provides an account of perception in animals, babies, and humans.

His theory is reductionist as it seeks to explain perception solely in terms of the environment. There is strong evidence to show that the brain and long-term memory can influence perception. In this case, it could be said that Gregory’s theory is far more plausible.

Gibson’s theory also only supports one side of the nature-nurture debate, that being the nature side. Again, Gregory’s theory is far more plausible as it suggests that what we see with our eyes is not enough, and we use knowledge already stored in our brains, supporting both sides of the debate.

Visual Illusions

Gibson’s emphasis on DIRECT perception provides an explanation for the (generally) fast and accurate perception of the environment. However, his theory cannot explain why perceptions are sometimes inaccurate, e.g., in illusions.

He claimed the illusions used in experimental work constituted extremely artificial perceptual situations unlikely to be encountered in the real world, however, this dismissal cannot realistically be applied to all illusions.

For example, Gibson’s theory cannot account for perceptual errors like the general tendency for people to overestimate vertical extents relative to horizontal ones.

Neither can Gibson’s theory explain naturally occurring illusions. For example, if you stare for some time at a waterfall and then transfer your gaze to a stationary object, the object appears to move in the opposite direction.

Bottom-up or Top-down Processing?

Neither direct nor constructivist theories of perception seem capable of explaining all perceptions all of the time.

Gibson’s theory appears to be based on perceivers operating under ideal viewing conditions, where stimulus information is plentiful and is available for a suitable length of time. Constructivist theories, like Gregory”s, have typically involved viewing under less-than-ideal conditions.

Research by Tulving et al. manipulated both the clarity of the stimulus input and the impact of the perceptual context in a word identification task. As the clarity of the stimulus (through exposure duration) and the amount of context increased, so did the likelihood of correct identification.

However, as the exposure duration increased, so the impact of context was reduced, suggesting that if stimulus information is high, then the need to use other sources of information is reduced.

One theory that explains how top-down and bottom-up processes may be seen as interacting with each other to produce the best interpretation of the stimulus was proposed by Neisser (1976) – known as the “Perceptual Cycle.”

DeCasper, A. J., & Fifer, W. P. (1980). Of human bonding: Newborns prefer their mothers” voices . Science , 208(4448), 1174-1176.

Gibson, J. J. (1966). The Senses Considered as Perceptual Systems. Boston: Houghton Mifflin.

Gibson, J. J. (1972). A Theory of Direct Visual Perception. In J. Royce, W. Rozenboom (Eds.). The Psychology of Knowing . New York: Gordon & Breach.

Gregory, R. (1970). The Intelligent Eye . London: Weidenfeld and Nicolson.

Gregory, R. (1974). Concepts and Mechanisms of Perception . London: Duckworth.

Necker, L. (1832). LXI. Observations on some remarkable optical phenomena seen in Switzerland; and on an optical phenomenon which occurs on viewing a figure of a crystal or geometrical solid . The London and Edinburgh Philosophical Magazine and Journal of Science, 1 (5), 329-337.

Slater, A., Morison, V., Somers, M., Mattock, A., Brown, E., & Taylor, D. (1990). Newborn and older infants” perception of partly occluded objects. Infant behavior and Development , 13(1), 33-49.

Further Information

Trichromatic Theory of Color Vision

Held and Hein (1963) Movement-Produced Stimulation in the Development of Visually Guided Behavior

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