Studies have shown that both absolute and relative sensitivity can vary widely: in the dark, vision becomes sharper, and in strong light, its sensitivity decreases. Depending on the environment, the sensitivity (for example, visual) of a person changes dramatically. Studies have also shown that the sensitivity of the eye in the dark increases in 200000 (!) once.
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 the stimuli acting on it. Adaptation means:
When the sensory organs are exposed to sufficiently strong stimuli, sensitivity decreases,
When exposed to weak stimuli (or lack thereof), sensitivity increases.
Such a change in sensitivity does not occur immediately, it takes a certain time. For different sense organs, these time characteristics are different. In order for vision in a dark room to acquire the necessary sensitivity, about 30 minutes should pass. The adaptation of the auditory organs is much faster, they adapt to the surrounding background after 15 seconds. Just as quickly, there is a change in the sensitivity of touch (a weak touch on the skin ceases to be perceived after a few seconds).
There is an adaptation to smells. There is thermal adaptation (getting used to changes in ambient temperature). However, these phenomena are clearly expressed only in the middle range, and addiction to extreme cold or extreme 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, visual purple, located in the rods of the retina, decomposes (fades). In the dark, visual purple is restored, sensitivity increases.
Adaptation is also connected with the processes taking place in the central sections of the analyzers. The change in sensitivity is affected by different excitability of the nerve centers. Prolonged stimulation of the cerebral cortex provokes protective inhibition, which also reduces sensitivity. Adaptation demonstrates the greater plasticity of the organism in its adaptation to environmental conditions.
Interaction of sensations
The sensitivity of the analyzer 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 different kinds of sensations.
P. P. Lazarev found that eye lighting makes audible sounds louder. S. V. Kravkov showed that no sense organ can work without affecting the functioning of other organs. In his experiments, for example, sound stimulation (whistling) sharpened the work of visual sensation, increased its sensitivity to light stimuli.
Smells can also increase or decrease light and auditory sensitivity. All analyzers are able to influence each other. The interaction of sensations is manifested in two opposite processes (and this shows a relationship with the processes of adaptation): an increase in sensitivity, a decrease in sensitivity.
The 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 types. 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 color on a white background will look darker, and surrounded by black color - lighter.
Sensitization
There are ways to increase the sensitivity of the senses. This increase in sensitivity is called sensitization. A. R. Luria singled out two sides of increased sensitivity according to the type of sensitization:Having a long-term, permanent character and depending mainly on stable changes occurring in the body,
It is temporary and depends on the physiological and mental state of the person.
The first type of sensitization is closely related to the change in sensitivity. Studies have shown that the acuteness of the sensitivity of the sense organs increases with age, reaching a maximum by the age of 20-30, then stabilization occurs, followed by a decrease in sensitivity to old age.
Synesthesia
Synesthesia is the occurrence under the influence of irritation of one analyzer of a sensation characteristic of another analyzer. For many people, sound waves are able to create the illusion of coloring the surrounding space in one color or another.Synesthesia, according to some assumptions, can serve as the basis of outstanding abilities. Many composers have a so-called color hearing. The well-known mnemonist Sh., who has a phenomenal memory and was studied by A. R. Luria, could characterize the voice of a person as “yellow and crumbly” (sounds of different tones evoked different visual sensations in him).
The phenomena of synesthesia clearly show the close connection of the analyzers with each other.
1.3.1. Cognitive processes. Feeling. Perception. Attention, memory, thinking and speech are among the cognitive processes of a person and provide him with the opportunity to retain the imprinted in his mind, express the latter and transfer it to other people. The human psyche is based on sensory-perceptual processes that provide reflection and perception of the influences of the surrounding reality (sensation, perception, representation and imagination).
Feeling represents the initial stage of human cognition of the surrounding world. According to the dialectical-materialist theory of the reflection of sensation, there is a direct connection between consciousness and the external world, the transformation of the energy of external stimulation into a fact of consciousness.
