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Introduction

Variability in the sensitivity of analyzers and its causes

Conclusion

Literature

Introduction

We learn about the richness of the world around us, about sounds and colors, smells and temperature, size and much more through the senses. Through the senses human body receives in the form of sensations a variety of information about the state of the external and internal environment.

Sensation is the simplest mental process, consisting in the reflection of individual properties of objects and phenomena of the material world, as well as internal states organism under the direct action of stimuli on the corresponding receptors.

The sense organs receive, select, accumulate information and transmit it to the brain, which receives and processes this huge and inexhaustible stream every second. As a result, there is an adequate reflection of the surrounding world and the state of the organism itself.

Sensations are a form of reflection of adequate stimuli. An adequate exciter of visual sensation is electromagnetic radiation, characterized by wavelengths in the range from 380 to 770 millimicrons, which are transformed in the visual analyzer into a nervous process that generates a visual sensation. Auditory sensations are the result of exposure to receptors of sound waves with an oscillation frequency of 16 to 20,000 Hz. Tactile sensations are caused by the action of mechanical stimuli on the surface of the skin. Vibratory, which acquire special significance for the deaf, are caused by the vibration of objects. Other sensations (temperature, olfactory, taste) also have their own specific stimuli. However, different types of sensations are characterized not only by specificity, but also by properties common to them. These properties include quality, intensity, duration, and spatial localization.

Variability in the sensitivity of analyzers and its causes

Quality is the main feature of a given sensation, distinguishing it from other types of sensations and varying within a given type. Auditory sensations differ in pitch, timbre, loudness; visual - by saturation, color tone, etc. The qualitative variety of sensations reflects the infinite variety of forms of motion of matter.

The intensity of sensation is its quantitative characteristic and is determined by the strength of the acting stimulus and the functional state of the receptor.

The duration of a sensation is its temporal characteristic. It is also determined by the functional state of the sense organ, but mainly by the duration of the stimulus and its intensity. When a stimulus is applied to a sense organ, sensation does not occur immediately, but after some time, which is called the latent (hidden) period of sensation. The latent period for different types of sensations is not the same: for tactile sensations, for example, it is 130 milliseconds, for pain - 370 milliseconds. The taste sensation occurs 50 milliseconds after the application of a chemical stimulus to the surface of the tongue.

Just as a sensation does not arise simultaneously with the beginning of the action of the stimulus, it does not disappear simultaneously with the termination of its action. This inertia of sensations is manifested in the so-called aftereffect.

The visual sensation has some inertia and does not disappear immediately after the stimulus that caused it ceases to act. The principle of cinematography is based on the inertia of vision, on the preservation of a visual impression for some time.

A similar phenomenon occurs in other analyzers. For example, auditory, temperature, pain and taste sensations also continue for some time after the action of the stimulus.

Sensations are also characterized by the spatial localization of the stimulus. Spatial analysis, carried out by distant receptors, gives us information about the localization of the stimulus in space. Contact sensations (tactile, pain, taste) correspond to that part of the body that is affected by the stimulus. At the same time, the localization of pain sensations is diffuse and less accurate than tactile ones.

Various sense organs that give us information about the state of the external world around us can display these phenomena with greater or lesser accuracy. The sensitivity of the sense organ is determined by the minimum stimulus that, under given conditions, is capable of causing a sensation. The minimum strength of the stimulus that causes a barely noticeable sensation is called the lower absolute threshold of sensitivity.

Irritants of lesser strength, the so-called subthreshold ones, do not cause sensations, and signals about them are not transmitted to the cerebral cortex. Bark in each separate moment of an infinite number of impulses, it perceives only vital ones, delaying all the rest, including impulses from internal organs. This position is biologically reasonable. It is impossible to imagine the life of an organism in which the cortex hemispheres would equally perceive all impulses and provide reactions to them. This would lead the body to inevitable death.

The lower threshold of sensations determines the level of absolute sensitivity of this analyzer. There is an inverse relationship between absolute sensitivity and the threshold value: the lower the threshold value, the higher the sensitivity of this analyzer.

Our analyzers have different sensitivities. The threshold of one human olfactory cell for the corresponding odorous substances does not exceed 8 molecules. It takes at least 25,000 times more molecules to produce a taste sensation than it does to create an olfactory sensation.

The sensitivity of the visual and auditory analyzer is very high. The human eye, as shown by the experiments of S.I. Vavilov, is able to see light when only 2 - 8 quanta of radiant energy hit the retina. This means that we would be able to see a burning candle in complete darkness at a distance of up to 27 kilometers. At the same time, in order for us to feel touch, we need 100-10,000,000 times more energy than with visual or auditory sensations.

