What is the peculiarity of human higher nervous activity. Higher nervous activity

For animals, the role of conditioned (signal) stimuli is played by objects and phenomena (light, sound, temperature, etc.) of the surrounding world. For a person, the meaning of a signal is acquired by a word. It is the same real conditioned stimulus, like any object or natural phenomenon. A hungry person "drools" not only at the sight of food, but also when talking about it. The word can replace all natural irritants and cause the same reactions that these irritants cause. Word and speech constitute the second signaling system, peculiar only to humans. It may be objected that words are understood by dogs, horses, and birds: starlings, crows, parrots - even talk. But for animals, a word is a complex of sounds, a sound stimulus. For a person, a word is a concept. It is not only a conditioned stimulus that signals everything and can cause any activity, but also a fundamentally new signal. With the help of words, general concepts are formed, verbal human thinking arises.

How does the second signaling system arise? Joint work activity gives rise to speech as a means of communication between people, as an interpersonal signaling. Labor inevitably gives rise to speech, there is not a single nation that does not have verbal speech.

F. Engels wrote that first work and then speech made us people. The word heard, visible (written speech), tangible (alphabet for the blind), pronounced (kinesthetic sensations arising in the muscles of the tongue, larynx, when we speak) becomes the second signaling system.

In humans, the vast majority of temporary connections are formed with the help of a second signaling system, with the help of speech. A man, unlike an animal, does not necessarily himself get acquainted with an object or phenomenon of nature. Oral and especially written speech has created conditions for the transfer and storage of knowledge. Language, being a means of communication, becomes an instrument of the struggle and development of society, as it fixes the results of human thinking in words, creates science and thereby ensures the progress of culture. The first 6 years of life are of decisive importance for the development of the second human signaling system.

There is a certain time for the formation of each skill when it is most easily developed. Learning a foreign language is easier at preschool age.

Animals have a special way of learning at first sight, which is called imprinting, or imprinting. A duckling or gosling hatched from an egg recognizes the first moving object it sees as its mother and will follow it, whether it is a duck or a goose, a soccer ball or a hen. The most lasting impression occurs in the period from 13 to 17 hours, and after 30 hours it is no longer possible. The following response is also very important for ungulates. If it does not arise, then the animal will never be able to join the herd.

Cortical inhibition (human anatomy)

In nervous activity, two processes interact - excitation and inhibition. IP Pavlov called these two antagonistic, but inextricably linked active processes the true creators of nervous activity.

Excitation is involved in the formation of a conditioned reflex and in its implementation. The role of inhibition is more complex and varied. It is the process of inhibition that makes conditioned reflexes a mechanism of subtle, precise and perfect adaptation to the environment.

According to IP Pavlov, the cortex is characterized by two types of inhibition: unconditional and conditional. The unconditional does not require elaboration; arises immediately. Conditional inhibition is developed in the process of individual experience.

Types of braking according to I.P. Pavlov:

I. Unconditional (external)

External or damping brake

II. Conditional (internal)

1. Extinction.

2. Differentiation.

3. Lagging.

4. Conditional brake.

Unconditional braking. Let's start with the facts. The employee has developed a strong conditioned reflex to light in the dog and wants to show it at the lecture. The experiment fails - there is no reflex. The noise of a crowded audience, new signals completely turn off conditioned reflex activity, a new dominant appears, a new work of the cortex. Such inhibition of conditioned reflexes under the action

extraneous stimuli is called external inhibition. It is innate and therefore unconditional. It is called a fading brake because if the dog is taken out into the audience several times, then new signals that have turned out to be biologically indifferent, fade away and conditioned reflexes are carried out without hindrance. Also, the artist gradually learns to freely stand on stage.

Conditional inhibition. For internal conditioned inhibition, it is characteristic that it is just as temporary and conditioned as the conditioned reflex itself; it is produced, acquired in individual life and plays a special role in conditioned reflex activity. All types of internal inhibition are developed in one way - by not reinforcing a conditioned stimulus with an unconditioned one. If the food conditioned stimulus - a call - is not repeatedly reinforced with food, then the conditioned reaction will disappear, and extinguishing inhibition will develop. Its biological significance lies in the fact that in response to signals that are not accompanied by unconditioned, that is, vital, stimuli, the animal does not develop useless activity. However, the extinction is not the disappearance of a temporary connection. The extinguished reflex upon reinforcement can be quickly restored. This proves that extinction is the result of active braking.

Differential inhibition is developed when one signal stimulus, for example, the note "do", is reinforced by an unconditioned stimulus, but the note "salt" is not reinforced. After a certain number of applications of the stimulus, the dog will accurately respond to it: "before" will cause a positive conditioned reflex, and "salt" - inhibitory, negative. Consequently, differential inhibition provides a subtle analysis of the surrounding world. The red light of the traffic light, the horn of the car, the type of spoiled food, the fly agaric - these are all stimuli to which negative, inhibitory conditioned reflexes have been developed, which delay the body's response.

Delayed inhibition precisely timed the unconditioned reflex to the time of the unconditioned stimulus. For example, they turn on the light, and reinforce it with food only after 3 minutes. The saliva separation, after the delayed inhibition has developed, begins by the end of the 3rd minute. The dog "does not drool" is useless. The conditioned stimulus first causes inhibition in the cortex, which is replaced by excitation only before the action of the unconditioned stimulus.

The conditioned brake also contributes to flexibility and accuracy of conditioned reflexes. Let us explain it by the example of one of the experiments of I.P. Pavlov. Monkey Raphael was served a basket of fruit high under the ceiling. To get the fruit, he had to build a pyramid of boxes. In some experiments, a gray circle appeared before the appearance of the basket, and in this case the basket was empty. After several such combinations of a circle and a basket and useless attempts to get fruit, Raphael, before starting the construction of the pyramid, carefully looked to see if a circle appeared, which acquired the meaning of a conditional brake for him. Any stimulus can be turned into a conditioned brake. After that, feeding it in front of any positive stimulus causes inhibition of reflexes. Conditioned inhibition is the basis of negative, inhibitory conditioned reflexes that turn off the body's response to stimuli that have no biological significance.

Outrageous braking. If unconditioned and conditioned inhibition plays a coordinating role, that is, it turns off all reflexes that interfere with the implementation of the nervous activity necessary at a given moment, then the role of transcendental inhibition is completely different. Within certain limits, the stronger the irritation, the stronger the excitement caused by it. This law is called the law of power relationships. However, if the stimulus is so strong that exhaustion, breakage and even death of the nerve cell can occur during its action, then protective inhibition comes to the rescue. An excessively strong stimulus causes in the cortex not excitation, but inhibition. This special type of inhibition was discovered by I.P. Pavlov and called protective.

Sleep (human anatomy)

The alternation of sleep and wakefulness is an indispensable condition for life. Sleep deprivation is very difficult for humans and animals. The person develops muscle weakness, increases sensitivity to pain, hallucinations appear, and severe mental disorders develop. A person should spend a third of his life in a state of sleep!

The state of sleep differs from wakefulness by a decrease in muscle tone, all types of sensitivity and a shutdown of consciousness. At the same time, vegetative functions also change: energy exchange, heart rate, blood pressure, body temperature decrease, and breathing decreases.

There are two phases of sleep: the phase of "slow" sleep and the phase of "REM" sleep. The phase of "slow" sleep is characterized by the appearance on the EEG of slow waves with a large amplitude - delta waves (see Fig. 121). During "REM" sleep, which occurs periodically after 60 - 80 minutes and lasts about half an hour, fast low-amplitude waves are recorded on the EEG - beta waves, characteristic of the state of wakefulness. REM sleep periods are accompanied by rapid eye movements. The person awakened at this moment says that he had a dream. These periods are called paradoxical sleep. Depriving a person of "REM" sleep and dreams leads to memory disorders and mental disorders.

External stimuli: cold, noise, smell - are often included in the content of sleep. With the smell of burning, the sleeper can see in a dream that he is extinguishing a fire; when his legs are cooled, he walks barefoot on dewy grass. According to I.M.Sechenov, dreams are unprecedented combinations of experienced impressions.

Under natural conditions, partial sleep can be observed, when individual, so-called sentry, points of the cortex remain free from inhibition. The mother sleeps with a lot of noise, but the slightest rustle from the child's side wakes her up. Riders can sleep sitting in the saddle, soldiers sleep on the march.

According to IP Pavlov, sleep is a protective inhibition that prevents overwork and depletion of nerve cells.

Sleep, which develops under the influence of inhibitory conditioned stimuli, I.P. Pavlov called active sleep, in contrast to passive sleep, which arises as a result of the cessation or limitation of the influx of afferent impulses from the receptors to the cortex.

At present, sleep is understood as the transition of the activity of the cortex to a new mode of operation. For brain cells disconnected from new stimuli, it becomes possible to process information received during wakefulness. This process occurs during REM sleep, which is deeper than NREM sleep. (During REM sleep, it is more difficult to wake the sleeper.) It is believed that the intense work of the cortex during REM sleep is necessary for analysis, comprehension, ordering and consolidation of information received during wakefulness. There is a processing of existing ideas and their fixation in the long-term memory of the brain.

The structures of the brain that regulate the state of sleep and wakefulness are the diencephalon (thalamus and hypothalamus) and the reticular formation. Turning it off with sleeping pills (such as barbiturates) induces deep sleep.

The clinic describes cases of prolonged pathological sleep, called lethargic. The patient, observed by I.P. Pavlov, slept for 22 years. At autopsy, damage to the hypothalamus or midbrain was observed in such patients.

