PERCEPTION, EXPLANATION, FACTORS

In philosophy, psychology, and cognitive science, perception is the process of attaining awareness or understanding of sensory information. The word "perception" comes from the Latin words perceptio, percipio, and means "receiving, collecting, action of taking possession, apprehension with the mind or senses."

PERCEPTION EXPLANATION

Perception refers to how the brain organizes and interprets sensory information. Until fairly recently, perception was considered by the school of psychology called behaviorism to be largely a passive and inevitable response to stimuli. Today's cognitive scientists, however, explain perception as an active process in which the brain treats external stimuli as raw material to be shaped, aided by our experience. Earlier in this century gestalt psychologists made a major contribution to the theory of perception by studying the ways people organize and select from the multitude of stimuli that are presented to them.

Receives information: The brain receives information from the environment by way of specialized sensors called receptors. These receptors respond to physical stimuli such as light, sound, touch, taste, and smell. Nature has conveniently distributed these receptors in places on the body where they will be most useful, for example, in the retina, tongue, ears, nose, and skin--what we call our sensory apparatus. Environmental inputs are received by the senses and distributed to different parts of the brain for analysis. By a process that is not understood, the brain assembles the different elements into the perceptual experiences that make up our everyday lives.

Vision: Vision is our most important sense. If our brains had to process every bit ofsensory stimulus we receive from the world, we would soon be overwhelmed. Selective attention helps us to focus only on stimuli that are needed or wanted at any instant, and to ignore less important ones. Perceptual constancy explains our tendency to interpret one object in the same way, no matter how nearer far away it is, the angle we are viewing it from, or how bright it is. In other words, the world should look chaotic, but it doesn't.

Context: The setting in which something happens--is important to perception because we do not perceive objects in isolation. So how near one stimulus element (object in the environment) is to another, how similar the elements are, the human tendency to see complete figures, and our ability to distinguish important figures from the background will all contribute to the pattern that we perceive. Perception is also influenced by the intensity and physical dimensions of the stimulus, our own past experience, how ready we are to respond, and our motivation and emotional state.

Innate: Some perceptual abilities appear to be innate. For example, six-month-old infants are able to perceive depth. Similarly, experiments with young animals inthe laboratory show that they are reluctant to step off the edge of what appears to be a steep cliff. But learning is also assumed to play a role in perception, since infants who are deprived of sensory experience show impaired perception.

Perceptual disturbances: Normally the brain is able to seamlessly integrate its mental equivalent of the world outside our bodies, based on an interplay between the physiological  activity of the brain and external sensory stimuli. When the interplay breaks down, however, owing to a variety of causes, perceptual disturbances can result. 

FACTORS INFLUENCING PEOPLES PERCEPTION:

Psychological factors that can affect people's perceptions: Perception is influenced by a number of psychological factors, including assumptions based on past experiences (that often operate at an almost unconscious level), cultural expectations, motivation (needs), moods, and attitudes. A number of experiments have demonstrated the effects of these factors on perception.

Assumptions and Perception: Much of the research showing that perception is influenced by assumptions has come from a group of researchers working at one time or another at Princeton University. These re¬searchers have presented what has been called the "transactional view" of perception. The concept is abstract and some-'what philosophical, but essentially it means that both the perceiver and the world are active participants in an act of perception (Toch & MacLean, 1962).The transactional thinkers have developed a number of convincing demonstrations that perception is based on assumptions. Research experiments proved the affect on perception through assumptions based on past experiences.

Cultural Expectations and Perception: Some of the most striking evidence for the influence of cultural expectations on perception comes from research on binocular rivalry (Bagby, 1957). It is possible to construct a device that has two eyepieces like a pair of binoculars, but can be used to present a different picture to each eye. When this is done, people seldom see both pictures. They more often see one picture and not the other or one picture and then the other. Sometimes they see a mixture of some elements of each picture, but this usually occurs after seeing one picture alone first. Bagby used this instrument to investigate the effect of cultural background on perception.

Motivation and Perception: One of a number of experiments that show the effect of motivation on perception was done by McClelland and Atkinson (1948). The type of motivation being investigated was hun¬ger. Subjects were Navy men waiting for admission to a submarine training school. The results showed that the frequency of food-related responses increased reliably as the hours of food deprivation increased. Furthermore, in another phase of the experiment food-related objects were judged larger than neutral objects by hungry subjects but not by subjects who had recently eaten.

Mood and Perception: An experiment using hypnosis demonstrated that mood has an effect on perception. Leuba and Lucas (1945) hypnotized subjects, suggested to them that they were experiencing a certain mood, and then asked them to tell what they saw in a picture. They experimented on happy, anxious and critical mood and obtain useful results.

Attitude and Perception: The effects of attitude on perception were documented in a study of perception of a foot¬ball game by Hastorf and Cantril (1954). The 1951 football clash between Dartmouth and Princeton was an exciting and controversial one. Princeton's star player Dick Kazmaier was taken out of the game in the second quarter with a broken nose. In the third quarter, a Dartmouth player received a broken leg. Discussion of the game continued for weeks, with editorials in the two campus newspapers charging the other school with rough play. Hastorf and Cantril took advantage of this situation to conduct a study in perception. They showed a film of the game to two groups: two fraternities at Dartmouth and two under-graduate clubs at Princeton. Students from both schools saw about the same number of infractions by the Princeton team. But Princeton students saw an average of 9.8 infractions; by the Dartmouth team, while Dartmouth students saw an average of 4.3 infractions by the Dartmouth team. That is, the Princeton students saw more than twice as many violations by the Dartmouth team as did the Dartmouth students. Hastorf and Cantril state, "It seems clear that the 'game' actually was many different games and that each version of the events that transpired was just as 'real' to a particular person as other versions were to other people".