The absolute sensitivity of the analyzer is limited not only by the lower, but also by the upper threshold of sensation. The upper absolute threshold of sensitivity is the maximum strength of the stimulus at which a sensation adequate to the acting stimulus still arises. A further increase in the strength of stimuli acting on our receptors causes only a painful sensation in them (for example, a very loud sound, blinding brightness).

The value of absolute thresholds, both lower and upper, varies depending on various conditions: the nature of the activity and growth of a person, the functional state of the receptor, the strength and duration of irritation, etc.

With the help of the sense organs, we can not only ascertain the presence or absence of a particular stimulus, but also distinguish stimuli by their strength and quality. The minimum difference between two stimuli that causes a barely noticeable difference in sensations is called the discrimination threshold or difference threshold.

Difference sensitivity, or discrimination sensitivity, is also inversely related to the difference threshold value: the higher the discrimination threshold, the lower the difference sensitivity.

Feeling occurs as a reaction nervous system to one or another stimulus and has a reflex character. The physiological basis of sensation is a nervous process that occurs when a stimulus acts on an analyzer adequate to it.

The analyzer consists of three parts: 1) a peripheral section (receptor), which is a special transformer of external energy into the nervous process; 2) afferent (centripetal) and efferent (centrifugal) nerves - pathways connecting the peripheral section of the analyzer with the central one; 3) subcortical and cortical sections (brain end) of the analyzer, where the processing of nerve impulses coming from the peripheral sections takes place.

For a sensation to arise, the work of the entire analyzer as a whole is necessary. The impact of the stimulus on the receptor causes the appearance of irritation. The beginning of this irritation is expressed in the transformation of external energy into a nervous process, which is produced by the receptor. From the receptor, this process along the centripetal nerve reaches the nuclear part of the analyzer. When excitation reaches the cortical cells of the analyzer, the body responds to irritation. We sense light, sound, taste, or other qualities of stimuli.

The analyzer constitutes the initial and most important part of the entire path of nervous processes, or the reflex arc. The reflex ring consists of a receptor, pathways, a central part, and an effector. The interconnection of the elements of the reflex ring provides the basis for the orientation of a complex organism in the surrounding world, the activity of the organism, depending on the conditions of its existence.

The process of visual sensation not only begins in the eye, but also ends in it. The same is true for other analyzers. Between the receptor and the brain there is not only a direct (centripetal), but also a reverse (centrifugal) connection. The feedback principle discovered by I.M. Sechenov, requires the recognition that the sense organ is alternately a receptor and an effector. Sensation is not the result of a centripetal process; it is based on a complete and, moreover, complex reflex act, which, in its formation and course, obeys the general laws of reflex activity.

The dynamics of the processes occurring in such a reflex ring is a kind of assimilation to the properties of an external influence. For example, touch is just such a process in which the movements of the hands repeat the outlines of a given object, as if becoming like its shape. The eye operates on the same principle due to the combination of the activity of its optical “device” with oculomotor reactions. The movements of the vocal cords also reproduce the objective pitch nature. When the vocal-motor link was turned off in the experiments, the phenomenon of a kind of pitch deafness inevitably arose. Thus, due to the combination of sensory and motor components, the sensory (analyzing) apparatus reproduces the objective properties of the stimuli affecting the receptor and is likened to their nature.

The sense organs are, in fact, energy filters through which the corresponding changes in the environment pass.

According to one of the hypotheses, which is closest to me, the selection of information in sensations occurs on the basis of the criterion of novelty. Indeed, in the work of all sense organs there is an orientation to the change in stimuli. Under the action of a constant stimulus, the sensitivity seems to be dulled and the signals from the receptors cease to flow to the central nervous apparatus. Thus, the sensation of touch tends to fade away. It can completely disappear if the irritant suddenly stops moving across the skin. Sensitive nerve endings signal the brain that irritation is present only when the strength of the irritation changes, even if the time during which it presses harder or weaker on the skin is very short.

The facts testifying to the extinction of the orienting reaction to a constant stimulus were obtained in the experiments of E.N. Sokolov. The nervous system finely models the properties of external objects acting on the sense organs, creating their neural models. These models perform the function of a selectively acting filter. If the stimulus acting on the receptor does not match in this moment Mismatch impulses appear with the previously formed nervous model, causing an orienting reaction. Conversely, the orienting reaction fades to the stimulus that was previously used in the experiments.

The sensitivity of analyzers, determined by the magnitude of absolute thresholds, is not constant and changes under the influence of a number of physiological and psychological conditions, among which the phenomenon of adaptation occupies a special place.