Types and nature of higher nervous activity (human anatomy)

A huge number of dogs passed through the laboratory of I.P. Pavlov, and the researchers noted that they were very different from each other in their behavior and temperament. The method of conditioned reflexes made it possible to establish that this is based on differences in the properties of the main nervous processes - excitation and inhibition, from the interaction of which nervous activity is formed.

It has been found that nervous processes differ in three main indicators: strength, balance, and mobility. The main feature that allows you to divide animals into two large groups is the strength of the nervous processes. It determines the performance of nerve cells. One and the same stimulus can cause a positive conditioned reflex in one dog, but for another it can turn out to be super strong and cause transcendental inhibition. Depending on the strength of the nervous processes, animals are divided into strong and weak.

The strong type of nervous system is divided into two: balanced and unbalanced. In the latter, the process of excitation is stronger than the process of inhibition. IP Pavlov otherwise called him excitable, unrestrained. In turn, the balanced type of the nervous system occurs in two variants, differing in the degree of mobility of the nervous processes. Mobility is determined by the rapidity of changes in the behavior of the animal. If the positive conditioned stimulus is no longer reinforced with an unconditioned one (food, electric current), and the negative stimulus is reinforced with an unconditioned one, then the animal with a mobile nervous system quickly rebuilds in a new way and reacts correctly. For an immobile, inert type, restructuring is difficult and occurs slowly.

Scheme of four types of higher nervous activity (according to I.P. Pavlov):

It turned out that the types of the nervous system identified by I.P. Pavlov coincided with the classification of human temperaments given by Hippocrates 2500 years ago. He divided people into choleric (I - easily excitable, aggressive), sanguine (II - lively, mobile, cheerful), phlegmatic (III - calm, sedentary, solid) and melancholic (IV - depressed, with a gloomy mood).

The type of the nervous system is congenital, due to heredity, but it is significantly influenced by the environment, which forms an alloy from the type and acquired properties, that is, character. Properties are inherited from parents, and character traits are acquired in individual life.

The weak type is formed during upbringing in a "greenhouse", as IP Pavlov put it, in an environment where strong and unusual stimuli are absent, one does not have to overcome obstacles and engage in intense work. Famous isolation and shielding of the child from influences environment can form passive-defensive reactions in the strong type. In puppies raised in "prison conditions", the approach of a person caused cowardly behavior, they pressed themselves to the floor or wall, or froze in immobility.

Neuroses. Particularly susceptible to the emergence of neuroses - functional disorders of the nervous system - weak and strong, unrestrained, types. When presented with unbearably difficult tasks that overstrain the cortical processes of excitation or inhibition, breakdowns of nervous activity occur.

Overstrain of excitement can be caused by some strong external stimulus. In 1924, during a flood in Leningrad, experimental Pavlovian dogs were rescued on boats, after which their conditioned reflex activity was impaired. Overstrain of the inhibitory process can occur during the development of fine differentiations that require a difference in stimuli that differ little from each other. In this case, the developed conditioned reflexes may disappear or the dependence of the magnitude of the reflex on the strength of the stimulus may be disrupted: a strong reaction arises to a weak irritation and, conversely, to a strong one, a weak one. Along with this, the behavior of the animal also changes: it either barks for no reason, breaks out of the pen, or is in a state of drowsiness. In this case, the functions of internal organs are disrupted, hypertension occurs, and often skin lesions such as eczema.

In humans, mental functions are also impaired under the influence of even very small doses of alcohol (30 - 50 ml). Concentration of attention, speed and accuracy of perception, speed of reaction, sense of responsibility suffer, that is, all the mechanisms of brain activity necessary in modern conditions of labor mechanization.

1. Congenital forms of behavior (instincts and innate reflexes), their importance in the adaptive activity of the organism.

Unconditioned reflexes - these are innate reflexes, carried out along constant reflex arcs that are present from birth. An example of an unconditioned reflex is the activity of the saliva gland during the act of eating, blinking when a speck gets into the eye, defensive movements during painful irritations, and many other reactions of this type. Unconditioned reflexes in humans and higher animals are carried out through the subcortical parts of the central nervous system (dorsal, oblong, midbrain, diencephalon and basal ganglia). At the same time, the center of any unconditioned reflex (BR) is connected by nerve connections with certain parts of the cortex, i.e. there is a so-called cortical representation of BR. Different BRs (food, defensive, sexual, etc.) can have different complexity. BR, in particular, includes such complex innate forms of animal behavior as instincts.

BRs undoubtedly play a large role in the adaptation of the organism to the environment. Thus, the presence of congenital reflex sucking movements in mammals provides them with the opportunity to feed on mother's milk in the early stages of ontogenesis. The presence of innate defense reactions (blinking, coughing, sneezing, etc.) protects the body from foreign bodies entering the respiratory tract. Even more obvious is the exceptional significance for the life of animals of various kinds of innate instinctual reactions (building nests, burrows, shelters, caring for offspring, etc.).

It should be borne in mind that BRs are not completely constant, as some believe. Within certain limits, the nature of an innate, unconditioned reflex can change depending on the functional state of the reflex apparatus. For example, in a spinal frog, irritation of the skin of the foot can cause a completely different reflex reaction depending on the initial state of the irritated paw: when the paw is extended, this irritation causes it to bend, and when it is bent, it is extended.

Unconditioned reflexes ensure the adaptation of the organism only under relatively constant conditions. Their variability is extremely limited. Therefore, unconditioned reflexes alone are not enough to adapt to continuously and sharply changing conditions of existence. This is convinced by the often encountered cases when instinctive behavior, so striking in its "rationality" in normal conditions, not only does not provide adaptation in a dramatically changed situation, but even becomes completely meaningless.

For a more complete and subtle adaptation of the organism to constantly changing living conditions in animals in the process of evolution, more perfect forms of interaction with the environment have been developed in the form of the so-called. conditioned reflexes.

2. The meaning of the teachings of I.P. Pavlova on higher nervous activity for medicine, philosophy and psychology.

1 - strong unbalanced

4 - weak type.

1. Animals with strong, unbalanced

People of this type (choleric people)

2. Dogs strong, balanced, mobile

People of this type ( sanguine

3. For dogs

People of this type (phlegmatic

4. In the behavior of dogs weak

melancholic

1. Art

2. Thinking type

3. Medium type

3. Rules for the development of conditioned reflexes. The law of power. Classification of conditioned reflexes.

Conditioned reflexes are not congenital, they are formed in the process of the individual life of animals and humans on the basis of unconditional. A conditioned reflex is formed due to the emergence of a new neural connection (a temporary connection according to Pavlov) between the center of the unconditioned reflex and the center that perceives the accompanying conditioned stimulus. In humans and higher animals, these temporary connections are formed in the cerebral cortex, and in animals without a cortex, in the corresponding higher parts of the central nervous system.

Unconditioned reflexes can be combined with a wide variety of changes in the external or internal environment of the body, and therefore, on the basis of one unconditioned reflex, many conditioned reflexes can be formed. This greatly expands the possibilities of adaptation of the animal organism to the conditions of life, since the adaptive reaction can be caused not only by those factors that directly cause changes in the functions of the organism, and sometimes threaten its very life, but also by those that only signal the former. Thanks to this, the adaptive reaction occurs in advance.

Conditioned reflexes are characterized by extreme variability depending on the situation and on the state of the nervous system.

So, in difficult conditions of interaction with the environment, the adaptive activity of the organism is carried out both unconditionally reflex, so conditionally reflex, most often in the form of complex systems of conditioned and unconditioned reflexes. Consequently, the higher nervous activity of humans and animals is an indissoluble unity of congenital and individually acquired forms of adaptation, is the result of the joint activity of the cerebral cortex and subcortical formations. However, the leading role in this activity belongs to the bark.

A conditioned reflex in animals or humans can be developed on the basis of any unconditioned reflex, subject to the following basic rules (conditions). Actually, this type of reflexes was called "conditioned", since it requires certain conditions for its formation.

1. It is necessary to coincide in time (combination) of two stimuli - unconditioned and some indifferent (conditioned).

2. It is necessary that the action of the conditioned stimulus somewhat precedes the action of the unconditioned.

3. The conditioned stimulus should be physiologically weaker than the unconditioned one, and possibly more indifferent, ie. not causing a significant reaction.

4. A normal, active state of the higher parts of the central nervous system is necessary.

5. During the formation of a conditioned reflex (UR), the cerebral cortex should be free from other types of activity. In other words, during the development of UR, the animal must be protected from the action of extraneous stimuli.

6. A more or less prolonged (depending on the evolutionary advancement of the animal) repetition of such combinations of a conditioned signal and an unconditioned stimulus is necessary.

If these rules are not followed, SDs are not formed at all, or they are formed with difficulty and quickly fade away.

To develop SD in various animals and humans, various techniques have been developed (registration of salivation is the classic Pavlovian technique, registration of motor-defensive reactions, food-processing reflexes, labyrinth methods, etc.). The mechanism of formation of a conditioned reflex. A conditioned reflex is formed when BR is combined with an indifferent stimulus.

Simultaneous excitation of two points of the central nervous system ultimately leads to the emergence of a temporary connection between them, due to which an indifferent stimulus, previously never associated with a combined unconditioned reflex, acquires the ability to cause this reflex (becomes a conditioned stimulus). Thus, the physiological mechanism of UR formation is based on the process of closing a temporary connection.

The process of UR formation is a complex act characterized by certain sequential changes in the functional relationships between the cortical and subcortical nervous structures involved in this process.

