Sensory adaptation. The phenomenon of sensory adaptation To characterize sensory adaptation and the interaction of sensations
It would be wrong to think that the sensitivity of our senses (both absolute and relative) remains unchanged and its thresholds are expressed in constant numbers. Studies show that the sensitivity of our senses can vary, and within very large limits. So, it is known that in the dark, our vision is sharpened, and with strong illumination, its sensitivity decreases. This can be observed when you move from a dark room to light or from a brightly lit room to darkness. In the first case, a person's eyes begin to experience pain, the person temporarily “goes blind”, it takes some time for the eyes to adapt to bright lighting. In the second case, the opposite occurs. A person who has moved from a brightly lit room or open place with sunlight to a dark room at first does not see anything and it takes 20-30 minutes for him to become sufficiently well oriented in the dark. This suggests that depending on the environment (illumination), human visual sensitivity changes dramatically. Studies have shown that this change is very large and the sensitivity of the eye during the transition from bright illumination to darkness is exacerbated 200,000 times.
The described changes in sensitivity, depending on environmental conditions and bearing the name adaptation sense organs to the environment (or sensory adaptation) exist both in the auditory sphere and in the sphere of smell, touch, and taste. The change in sensitivity, which occurs according to the type of adaptation, does not occur immediately, it requires a certain time and has its own temporal characteristics. It is essential that these temporal characteristics are different for different senses. So, in order for vision in a dark room to acquire the desired sensitivity, it should take about 30 minutes. Only after this does a person acquire the ability to navigate well in the dark. The adaptation of the auditory organs is much faster. Human hearing adapts to the surrounding background within 15 seconds. Sensitivity in touch changes just as quickly (a weak touch on the skin is no longer perceived after a few seconds).
The phenomena of thermal adaptation (habituation to temperature changes) are well known. However, these phenomena are clearly expressed only in the middle range, and addiction to severe cold or intense heat, as well as to painful irritations, almost does not occur. The phenomena of adaptation to odors are also known. There are three types of the phenomenon of adaptation (A.V. Petrovsky and others):
- 1. Adaptation as the complete disappearance of sensation with prolonged action of the stimulus.
- 2. Adaptation as dulling sensation under the influence of a strong stimulus.
- (These two types of adaptation are combined by the term “Negative adaptation”, since it reduces the sensitivity of the analyzers.)
- 3. Adaptation is also called an increase in sensitivity under the influence of a weak stimulus. This type of adaptation is defined as positive adaptation. In the visual analyzer, the dark adaptation of the eye, when its sensitivity increases under the influence of darkness, is a positive adaptation. A similar form of auditory adaptation is silence adaptation.
The change in sensitivity that occurs as a result of the adaptation of the sense organ to stimuli acting on it is called sensory adaptation. There are three sensory adaptation modalities:
1. Complete disappearance of sensation during prolonged action of the stimulus. Examples of this are: adaptation to the smell of the olfactory analyzer in a person who has been working with odorous substances for a long time; auditory adaptation to constantly exposed noise, etc.
2. Dullness of sensation under the influence of the action of a strong irritant. for example, a temporary decrease in the sensitivity of the visual analyzer, after a person gets from a semi-dark room into conditions of bright illumination (light adaptation). This modality is called negative because it leads to a decrease in the analyzer's sensitivity. Adaptation to light and dark has a negative impact, especially in low light conditions.
3. Increased sensitivity under the influence of a weak stimulus.For example, when a weak stimulus is applied to the auditory analyzer in conditions of complete silence (the auditory analyzer begins to record rather weak auditory stimuli - auditory adaptation).
Examples. With the adaptation of the eye, associated with the transition from darkness to light, everything happens in the reverse order. The dark-adapted eye is more sensitive to electromagnetic waves, which are closer to the green-blue part of the spectrum than to the orange-red. This fact is illustrated by the following experience. If, in daylight, you show a person red and blue images on a black background, then they will be seen equally well. When looking at the same image at dusk, it will seem that the red part of it has disappeared and only blue remains. For this reason, for example, blue lamps are used in Aeroflot as identification marks indicating the contours of the runway.
The red color is capable of stimulating mainly only the cones. Wearing glasses with red lenses accelerates dark adaptation, and due to the fact that red color practically does not affect rod vision, the high sensitivity of the eye, which is necessary for working in the dark, remains in red light.
Some of the analyzers show a high adaptation rate, others - a low one. For example, receptors located in the skin (except for pain) are able to adapt very quickly. Visual adaptation occurs much more slowly, followed by hearing, smell and taste.