Adaptation, or adaptation, is a change in the sensitivity of the sense organs under the influence of the action of a stimulus.

Three varieties of this phenomenon can be distinguished.

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 resting 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 stabilization1 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.

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 sensation caused by a temperature stimulus decreases. When we move from a semi-dark room into a brightly lit space, we are at 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 combined with the term negative adaptation, since as a result of them the sensitivity of the analyzers decreases.

3. 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.

In the visual analyzer, this is dark adaptation, when the sensitivity of the eye increases under the influence of being in the dark. A similar form of auditory adaptation is silence adaptation.

Adaptive regulation of the level of sensitivity, depending on which stimuli (weak or strong) affect the receptors, is of great biological importance. Adaptation helps to catch weak stimuli through the sense organs 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 during 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. In the dark, on the contrary, visual purple is restored, which leads to an increase in sensitivity. 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 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.

The literature describes numerous facts of sensitivity changes caused by the interaction of sensations. Thus, the sensitivity of the visual analyzer changes under the influence of auditory stimulation.

Weak sound stimuli increase the color sensitivity of the visual analyzer. At the same time, it is observed sharp deterioration the distinctive sensitivity of the eye when, for example, the loud noise of an aircraft engine is used as an auditory stimulus.

Visual sensitivity also increases under the influence of certain olfactory stimuli. However, with a pronounced negative emotional coloring of the smell, a decrease in visual sensitivity is observed. Similarly, with weak light stimuli, auditory sensations are enhanced, and exposure to intense light stimuli worsens auditory sensitivity. There are known facts of increasing visual, auditory, tactile and olfactory sensitivity under the influence of weak pain stimuli.

A change in the sensitivity of any analyzer is also observed with subthreshold stimulation of other analyzers. So, P.P. Lazarev (1878-1942) obtained evidence of a decrease in visual sensitivity under the influence of skin irradiation with ultraviolet rays.

Thus, 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 here is that weak stimuli increase and strong ones decrease the sensitivity of the analyzers during their interaction.

The interaction of sensations is manifested in another kind of phenomena called synesthesia. Synesthesia is the occurrence under the influence of irritation of one analyzer of a sensation characteristic of another analyzer. Synesthesia is seen in most various types sensations. The most common visual-auditory synesthesia, when, under the influence of sound stimuli, the subject has visual images. At various people there is no overlap in these synesthesias, however, they are fairly constant for each individual.

The phenomenon of synesthesia is based on the creation in last years color-musical devices that turn sound images into color ones. Less common are cases of auditory sensations when exposed to visual stimuli, taste sensations in response to auditory stimuli, etc. Not all people have synesthesia, although it is quite widespread. The phenomenon of synesthesia is another evidence of the constant interconnection of the analyzer systems of the human body, the integrity of the sensory reflection of the objective world.

An increase in sensitivity as a result of the interaction of analyzers and exercise is called sensitization.

The physiological mechanism for the interaction of sensations is the processes of irradiation and concentration of excitation in the cerebral cortex, where the central sections of the analyzers are represented. According to I.P. Pavlov, a weak stimulus causes an excitation process in the cerebral cortex, which easily irradiates (spreads). As a result of the irradiation of the excitation process, the sensitivity of another analyzer increases. Under the action of a strong stimulus, a process of excitation occurs, which, on the contrary, has a tendency to concentration. According to the law of mutual induction, this leads to inhibition in the central sections of other analyzers and a decrease in the sensitivity of the latter.

Changes in the sensitivity of the analyzers can be caused by exposure to secondary signal stimuli. Thus, the facts of changes in the electrical sensitivity of the eyes and tongue in response to the presentation of the words "sour as a lemon" to the subjects were obtained. These changes were similar to those observed when the tongue was actually irritated with lemon juice.

Knowing the patterns of changes in the sensitivity of the sense organs, it is possible, by using specially selected side stimuli, to sensitize one or another receptor, i.e. increase its sensitivity.

Sensitization can also be achieved through exercise.

The possibilities for training the sense organs and their improvement are very great. Two areas can be distinguished that determine the increase in the sensitivity of the sense organs: 1) sensitization, which spontaneously leads to the need to compensate for sensory defects (blindness, deafness) and 2) sensitization caused by activity, the specific requirements of the subject's profession.

Loss of sight or hearing is compensated to a certain extent by the development of other types of sensitivity.

sensitivity analyzer sensation stimulus

Conclusion

Of particular interest is the emergence in humans of sensitivity to stimuli for which there is no adequate receptor. Such, for example, is the remote sensitivity to obstacles in the blind.