At the very beginning of the combination of indifferent and unconditioned stimuli, an orienting reaction occurs in the animal under the influence of the novelty factor. This innate, unconditioned reaction is expressed in inhibition of general motor activity, in turning the body, head and eyes towards stimuli, in alertness of the ears, olfactory movements, as well as in changes in respiration and cardiac activity. It plays a significant role in the formation of UR, increasing the activity of cortical cells due to the tonic influences from the subcortical formations (in particular, the reticular formation). Maintaining the required level of excitability in the cortical points that receive conditioned and unconditioned stimuli creates favorable conditions for closing the connection between these points. A gradual increase in excitability in these zones is observed from the very beginning of the development of Ur. And when it reaches a certain level, reactions to the conditioned stimulus begin to appear.

In the formation of UR, the emotional state of the animal caused by the action of stimuli is of no small importance. The emotional tone of the sensation (pain, disgust, pleasure, etc.) immediately determines the most general assessment of the acting factors - whether they are useful or harmful, and immediately activate the corresponding compensatory mechanisms, contributing to the urgent formation of an adaptive reaction.

The appearance of the first reactions to the conditioned stimulus marks only the initial stage of the formation of UR. At this time, it is still fragile (it does not appear for every application of the conditioned signal) and has a generalized, generalized character (the reaction is caused not only by a specific conditioned signal, but also by stimuli similar to it). Simplification and specialization of SD come only after additional combinations.

In the process of developing SD, its relationship with the orienting response changes. Sharply expressed at the beginning of the development of the SD, as the consolidation of the SD, the orienting reaction weakens and disappears.

In relation to the ratio of the conditioned stimulus to the reaction it signals, natural and artificial conditioned reflexes are distinguished.

Natural called conditioned reflexes, which are formed on stimuli, which are natural, necessarily accompanying signs, properties of an unconditioned stimulus, on the basis of which they are produced (for example, the smell of meat when feeding them). Natural conditioned reflexes, in comparison with artificial ones, are distinguished by greater ease of formation and greater strength.

Artificial called conditioned reflexes, formed on stimuli that are usually not directly related to the unconditioned stimulus that reinforces them (for example, a light stimulus reinforced by food).

Depending on the nature of the receptor structures on which conditioned stimuli act, there are exteroceptive, interoceptive, and proprioceptive conditioned reflexes.

Exteroceptive conditioned reflexes, formed in response to stimuli perceived by the external external receptors of the body constitute the bulk of conditioned reflex reactions that provide adaptive (adaptive) behavior of animals and humans in a changing environment.

Interoceptive conditioned reflexes, generated in response to physical and chemical stimulation of interoreceptors, provide physiological processes of homeostatic regulation of the function of internal organs.

Proprioceptive conditioned reflexes formed on the irritation of their own receptors of the striated muscles of the trunk and extremities, form the basis of all motor skills of animals and humans.

Depending on the structure of the applied conditioned stimulus, simple and complex (complex) conditioned reflexes are distinguished.

When simple conditioned reflex a simple stimulus (light, sound, etc.) is used as a conditioned stimulus. In real conditions of the organism functioning, as a rule, conditioned signals are not separate, single stimuli, but their temporal and spatial complexes.

In this case, either the entire environment of the animal or its parts in the form of a complex of signals acts as a conditioned stimulus.

One of the varieties of such a complex conditioned reflex is stereotyped conditioned reflex, formed on a certain temporal or spatial "pattern", a complex of stimuli.

There are also conditioned reflexes, developed for simultaneous and sequential complexes of stimuli, for a sequential chain of conditioned stimuli, separated by a certain time interval.

Trace conditioned reflexes are formed when the unconditioned reinforcing stimulus is presented only after the end of the conditioned stimulus.

Finally, a distinction is made between conditioned reflexes of the first, second, third, etc., order. If the conditioned stimulus (light) is reinforced by the unconditioned (food), a conditioned reflex of the first order. Conditioned reflex of the second order is formed if a conditioned stimulus (for example, light) is reinforced not by an unconditioned, but by a conditioned stimulus to which a conditioned reflex was previously formed. Conditioned reflexes of the second and more complex order are more difficult to form and are less durable.

Conditioned reflexes of the second and higher order include conditioned reflexes developed in response to a verbal signal (a word here represents a signal to which a conditioned reflex was previously formed when it was reinforced by an unconditioned stimulus).

4. Conditioned reflexes are a factor in the adaptation of the organism to changing conditions of existence. Methodology for the formation of a conditioned reflex. Differences between conditioned and unconditioned reflexes. The principles of the theory of I.P. Pavlova.

One of the basic elementary acts of higher nervous activity is a conditioned reflex. The biological significance of conditioned reflexes lies in a sharp expansion of the number of signal stimuli that are significant for the body, which provides an incomparably higher level of adaptive (adaptive) behavior.

The conditioned reflex mechanism underlies the formation of any acquired skill, the basis of the learning process. The structural and functional bases of the conditioned reflex are the cortex and subcortical formations of the brain.

The essence of the conditioned-reflex activity of the organism is reduced to the transformation of an indifferent stimulus into a signal, meaningful one, thanks to the repeated reinforcement of the stimulus by an unconditioned stimulus. Due to the reinforcement of the conditioned stimulus by the unconditioned, the previously indifferent stimulus is associated in the life of the organism with a biologically important event and thereby signals the onset of this event. In this case, any innervated organ can act as an effector link of the reflex arc of the conditioned reflex. In the body of humans and animals there is no organ, the work of which could not change under the influence of a conditioned reflex. Any function of the organism as a whole or of its individual physiological systems can be modified (strengthened or suppressed) as a result of the formation of a corresponding conditioned reflex.

In the area of \u200b\u200bthe cortical representation of the conditioned stimulus and the cortical (or subcortical) representation of the unconditioned stimulus, two excitation foci are formed. The focus of excitement, caused by an unconditioned stimulus from the external or internal environment of the organism, as a stronger (dominant) one, attracts excitement from the focus of weaker excitation caused by a conditioned stimulus. After several repeated presentations of the conditioned and unconditioned stimuli between these two zones, a stable path of excitation movement is "beaten": from the focus caused by the conditioned stimulus to the focus caused by the unconditioned stimulus. As a result, the isolated presentation of only the conditioned stimulus now leads to the reaction evoked by the previously unconditioned stimulus.

Intercalary and associative neurons of the cerebral cortex act as the main cellular elements of the central mechanism for the formation of a conditioned reflex.

For the formation of a conditioned reflex, the following rules must be observed: 1) an indifferent stimulus (which must become conditioned, signal) must have sufficient strength to excite certain receptors; 2) it is necessary that the indifferent stimulus be reinforced by an unconditioned stimulus, and the indifferent stimulus must either precede it somewhat or be presented simultaneously with the unconditioned one; 3) it is necessary that the stimulus used as a conditioned one be weaker than the unconditioned one. To develop a conditioned reflex, it is also necessary to have a normal physiological state of the cortical and subcortical structures that form the central representation of the corresponding conditioned and unconditioned stimuli, the absence of strong extraneous stimuli, and the absence of significant pathological processes in the body.

If these conditions are met, a conditioned reflex can be developed to practically any stimulus.

I.P. Pavlov, the author of the theory of conditioned reflexes as the basis of higher nervous activity, originally assumed that a conditioned reflex is formed at the level of the cortex - subcortical formations (a temporary connection is closed between cortical neurons in the zone of representation of an indifferent conditioned stimulus and subcortical nerve cells that make up the central representation unconditioned stimulus). In later works, IP Pavlov explained the formation of a conditioned reflex connection by the formation of a connection at the level of cortical zones of representation of conditioned and unconditioned stimuli.

Subsequent neurophysiological research led to the development, experimental and theoretical substantiation of several different hypotheses about the formation of a conditioned reflex. Data from modern neurophysiology indicate the possibility different levels closure, the formation of a conditioned reflex connection (cortex - cortex, cortex - subcortical formations, subcortical formations - subcortical formations) with a dominant role in this process of cortical structures. Obviously, the physiological mechanism of the formation of a conditioned reflex is a complex dynamic organization of the cortical and subcortical structures of the brain (L. G. Voronin, E. A. Asratyan, P. K. Anokhin, A. B. Kogan).

Despite certain individual differences, conditioned reflexes are characterized by the following general properties (signs):

1. All conditioned reflexes are one of the forms of the organism's adaptive reactions to changing environmental conditions.

2. Conditioned reflexes belong to the category of reflex reactions acquired in the course of individual life and are distinguished by individual specificity.

3. All types of conditioned reflex activity are of a signaling and preventive nature.

4. Conditioned reflex reactions are formed on the basis of unconditioned reflexes; without reinforcement, conditioned reflexes are weakened and suppressed over time.

5. Active forms of education. Instrumental reflexes.

6. Stages of the formation of conditioned reflexes (generalization, directed irradiation and concentration).

In the formation, strengthening of the conditioned reflex, two stages are distinguished: the initial (generalization of conditioned excitement) and the final stage of the strengthened conditioned reflex (concentration of conditioned excitement).