Sensation is a mental cognitive process of reflection in the mind of a person of individual properties and qualities of objects and phenomena that directly affect his senses. The sense organs are the mechanisms by which information about our environment enters the cerebral cortex. With the help of sensations, the main external signs of objects and phenomena (color, shape, size, features of the surface of objects, sound, taste, etc.) and the state of internal organs (muscle sensations, pain, etc.) are reflected.
Sensations are characterized by: quality - the difference between one type of sensation and another; intensity - the force of impact on the human senses; duration - the time during which the sensation lasts; sensual tone - a feeling of pleasant or unpleasant that is inherent in a given sensation (for example, a sensation of pain or taste, pleasant food).
The physiological basis of sensations is the activity of analyzers, which consist of:
a) from receptors that perceive irritation of the nervous apparatus and are located on the periphery of the central nervous system;
b) conducting, centripetal (afferent) nerve pathways, through which the excitation that occurs in the receptors is transmitted to the corresponding parts of the cerebral cortex of the human brain;
c) the central cortical sections of the analyzers, where the "processing" of the nerve signals coming from the receptors takes place.
Acting on the perceiving organ (receptor), various stimuli (color, sound, touch, movement, etc.) cause excitation in the receptor. This excitation from it is transmitted along the centripetal nerves to the central part of the analyzer, to the human cerebral cortex. Here, each analyzer has a central part, around which there is a mass of nerve cells. The core of each analyzer executes, analyzes and synthesizes the signals coming from the periphery.
The nerve cells of each analyzer, which are part of its nucleus, are located in that part of the brain where there are "entrances" of the centripetal nerves coming from the receptors. In the cerebral cortex, each analyzer is assigned a separate area. The region of the visual analyzer, for example, is located in the occipital lobes of the cerebral cortex; the auditory analyzer area is localized in the middle part of the superior temporal gyrus; motor sensitivity - in the central gyrus.
The constant orientation of a person in the environment is carried out according to the physiological mechanism of the “reflex ring”, which provides a constant feedback of a person with the world around him. The feedback principle discovered by I.M. Sechenov and developed later in the works of I.P. Pavlova, P.K. Anokhin, allows you to understand the beginning and end of the process of sensation according to the laws of reflex activity.
Sensations have certain properties: adaptation, contrast, thresholds of sensations, sensitization, consistent images. If you peer at any object that is far away for a long time, its outlines blur.
1. Adaptation. It is an increase or decrease in the sensitivity of the analyzers as a result of continuous or prolonged exposure to stimuli. Adaptation can manifest itself both as a complete disappearance of sensation during prolonged exposure to a stimulus, and as a decrease or increase in sensitivity under the influence of an irritant.
2. Contrast. The contrast phenomenon consists in the fact that weak stimuli increase sensitivity to other simultaneously acting stimuli, and strong ones decrease this sensitivity.
3. Thresholds of sensations. In order for sensitivity to a stimulus to appear, it must reach a certain intensity. The lower threshold of sensation is the minimum value or strength of the stimulus that can cause nervous excitation in the analyzer sufficient to cause a sensation. The smaller the value of this threshold, the higher the sensitivity of this analyzer.
The upper threshold of sensation is the maximum value of the stimulus, above which this irritation ceases to be felt. A person hears, for example, 20,000 oscillations in 1 second. The absolute threshold of sensation varies from person to person. The value of the threshold of sensations changes with age. In the elderly, the absolute upper threshold of audibility of tones is approximately 15,000 vibrations per 1 s. The magnitude of the absolute threshold can be influenced by the nature of human activity, its functional state, the strength and duration of irritation, etc.
The difference threshold of sensation (distinction threshold) is the minimum difference in the intensity of two homogeneous stimuli that a person is able to feel. In order to catch this difference, it is necessary that it reaches a certain value. For example, sounds of 400-402 oscillations of 1 s are perceived as sounds of the same pitch; 2 loads weighing 500 and 510 g seem equally heavy. The smaller the difference threshold, the higher the differentiation ability of this analyzer to distinguish between stimuli.