The phenomena of sensitization of the sense organs are observed in persons who have been engaged in certain special professions for a long time. Experienced pilots can easily determine the number of engine revolutions by ear. They freely distinguish between 1300 and 1340 rpm. Untrained people catch the difference only between 1300 and 1400 rpm.

All this is proof that our sensations develop under the influence of the conditions of life and the requirements of practical labor activity.

Despite a large number of such facts, the problem of exercising the sense organs has not yet been sufficiently studied. Studying it will significantly expand the abilities of a person!

Literature:

1. Nemov R.S. Psychology. In 3 books. Book 1. General foundations of psychology. - M .: VLADOS, 2000.

2. General psychology. /Under the editorship of A.V. Petrovsky. - M.: Enlightenment, 1991

3. Fundamentals of psychology. Workshop / Ed.-comp. L.D. Stolyarenko. Rostov n / a, 1999.

4. Rubinstein S.L. Basics general psychology. - in 2 volumes - M., 1984.

5. Stolyarenko L.D. Fundamentals of psychology. - Rostov-on-Don: Phoenix, 1997.

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The lower threshold of sensations - the smallest amount of stimulus that causes a barely perceptible sensation. The upper threshold of sensations - the maximum value of the stimulus that the analyzer is able to perceive adequately. Sensitivity range - the interval between the lower and upper threshold of sensations.

Differential threshold - the smallest difference between stimuli, when the difference between them is still captured (Weber's law).

Operational threshold - the amount of difference between signals at which the accuracy and speed of discrimination reach a maximum. The value of the operational threshold is 10-15 times greater than the value of the differential threshold.

Time threshold - the minimum duration of exposure to a stimulus required for a sensation to occur.

The latent period of the reaction - the time interval from the moment the signal is given to the moment the sensation occurs.

inertia - the time of disappearance of sensation after the end of exposure.

In order to effectively influence a person, it is necessary to take into account the characteristics of his analyzers, which are determined empirically (for example, a change in the rate of speech) or have already been determined and fixed in special literature. It is known, for example, that the inertia of vision in normal person is 0.1-0.2 sec, so the duration of the signal and the interval between the appearing signals should not be less than the time of preservation of sensations, equal to 0.2-0.5 sec. Otherwise, the speed and accuracy of the response will slow down, since during the arrival of a new signal, a person will still have an image of the previous one.

In the process of communication - the feeling of a person by a person - there is also inertia, dictating its own "law": as long as you see that the perception of your "old" image is still fresh in your memory, do not strive to quickly and obsessively manifest yourself in a new quality: this is explained by the fact that an adequate reaction will not follow, and the more impressionable the person who is affected, the more inert it will react to changes.

Feelings and their adequacy, or, in other words, the psychological capabilities of a person to receive information, are most important in the activities of those people whose work requires a high degree of accuracy: engineers, doctors, etc.

The sensitivity of the analyzers is not constant and changes under the influence of physiological and psychological conditions. The sense organs have the property fixtures, or adaptation. 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.

The intensity of sensations depends not only on the strength of the stimulus and the level of adaptation of the receptors, but also on the stimuli currently affecting other sense organs. A change in the sensitivity of analyzers under the influence of irritation of other sense organs is called the interaction of sensations. The interaction of sensations is manifested in an increase and decrease in sensitivity: weak stimuli increase the sensitivity of the analyzers, and strong ones decrease it.

The interaction of sensations is manifested in the phenomena of sensitization and synesthesia. Sensitization(lat. sensibilis - sensitive) - increased sensitivity of nerve centers under the influence of an irritant. Sensitization can develop not only through the use of adverse stimuli, but also through exercise. Thus, musicians develop high auditory sensitivity, tasters develop olfactory and gustatory sensations. Synesthesia - this is the emergence under the influence of irritation of some analyzer of a sensation characteristic of another analyzer. So, when exposed to sound stimuli, a person may experience visual images.

Perception, its types and properties

Perception is a holistic reflection of objects and phenomena of the objective world with their direct impact at the moment on the senses. Together with the processes of sensation, perception provides a direct sensory orientation in the surrounding world. Perception is the result of the activity of the system of analyzers; it involves the selection of the complex of influencing features of the main and most significant, with a simultaneous distraction from the non-essential. Perception makes it possible to create an integral picture of reality, in contrast to sensations that reflect individual qualities of reality.

Since perception requires combining the main essential features and comparing what is perceived with past experience, the phenomenon arises. stereotyping. A stereotype is a definite, stable for a given period of time, representation of an object or phenomenon.