All types of sensations are not isolated from each other, therefore their intensity depends not only on the strength of the stimulus and the level of adaptation of the receptor, but also on the stimuli acting on other senses at the moment. The change in the sensitivity of the analyzer under the influence of irritation of other sense organs is called the interaction of sensations (Fig. 7).
Sensitization(from Latin sensibilis - sensitive) is an increase in the sensitivity of analyzers under the influence of internal (mental) factors. Sensitization or aggravation of sensitivity can be caused by:
§ interaction of sensations (for example, weak taste sensations increase visual sensitivity). This is explained by the interconnection of the analyzers, their systemic work;
Fig. 7. Interaction of sensations
§ physiological factors (the state of the body, the introduction of certain substances into the body; for example, vitamin A is essential to increase visual sensitivity);
§ waiting this or that impact, its relevance, special setting to distinguish between certain stimuli;
§ exercise, experience (for example, tasters, specially exercising their gustatory and olfactory sensitivity, distinguish between various varieties of wines, teas, and can even determine when and where a product is made).
In people who are deprived of any kind of sensitivity, this deficiency is compensated (compensated) by increasing the sensitivity of other organs (for example, an increase in auditory and olfactory sensitivity in the blind). This is the so-called compensatory sensitization.
The absolute and relative sensitivity of sensations does not remain unchanged. Their thresholds cannot be expressed in constant numbers.Studies have shown that both absolute and relative sensitivity can vary over a wide range: in the dark, vision is sharpened, with strong illumination, its sensitivity decreases. Depending on the environment, the sensitivity (for example, visual) of a person changes dramatically. Studies have also shown that eye sensitivity in the dark is exacerbated by 200000 (!) times.
Such changes in sensitivity are associated with the phenomenon of sensory adaptation - a change in sensitivity that occurs as a result of the adaptation of the sense organ to stimuli acting on it. Adaptation is expressed in the following:
When the sensory organs are exposed to sufficiently strong stimuli, the sensitivity decreases,
When exposed to weak stimuli (or lack thereof), the sensitivity increases.
Such a change in sensitivity does not occur immediately, it takes a certain amount of time. These temporal characteristics differ for different senses. For vision in a dark room to acquire the desired sensitivity, it takes about 30 minutes. The adaptation of the auditory organs is much faster, they adapt to the surrounding background after 15 seconds. Sensitivity of touch changes just as quickly (a weak touch to the skin is no longer perceived after a few seconds).
There is an adaptation to odors. There is thermal adaptation (habituation to temperature changes environment). However, these phenomena are clearly expressed only in the middle range, and addiction to severe cold or intense heat, as well as to painful stimuli, is almost never encountered.
Basically, the adaptation of sensations depends on the processes occurring directly in the receptor. Under the influence of light, for example, the visual purple, located in the rods of the retina, decomposes (fades). In the dark, visual purple is restored, the sensitivity increases.
Adaptation is also associated with the processes taking place in the central departments of the analyzers. The change in sensitivity is influenced by the different excitability of the nerve centers. Prolonged irritation of the cerebral cortex provokes protective inhibition, which also reduces sensitivity. Adaptation demonstrates the great plasticity of the organism in its adaptation to environmental conditions.
Interaction of sensations
The analyzer's sensitivity can also change under the influence of stimulation of other (not "native" for the analyzer) sense organs. There are two types of interaction of sensations:Interaction between sensations of the same kind,
Interaction between sensations of different kinds.
P.P. Lazarev found that lighting the eyes makes audible sounds louder. SV Kravkov showed that no sense organ can function without influencing the functioning of other organs. In his experiments, for example, sound stimulation (whistle) exacerbated the work of visual sensation, increased its sensitivity to light stimuli.
Smells can also increase or decrease light and auditory sensitivity. All analyzers are capable of influencing each other. The interaction of sensations is manifested in two opposite processes (and this shows a relationship with adaptation processes): increased sensitivity, decreased sensitivity.
A general pattern in the interaction of sensations: weak stimuli increase, and strong ones decrease the sensitivity of the analyzers when they interact with each other.
The mechanism of interaction of sensations of one kind, in fact, is similar to the interaction of sensations of different kinds. A strong signal in some parts of the visual field, for example, can reduce sensitivity in other parts of the visual field (and vice versa). So, gray on a white background will look darker, and surrounded by black - lighter.
