perception importance essay

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

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

Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.

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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What Is Perception And Why Is It Important? (Essay Sample)

In general, perception is the ability to sense or be aware of anything based on the two senses sight and hearing. Anyone, so as long as their cognitive ability still functions, regardless of whether or not it is efficient, he or she still has perception.

Why is it important though?

Think of a situation when your judgment is needed. Say for example you are a doctor and the diagnosis taken says that your patient has terminal illness. You offer medicine to the patient but they refuse to take it whereas the family wants you to try anything that can help prolong the patient’s life. What would be your call? Do you want to save the patient even though they do not want to be saved or not?

Perception is one of the key components for judgment so as it is for other things such as analyzing. Data can come in so many forms but the most common ones are those that you see. In analyzing data such as statistical data, you must be aware of every little number/data that comes by to make an efficient analysis.

Other than that, perception is pivotal in giving everything a sound interpretation. In this perspective, you use your perception in order to understand the world around you such as how the stop light functions in controlling pedestrians, or why people get angry for simple things.

Perception is also known to help in the molding of a person’s characters and attitude. Due to experience, a person can perceive the emotions he or she felt at the time to know other emotions or characteristics such as love, hate, and kindness.

Other things about perception include the definition of happiness for what someone feels for another. We all have that one thing in life that can satisfy us no matter what we do and we love doing it. For example, you love the idea of falling in love then so be it. You may even love the art of earning money so you do everything in your power to earn money.

Perception is also important in the religious faith. Perception is used for religion in believing their God(s). Perception can also help you differentiate your own religion from others by studying or experiencing them yourselves.

Lastly, perception can help a person shape their goals and what they want to happen in their lives. Perception is anything that initiates elements such as beginnings, mid, and endings in life. Perception can make you visual what you want be it a doctor, a lawyer, a pilot, an engineer or anything in life.

Perception is cannot be bound, cannot be limited. Much like your dreams in life. Perception is not something that should be taken for granted, especially if you have a keen sense for it. Perception can be used in so many ways and can be advantageous as discussed earlier.

In essence, perception is such an important aspect of a person’s life that to hone and use perception to your advantage can not only mold you as a person but also create your future. After all, what better way to go through life with assurance on what to go with, why to go with them, and how to go about them?

Home — Essay Samples — Psychology — Perception — Sensation and Perception: World of Human Sensory Experience

Sensation and Perception: World of Human Sensory Experience

• Categories: Perception

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Words: 737 |

Published: Sep 12, 2023

Words: 737 | Pages: 2 | 4 min read

Table of contents

Understanding sensation, perception: making sense of sensation, the role of attention, perceptual illusions: when perception deceives, the influence of experience and culture, conclusion: the complex interplay of sensation and perception.

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Environment

The five senses and the nature of perception, perceiving the world looks, sounds, and feels easy. it isn't..

Posted November 11, 2014 | Reviewed by Jessica Schrader

We perceive the world through our five senses—our eyes, ears, skin, nose, and mouth are all receptors. Everything that comes into the brain enters through one of these doors. Because most of us take the world in through our senses effortlessly, we don’t give much thought or attention to how we do this.

Even scientists were guilty of underappreciating the complexity of the senses. Back in the 1950s and 1960s, when computers were in their infancy, the thinking was that it would take a decade or so to build “perceiving machines” that could respond to sight, sound, touch and so on as well as a human being. Such a machine still doesn’t exist.

Lose a sense, however, and you will quickly appreciate what is missing. I know because that’s what happened to me when I found out my son was deaf. There was so much to learn about the way hearing works and the role of sound in the brain that I wrote a whole book about it. That was the long version.

This is the short version. What has to happen to put on the show that is our awareness of our environment? An awful lot. Neuroscientists have recently done some radical rethinking about the very nature of perception .

“Historically, the way we intuitively think about all perception is that we’re like a passive recording device with detectors that are specialized for certain things, like a retina for seeing, a cochlea for hearing, and so forth,” says David Poeppel , a professor of psychology and neural science at New York University and a director of the newly established Max Planck Institute for Empirical Aesthetics . “We’re kind of a camera or microphone that gets encoded somehow and then magically makes contact with the stuff in your head.”

At the same time, many of the big thinkers who pondered perception, as far back as the 19th-century German physician Hermann von Helmholtz, knew that couldn’t be quite right. If we reached for a glass or listened to a sentence, didn’t it help to be able to anticipate what might come next?

In the mid-to-late 20th century, a handful of prominent researchers proposed models of perception that suggested that we engaged in “active sensing,” seeking out what was possible as we went along. Such ideas didn’t gain much traction until the past decade, when they suddenly became a hot topic in the study of cognition . What everyone is talking about today is the brain’s power of prediction.

On one level, prediction is just common sense, which may be one reason it didn’t get much scientific respect for so long. If you see your doctor in the doctor’s office, you recognize her quickly. If you see her in the grocery store dressed in jeans, you’ll be slower to realize you know her.

Predictable events are easy for the brain; unpredictable events require more effort. “Our expectations for what we’re going to perceive seem to be a critical part of the process,” says Greg Hickok , a neuroscientist at the University of California, Irvine. “It allows the system to make guesses as to what it might be seeing and to use computational shortcuts.”

In the old view of perception, a cascade of responses flows from the ear or the eye through the brain and ends with the ability to follow a complicated sentence or pick out the one person you are looking for in a crowded theater. That is known as bottom-up processing. It starts with basic input to any sense—raw data—and ends with such higher-level skills as reasoning and judgment and critical thinking—in other words, our expectations and knowledge.

But that is only half the story. Neuroscientists now believe that the process is also happening in reverse, that the cascade flows both ways, with information being prepared, treated, and converted in both directions simultaneously, from the bottom up and the top down.

This holds for simple responses as well as for complex thinking about philosophy or physics. If a sound is uncomfortably loud, for instance, it is the cortex that registers that fact and sends a message all the way back to the cochlea to stiffen hair cells as a protective measure. The same is true of the retina, adjusting for the amount of light available. It’s not your eye or ear doing that, it’s your brain.

Imagine someone beating rhythmically on a table with a pencil: tap, tap, tap, tap. By the third beat, you have anticipated the timing. By the fourth, scientists like Poeppel and Hickok could see activity in the brain that represents that prediction.

Perception then is an active process of constructing a reality, a conversation between the senses and the cortex that balances new information from the outside world with predictions from the interior world of our brain.

Parts of this post originally appeared in I Can Hear You Whisper: An Intimate Journey through the Science of Sound and Language (Dutton 2014).

Lydia Denworth is a science journalist and author of Friendship: The Evolution, Biology, and Extraordinary Power of Life’s Fundamental Bond.

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When we fall prey to perfectionism, we think we’re honorably aspiring to be our very best, but often we’re really just setting ourselves up for failure, as perfection is impossible and its pursuit inevitably backfires.

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