Perception is subjective, since people perceive the same information in different ways, depending on their interests, needs, abilities, etc. The dependence of perception on past experience, on the general content of a person’s mental activity and his individual characteristics is called apperception.

Perceptual Properties

Integrity - internal organic relationship of parts and the whole in the image. This property is manifested in two aspects: a) the union of different elements as a whole; b) the independence of the formed whole from the quality of its constituent elements.

Objectivity - the object is perceived by us as a separate physical body isolated in space and time. This property is most clearly manifested in the mutual isolation of the figure and the background.

Generalization - assignment of each image to a certain class of objects.

Constancy - relative constancy of image perception. Our perception, within certain limits, preserves their size, shape and color for the parameters, regardless of the conditions of perception (distance to the perceived object, lighting conditions, angle of perception).

Meaningfulness - connection with understanding the essence of objects and phenomena through the process of thinking.

Selectivity - preferential selection of some objects over others in the process of perception.

Perception is divided into the following types:

perception of objects and phenomena of the surrounding world;

perception of a person by a person;

perception of time;

perception of movements;

perception of space;

perception of the activity.

Perceptions time, movement And space - This complex shapes perceptions that have numerous characteristics: long - short-term, large - small, high - low, distant - close, fast - slow. Perception activities subdivided by type: artistic, technical, musical, etc.

Perceptions are outwardly directed(perception of objects and phenomena of the external world), and internally directed(perception of one's own thoughts and feelings).

According to the time of occurrence of perception, there are relevant And irrelevant.

Perception can be erroneous (illusory). Illusion is a distorted perception of a really existing reality. Illusions are found in the activities of various analyzers. The best known visual illusions, which have a variety of reasons: practical experience, features of analyzers, changes in familiar conditions. For example, due to the fact that the vertical movement of the eyes requires more effort than the horizontal movement, there is an illusion of perception of straight lines of the same length, located differently: it seems to us that the vertical lines are longer than the horizontal ones.

Perception can be not only erroneous, but also ineffective. Empirically, one can be convinced that the level of perception of the text when reading it by speaking aloud is much lower than when reading to oneself. The fact is that the bandwidth of hearing is lower than the bandwidth of vision.

Sensation and perception are processes, the sharpness of which can be developed by working on oneself and performing a series of special exercises. In order to train the eye, it is recommended to practice for several days, dividing a straight line in half on a clean (unlined) sheet of paper. 10 exercises should be carried out daily and the magnitude of deviations should be recorded.

In order to increase the speed of reading and get rid of the habit of saying what you are reading, you can use the following exercise: for several days, read a literary text to yourself for three minutes, saying the following aloud: "one, two, three." This is necessary in order to prevent the pronunciation of the text.

The development of perception has great importance for learning activities. Developed perception helps to assimilate a larger amount of information with a lesser degree of energy costs.

Chapter 2

Various sense organs that give us information about the state of the external world around us can be sensitive to the displayed phenomena with greater or lesser accuracy.

The sensitivity of our sense organs can vary within very large limits. There are two main forms of sensitivity variability, one of which depends on environmental conditions and is called adaptation, and the other depends on the conditions of the state of the organism and is called sensitization.

Adaptation- adaptation of the analyzer to the stimulus. It is known that in the dark our vision becomes sharper, and in strong light its sensitivity decreases. This can be observed during the transition from darkness to light: the human eye begins to experience pain, the person temporarily “blinds”.

The most important factor influencing the level of sensitivity is the interaction of the analyzers. Sensitization- this is an increase in sensitivity as a result of the interaction of analyzers and exercises. This phenomenon must be used when driving. So, the weak effect of side stimuli (for example, sponging cold water face, hands, back of the head, or slowly chewing a sweet and sour tablet, such as ascorbic acid) increases the sensitivity of night vision, which is very important when driving at night.

Various analyzers have different adaptability. There is practically no adaptation of a person to pain sensation, which is of great biological importance, since pain sensation is a signal of trouble in the body.

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 sensitivity in touch (a slight touch on the skin ceases to be perceived after a few seconds).

It is known that the conditions of activity associated with the constant re-adaptation of analyzers cause rapid fatigue. For example, driving a car at night on a motorway with changing illumination of the roadway.

A more significant and constant influence on the senses in the process of driving a car is exerted by such factors as noise and vibration.

Constant noise (and the noise generated by the movement of the car, as a rule, is constant) has a negative effect on the hearing organs. In addition, under the influence of noise, the latent period of the motor reaction lengthens, visual perception decreases, twilight vision weakens, coordination of movements and functions of the vestibular apparatus are disturbed, and premature fatigue occurs.