Sensitization
There are ways to increase the sensitivity of your senses. This increase in sensitivity is called sensitization. A.R. Luria singled out two aspects of increasing sensitivity by the type of sensitization:It has a long-term, permanent character and depends mainly on stable changes occurring in the body,
It has a temporary character and depends on the physiological and mental state of a person.
The first type of sensitization is closely related to a change in sensitivity. Studies have shown that the severity of the sensitivity of the sense organs increases with age, reaching a maximum by the age of 20-30, further stabilization occurs, followed by a decrease in sensitivity to old age.
Synesthesia
Synesthesia is the appearance under the influence of irritation of one analyzer of a sensation, characteristic of another analyzer. For many people, sound waves are capable of creating the illusion that the surrounding space is colored in one color or another.Synesthesia, according to some assumptions, can serve as the basis for outstanding abilities. Many composers have a so-called ear for color. The famous mnemonist Sh., Who possesses a phenomenal memory and was investigated by AR Luria, could characterize the voice of a person as "yellow and crumbly" (sounds of different tones caused different visual sensations in him).
The phenomena of synesthesia clearly show the close connection of analyzers with each other.
The phenomenon of adaptation takes an important place in the process of interaction of the individual with the environment. In psychology, the term "adaptation" came from biology. At present, in psychology, adaptation is understood as a set of adaptive reactions of a living organism to changing conditions of existence. Sensory adaptation is one of the types of such adaptive reactions related to the work of sensory systems. Thus, sensory adaptation is the adaptation of sensory systems to the characteristics of a stimulus acting for some time, as a result of which a change in sensitivity to this stimulus occurs. Sensitivity changes under the influence of a stimulus can occur in different directions. Depending on this, they divide negative and positive adaptation. Negative adaptation takes place when there is either a complete disappearance of sensation with prolonged action of the stimulus, or dullness of sensation under the influence of a strong stimulus. This adaptation is called negative adaptation, as it reduces the sensitivity of the sensory system. Positive adaptation is called an increase in iodine sensitivity by the influence of a weak stimulus.
Adaptation should not be confused with habituation and sensory fatigue. During adaptation, a real change occurs in the work of the sensory system; during habituation, we do not stop feeling the stimulus, we stop paying attention to it. Sensory fatigue - this is a process of a temporary decrease in excitability in the corresponding cortical representations of the sensory systems and a deterioration in sensory functions. Sensory fatigue is caused by prolonged and (or) intense stimulus exposure, leading to exhaustion, reduction of physiological reserves and transition to energetically less favorable types of reactions. If we are talking about adaptation, we mean a purposeful systemic response of the sensory system, focused on adapting to an acting stimulus in order to ensure the possibility of further functioning.
The change in sensitivity, carried out according to the type of adaptation, does not occur immediately, it takes time, has its own temporal characteristics and depends on the modality. Different sensory systems adapt to exposure in different ways. For example, temperature, skin, visual, olfactory and taste sensations are highly susceptible to adaptive effects. It is believed that the English philosopher John Locke was the first to point to temperature adaptation. He is credited with the authorship of such an experiment: if you lower the right hand into water, the temperature of which is 40 ° C, and the left - into water, the temperature of which is 20 ° C, then it is obvious that the right hand will feel warm, and the left hand will feel cold. But after a few minutes, thermal adaptation sets in, and neither the right nor the left hand experience any sensations. If, after the onset of adaptation, the hands of both hands are lowered into water, the temperature of which is 33 ° C, then the right hand, which has adapted to warm water (at 40 ° C), will perceive it as cold, and the left hand, which has adapted to cold water (at 20 ° C), will perceive it as warm. It is with thermal adaptation that we are dealing with, when we approach the water and taste it with our fingertips, we first experience the sensation of very cold water, but gradually we get used to it and enjoy bathing. However thermal adaptation - adaptation to temperature changes - clearly expressed only in the middle temperature range.
With prolonged exposure to gustatory stimuli, a decrease in sensitivity occurs, which depends on the nature of this stimulus: faster negative adaptation occurs to sweet and salty substances, slower to sour and bitter ones. In the gustatory modality, there are cases when adaptation to a high concentration of one substance leads to the fact that when the same substance is used, but in a small amount, it leads to the appearance of the opposite taste - "anti-taste". The use of several gustatory stimuli simultaneously or sequentially gives flavor contrast effect, or mixing flavors. For example, after adaptation to the taste of table salt (i.e. sodium chloride), the use of salt causes the taste of sour and / or bitter, adaptation to bitter increases the sensitivity to sour, adaptation to sweet increases the sensitivity of all other taste stimuli.
