RECEPTION

From Big Medical Encyclopedia

RECEPTION (Latin receptio acceptance) — process of perception and processing of information coming to an organism from touch systems (analyzers) at action on them adequate irritants. The river can be followed by emergence feelings (see) — in case of involvement in activity of a cortical link analyzer (see) or the phenomena subconscious when only the below-located departments of c participate in R.'s act. N of page — e.g., spinal cord (see).

Morphological substrate P. on the periphery are receptors (see). In formation of a touch flow receptive fields are important (see. Reflexogenic zones ). At the functional assessment having special value in understanding of the phenomenon of R., the receptive field — a concept dynamic, i.e. in various intervals of time depending on specific features of the moment (characteristics of irritation, a functional condition of receptors etc.) the same neuron can perceive impulses from various number of touch devices. The phenomena of lateral braking can be involved in formation of such changing receptive field (see. Braking ), efferent influences, level of excitability of the central educations etc.

R.'s process is regulated by overlying departments of the central nervous system (see. Cerebral cortex ). Morphologically it is expressed in existence of the special efferent structures sending fibers to touch educations (e.g., in case of an innervation of an acoustic organ by fibers of the direct and crossed olivokokhlearny bunches having the oppressing effect on an afferent flow of an impulsation).

Specificity of information coming to an organism in the course of R. is defined first of all by specificity of the activated receptors and specificity of bonds in c. N of page. However the important role in coding of specifics of signals belongs also to features of distribution of the afferent impulses addressed in the highest parts of the nervous system at irritation of peripheral touch educations.

The river of an organism is very closely coordinated to features of his life: specifics of the habitat, food, reproduction etc. Distinctions in extents of development of these or those touch systems in different animals, and also emergence in a number of organisms of ability to perceive signals of the outside world, specific to them, are a consequence of it. So, at birds sight is more developed; at dogs — sense of smell (it prevails over sight); at dolphins and bats ability of perception of audibles signal in ultrasonic area developed; fishes and amphibians have a specific touch system of a sideline, edges at a number of fishes contains special highly sensitive electroreceptors; nek-ry snakes have highly sensitive thermoreceptors.

Integrative mutually activity of various touch systems in the course of R. provides to an organism complete and many-sided perception of the world around (see. Perception ). The underdevelopment or damage of this or that analyzing system leads to compensatory increase of a role of other touch educations. E.g., at blind people considerable development is gained by tactile feeling (see. Tactile analyzer ), with the help to-rogo they are capable to perceive information normal arriving via the visual analyzer (e.g., during the reading). Tactile reception can offset to a certain extent and loss of acoustical function, than use during the designing of special vibrotactile devices (see. Hearing ).

In psychophysiological experiments in public it was succeeded to compare subjective feelings with electrophysiologic indicators. At the same time it turned out that at irritation of skin the threshold of feeling often exceeds the threshold estimated according to electrophysiologic characteristics. In nek-ry cases the threshold feeling was reached by excitement of single receptors and even the unique impulse in separate afferent nerve fibril, e.g., from a bulb of a human hair. During the studying of hearing of the person it was revealed that definition of localization of an incentive in space is carried out at the expense of an initial phase of the touch category of neuron, and the subsequent parts of the answer bear information already on the size and quality of an incentive (irritant).

Studying of a ratio between the size of feeling and power of irritation led to establishment of the so-called law of Weber — Fekhnera (see. Feeling ), according to Krom this dependence has logarithmic character:

S = algI + b,

where S — feeling; and — coefficient of transition to decimal logarithms, I — power of irritation, b — a constant of integration. However the subsequent psychophysiological researches allowed to specify pattern of communication of feeling and power of irritation. According to Stephens's law the specified dependence is characterized by a power function more precisely, i.e. feeling of S = a (I — R) x , where and — the constant depending on the chosen units; I \power of irritation, R — a threshold incentive, x — an exponent.

If at early stages of studying of R. dominating were psychophysiological methods, then in the subsequent electrophysiologic, morphological, biochemical and other methods began to be used widely. An important role is played by use of computer facilities as at implementation of model experiments (creation of mathematical models of various parties of processes of R.), and in the analysis of the received results.

See also Sensitivity .



Bibliography: Granite P. An electrophysiologic research of reception, the lane with English, M., 1957; Tamar G. Fundamentals of touch physiology, the lane with English, M., 1976; Physiology of touch systems, under the editorship of A.S. Batuyev, L., 1976; H e n s e 1 H. Allgemeine Sinnesphysiologie, Hautsinne, Geschmack, Geruch, B., 1966, Bibliogr.


O. B. Ilyinsky.

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