4. Sensitization. It is an increase in the sensitivity of analyzers due to an increase in the excitability of the cerebral cortex under the influence of the simultaneous activity of other analyzers. The sensitivity of the analyzer can be increased with the help of pharmacological agents, as well as with the activity of other analyzers; for example, sensations of rhythm contribute to increased musculoskeletal sensitivity. It can also be developed through exercise (for example, musicians develop high auditory sensitivity, tasting experts develop olfactory and gustatory sensations).
5. Consistent images. They are expressed in the continuation of the sensation when the action of the stimulus has already ceased. When feeling, the receptor of one or another sense organ is in a state of excitation for some time. After the cessation of exposure to the stimulus, the excitation in the receptor does not disappear immediately. For example, after exiting the subway car, it seems to us for several seconds that we are still moving in the train.
Any sensation is caused by one or another stimulus, which can be acting from the outside - color, sound, smell, taste; acting from within - hunger, thirst, nausea, suffocation; acting simultaneously from the outside and from the inside - pain.
According to the nature of the action of the stimulus on the receptors, sensations are divided into three groups: exteroceptive, interoreceptive and proprioceptive.
1. Exteroreceptive sensations. Reflect the properties of objects and phenomena of the external environment. These include visual, auditory, taste, temperature and tactile sensations. Visual sensations arise as a result of the action of electromagnetic waves on the human eye. With their help, people are able to distinguish up to 180 tones of color and more than 000 shades in between. Auditory sensations are a reflection in the human mind of the noises emitted by the surrounding objects. With their help, he perceives the speech of other people, controls many types of work, enjoys music, etc. Olfactory sensations are a reflection of the smells that are inherent in certain objects. They help a person to distinguish between volatile substances and odors common in the air. Taste sensations reflect the taste properties of objects: sweet and bitter, salty and sour, etc. They determine the qualitative characteristics of food taken by a person and are highly dependent on the feeling of hunger. Temperature sensations are sensations of heat and cold. Tactile sensations reflect the impact on the surface of the body, including the external and internal mucous membranes. They, together with musculoskeletal, make up the sense of touch, with the help of which a person reflects the qualitative features of objects - their smoothness, roughness, density, as well as the touch of the object to the body, the location and size of the irritated skin area.
2. Interoreceptive sensations. Reflect the state of internal organs. These include the feeling of pain, balance, acceleration, etc. Painful sensations signal damage and irritation of human organs, are a kind of manifestation of the protective functions of the body. The intensity of pain sensations can be different, reaching in some cases great strength, which can even lead to a state of shock. Feelings of Balance provide the vertical position of the human body. They arise as a result of the functional activity of the vestibular analyzer. Sensations of acceleration are sensations that reflect the centrifugal and centripetal forces developing during the movement of a person.
3. Proprioceptive (muscle-motor) sensations. These are sensations that reflect the movement of our body. With the help of muscle-motor sensations, a person receives information: about the position of the body in space, about the relative position of all its parts, about the movement of the body and its parts, about contraction, stretching and relaxation of muscles, etc. Muscular-motor sensations are complex. Simultaneous stimulation of receptors of different quality gives sensations of a peculiar quality: irritation of the receptor endings in the muscles creates a feeling of muscle tone when performing a movement; sensations of muscle tension and effort are associated with irritation of the nerve endings of the tendons; irritation of the receptors of the articular surfaces gives a sense of direction, shape and speed of movement.
Page 8 of 10
ADAPTATION OF THE SENSORS.
Although our sense organs are limited in their ability to perceive signals, nevertheless, they are under the constant influence of stimuli. The brain, which must process the received signals, is often threatened by information overload, and it would not have time to “sort and arrange” it if there were no regulatory mechanisms that maintain the number of perceived stimuli at a more or less constant acceptable level.
This mechanism, called sensory adaptation, operates in the receptors themselves. Sensory adaptation, or adaptation is a change in the sensitivity of the sense organs under the influence of the action of a stimulus. It reduces their sensitivity to repetitive or long-term (weak, strong) stimuli. There are three types of this phenomenon.