Adaptation to skin sensations, namely pressure and touch sensations, occurs quickly. This is manifested in the fact that we soon cease to notice the pressure of clothing or jewelry (watches, bracelets, rings) on the skin. Experiments have shown that after 3 s the feeling of pressure is only 1/5 of the force that it had immediately after touching.
Adaptation to vibration sensitivity is much slower than adaptation to touch and pressure. JF Khan measured the effect of adaptation to vibration and found that, depending on the vibration frequency, adaptation occurs on average from 10 to 25 minutes.
Adaptation occurs extremely quickly in olfactory sensations. Often, entering an unfamiliar house, we first feel its smell, but over time this smell ceases to be felt by us, or, entering from the street into a poorly ventilated room, at the first moment we often feel an unpleasant smell, but also after a few minutes it ceases to be felt ... The rate of adaptation to odors depends on its chemical composition, the concentration of the substance in the air and its duration. For example, complete adaptation to the smell of iodine occurs after 50-60 s, to the smell of camphor - after 1.5 minutes. For full restoration of olfactory sensitivity, a break of 1 to 3 minutes is required. In the olfactory modality, the effect of cross-adaptation is very strong, when prolonged exposure to any odor causes an increase in the threshold for its sensation and, at the same time, a decrease in the threshold for sensation of another odorous substance.
Hearing is characterized by a low degree of adaptation. The most studied adaptation to the strength of a sound stimulus, as a result of which there is a change in the sensation of the loudness of this stimulus. According to von Bekesy, when exposed to a stimulus with a frequency of 200 Hz for 15 minutes, the threshold did not change. The magnitude of auditory adaptation is influenced by many variables, among which the frequency and intensity of the sound stimulus are of great importance. For a long time, it was believed that adaptation in the auditory modality is the same for all intensities, however, relatively recent experiments demonstrate that adaptation is extremely low at high values \u200b\u200bof the sound signal intensity. In the experiments of Hellman, Miskevich and Charf, it was shown that after exposure to a stimulus of 5 dB for 6 minutes, the sensation of loudness decreases by 70%, and sometimes 100%, for a stimulus of 40 dB - already by 20%, and at high values the sense of volume remains virtually unchanged. Also, these authors have shown that the value of adaptation in the auditory modality increases with an increase in the frequency (and hence the perceived height) of the sound signal.
In the auditory modality, adaptation can lead to both an increase and a decrease in sensitivity to an acting stimulus. If the auditory system has adapted to the acting stimulus, then its sensitivity to distinguish between the two stimuli increases in comparison with the unadapted state.
One of the most studied is adaptation in visual modality. In the visual modality, adaptation can be both negative and positive. In general, visual adaptation is the adaptation of the visual sensory system to different levels of illumination. Sensitivity to light during visual adaptation increases sharply in the dark (then we are talking about tempo adaptation, which is positive), which makes it possible to perceive very weak light sources, and decreases when going from lower illumination to higher (in this case, we are talking about light adaptation which is negative).
With light adaptation, light sensitivity decreases, but at the same time, the reaction to spatial and temporal differentiation of objects is aggravated. Light adaptation occurs quickly enough, on average 1-2 minutes.
A striking example of dark adaptation is the situation when, getting into a darkened room, a person at first does not see anything and after 2–3 minutes only begins to distinguish objects in this room. Being in absolute darkness increases the sensitivity to light by about 200 thousand times in 40 minutes. On average, dark adaptation is achieved from 30 to 60 minutes. Periodic measurements of the increasing photosensitivity in the persisting darkness (with an interval of 5-10 min) make it possible to construct a dark adaptation curve. The light thresholds of visual adaptation in healthy people vary widely, therefore, when assessing it, the normal band is used (Fig. 1.7). With age, photosensitivity changes: it is maximally high in 20-year-olds and after this age begins to decline, reaching its minimum values \u200b\u200bby old age. The range of illumination within which visual adaptation is carried out is enormous; in quantitative terms, it is measured from a billion to several units. For convenience in comparing data, it is usually not these numbers that are manipulated, but their decimal logarithms. In logarithmic units (log units), the limits of the considered boundaries are divided into only ten levels (from 0 to 9), and then the zero level will correspond to lgl, the first - lglO, the second - IglOO, etc. up to the ninth level.