The initial stage of generalized conditioned arousal in essence, it is a continuation of a more general universal reaction of the organism to any stimulus new to it, represented by an unconditioned orienting reflex. The orienting reflex is a generalized multicomponent complex reaction of the body to a sufficiently strong external stimulus, covering many of its physiological systems, including vegetative ones. The biological significance of the orienting reflex lies in the mobilization of the functional systems of the body for a better perception of the stimulus, that is, the orienting reflex is adaptive (adaptive) in nature. Outwardly, the orienting reaction, called by IP Pavlov the reflex "what is it?", Manifests itself in an animal in alertness, listening, sniffing, turning the eyes and head towards the stimulus. Such a reaction is the result of a wide spread of the excitatory process from the focus of initial excitation, caused by the active agent, to the surrounding central nervous structures. The orienting reflex, in contrast to other unconditioned reflexes, is quickly suppressed, suppressed with repeated applications of the stimulus.

The initial stage of the formation of a conditioned reflex consists in the formation of a temporary connection not only to a given specific conditioned stimulus, but also to all stimuli related to it in character. The neurophysiological mechanism is irradiation of excitement from the center of the projection of the conditioned stimulus onto the nerve cells of the surrounding projection zones, which are functionally close to the cells of the central representation of the conditioned stimulus, to which the conditioned reflex is formed. The farther from the initial initial focus, caused by the main stimulus, reinforced by the unconditioned stimulus, is the zone covered by the irradiation of excitation, the less is the probability of activation of this zone. Therefore, at the initial stages of generalization of conditioned excitement, characterized by a generalized generalized reaction, a conditioned reflex response is observed to similar stimuli that are close in meaning as a result of the propagation of excitation from the projection zone of the main conditioned stimulus.

As the conditioned reflex strengthens, the processes of irradiation of excitation are replaced concentration processes, limiting the focus of excitation only by the zone of representation of the main stimulus. The result is a refinement, specialization of the conditioned reflex. At the final stage of the strengthened conditioned reflex, concentration of conditioned excitement: a conditioned reflex reaction is observed only to a given stimulus, to side stimuli close in meaning - it stops. At the stage of concentration of conditioned excitation, the excitatory process is localized only in the zone of central representation of the conditioned stimulus (the reaction is realized only to the main stimulus), accompanied by inhibition of the reaction to side stimuli. An external manifestation of this stage is the differentiation of the parameters of the acting conditioned stimulus - the specialization of the conditioned reflex.

7. Inhibition in the cerebral cortex. Types of inhibition: unconditional (external) and conditional (internal).

The formation of a conditioned reflex is based on the processes of interaction of excitations in the cerebral cortex. However, for the successful completion of the process of closing a temporary connection, it is necessary not only to activate the neurons involved in this process, but also to suppress the activity of those cortical and subcortical structures that impede this process. Such oppression is carried out through the participation of the inhibition process.

In terms of its external manifestation, inhibition is the opposite of arousal. With it, a weakening or cessation of neuronal activity is observed, or possible excitation is prevented.

Cortical inhibition is usually subdivided into unconditional and conditionalacquired. The unconditional forms of inhibition include externalarising in the center as a result of its interaction with other active centers of the cortex or subcortex, and transcendent, which occurs in cortical cells with excessively strong irritation. These types (forms) of inhibition are congenital and are already manifested in newborns.

8. Unconditional (external) braking. Dying and permanent brake.

External unconditional braking manifests itself in the weakening or termination of conditioned reflex reactions under the action of any extraneous stimuli. If a dog calls UR to a call, and then acts on a strong extraneous stimulus (pain, smell), then the salivation that has begun will stop. Unconditioned reflexes are also inhibited (Türk's reflex in a frog when pinching the second paw).

Cases of external inhibition of conditioned reflex activity are encountered at every step and in the natural life of animals and humans. This includes the constantly observed decrease in activity and indecision of actions in a new, unusual environment, a decrease in the effect or even complete impossibility of activity in the presence of extraneous stimuli (noise, pain, hunger, etc.).

External inhibition of conditioned reflex activity is associated with the appearance of a reaction to an extraneous stimulus. It comes the easier, and is the stronger, the stronger the extraneous stimulus and the less strong the conditioned reflex. External inhibition of the conditioned reflex occurs immediately upon the first application of an external stimulus. Consequently, the ability of cortical cells to enter a state of external inhibition is an innate property of the nervous system. This is one of the manifestations of the so-called. negative induction.

9. Conditional (internal) inhibition, its meaning (limitation of conditioned reflex activity, differentiation, timing, protective). Types of conditioned inhibition, especially in children.

Conditioned (internal) inhibition develops in cortical cells under certain conditions under the influence of the same stimuli that previously caused conditioned reflex reactions. In this case, inhibition does not occur immediately, but after more or less prolonged production. Internal inhibition, like a conditioned reflex, arises after a series of combinations of a conditioned stimulus with the action of a certain inhibitory factor. Such a factor is the cancellation of unconditional reinforcement, a change in its character, etc. Depending on the condition of occurrence, the following types of conditioned inhibition are distinguished: extinguishing, retarded, differentiating and signal ("conditional brake").

Fading inhibition develops when the conditioned stimulus is not reinforced. It is not associated with fatigue of the cortical cells, since an equally prolonged repetition of the conditioned reflex with reinforcement does not lead to a weakening of the conditioned reaction. The less strong the conditioned reflex and the weaker the unconditioned on the basis of which it is developed, the easier and faster the extinguishing inhibition develops. Extinguishing inhibition develops the faster the smaller the interval between conditioned stimuli repeated without reinforcement. Extraneous stimuli cause temporary weakening and even complete cessation of extinguishing inhibition, i.e. temporary restoration of the extinguished reflex (disinhibition). The developed extinguishing inhibition causes suppression of other conditioned reflexes, weak and those whose centers are located close to the center of the initially extinguished reflexes (this phenomenon is called secondary extinction).

The extinguished conditioned reflex is restored by itself after some time, i.e. fading inhibition disappears. This proves that extinction is associated precisely with temporary inhibition, not with the breaking of a temporary connection. The extinguished conditioned reflex is restored the faster, the stronger it is and the weaker it was inhibited. Repeated suppression of the conditioned reflex occurs faster.

The development of extinguishing inhibition is of great biological importance, since it helps animals and humans to free themselves from previously acquired conditioned reflexes that have become useless in new, changed conditions.

Retarded braking develops in cortical cells when the reinforcement lags behind in time from the onset of the conditioned stimulus. Outwardly, this inhibition is expressed in the absence of a conditioned reflex reaction at the beginning of the action of the conditioned stimulus and its appearance after a certain delay (delay), and the time of this delay corresponds to the duration of the isolated action of the conditioned stimulus. The retarded inhibition develops the faster, the smaller the delay of reinforcement from the onset of the conditioned signal. With the continuous action of the conditioned stimulus, it develops faster than with the intermittent one.

Extraneous stimuli cause temporary release of delayed inhibition. Thanks to its development, the conditioned reflex becomes more accurate, being timed to the desired moment with a distant conditioned signal. This is its great biological significance.

Differential inhibition develops in cortical cells with the intermittent action of a constantly reinforced conditioned stimulus and non-reinforced stimuli similar to it.

The newly formed SD usually has a generalized, generalized character, i.e. It is caused not only by a specific conditioned stimulus (for example, a tone of 50 Hz), but by numerous similar stimuli addressed to the same analyzer (tones of 10-100 Hz). However, if in the future only sounds with a frequency of 50 Hz are reinforced, and others are left without reinforcement, then after a while the reaction to similar stimuli will disappear. In other words, out of the mass of similar stimuli, the nervous system will respond only to the one being reinforced, i.e. biologically significant, and the reaction to other stimuli is inhibited. This inhibition ensures the specialization of the conditioned reflex, vital discrimination, differentiation of stimuli according to their signal value.

Differentiation is developed the easier, the greater the difference between conditioned stimuli. With the help of this inhibition, it is possible to investigate the ability of animals to distinguish sounds, shapes, colors, etc. So, according to Gubergritz, a dog can distinguish a circle from an ellipse with a semiaxis ratio of 8: 9.

Extraneous stimuli cause disinhibition of differential inhibition. Starvation, pregnancy, neurotic conditions, fatigue, etc. can also lead to disinhibition and perversion of previously developed differentiations.

Signal braking ("conditional brake"). Inhibition of the "conditioned brake" type develops in the cortex when the conditioned stimulus is not reinforced in combination with some additional stimulus, and the conditioned stimulus is reinforced only when it is applied in isolation. Under these conditions, the conditioned stimulus in combination with an outsider becomes, as a result of the development of differentiation, inhibitory, and the outside stimulus itself acquires the property of an inhibitory signal (conditioned brake), it becomes capable of inhibiting any other conditioned reflex if it is attached to the conditioned signal.

The conditioned brake easily develops when the conditioned and the surplus stimulus act simultaneously. In a dog, it is not produced if this interval is more than 10 seconds. Extraneous stimuli cause disinhibition of signal inhibition. Its biological significance lies in the fact that it clarifies the conditioned reflex.

10. The concept of the limit of performance of cells of the cerebral cortex. Outrageous braking.

Outrageous braking develops in cortical cells under the action of a conditioned stimulus, when its intensity begins to exceed a certain limit. Extreme inhibition also develops with the simultaneous action of several separately weak stimuli, when the total effect of the stimuli begins to exceed the limit of the efficiency of the cortical cells. An increase in the frequency of the conditioned stimulus also leads to the development of inhibition. The development of transcendental inhibition depends not only on the strength and nature of the action of the conditioned stimulus, but also on the state of the cortical cells, on their performance. At a low level of efficiency of cortical cells, for example, in animals with a weak nervous system, in old and sick animals, a rapid development of transcendental inhibition is observed even with relatively weak stimuli. The same is observed in animals brought to significant nervous exhaustion by prolonged exposure to stimuli of moderate strength.