1. Adaptation as the complete disappearance of sensation in the process of prolonged action of the stimulus.
In the case of constant stimuli, the sensation tends to fade. For example, a light load lying on the skin soon ceases to be felt. The distinct disappearance of olfactory sensations shortly after we enter an atmosphere with an unpleasant odor is also a common fact. The intensity of the taste sensation weakens if the corresponding substance is kept in the mouth for some time, and finally the sensation may die out altogether.
Full adaptation of the visual analyzer under the action of a constant and immobile stimulus does not occur. This is due to compensation for the immobility of the stimulus due to the movements of the receptor apparatus itself. Constant voluntary and involuntary eye movements ensure the continuity of the visual sensation. Experiments in which the conditions for image stabilization relative to the retina were artificially created showed that in this case, the visual sensation disappears 2–3 seconds after its occurrence, i.e. complete adaptation occurs (stabilization in the experiment was achieved using a special suction cup, on which an image was placed that moved with the eye).
2. Adaptation is also called another phenomenon close to the one described, which is expressed in the dulling of sensation under the influence of a strong stimulus. For example, when a hand is immersed in cold water, the intensity of the sensation caused by a cold stimulus decreases. When we get from a semi-dark room into a brightly lit space (for example, leaving the cinema to the street), we are first blinded and unable to distinguish any details around. After some time, the sensitivity of the visual analyzer decreases sharply, and we begin to see normally. This decrease in the sensitivity of the eye to intense light stimulation is called light adaptation.
The described two types of adaptation can be called negative adaptation, since as a result of them the sensitivity of the analyzers decreases. Negative adaptation- a type of sensory adaptation, expressed in the complete disappearance of sensation in the process of prolonged action of the stimulus, as well as in the dulling of sensation under the influence of the action of a strong stimulus.
3. Finally, adaptation is called an increase in sensitivity under the influence of a weak stimulus. This kind of adaptation, which is characteristic of certain types of sensations, can be defined as positive adaptation. Positive adaptation- a type of increased sensitivity under the influence of the action of a weak stimulus.
In the visual analyzer, this is adaptation to darkness, when the sensitivity of the eye increases under the influence of being in the dark. A similar form of auditory adaptation is silence adaptation. In temperature sensations, positive adaptation is found when a pre-cooled hand feels warm, and a pre-heated hand feels cold when immersed in water of the same temperature. The question of the existence of negative pain adaptation has long been controversial. It is known that repeated use of a painful stimulus does not reveal negative adaptation, but on the contrary, it acts more and more strongly over time. However, new facts indicate the presence of a complete negative adaptation to needle pricks and intense hot irradiation.
Studies have shown that some analyzers detect fast adaptation, others slow. For example, touch receptors adapt very quickly. When exposed to any prolonged stimulus, only a small “volley” of impulses runs through their sensory nerve at the beginning of the stimulus. The visual receptor adapts relatively slowly (the time of tempo adaptation reaches several tens of minutes), the olfactory and gustatory receptors.
Adaptive regulation of the level of sensitivity, depending on which stimuli (weak or strong) affect the receptors, is of great biological importance. Adaptation helps (through the sense organs) to catch weak stimuli and protects the sense organs from excessive irritation in case of unusually strong influences.
The phenomenon of adaptation can be explained by those peripheral changes that occur in the functioning of the receptor with prolonged exposure to a stimulus. So, it is known that under the influence of light, visual purple, located in the rods of the retina, decomposes (fades). In the dark, on the contrary, visual purple is restored, which leads to an increase in sensitivity.
In order for the human eye to be able to fully adapt to darkness after daylight, i.e. it takes 40 minutes for its sensitivity to approach the absolute threshold. During this time, vision changes according to its physiological mechanism: from cone vision, characteristic of daylight, within 10 minutes, the eye passes to rod vision, typical of the night. At the same time, the sensations of color disappear, they are replaced by black and white tones, characteristic of achromatic vision.
With regard to other sense organs, it has not yet been proven that their receptor apparatuses contain any substances that chemically decompose when exposed to a stimulus and are restored in the absence of such exposure.