Proprioceptive sensations are subject to adaptation to a weak degree or not at all, since even if we move the limbs for a long period (for example, sleep), our sensation of their relative position still remains at the same level. The same goes for adaptation to painful stimuli. Pain signals the destruction of an organ, and therefore, adaptation to pain can lead to the death of the body. There is no adaptation to visceral sensations, especially to thirst and hunger.
Figure: 1.7. Temporal adaptation curve and its normal band: the dependence of the threshold value on time 1
An increase in sensitivity as a result of the action of a stimulus is possible not only with adaptation of the sensory system. If an increase in sensitivity occurs as a result of exercise, then they talk about sensitization. For example, experienced drivers can detect engine malfunctions by the noise of a running engine, while professional colorists can distinguish up to 50 shades of color that untrained people will perceive as the same. AR Luria notes the fundamental difference between sensitization and adaptation. In the process of adaptation, the sensitivity can change in both directions; in the process of sensitization, as already noted, there is an exclusively increase in sensitivity (and a decrease in the threshold, respectively). Also, changes in sensitivity during adaptation depend on environmental conditions, and during sensitization - mainly from changes in the organism itself - physiological or psychological 1.
Often (but not always) sensitization occurs either as a result of professional exercise or as a result of compensation for a defect in some sensory system. Sensitization resulting from a defect in the sensory system manifests itself as an increase in other types of sensitivity. There are cases when people without sight are engaged in sculpture, and their sense of touch is largely developed. Sensitization occurs even with severe defects, for example, with deaf-blindness, which is defined as congenital or early childhood loss of vision and hearing and dumbness associated with a lack of hearing. Deaf-blindness is not a simple sum of features that are present separately in blindness and deaf-dumbness. With deaf-blindness, there is no compensation for hearing due to vision, as is the case in the deaf-mute, and there is no compensation for vision due to hearing and speech, as is the case with the blind. However, with a special organization of education and training, such children eventually learn to read and receive a full-fledged education, and their tactile sensitivity develops to a strong extent. One of the most illustrative examples is the case of the deaf-blind Olga Ivanovna Skorokhodova, who could recognize a person and understand what he was talking about by holding her hand on the speaker's throat. These cases show that different types of sensitivities are interrelated.
For persons deprived of hearing, vibrational sensations are of great importance. There are cases when deaf people were able to perceive music, to distinguish one piece of music from another, placing their hand on the lid of an instrument (for example, a grand piano) or sitting with their backs to the stage, since their backs are best perceived by air vibrations. Vibrational sensations in the deaf-blind are even more important. Deaf-blind people with the help of vibrational sensations perceive a knock on the door, recognize when someone enters their room, they can even recognize familiar people by their gait; on the street, they notice the approach of a car from a distance with the help of vibrational sensations. Vibrational sensations are of particular importance in teaching the deaf and deaf-blind speech. Some vibrations that occur during speech are captured by the deaf when the palm is applied to the speaker's neck, mouth, face, and also through special devices, including a microphone, amplifier and vibrator. Some of the deafblind people can be spoken to from the other end of the room using Morse code, knocking on the floor; they feel vibrations and understand everything that is transmitted to them. Sensitization can result from the interaction of sensations. We will consider the problem of the interconnection of sensations in the next paragraph.
- Schiffmap H. R. Sensation and Perception. P. 675.
- Lltner X. Physiology of taste // Fundamentals of sensory physiology / ed. R. Schmidt. S. 237-247.
Sensory adaptation (English sensory adaptation) - change in the sensitivity of sensory systems under the influence of an irritant. The concept of sensory adaptation (or, which is not very accurate, the A. of the sensory organs) combines various phenomena of changes in sensitivity, which sometimes have completely different physiological nature. There are at least 3 varieties of A. c.
- A. - complete disappearance of sensation in the course of prolonged action of a constant stimulus. For example, a light weight resting on the skin soon ceases to be felt. A person feels the touch of clothes and shoes only at the moment of putting them on. The pressure of the watch on the skin of the hand or glasses on the bridge of the nose is also very quickly lost. These changes in sensitivity, according to L.M. Vekker (1998), are associated with the fact that when a stationary state of interaction with a stimulus is established, the attenuation of centripetal impulses automatically stops the entire further process of sensation, although the process of stimulation of the receptors continues. The absence of the phenomenon of complete adaptation of the visual analyzer under the action of a constant and immobile stimulus is explained by the fact that in this case there is compensation for the immobility of the stimulus due to the movements of the receptor apparatus itself.
