PERCEPTION (the name of one of the basic mental processes)

PERCEPTION, the name of one of the basic mental processes in humans, by means of which he cognizes the environment surrounding him. The school of associative psychology, which sought to break down all psychological acts and states into their simplest elements, understood P. as the sum of sensations in the case when they give us an impression of some object (e.g., the sum of visual, olfactory, gustatory, and kinesthetic sensations constituted the P. of an apple). The school of associative psychology, in explaining the nature of perception, derived it, mainly, from the activity of memory. Usually three types of gradually complicating P. were distinguished: simple, complex, and final. The first was understood as the simple recognition of a given irritation in sensation (for example, recognizing the red color of an object). The second type of P. arose when the perceived object, along with red color, also has, for example, a certain smell and taste. In such a case, the subject, on the basis of past experience, recognized, recalled, that the perceived object is, for example, an apple. But an apple cannot be perceived simply as an apple - it must be related to a specific time and space. In the process of this relating, the final P. occurs, precisely at the moment when the subject remembers that the apple before him is of such and such a sort or that it was left here for such and such a purpose, etc. However, this kind of explanation of P. indicates only the significance for a given act of P. of past acts of it, but does not explain the process of P. itself. At the present time, on the basis of the latest experimental-psychological research, it is possible to indicate the following conditions for the formation of perception. 1. A complex object, acting on the organism, causes not a mosaic of separate sensations, but a holistic perception of the object (e.g., six tones of some melody constitute a whole - a musical phrase, which is perceived as a certain holistic image, form). 2. Form-formation as the basis of any perception has its experimentally proven laws and features, namely: a) the presence of a preliminary period, b) the suddenness and dynamism of formation, c) permeation with a sensory tone, d) the special relationship between whole and parts, e) the presence of a dominant value. 3. (a, b, c) The P. of an object, especially a new one or one in unknown relationships with the general situation, does not occur immediately. An example can be the mastery of some unfamiliar, not especially understandable picture or map. In such a case, it is customary to speak of a preliminary period of P., characterized by greater or lesser general emotional excitement of the subject. This emotional experience is connected with the subject's striving to organize a whole P. from its scattered parts. This process is completed suddenly by a reaction indicating the emergence of P. 4. (d, e). In form-formation of P., the relationship between whole and parts plays a large role. It turns out that in the act of P. the whole determines its constituent parts. An example can be the accompanying illustration, where, depending on the inclusion in the composition of different ornaments, circle a seems the smallest, c-the largest, and b - intermediate between them, while mathematically they are equal to each other. In a musical melody, the qualitative value of an individual sound as a part of this melody is entirely determined by the melody as a whole. The same sound 'do' can serve to express joy, sadness, ecstasy, etc. Everything depends on what melodic structure it enters. It also turns out that the whole P. is influenced by its parts, and in form-formation of the whole, its individual parts have different significance. For example, some musical phrase (leitmotif) colors the entire musical composition. It dominates over individual phrases. It is the 'dominant' of a given musical work (form-formation). The physiological basis of perception is apparently the complex activity of the brain's special organs that receive perceptions (analyzers). In addition, the process of P. is inextricably linked with certain vegetative and motor reactions. This is especially clearly manifested in cases of particular difficulty in P. Vegetative reactions consist mainly of changes in respiration and blood circulation, and motor reactions - in a series of orienting and adjusting movements. Conversely, changes of a physiological nature, for example, fatigue, excitement or pathological state, sharply change the properties of the usual process of P. V. Artemov. Disorders of perception provide rich material for a more detailed clarification of the structure of the latter. In this respect, agnostic disorders (see Agnosia) have proven especially valuable. Thus, Poppelreuter, studying visual disorders after brain injuries, discovered that in any normal visual perception, a whole series of mechanisms participate, which correspond to such partial systems of the quality of visual images as the system of light-dark, colors, forms, movements, and perhaps also direction. In this case, the color system is independent of others, while the systems of form and movements are built upon the system of light-dark. The most important conclusion resulting from Poppelreuter's data is the circumstance that disorders within each individual system occur not according to the principle of complete loss, but according to the principle of disruption of integrity and completeness. The impression does not disappear completely, but only becomes less differentiated. Accordingly, in brain injuries, complete blindness never developed: in persons with the most severe disorders, it was still possible to detect the ability to perceive light sensations - such subjects only distinguished more or less light, and it is interesting that even for them lightness was perceived not as something homogeneous, but in the form of certain cloudinesses and spots. Consequently, even in these cases, impressions had the character of images, i.e., possessed structure. At the next higher level, an impression of size and an indefinite P. of direction was obtained. The next is the level of amorphous forms, in which, however, there are no definite outlines (for example, a triangle was perceived as 'below larger and lighter than above'). Perception of multiplicity was achieved only at an even higher level, which corresponded to more distinct perceptions of form. Further follows a series of transitions to normal visual images corresponding to perceptions caused in healthy persons by distant or located outside the field of clear vision objects (amblyopia). Color impressions in pathological cases, apparently, can be perceived independently of objects, as if separating from them: thus, in the blind-born who received sight only after an operation, the connection of colors with other visual impressions occurs gradually, as experience accumulates. Poppelreuter assumes that just as ontogenetic, so also phylogenetic development of the ability to see passes through the same series of stages of increasing complexity and differentiation, and any damage primarily affects phylogenetically later systems. A natural supplement to the data collected by Poppelreuter are the observations of Petzl and the psychological experiments of Gelb and Goldstein. The latter two authors observed a patient who, after an injury to the occipital lobe, lost the ability to perceive the outlines of objects, but later learned to compensate for his defect by following these outlines with sequential head movements. Another patient of the same authors was unable to perceive movement and saw only a series of successive positions of the object that the latter occupied in this movement. These and many other observations lead to the conclusion that motor factors in general play a very essential role in the construction of not only visual, but generally all P. More complex disorders of P. are characterized by the inability, with relatively correct recognition of simple forms, to master more complex combinations, and especially to identify them with data from past experience (e.g., inability to perceive letters as certain symbolic signs). In such cases, correct P. still sometimes occurs with longer concentration of attention and with the use of auxiliary movements (of the eyes, head, palpation, etc.). Here, apparently, sometimes it is a matter of compensatory replacement of the function of the affected area of the cortex by the intensified activity of other, adjacent areas. A completely different character than the recently described focal disorders are so-called abnormal P.s, characterized either by changes in spatial relationships of images, or by deepening of their shades, or by acquiring the character of unusualness, etc. - phenomena quite often observed in poisonings (mescaline, hashish, etc.), as well as in some acute schizophrenic states: time and space begin to seem infinite, colors become extraordinarily bright, objects appear to have changed their proportions, etc. Such disorders are still little studied.

In addition, they are difficult to distinguish from such pathological phenomena, also belonging to disorders of perception, as hallucinations (see) and illusions (see). An interesting group of cases, standing on the border of pathology, is constituted by the so-called automatic perceptions. This term denotes the assimilation of impressions, unnoticed and not attracting attention and therefore remaining outside the field of clear consciousness. Traces of such P. are often discovered only under special conditions, for example, from the statements of patients in feverish delirium, in the twilight state, etc.

P. Zinoviev.