The phenomenon of adaptation is also explained by the processes taking place in the central sections of the analyzers. With prolonged stimulation, the cerebral cortex responds with internal protective inhibition, which reduces sensitivity. The development of inhibition causes increased excitation of other foci, which contributes to an increase in sensitivity in new conditions (the phenomenon of successive mutual induction).
Another regulatory mechanism is located at the base of the brain, in the reticular formation. It enters into action in the case of more complex stimulation, which, although captured by receptors, is not so important for the survival of the organism or for the activity in which it is currently engaged. We are talking about addiction, when certain stimuli become so habitual that they cease to affect the activity of the higher parts of the brain: the reticular formation blocks the transmission of the corresponding impulses so that they do not “clutter up” our consciousness. For example, the greenery of meadows and foliage after a long winter seems very bright to us at first, and after a few days we get used to it so much that we simply stop noticing it. A similar phenomenon is observed in people living near an airfield or highway. They no longer “hear” the noise of planes taking off or passing trucks. The same thing happens with a city dweller who ceases to feel the chemical taste of drinking water, and on the street does not smell the exhaust gases of cars or does not hear car signals.
Thanks to this useful mechanism (the mechanism of habituation), it is easier for a person to notice any change or a new element in the environment, it is easier to concentrate his attention on it, and, if necessary, to resist it. This kind of mechanism allows us to focus all our attention on some important task, ignoring the usual noise and bustle around us.
Speaking about the properties of sensations, we cannot but dwell on a number of phenomena associated with sensations. It would be wrong to assume that absolute and relative sensitivity remain unchanged and their thresholds are expressed in constant numbers. Studies show that sensitivity can vary over a very wide range. For example, in the dark, our vision becomes sharper, and in strong light, 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 both cases, the person is temporarily "blind", it takes some time for the eyes to adjust to bright light or darkness. This suggests that, depending on the environment (illumination), the visual sensitivity of a person changes dramatically. Studies have shown that this change is very large and the sensitivity of the eye in the dark is aggravated by 200,000 times.
The described changes in sensitivity, depending on environmental conditions, are associated with the phenomenon of sensory adaptation. Sensory adaptation is called a change in sensitivity that occurs as a result of the adaptation of the sense organ to the stimuli acting on it. As a rule, adaptation is expressed in the fact that when sufficiently strong stimuli act on the sense organs, sensitivity decreases, and when weak stimuli or in the absence of a stimulus act, sensitivity increases.
Such a change in sensitivity does not occur immediately, but requires a certain time. Moreover, the time characteristics of this process are not the same for different sense organs. So, in order for vision in a dark room to acquire the necessary sensitivity, about 30 minutes should pass. Only after that a person acquires the ability to navigate well in the dark. The adaptation of the auditory organs is much faster. Human hearing adapts to the surrounding background after 15 seconds. Just as quickly, there is a change in the sensitivity of touch (a weak touch on the skin ceases to be perceived after a few seconds).
Phenomena well known thermal adaptation (getting used to changes in ambient temperature). However, these phenomena are clearly expressed only in the middle range, and addiction to extreme cold or extreme heat, as well as to pain stimuli, is almost never encountered. The phenomena of adaptation to smells are also known.
The adaptation of our sensations mainly depends on the processes occurring in the receptor itself. So, for example, under the influence of light, visual purple, located in the rods of the retina, decomposes (fades). In the dark, on the contrary / visual purple is restored, which leads to an increase in sensitivity. However, the phenomenon of adaptation is also associated with the processes taking place in the central sections of the analyzers, in particular with a change in the excitability of the nerve centers. With prolonged stimulation, the cerebral cortex responds with internal protective inhibition, which reduces sensitivity. The development of inhibition causes increased excitation of other foci, contributing to an increase in sensitivity in new conditions. In general, adaptation is an important process, indicating a greater plasticity of the organism in its adaptation to environmental conditions.
There is another phenomenon that we must consider. All types of sensations are not isolated from each other, therefore the intensity of sensations depends not only on the strength of the stimulus and the level of adaptation of the receptor, but also on the stimuli currently affecting other sense organs. A change in the sensitivity of the analyzer under the influence of irritation of other sense organs is called the interaction of sensations.
should be distinguished two types of interaction of sensations:
- interaction between sensations of the same kind,
- interaction between different types of sensations.