- A. is also called a deterioration in the ability to feel weak stimuli and, consequently, an increase in the lower absolute threshold under the influence of a strong light stimulus. The phenomenon of a decrease in the absolute sensitivity of the visual system under the influence of intense light stimulation is called light A. Described 2 types of A. can be combined with the general term negative A., because their result is a decrease in the sensitivity of analyzers.
- A. is called an increase in sensitivity under the influence of a weak stimulus; this is positive A. In the visual analyzer, positive A. is called dark A., it is expressed in an increase in the absolute sensitivity of the eye under the influence of being in the dark.
Adaptive regulation of the level of sensitivity, depending on which stimuli (weak or strong) act on the receptors, is of great biological importance. A. protects the senses from excessive irritation in case of exposure to strong stimuli. At the same time, it does not allow constant acting irritants mask new signals or divert attention from more important stimuli. A.'s phenomenon is explained by the peripheral changes that take place in the functioning of receptors with prolonged exposure to an irritant, as well as by the processes occurring in the central parts of the analyzers. With prolonged irritation, the cerebral cortex responds with internal “protective”, transcendental inhibition, which reduces sensitivity.
Other phenomena should be distinguished from the considered A. phenomena, for example, sensorimotor A. to inversion or displacement of retinal images (see. Displaced vision). It was found that the subjects wearing inverting prisms gradually adapt to inversion conditions and perceive the surrounding objects as correctly oriented in space. I. Koller (1964) suggested the possibility under these conditions of 2 types of A.: physiological A., not depending on K.-L. forms of activity on the part of the subject, and A. as a result of practical activity. (See also Adaptation, Visual adaptation, Vision, Sensation thresholds, Temperature sensations.) (T.P. Zinchenko)
Adding:
- Usually in the definitions of A. indicate not just a change in sensitivity, but an adaptive (useful, positive) change, and it is understood that the adaptive effect is manifested in the sensory sphere itself. The term "negative A." can create an incorrect idea of \u200b\u200blight A. as a phenomenon that is characterized only by a deterioration in perception, which in itself can also have a positive meaning in the light of other "interests" of the subject (for example, protection from sensory overload or from irritants that are dangerous in strength, filtration informative signals). However, light A. cannot be limited only to the noted process of lowering the absolute sensitivity, since (this is precisely its adaptive value), in parallel with the decrease in absolute sensitivity, an increase in differential light (or contrast) sensitivity occurs - the observer's ability to notice differences, details, contrasts (any a person with normal vision knows that when moving from a dark room to a bright street, it takes some time for the blinding to pass and objects begin to be distinguished).
- The phenomena of sensory A. often have a certain selectivity (selectivity): changes in sensitivity occurring in the sensory system are specific to a certain range of stimulus characteristics close to the characteristics of the adaptive stimulus (movement speed, orientation, color, spatial frequency, etc.) (B. M.)
Psychological Dictionary. A.V. Petrovsky M.G. Yaroshevsky
Sensory adaptation (from Latin sensus - feeling, sensation) - adaptive change in sensitivity to the intensity of the stimulus acting on the sense organ; can also manifest itself in a variety of subjective effects (see sequential image). sensory adaptation can be achieved by increasing or decreasing absolute sensitivity (eg, visual dark and light adaptation).
Dictionary practical psychologist... S.Yu. Golovin
Sensory adaptation - a change in the sensitivity of the analyzer, which serves to adjust it to the intensity of the stimulus; in general, an adaptive change in sensitivity to the intensity of the stimulus. It also manifests itself in a variety of subjective effects (-\u003e consistent image). Can be achieved by increasing or decreasing overall sensitivity. It is characterized by the range of changes in sensitivity, the rate of this change and selectivity (selectivity) of changes in relation to the adaptive effect. With the help of sensory adaptation, an increase in the differential sensitivity is achieved in the zone bordering on the magnitude of the stimulus. This process includes both peripheral and central links of the analyzer. The patterns of adaptation show how the thresholds of sensitivity change with prolonged stimulus action.
Physiological changes underlying adaptation affect both the peripheral and central parts of the analyzer. A combination of neurophysiological and psychophysical methods (-\u003e psychophysics) is of great importance for studying the mechanisms of sensory adaptation and perception processes in general.
Neurology. Full dictionary... Nikiforov A.S.
Oxford Explanatory Dictionary of Psychology
there is no meaning and interpretation of the word
subject area of \u200b\u200ba term