The change in the sensitivity of the sense organs also changes with the age of a person. Already after 35 years, visual acuity and its adaptation generally decrease, and hearing deteriorates. And although many drivers attribute this to poor lighting, weak headlights, the fact remains that their eyes do not see equally well. With age, they not only see worse, but are also more easily blinded, and the field of vision narrows more often.

Consider now the effects of alcohol and other psychoactive and medicines on human mental activity.

When taking sleeping pills, sedatives, antidepressants, anticonvulsants (phenobarbital) and antiallergic drugs (pipolfen, tavegil, suprastin), drowsiness, dizziness, decreased attention and reaction time occur. Harmless cough or headache medicines can depress the central nervous system, reducing attention and slowing down the reaction rate. First of all, these are drugs containing codeine (tramadol, tramalt, retard, pentalgin, spasmoveralgin, sedalgin).

Thus, you should carefully study the instructions for the drug that the driver is going to take before driving.

Consider now the effect of alcohol on driving. Although the Rules of the Road prohibit driving while intoxicated, in our country, unfortunately, there is a strong tradition of doubting the correctness of the actions and / or the result of an examination for intoxication. Believing that “I am fine,” the driver gets behind the wheel drunk and puts other people and himself in danger.

So, studies have found significant impairment of the functions of the nervous system even from fairly small doses of alcohol. Objectively established a noticeable weakening of the functions of all the senses from very small doses of alcohol, including beer.

Under the influence of medium doses, that is, one to one and a half glasses of vodka, motor acts are accelerated at first, and then slow down. Another feeling that is easily lost by a drunk person is the feeling of fear.

In addition, it should be borne in mind that when the temperature drops by 5 °, the harmful effect of alcohol increases almost tenfold! But people are sure that alcohol has a warming effect, and they believe that for a frozen person, a sip of something strong is the best medicine.

Thus, our ability to see, hear, feel is influenced by many things familiar to us: light and darkness, drugs, alcohol. When driving a car, it is necessary to take this into account in order to avoid dangerous situations and accidents.

The world around us, its beauty, sounds, colors, smells, temperature, size and much more we learn through the senses. With the help of the sense organs, the human body receives in the form of sensations a variety of information about the state of the external and internal environment.

SENSATION is a simple mental process, which consists in reflecting the individual properties of objects and phenomena of the surrounding world, as well as the internal states of the body with the direct action of stimuli on the corresponding receptors.

The sense organs are irritated. It is necessary to distinguish between stimuli that are adequate for a particular sense organ and inadequate for it. Sensation is the primary process from which the knowledge of the surrounding world begins.

SENSATION is a cognitive mental process of reflection in the human psyche of individual properties and qualities of objects and phenomena with their direct impact on his senses.

The role of sensations in life and cognition of reality is very important, since they constitute the only source of our knowledge about the external world and about ourselves.

The physiological basis of sensations. Sensation occurs as a reaction of the nervous system to a particular stimulus. The physiological basis of sensation is a nervous process that occurs when a stimulus acts on an analyzer adequate to it.

The sensation has a reflex character; physiologically it provides the analyzer systems. The analyzer is a nervous apparatus that performs the function of analyzing and synthesizing stimuli that come from the external and internal environment of the body.

ANALYZERS- these are the organs of the human body that analyze the surrounding reality and single out certain or other types of psycho-energy in it.

The concept of analyzer was introduced by I.P. Pavlov. The analyzer consists of three parts:

The peripheral section is a receptor that converts a certain type of energy into a nervous process;

Afferent (centripetal) pathways that transmit the excitation that has arisen in the receptor in the higher centers of the nervous system, and efferent (centrifugal), along which impulses from the higher centers are transmitted to lower levels;

Subcortical and cortical projective zones, where the processing of nerve impulses from the peripheral regions takes place.

The analyzer constitutes the initial and most important part of the entire path of nervous processes, or the reflex arc.

Reflex arc = analyzer + effector,

An effector is a motor organ (a certain muscle) that receives a nerve impulse from the central nervous system (brain). The relationship of the elements of the reflex arc provides the basis for the orientation of a complex organism in the environment, the activity of the organism, depending on the conditions of its existence.

For a sensation to arise, the work of the entire analyzer as a whole is necessary. The action of the stimulus on the receptor causes the appearance of irritation.

Classification and varieties of sensations, There are various classifications sensory organs and sensitivity of the body to stimuli entering the analyzers from the outside world or from within the body.