Interactions between sensations of different types can be illustrated by the studies of Academician P.P. Lazarev, who found that eye lighting makes audible sounds louder. Similar results were obtained by Professor S. V. Kravkov. He established that no sense organ can work without affecting the functioning of other organs. So, it turned out that sound stimulation (for example, whistling) can sharpen the work of visual sensation, increasing its sensitivity to light stimuli. Some odors also affect in a similar way, increasing or decreasing light and auditory sensitivity. All our analyzer systems are capable of influencing each other to a greater or lesser extent. At the same time, the interaction of sensations, like adaptation, manifests itself in two opposite processes - an increase and a decrease in sensitivity. The general pattern is that weak stimuli increase, and strong ones decrease the sensitivity of the analyzers during their interaction.
A similar picture can be observed in the interaction of sensations of the same kind. For example, a point in the dark is easier to see against a light background. As an example of the interaction of visual sensations, one can cite the phenomenon of contrast, which is expressed in the fact that the color changes in the opposite direction in relation to the colors surrounding it. For example, a gray color on a white background will look darker, and surrounded by black color will look lighter.
As follows from the above examples, there are ways to increase the sensitivity of the senses. An increase in sensitivity as a result of the interaction of analyzers or exercises is called sensitization. A. R. Luria distinguishes two sides of increased sensitivity according to the type of sensitization. The first is of a long-term, permanent nature and depends mainly on stable changes occurring in the body, so the age of the subject is clearly associated with a change in sensitivity. Studies have shown that the acuteness of the sensitivity of the sense organs increases with age, reaching a maximum by the age of 20-30, in order to gradually decrease in the future. The second side of the increase in sensitivity according to the type of sensitization is temporary and depends on both physiological and psychological emergency effects on the subject's condition.
The interaction of sensations is also found in a phenomenon called synesthesia- the appearance under the influence of irritation of one analyzer of a sensation characteristic of other analyzers. In psychology, the facts of “colored hearing” are well known, which occurs in many people, and especially in many musicians (for example, in Scriabin). So, it is widely known that we regard high sounds as “light”, and low ones as “dark”.
In some people, synesthesia manifests itself with exceptional clarity. One of the subjects with exceptionally pronounced synesthesia - the famous mnemonist Sh. - was studied in detail by A. R. Luria. This person perceived all voices as colored and often said that the voice of a person addressing him, for example, was “yellow and crumbly.” The tones he heard caused him visual sensations of various shades (from bright yellow to purple). Perceived colors were perceived by him as "sonorous" or "deaf", as "salty" or "crunchy". Similar phenomena in more obliterated forms occur quite often in the form of a direct tendency to "color" numbers, days of the week, names of months in different colors. The phenomena of synesthesia are another evidence of the constant interconnection of the analyzer systems of the human body, the integrity of the sensory reflection of the objective world.
A separate area of psychology studies the phenomenon of sensitization - a peculiar process of increasing the sensitivity of receptors depending on the constant exposure to a specific stimulus.
As a rule, this process is also accompanied by a natural mechanism of sensor adaptation. In other words, sensitization of the organism is an increased sensitivity due to the coordinated work of the analyzers or regular exercises.
Indeed, sensitization can occur not only as a response to the influence of various natural stimuli, but also as a result of regular targeted exercises, forming in the form of compensation. In general, there are two mechanisms for the formation of such sensitization: a violation of one of the analyzers or the specifics of the activity.
For example, blindness is a violation of the work of visual analyzers. As a rule, with the development of this pathology, a compensatory reaction occurs, which manifests itself in the form of increased sensitivity, that is, sensitization of analyzers of another series. Another option for the formation of sensitization is the development of receptor sensitivity as a result of the body's adaptability to a certain specificity of constant work.