Transcendental inhibition has a protective value for the cells of the cortex. This is a parabiotic type phenomenon. During its development, similar phases are noted: equalizing, when both strong and moderate in strength conditioned stimuli cause a response of the same intensity; paradoxical, when weak stimuli produce a stronger effect than strong stimuli; ultraparadoxical phase, when inhibitory conditioned stimuli produce an effect, but positive ones do not; and, finally, the inhibitory phase, when no stimuli cause a conditioned reaction.

11. The movement of nervous processes in the cerebral cortex: irradiation and concentration of nervous processes. Phenomena of mutual induction.

Movement and interaction of processes of excitation and inhibition in the cortex of the cerebral hemispheres. Higher nervous activity is determined by a complex relationship between the processes of excitation and inhibition that arise in cortical cells under the influence of various influences from the external and internal environment. This interaction is not limited only to the framework of the corresponding reflex arcs, but is played out far beyond them. The fact is that with any effect on the body, not only the corresponding cortical foci of excitation and inhibition arise, but also various changes in the most diverse areas of the cortex. These changes are caused, firstly, by the fact that nervous processes can spread (radiate) from the place of their origin to the surrounding nerve cells, and the irradiation is replaced after a while by the reverse movement of the nervous processes and their concentration at the starting point (concentration). Secondly, changes are caused by the fact that nervous processes, when concentrated in a certain place of the cortex, can cause (induce) the appearance of an opposite nervous process in the surrounding neighboring points of the cortex (spatial induction), and after the termination of the nervous process, induce the opposite nervous process in the same paragraph (temporary, sequential induction).

The irradiation of nervous processes depends on their strength. At low or high intensity, the tendency to irradiation is clearly expressed. With medium strength - to concentration. According to Kogan's data, the excitation process radiates along the cortex at a speed of 2-5 m / s, the inhibitory process - much slower (several millimeters per second).

Strengthening or the emergence of the process of excitation under the influence of the focus of inhibition is called positive induction... The emergence or intensification of the inhibitory process around (or after) excitation is called negativeinduction.Positive induction is manifested, for example, in an increase in the conditioned reflex reaction after the application of a differentiating stimulus or excitation before bedtime. One of the most common manifestations of negative induction is the inhibition of UR under the action of extraneous stimuli. With weak or overly strong stimuli, there is no induction.

It can be assumed that the induction phenomena are based on processes similar to electrotonic changes.

Irradiation, concentration and induction of nervous processes are closely related to each other, mutually limiting, balancing and strengthening each other, and thus conditioning the exact adaptation of the body's activity to environmental conditions.

12. Analysis and synthesis in the cerebral cortex. The concept of a dynamic stereotype, especially in childhood. The role of a dynamic stereotype in the work of a doctor.

Analytical and synthetic activity of the cerebral cortex... The ability to form SD, temporary connections shows that the cerebral cortex, firstly, can isolate its individual elements from the environment, distinguish them from each other, i.e. has the ability to analyze. Secondly, it has the ability to combine, merge elements into a single whole, i.e. the ability to synthesize. In the process of conditioned reflex activity, a constant analysis and synthesis of stimuli of the external and internal environment of the body is carried out.

The ability to analyze and synthesize stimuli is inherent in the simplest form already in the peripheral parts of the analyzers - receptors. Due to their specialization, a qualitative separation is possible, i.e. analysis of the environment. Along with this, the combined action of various stimuli, their complex perception creates conditions for their fusion, synthesis into a single whole. Analysis and synthesis due to the properties and activity of receptors are called elementary.

The analysis and synthesis carried out by the cortex are called higher analysis and synthesis. The main difference is that the cortex analyzes not so much the quality and quantity of information as its signal value.

One of the brightest manifestations of the complex analytical and synthetic activity of the cerebral cortex is the formation of the so-called. dynamic stereotype... A dynamic stereotype is a fixed system of conditioned and unconditioned reflexes, combined into a single functional complex, which is formed under the influence of stereotypically repeated changes or influences of the external or internal environment of the body, and in which each previous act is a signal of the next one.

The formation of a dynamic stereotype is of great importance in conditioned reflex activity. It facilitates the activity of cortical cells when performing a stereotypically repeating system of reflexes, makes it more economical, and at the same time automatic and precise. In the natural life of animals and humans, reflex stereotypes are developed very often. We can say that the basis of the individual form of behavior characteristic of each animal and human is a dynamic stereotype. Dynamic stereotypy underlies the development of various habits in a person, automatic actions in the labor process, a certain system of behavior in connection with the established daily routine, etc.

The dynamic stereotype (DS) is developed with difficulty, but, once formed, it acquires a certain inertia and, with the invariability of external conditions, becomes stronger and stronger. However, when the external stereotype of stimuli changes, the previously recorded system of reflexes begins to change: the old one is destroyed and a new one is formed. Thanks to this ability, the stereotype is called dynamic. However, the alteration of a durable DS presents a great difficulty for the nervous system. It is known how difficult it is to change a habit. Alteration of a very strong stereotype can even cause a breakdown of higher nervous activity (neurosis).

Complex analytical and synthetic processes underlie such a form of integral brain activity as conditioned reflex switchingwhen the same conditioned stimulus changes its signal value with a change in the situation. In other words, an animal reacts to the same stimulus in different ways: for example, in the morning a call is a signal to write, and in the evening - pain. Conditioned reflex switching is manifested everywhere in a person's natural life in different reactions and different forms of behavior for the same reason in different settings (at home, at work, etc.) and has a great adaptive value.

13. The doctrine of I.P. Pavlova on the types of higher nervous activity. Classification of types and the principles underlying it (the strength of nervous processes, balance and mobility).

The higher nervous activity of man and animals sometimes reveals rather pronounced individual differences. Individual features of GNI are manifested in different rates of formation and strengthening of conditioned reflexes, in different rates of development of internal inhibition, in different difficulties in altering the signal value of conditioned stimuli, in different performance of cortical cells, etc. Each individual is characterized by a certain combination of the basic properties of cortical activity. She received the name of the VND type.

Features of VND are determined by the nature of the interaction, the ratio of the main cortical processes - excitation and inhibition. Therefore, the classification of the types of GNI is based on the differences in the basic properties of these nervous processes. These properties are:

1.Power nervous processes. Depending on the efficiency of the cortical cells, nervous processes can be strongand weak.

2. Equilibrium nervous processes. Depending on the ratio of excitation and inhibition, they can be balancedor unbalanced.

3. Mobility nervous processes, i.e. the speed of their occurrence and termination, the ease of transition from one process to another. Depending on this, the nervous processes can be mobile or inert.

Theoretically, 36 combinations of these three properties of nervous processes are conceivable, i.e. a wide variety of types of GNI. I.P. Pavlov, however, identified only 4 of the most striking types of VND in dogs:

1 - strong unbalanced (with a sharp predominance of excitement);

2 - strong unbalanced mobile;

3 - strong balanced inert;

4 - weak type.

The identified types Pavlov considered common for both humans and animals. He showed that the four established types coincide with the Hippocratic description of the four human temperaments - choleric, sanguine, phlegmatic and melancholic.

Along with genetic factors (genotype), the external environment and upbringing (phenotype) take an active part in the formation of the type of GNI. In the course of further individual development of a person, on the basis of innate typological characteristics of the nervous system under the influence of the external environment, a certain set of properties of GNI is formed, which manifests itself in a stable direction of behavior, i.e. what we call character. The type of GNI contributes to the formation of certain character traits.

1. Animals with strong, unbalanced type are, as a rule, bold and aggressive, extremely excitable, difficult to train, cannot stand restrictions in their activities.

People of this type (choleric people) characterized by incontinence, slight excitability. These are energetic, enthusiastic people, courageous in judgments, prone to decisive actions, not knowing measures in work, often reckless in their actions. Children of this type are often able to learn, but they are hot-tempered and unbalanced.

2. Dogs strong, balanced, mobiletype in most cases are sociable, mobile, react quickly to each new stimulus, but at the same time they easily restrain themselves. They quickly and easily adapt to changes in their environment.

People of this type ( sanguine) are distinguished by restraint of character, great self-control, and at the same time ebullient energy and exceptional efficiency. Sanguine people are lively, inquisitive people who are interested in everything and are quite versatile in their activities, in their interests. On the contrary, one-sided, monotonous activity is not in their nature. They are persistent in overcoming difficulties and easily adapt to any changes in life, quickly rebuilding their habits. Children of this type are distinguished by liveliness, mobility, curiosity, discipline.

3. For dogs strong, balanced, inert type of characteristic feature is slowness, calmness. They are uncommunicative and do not show excessive aggression, reacting poorly to new stimuli. They are characterized by the stability of habits and developed stereotypes in behavior.

People of this type (phlegmatic) are distinguished by their slowness, exceptional balance, calmness and evenness in behavior. With their slowness, phlegmatic people are very energetic and persistent. They are distinguished by the constancy of habits (sometimes to pedantry and stubbornness), the constancy of attachments. Children of this type are distinguished by good behavior and hard work. They are characterized by a certain slowness of movements, slow calm speech.

4. In the behavior of dogs weak type, cowardice, a tendency to passive-defensive reactions are noted as a characteristic feature.

A distinctive feature in the behavior of people of this type ( melancholic) is shyness, isolation, weak will. Melancholic people often tend to exaggerate the difficulties they face in life. They are highly sensitive. Their feelings often turn out to be painted in dark colors. Children of the melancholic type outwardly look quiet, timid.