Depending on the degree of contact of the sense organs with stimuli, contact (tangential, gustatory, pain) and distant (visual, auditory, olfactory) sensitivity are distinguished. Contact receptors transmit irritation through direct contact with objects that affect them; such are the tactile, taste buds. Distant receptors respond to irritation * that comes from a distant object; distantreceptors are visual, auditory, olfactory.

Since sensations arise as a result of the action of a certain stimulus on the corresponding receptor, the classification of sensations takes into account the properties of both the stimuli that cause them and the receptors that are affected by these stimuli.

Behind the placement of receptors in the body - on the surface, inside the body, in muscles and tendons - sensations are emitted:

Exteroceptive, reflecting the properties of objects and phenomena of the outside world (visual, auditory, olfactory, gustatory)

Interoceptive, containing information about the state of internal organs (hunger, thirst, fatigue)

Proprioceptive, reflecting the movements of the organs of the body and the state of the body (kinesthetic and static).

According to the system of analyzers, there are such types of sensations: visual, auditory, tactile, pain, temperature, taste, olfactory, hunger and thirst, sexual, kinesthetic and static.

Each of these varieties of sensation has its own organ (analyzer), its own patterns of occurrence and function.

A subclass of proprioception, which is sensitivity to movement, is also called kinesthesia, and the corresponding receptors are kinesthetic, or kinesthetic.

Independent sensations include temperature, which is a function of a special temperature analyzer that performs thermoregulation and heat exchange of the body with the environment.

For example, the organ of visual sensations is the eye. The ear is the organ of perception of auditory sensations. Tactile, temperature and pain sensitivity is a function of organs located in the skin.

Tactile sensations provide knowledge about the measure of equality and relief of the surface of objects, which can be felt during their palpation.

Pain signals a violation of the integrity of the tissue, which, of course, causes a protective reaction in a person.

Temperature sensation - a sensation of cold, heat, it is caused by contact with objects that have a temperature higher or lower than body temperature.

An intermediate position between tactile and auditory sensations is occupied by vibrational sensations, signaling the vibration of an object. The organ of vibrational sense has not yet been found.

Olfactory sensations signal the state of the food's suitability for consumption, clean or polluted air.

The organ of taste sensations is special cones sensitive to chemical irritants located on the tongue and palate.

Static or gravitational sensations reflect the position of our body in space - lying, standing, sitting, balancing, falling.

Kinesthetic sensations reflect the movements and states of individual parts of the body - arms, legs, head, body.

Organic sensations signal such states of the body as hunger, thirst, well-being, fatigue, pain.

Sexual sensations signal the body's need for sexual release, providing pleasure due to irritation of the so-called erogenous zones and sex in general.

In terms of data modern science The accepted division of sensations into external (exteroceptors) and internal (interoceptors) is insufficient. Some kinds of sensations can be considered externally internal. These include temperature, pain, taste, vibration, musculo-articular, sexual and static di and amich n and.

General properties of sensations. Sensation is a form of reflection of adequate stimuli. However, different types of sensations have not only specificity, but also common properties for them. These properties include quality, intensity, duration, and spatial localization.

Quality is the main feature of a certain sensation that distinguishes it from other types of sensations and varies within a given type. So, auditory sensations differ in pitch, timbre, loudness; visual - by saturation, color tone and the like.

The intensity of sensations is its quantitative characteristic and is determined by the strength of the stimulus and the functional state of the receptor.

The duration of a sensation is its temporal characteristic. it is also determined by the functional state of the sense organ, but mainly by the duration of the stimulus and its intensity. During the action of the stimulus on the sense organ, the sensation does not occur immediately, but after a while, which is called the latent (hidden) period of sensation.

General laws of sensations. General patterns sensations are thresholds of sensitivity, adaptation, interaction, sensitization, contrast, synesthesia.

Sensitivity. The sensitivity of the sense organ is determined by the minimum stimulus that, under specific conditions, becomes capable of causing a sensation. The minimum strength of the stimulus that causes a barely noticeable sensation is called the lower absolute threshold of sensitivity.

Irritants of lesser strength, the so-called subthreshold ones, do not cause sensations, and signals about them are not transmitted to the cerebral cortex.

The lower threshold of sensations determines the level of absolute sensitivity of this analyzer.

The absolute sensitivity of the analyzer is limited not only by the lower, but by the upper threshold of sensation.

The upper absolute threshold of sensitivity is called the maximum strength of the stimulus, at which there is still an adequate sensation for a certain stimulus. A further increase in the strength of stimuli acting on our receptors causes only a painful sensation in them (for example, a super-loud sound, dazzling brightness).

The difference in sensitivity, or sensitivity to discrimination, is also inversely related to the value of the discrimination threshold: the larger the discrimination threshold, the smaller the difference in sensitivity.