Sensitivity of sensations
A number of sensations of the human body almost always undergo changes due to the influence of the environment or changes in the body itself. By definition, sensation is the simplest mental process. It is a combination of displaying a separate set of characteristics of objects, phenomena and effects of the surrounding world, as well as the internal state of the organism itself, which is a consequence of receptor irritation by all external factors.
The sensitivity of sensations from the point of view of psychology is an increase in sensitivity, an increase in sensitization, due to the directed regular exposure to stimuli from the outside world.
It should also be noted the concept of "interaction of sensations", which implies the possibility of changing the sensitivity of one specific receptor as a result of the influence of various stimuli on another group of receptors. This regularity finds its expression in another fact: a strong and intense effect of the stimulus on the receptor over time has a suppressing effect on its sensitivity, while a weak effect enhances it.
The term increased sensitization of the body is also understood as an increase in the irritability of a certain type of receptors under the influence of a number of factors of a purely psychological nature.
These most often include:
- General work of receptor complexes and their further interaction with each other. With a weak saturation of one particular factor and modality, the saturation of another increases. For example, with a slight cooling of the skin surface, increased light sensitivity can be observed.
- Various psychological settings. Among them is self-persuasion or a recapitulation of previously experienced experience, which can set you up for the clearest feeling of one or another stimulus expected in the near future. A striking example is the fear of visiting the dentist, which can increase toothache.
- Previous experience. This means that certain groups of analyzers acquire increased sensitivity in the course of the practice of some specific activity. For example, experienced musicians are able to determine the relative duration of a note by ear, and tasters can identify the specifics of a drink or food by taste.
- The use of pharmacological drugs from a number or groups that can enhance the perception of a particular kind of stimulus.
As a result of too high excitation and an increase in the sensitivity of one analyzer system, a corresponding decrease in the same characteristics is observed in the other system. The process of interactions of purely physiological sensations is based on the mechanisms of irradiation and concentration of excitation in the cerebral cortex, where the centers of all groups of analyzers are located.
Knowledge of the patterns of interaction of receptors, as well as the increase and decrease in their sensitization, make various methods of treatment possible. They are produced by using one or another set of various kinds of artificial or natural stimuli, selected in the required quantity, quality, and with given configurations.
By influencing such a "set" of stimuli with a specifically given strength and intensity, one can experimentally increase or decrease the sensitization of the desired type of analyzers. This technique is increasingly recommended in the fight against alcohol or drug addiction.
Sensitization and adaptation process
In psychology and physiology, two main forms of sensitivity change are distinguished, which are conventionally called sensitization and adequacy. The difference between adaptation and sensitization is that adaptation processes are oriented directly to external factors and conditions. While sensitization depends on the internal state of the body.
It should also be noted that adaptation can be more clearly expressed in changes in the sensitivity of various external analyzers, for example, auditory or visual, being an indicator of the "plasticity" of the organism. In other words, adaptation is a kind of balancing mechanism that ensures the most optimal functioning of the body's receptors under conditions of environmental changes, as well as their protection from overload. In most cases, adaptation occurs almost instantly, however, in especially extreme situations, three stages of adaptation can be distinguished: superficial decompensation, partial, and then a deep stage of compensation.
It is also important that all changes in the body that accompany the processes of adaptation relate to almost all levels of physiology. Thus, the effectiveness and speed of adaptation can directly depend on the physical fitness, mental and general state of the body itself.
Thus, sensitization and the process of adaptation are quite clearly interconnected with each other, as well as with a change in the sensitivity of the analyzers. Widespread methods of sensitization and desensitization are based on this relationship.
The desensitization technique is an artificial stimulation of receptors, the activity of which inhibits the activity of another group of receptors, which are "anxious". In other words, this is a targeted activation of antagonist receptors. When a reaction is triggered in the body. Which is inherently incompatible with the stimulus that previously caused only anxiety, the connection between the alarming stimulus and its specific receptors is weakened.
In contrast, the method of sensitization is the induction of anxiety through the use of stress-causing factors and stimuli, as a result of which the patient experiences fear or stress. This technique makes it possible for a person to adapt to extreme or stressful conditions that he may encounter in the future, in experimental, laboratory conditions.