It should be noted that there are few representatives of such pure types, no more than 10% of the human population. The rest of the people have numerous transitional types, combining in their character the features of neighboring types.

The type of GNI largely determines the nature of the course of the disease, so it must be taken into account in the clinic. The type should be taken into account at school, when educating an athlete, a warrior, when determining aptitude, etc. To determine the type of GNI in a person, special techniques have been developed, including studies of conditioned reflex activity, excitation and conditioned inhibition processes.

After Pavlov, his students carried out numerous studies of the types of GNI in humans. It turned out that the Pavlovian classification requires substantial additions and changes. Thus, studies have shown that a person has numerous variations within each Pavlovian type due to the gradation of three basic properties of nervous processes. The weak type especially has many variations. Some new combinations of the basic properties of the nervous system have also been established, which do not fit the characteristics of any Pavlovian type. These include - a strong unbalanced type with a predominance of inhibition, an unbalanced type with a predominance of excitation, but in contrast to a strong type with a very weak inhibitory process, unbalanced in mobility (with labile excitation, but inert inhibition), etc. Therefore, work is now underway to clarify and supplement the classification of types of IRR.

In addition to the general types of GNI, in humans there are also particular types characterized by a different ratio between the first and second signaling systems. On this basis, there are three types of GNI:

1. Art, in which the activity of the first signal system is especially pronounced;

2. Thinking type, in which the second signal system is noticeably predominant.

3. Medium type, in which 1 and 2 signaling systems are balanced.

The overwhelming majority of people are of the average type. This type is characterized by a harmonious combination of figurative-emotional and abstract-verbal thinking. The art type supplies artists, writers, musicians. Thinking - mathematicians, philosophers, scientists, etc.

14. Peculiarities of human higher nervous activity. The first and second signaling systems (I.P. Pavlov).

General patterns of conditioned reflex activity, established in animals, inherent in human GNI. However, human GNI in comparison with animals is characterized by the highest degree of development of analytical and synthetic processes. This is due not only to the further development and improvement in the course of evolution of those mechanisms of cortical activity that are inherent in all animals, but also to the emergence of new mechanisms of this activity.

Such a specific feature of human GNI is the presence in him, in contrast to animals, of two systems of signal stimuli: one system, the first, consists, like animals, of direct effects of factors of the external and internal environment organism; the other consists from wordsindicating the impact of these factors. I.P. Pavlov named her second signaling systemsince the word is " signal signalThanks to the second human signaling system, analysis and synthesis of the surrounding world, its adequate reflection in the cortex, can be carried out not only by operating with direct sensations and impressions, but also by operating only with words. Opportunities are created for distraction from reality, for abstract thinking.

This greatly expands the possibilities of human adaptation to the environment. He can get a more or less correct idea of \u200b\u200bthe phenomena and objects of the external world without direct contact with reality itself, but from the words of other people or from books. Abstract thinking makes it possible to develop appropriate adaptive reactions also outside of contact with those specific living conditions in which these adaptive reactions are appropriate. In other words, a person determines in advance, develops a line of behavior in a new, never before seen environment. So, going on a journey to new unfamiliar places, a person nevertheless prepares appropriately for unusual climatic conditions, for specific conditions of communication with people, etc.

It goes without saying that the perfection of a person's adaptive activity with the help of verbal signals will depend on how accurately and fully the surrounding reality is reflected in the cerebral cortex with the help of a word. Therefore, the only correct way to check the correctness of our ideas about reality is practice, i.e. direct interaction with the objective material world.

The second signaling system is socially conditioned. A person is not born with it, he is born only with the ability to form it in the process of communicating with his own kind. The Mowgli children do not have a human second signaling system.

15. The concept of higher mental functions of a person (sensation, perception, thinking).

The basis of the mental world is consciousness, thinking, human intellectual activity, which are the highest form of adaptive behavior. Mental activity is a qualitatively new level of higher nervous activity inherent in humans, higher than conditioned reflex behavior. In the world of higher animals, this level is presented only in its infancy.

In the development of the human mental world as an evolving form of reflection, the following 2 stages can be distinguished: 1) the stage of the elementary sensory psyche - the reflection of individual properties of objects, phenomena of the surrounding world in the form sensations. Unlike the sensations perception - the result of the reflection of the object as a whole and at the same time something still more or less dismembered (this is the beginning of the construction of one's “I” as a subject of consciousness). A more perfect form of concrete-sensory reflection of reality, formed in the process of individual development of the organism, is representation. Performance - a figurative reflection of an object or phenomenon, manifested in the spatio-temporal connection of its constituent features and properties. The neurophysiological basis of representations is based on chains of associations, complex temporal connections; 2) stage of formation intelligence and consciousness, which is realized on the basis of the emergence of holistic meaningful images, a holistic perception of the world with an understanding of one's “I” in this world, one's cognitive and creative creative activities. Human mental activity, which most fully realizes this higher level of the psyche, is determined not only by the quantity and quality of impressions, meaningful images and concepts, but also by a significantly higher level of needs that go beyond purely biological needs. A person already desires not only "bread", but also "circuses" and accordingly builds his behavior. His actions, behavior become both a consequence of the impressions received and the thoughts generated by them, and a means of actively obtaining them. Correspondingly changes in evolution and the ratio of the volumes of the cortical zones providing sensory, gnostic and logical functions in favor of the latter.

Human mental activity consists not only in the construction of more complex nervous models of the surrounding world (based on the cognition process), but also in the production of new information, different forms of creativity. Despite the fact that many manifestations of the human mental world turn out to be divorced from direct stimuli, events of the external world and seem to have no real objective reasons, there is no doubt that the initial, triggering factors are completely deterministic phenomena and objects reflected in the structures of the brain based on universal neurophysiological mechanism - reflex activity. This idea, expressed by I. M. Sechenov in the form of the thesis "All acts of conscious and unconscious human activity according to the mode of origin are the essence of reflexes", remains generally recognized.

The subjectivity of mental nervous processes lies in the fact that they are a property of the individual organism, do not exist and cannot exist outside a specific individual brain with its peripheral nerve endings and nerve centers, and are not an absolutely exact mirror copy of the real world around us.

The simplest, or basic, mental element in the work of the brain is feeling. It serves as that elementary act that, on the one hand, connects our psyche directly with external influences, and on the other, is an element in more complex mental processes. Sensation is a conscious reception, that is, a certain element of consciousness and self-awareness is present in the act of sensation.

Sensation arises as a result of a certain spatio-temporal distribution of the excitation pattern, however, for researchers, the transition from knowledge of the spatio-temporal picture of excited and inhibited neurons to the sensation itself as a neurophysiological basis of the psyche seems to be insurmountable. According to LM Chailakhyan, the transition from a neurophysiological process that is amenable to complete physicochemical analysis to sensation is the basic phenomenon of an elementary mental act, a phenomenon of consciousness.

In this regard, the concept of "mental" is presented as a conscious perception of reality, a unique mechanism for the development of the process of natural evolution, a mechanism for the transformation of neurophysiological mechanisms in the category of psyche, consciousness of the subject. Human mental activity is largely due to the ability to be distracted from reality and make the transition from direct sensory perceptions to imaginary reality ("virtual" reality). The human ability to imagine the possible consequences of one's actions is the highest form of abstraction that is inaccessible to an animal. A striking example is the behavior of a monkey in the laboratory of I.P. Pavlov: each time the animal extinguished the fire on the raft with water, which it brought in a mug from a tank on the shore, although the raft was in the lake and was surrounded by water on all sides.

The high level of abstraction in the phenomena of the human mental world determines the difficulties in solving the cardinal problem of psychophysiology - finding the neurophysiological correlates of the mental, the mechanisms of transformation of the material neurophysiological process into a subjective image. The main difficulty in explaining the specific features of mental processes on the basis of the physiological mechanisms of the nervous system is the inaccessibility of mental processes to direct sensory observation and study. Mental processes are closely related to physiological ones, but they are not reducible to them.

Thinking is the highest stage of human cognition, the process of reflection in the brain of the surrounding real world, based on two fundamentally different psychophysiological mechanisms: the formation and continuous replenishment of concepts, ideas and the conclusion of new judgments and inferences. Thinking allows you to gain knowledge about such objects, properties and relationships of the surrounding world that cannot be directly perceived using the first signaling system. The forms and laws of thinking are the subject of consideration of logic, and psychophysiological mechanisms - respectively - of psychology and physiology.

Human thought activity is inextricably linked with the second signaling system. At the heart of thinking, two processes are distinguished: the transformation of thought into speech (written or oral) and the extraction of thought, content from a certain verbal form of the message. Thought is a form of the most complex generalized abstracted reflection of reality, conditioned by some motives, a specific process of integration of certain ideas, concepts in specific conditions of social development. Therefore, thought as an element of higher nervous activity is the result of the socio-historical development of the individual with the advancement of the linguistic form of information processing to the fore.

Human creative thinking is associated with the formation of more and more new concepts. A word as a signal of signals denotes a dynamic complex of specific stimuli, generalized in a concept expressed by a given word and having a wide context with other words, with other concepts. Throughout life, a person continuously replenishes the content of concepts that are being formed in him by expanding the contextual connections of the words and phrases he uses. Any learning process, as a rule, is associated with the expansion of the meaning of old and the formation of new concepts.