Adaptation. The sensitivity of analyzers, determined by the magnitude of the absolute thresholds, is not constant and changes under the influence of a number of physiological and psychological conditions, among which the phenomenon of adaptation occupies a special place.

Adaptation, or adaptation, is a change in the sensitivity of the sense organs under the influence of the action of a stimulus.

There are three types of this phenomenon:

Adaptation as a continuous disappearance of sensation in the process of prolonged action of the stimulus.

Adaptation as a dulling of sensation under the influence of a strong stimulus. The described two types of adaptation can be combined by the term negative adaptation, since it results in a decrease in the sensitivity of the analyzers.

Adaptation as an increase in sensitivity under the influence of a weak stimulus. This type of adaptation, inherent in some types of sensations, can be defined as positive adaptation.

The phenomenon of increasing the sensitivity of the analyzer to the stimulus under the influence of mindfulness, orientation, installation is called sensitization. This phenomenon of the sense organs is possible not only as a result of the use of indirect stimuli, but also through exercise.

The interaction of sensations is a change in the sensitivity of one analyzer system under the influence of another. 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 that affect other sense organs at that moment. Change in the sensitivity of the analyzer under the influence of irritation of other senses. the name of the interaction of sensations.

In this case, the interaction of sensations, as well as adaptations, will turn out to be in two opposite processes: an increase and a decrease in sensitivity. The main regularity here is that weak stimuli increase, and strong ones decrease, the sensitivity of the analyzers by their interaction.

A change in the sensitivity of the analyzers can cause the action of all-round signal stimuli.

If you carefully, carefully peer, listen, savor, then the sensitivity to the properties of objects and phenomena becomes clearer, brighter - objects and their properties are much better distinguished.

The contrast of sensations is a change in the intensity and quality of sensations under the influence of a previous or accompanying stimulus.

With the simultaneous action of two stimuli, a simultaneous contrast occurs. Such a contrast can be well traced in visual sensations. One and you yourself figure on a black background will seem lighter, on a white - darker. A green object on a red background is perceived as more saturated. Therefore, military objects are often masked so that there is no contrast. This should include the phenomenon of consistent contrast. After a cold, a weak warm stimulus will seem hot. The sensation of sour increases the sensitivity to sweet.

Synesthesia of feelings is the occurrence of a floor by an outpouring of an irritant of one analyzer of nidchutgiv. which are specific to another analyzer. In particular, during the action of sound stimuli, such as aircraft, rockets, etc., a person has visual images of them. Or whoever sees a wounded person also feels pain in a certain way.

The activities of the analyzers will be in interaction. This interaction is not isolated. It has been proven that light increases hearing sensitivity, and weak sounds increase visual sensitivity, cold washing of the head increases sensitivity to red, and the like.

The sensitivity of analyzers, determined by the magnitude of absolute thresholds, is not constant and changes under the influence of a number of physiological and psychological conditions, among which the phenomenon of adaptation occupies a special place.

adaptation or adjustment , is a change in the sensitivity of the sense organs under the influence of the action of the stimulus. Three varieties of this phenomenon can be distinguished. Adaptation as the complete disappearance of sensation during prolonged action of the stimulus. For example, a light load resting on the skin soon ceases to be felt. 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.. The two types of adaptation described can be combined with the term Negative adaptation, since as a result of them the sensitivity of the analyzers decreases. Finally, adaptation is called Increased 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.

The contrast of sensations This is a change in the intensity and quality of sensations under the influence of a preliminary or accompanying stimulus. In the case of the simultaneous action of two stimuli, a simultaneous contrast occurs. Such a contrast can be traced in visual sensations. The same figure appears lighter on a black background, darker on a white one. A green object on a red background seems more saturated. The phenomenon of consistent contrast is also well known. After a cold, a weak warm stimulus seems hot. The sensation of sour increases the sensitivity to sweet.

Sensitization. An increase in sensitivity as a result of the interaction of analyzers and exercise is called sensitization. Knowing the patterns of changes in the sensitivity of the sense organs, it is possible, by using specially selected side stimuli, to sensitize one or another receptor, that is, to increase its sensitivity. Sensitization can also be achieved through exercise. It is known, for example, how pitch hearing develops in children who study music.

Synesthesia. The interaction of sensations is manifested in another kind of phenomena called synesthesia. Synesthesia is the occurrence under the influence of irritation of one analyzer of a sensation characteristic of another analyzer. Synesthesia is seen in a wide variety of sensations. The most common visual-auditory synesthesia, when, under the influence of sound stimuli, the subject has visual images.