The verbal basis of mental activity largely determines the nature of the development, the formation of thinking processes in a child, manifests itself in the formation and improvement of the nervous mechanism for providing the conceptual apparatus of a person based on the use of logical laws of inference, reasoning (inductive and deductive thinking). The first speech-motor temporary connections appear by the end of the first year of a child's life; at the age of 9-10 months, the word becomes one of the significant elements, components of a complex stimulus, but does not yet act as an independent stimulus. The combination of words into successive complexes, into separate semantic phrases is observed in the second year of a child's life.

The depth of mental activity, which determines mental characteristics and forms the basis of human intelligence, is largely due to the development of the generalizing function of the word. In the formation of the generalizing function of a word in a person, the following stages, or stages, of the integrative function of the brain are distinguished. At the first stage of integration, the word replaces the sensory perception of a certain object (phenomenon, event) designated by it. At this stage, each word acts as a conventional sign of one specific object; the word does not express its generalizing function, which unites all unambiguous objects of this class. For example, the word "doll" for a child means specifically that doll that he has, but not a doll in a shop window, in a manger, etc. This stage occurs at the end of the 1st - the beginning of the 2nd year of life.

At the second stage, the word replaces several sensory images that unite homogeneous objects. The word "doll" for the child becomes a general designation of the various dolls that he sees. This understanding and use of the word occurs by the end of the 2nd year of life. At the third stage, the word replaces a number of sensory images of heterogeneous objects. The child develops an understanding of the generalized meaning of words: for example, the word "toy" for a child means a doll, a ball, a cube, etc. This level of word manipulation is achieved in the third year of life. Finally, the fourth stage of the integrative function of the word, characterized by verbal generalizations of the second or third order, is formed in the 5th year of a child's life (he understands that the word "thing" denotes integrating words of the previous level of generalization, such as "toy", "food", "Book", "clothes", etc.).

The stages of the development of the integrative generalizing function of the word as a constituent element of mental operations are closely related to the stages, periods of development of cognitive abilities. The first initial period falls on the stage of development of sensorimotor coordination (a child aged 1.5-2 years). The next one is the period of preoperative thinking (age 2–7 years) is determined by the development of language: the child begins to actively use sensorimotor thinking schemes. The third period is characterized by the development of coherent operations: the child develops the ability for logical reasoning using specific concepts (age 7-11). By the beginning of this period, verbal thinking begins to predominate in the child's behavior, the activation of the child's inner speech. Finally, the last, final stage of the development of cognitive abilities is the period of the formation and implementation of logical operations based on the development of elements of abstract thinking, logic of reasoning and inferences (11-16 years). At the age of 15-17, the formation of neuro- and psychophysiological mechanisms of mental activity is basically completed. Further development of the mind, intelligence is achieved through quantitative changes, all the basic mechanisms that determine the essence of human intelligence have already been formed.

To determine the level of human intelligence as a general property of the mind, talents, IQ 1 is widely used - iQ, calculated based on the results of psychological testing.

The search for unambiguous, sufficiently substantiated correlations between the level of a person's mental abilities, the depth of mental processes and the corresponding brain structures are still unsuccessful.

16. Fatnktsiandspeech, localization of their sensory and motor zones in the cortex of the human cerebral hemispheres. Development of speech function in children.

The function of speech includes the ability not only to encode, but also to decode a given message using the appropriate conventional signs, while maintaining its meaningful semantic meaning. In the absence of such informational modeling isomorphism, it becomes impossible to use this form of communication in interpersonal communication. So, people cease to understand each other if they use different code elements (different languages, inaccessible to all persons participating in communication). The same mutual misunderstanding also occurs when different semantic content is embedded in the same speech signals.

The system of symbols used by a person reflects the most important perceptual and symbolic structures in the communication system. It should be noted that language mastery substantially complements its ability to perceive the world around it on the basis of the first signaling system, thereby constituting that "extraordinary increase" that IP Pavlov spoke about, noting a fundamentally important difference in the content of human higher nervous activity compared to animals.

Words as a form of thought transmission form the only really observable basis of speech activity. While the words that make up the structure of a particular language can be seen and heard, their meaning and content remain outside the means of direct sensory perception. The meaning of words is determined by the structure and volume of memory, the informational thesaurus of the individual. The semantic (semantic) structure of the language is contained in the subject's information thesaurus in the form of a certain semantic code that converts the corresponding physical parameters of the verbal signal into its semantic code equivalent. At the same time, oral speech serves as a means of direct direct communication, written language allows you to accumulate knowledge, information and acts as a means of communication mediated in time and space.

In neurophysiological studies of speech activity, it has been shown that when perceiving words, syllables and their combinations, specific patterns with a certain spatial and temporal characteristic are formed in the impulse activity of neural populations of the human brain. The use of different words and parts of words (syllables) in special experiments makes it possible to differentiate in electrical reactions (impulse flows) of central neurons both physical (acoustic) and semantic (semantic) components of the brain codes of mental activity (N.P. Bekhtereva).

The presence of an individual's information thesaurus and its active influence on the processes of perception and processing of sensory information are an essential factor explaining the ambiguous interpretation of input information at different times and in different functional states of a person. To express any semantic structure, there are many different forms of representation, such as sentences. The well-known phrase: “He met her in a meadow with flowers,” admits three different semantic concepts (flowers in his hands, in her hands, flowers in the meadow). The same words, phrases can also mean different phenomena, objects (boron, weasel, scythe, etc.).

The linguistic form of communication as the leading form of information exchange between people, the daily use of the language, where only a few words have an exact unambiguous meaning, greatly contributes to human development intuitive ability think and operate with imprecise vague concepts (which are words and phrases - linguistic variables). During the development of its second signaling system, the human brain, whose elements allow for ambiguous relationships between a phenomenon, an object and its designation (a sign - a word), has acquired a remarkable property that allows a person to act rationally and sufficiently rationally under conditions of a probabilistic, "blurred" environment, significant information uncertainty. This property is based on the ability to manipulate, to operate with inaccurate quantitative data, "fuzzy" logic, as opposed to formal logic and classical mathematics, dealing only with precise, unambiguously defined cause-and-effect relationships. Thus, the development of the higher parts of the brain leads not only to the emergence and development of a fundamentally new form of perception, transmission and processing of information in the form of a second signal system, but the functioning of the latter, in turn, results in the emergence and development of a fundamentally new form of mental activity, the construction of inferences based on the use of multivalued (probabilistic, "fuzzy") logic, the Human brain operates with "fuzzy", imprecise terms, concepts, qualitative assessments more easily than quantitative categories, numbers. Apparently, the constant practice of using language with its probabilistic relationship between a sign and its denotation (the phenomenon or object it denotes) served as an excellent training for the human mind to manipulate fuzzy concepts. It is the "fuzzy" logic of human mental activity, based on the function of the second signal system, that provides him with the opportunity heuristic solution many complex problems that cannot be solved by conventional algorithmic methods.

The function of speech is carried out by certain structures of the cerebral cortex. The motor center of speech, which provides oral speech, known as Broca's center, is located at the base of the inferior frontal gyrus (Fig. 15.8). When this part of the brain is damaged, there are disorders of motor reactions that provide oral speech.

The acoustic center of speech (Wernicke's center) is located in the region of the posterior third of the superior temporal gyrus and in the adjacent part - the supramarginal gyrus (gyrus supramarginalis). Damage to these areas leads to a loss of the ability to understand the meaning of the words heard. The optical center of speech is located in the angular gyrus (gyrus angularis), the defeat of this part of the brain makes it impossible to recognize the written.

The left hemisphere is responsible for the development of abstract logical thinking associated with the predominant processing of information at the level of the second signal system. The right hemisphere provides the perception and processing of information, mainly at the level of the first signaling system.

Despite the indicated certain left-hemispheric localization of speech centers in the structures of the cerebral cortex (and, as a result, corresponding violations of oral and written speech when they are damaged), it should be noted that dysfunctions of the second signaling system are usually observed when many other structures of the cortex and subcortical formations are affected. The functioning of the second signaling system is determined by the work of the whole brain.

Among the most common dysfunctions of the second signaling system, there are agnosia - loss of the ability to recognize words (visual agnosia occurs with damage to the occipital zone, auditory agnosia - with damage to the temporal zones of the cerebral cortex), aphasia - speech impairment, agraphia - violation of the letter, amnesia - forgetting words.

The word as the main element of the second signaling system turns into a signal of signals as a result of the process of learning and communication between the child and adults. The word, as a signal of signals, with the help of which generalization and abstraction, which characterize human thinking, are carried out, has become that exclusive feature of higher nervous activity that provides the necessary conditions for the progressive development of the human individual. The ability to pronounce and understand words develops in a child as a result of the association of certain sounds - the words of spoken speech. Using language, the child changes the way of cognition: the sensory (sensory and motor) experience is replaced by the operation of symbols, signs. Learning no longer requires your own sensory experience, it can happen indirectly with the help of language; feelings and actions give way to words.

As a complex signal stimulus, the word begins to form in the second half of the first year of a child's life. As the child grows and develops, as his life experience is replenished, the content of the words he uses expands and deepens. The main trend in the development of the word is that it generalizes a large number of primary signals and, abstracting from their specific variety, makes the concept contained in it more and more abstract.

The highest forms of abstraction in the signaling systems of the brain are usually associated with the act of artistic, creative human activity, in the world of art, where the product of creativity acts as one of the varieties of encoding and decoding information. Even Aristotle emphasized the ambiguous probabilistic nature of the information contained in a work of art. Like any other sign signaling system, art has its own specific code (due to historical and national factors), a system of conventions .. In terms of communication, the information function of art allows people to exchange thoughts and experiences, gives a person the opportunity to join the historical and national experience of others, far people who are distant (both temporally and spatially) from him. Significant or figurative thinking underlying creativity is carried out through associations, intuitive anticipations, through a "gap" in information (P. V. Simonov). Apparently, this is related to the fact that many authors of works of art, artists and writers usually begin to create a work of art in the absence of preliminary clear plans, when the final form of the product of creativity perceived by other people is far from clear to them (especially if it is a work of abstract art). The source of the versatility and ambiguity of such a work of art is understatement, a lack of information, especially for the reader, viewer in terms of understanding and interpreting the work of art. Hemingway spoke about this, comparing a work of art with an iceberg: only a small part of it is visible on the surface (and can be perceived by everyone more or less unambiguously), a large and significant part is hidden under water, which provides the viewer and reader with a wide field for imagination.

17. The biological role of emotions, behavioral and vegetative components. Negative emotions (sthenic and asthenic).

Emotion is a specific state of the mental sphere, one of the forms of a holistic behavioral reaction that involves many physiological systems and is conditioned by both certain motives, the needs of the body, and the level of their possible satisfaction. The subjectivity of the category of emotion is manifested in a person's experience of his relationship to the surrounding reality. Emotions are reflex reactions of the body to external and internal stimuli, characterized by a pronounced subjective color and including almost all types of sensitivity.

Emotions have no biological and physiological value if the body has sufficient information to satisfy its desires, its basic needs. The breadth of needs, and hence the variety of situations when an individual forms, shows an emotional reaction, vary significantly. A person with limited needs is less likely to give emotional reactions in comparison with people with high and diverse needs, for example, with needs related to his social status in society.

Emotional arousal as a result of a certain motivational activity is closely related to the satisfaction of three basic human needs: food, protective and sexual. Emotion as an active state of specialized brain structures determines changes in the behavior of the organism in the direction of either minimizing or maximizing this state. Motivational arousal associated with different emotional states (thirst, hunger, fear) mobilizes the body to quickly and optimally satisfy the need. A satisfied need is realized in a positive emotion, which acts as a reinforcing factor. Emotions arise in evolution in the form of subjective sensations that allow an animal and a person to quickly assess both the needs of the organism themselves and the actions of various factors of the external and internal environment on it. A satisfied need causes a positive emotional experience and determines the direction of behavioral activity. Positive emotions, being fixed in memory, play an important role in the mechanisms of formation of purposeful activity of the organism.

Emotions, realized by a special nervous apparatus, are manifested when there is a lack of accurate information and ways to achieve vital needs. This idea of \u200b\u200bthe nature of emotion allows you to form its informational nature in the following form (P.V.Simonov): E \u003d P (N-S), where E - emotion (a specific quantitative characteristic of the emotional state of the body, usually expressed by important functional parameters of the physiological systems of the body, for example, heart rate, blood pressure, adrenaline level in the body, etc.); P- a vital need of the body (food, defensive, sexual reflexes), aimed at the survival of the individual and the continuation of the race, in a person is additionally determined by social motives; H - information necessary to achieve the goal, to meet this need; FROM - information possessed by the body and which can be used to organize targeted actions.

This concept was further developed in the works of G.I.Kositsky, who proposed to evaluate the value of emotional stress by the formula:

CH \u003d C (I n ∙ V n ∙ E n - I s ∙ V s ∙ E s),

where CH - voltage state, C- target, Ying, Vn, En - the necessary information, time and energy, I s, D s, E s - information, time and energy existing in the organism.

The first stage of tension (CHI) is a state of attention, mobilization of activity, increased efficiency. This stage is of training importance, increasing the functional capabilities of the body.

The second stage of tension (CHII) is characterized by a maximum increase in the body's energy resources, an increase in blood pressure, an increase in the frequency of heartbeats and respiration. A sthenic negative emotional reaction arises, which has an external expression in the form of rage, anger.

The third stage (SNS) is an asthenic negative reaction, characterized by the depletion of the body's resources and finding its psychological expression in a state of horror, fear, melancholy.

The fourth stage (CHIV) is the stage of neurosis.

Emotions should be considered as an additional mechanism of active adaptation, adaptation of the body to the environment with a lack of accurate information about how to achieve its goals. The adaptability of emotional reactions is confirmed by the fact that they involve in intensified activity only those organs and systems that ensure the best interaction between the organism and the environment. The same circumstance is indicated by a sharp activation during emotional reactions of the sympathetic division of the autonomic nervous system, which ensures the adaptive trophic functions of the body. In an emotional state, there is a significant increase in the intensity of oxidative and energy processes in the body.

Emotional response is the total result of both the magnitude of a certain need and the possibility of satisfying this need at a given moment. Ignorance of the means and ways to achieve the goal seems to be a source of strong emotional reactions, while anxiety grows, obsessive thoughts become irresistible. This is true for all emotions. So, an emotional feeling of fear is characteristic of a person if he does not have the means of possible protection from danger. The feeling of rage arises in a person when he wants to crush an opponent, this or that obstacle, but does not have the appropriate strength (rage as a manifestation of powerlessness). A person experiences grief (a corresponding emotional reaction) when they are unable to make up for the loss.

The sign of the emotional reaction can be determined by the formula of P.V. Simonov. Negative emotion arises when H\u003e C and, on the contrary, positive emotion is expected when H < C. So, a person experiences joy when he has an excess of information necessary to achieve a goal, when the goal is closer than we thought (the source of emotion is an unexpected pleasant message, unexpected joy).

In PK Anokhin's theory of the functional system, the neurophysiological nature of emotions is associated with the concept of the functional organization of adaptive actions of animals and humans on the basis of the concept of an "acceptor of action." The signal for the organization and functioning of the nervous apparatus of negative emotions is the fact of the mismatch of the "action acceptor" - the afferent model of the expected results with the afferentation about the real results of the adaptive act.

Emotions have a significant impact on the subjective state of a person: in a state of emotional uplift, the intellectual sphere of the body works more actively, a person is visited by inspiration, and creative activity increases. Emotions, especially positive ones, play an important role as powerful life stimuli for maintaining high performance and human health. All this gives reason to believe that emotion is a state of the highest ascent of a person's spiritual and physical strength.

18. Memory. Short-term and long-term memory. The value of consolidation (stabilization) of memory traces.

19. Types of memory. Memory processes.

20. Nervous structures of memory. Molecular theory of memory.

(combined for convenience)

In the formation and implementation of higher brain functions, the general biological property of fixing, storing and reproducing information, united by the concept of memory, is very important. Memory as the basis of learning and thinking processes includes four closely related processes: memorization, storage, recognition, reproduction. Throughout a person's life, his memory becomes a repository of a huge amount of information: during 60 years of active creative activity, a person is able to perceive 10 13-10 bits of information, of which no more than 5-10% is actually used. This indicates a significant redundancy in memory and the importance not only of memory processes, but also of the forgetting process. Not everything that is perceived, experienced or done by a person is stored in memory, a significant part of the perceived information is forgotten over time. Forgetting is manifested in the impossibility of knowing, remembering something, or in the form of erroneous recognition, recall. Forgetting can be caused by various factors related both to the material itself, its perception, and to the negative influences of other stimuli acting immediately after memorization (the phenomenon of retroactive inhibition, memory suppression). The forgetting process largely depends on the biological significance of the perceived information, the type and nature of memory. Forgetting in some cases can be positive, for example, memory for negative signals, unpleasant events. This is the truth of the wise oriental saying: "Memory is joy with happiness, friend is burning for oblivion."

As a result of the learning process, physical, chemical and morphological changes occur in the nervous structures, which persist for some time and have a significant effect on the reflex reactions carried out by the body. The set of such structural and functional changes in nerve formations, known as "Engram" (trace) of acting stimuli becomes an important factor determining the whole variety of adaptive adaptive behavior of the organism.

Types of memory are classified according to the form of manifestation (figurative, emotional, logical, or verbal-logical), according to the temporal characteristic, or duration (instantaneous, short-term, long-term).

Figurative memory manifests itself in the formation, storage and reproduction of a previously perceived image of a real signal, its nervous model. Under emotional memory understand the reproduction of some previously experienced emotional state upon repeated presentation of the signal that caused the initial occurrence of such an emotional state. Emotional memory is fast and durable. This, obviously, is the main reason for the easier and more stable memorization of emotionally colored signals and stimuli by a person. On the contrary, gray, boring information is memorized much more difficult and quickly erased in memory. Logical (verbal-logical, semantic) memory - memory for verbal signals, designating both external objects and events, and the sensations and representations caused by them.

Instant (iconic) memory consists in the formation of an instant imprint, a trace of the acting stimulus in the receptor structure. This imprint, or the corresponding physicochemical engram of an external stimulus, is distinguished by high information content, completeness of signs, properties (hence the name "iconic memory", that is, a reflection clearly worked out in detail) of the active signal, but also by a high rate of extinction (not stored more than 100-150 ms, if not reinforced, not reinforced by repeated or continued stimulus).

The neurophysiological mechanism of iconic memory, obviously, consists in the processes of reception of the active stimulus and the immediate aftereffect (when the real stimulus no longer acts), expressed in trace potentials formed on the basis of the receptor electric potential. The duration and severity of these trace potentials is determined both by the strength of the acting stimulus and by the functional state, sensitivity and lability of the receptive membranes of receptor structures. The erasure of the memory trace occurs in 100-150 ms.

The biological significance of iconic memory lies in providing the analyzer structures of the brain with the ability to isolate individual features and properties of the sensory signal, and to recognize the image. Iconic memory stores not only information necessary for a clear understanding of sensory signals arriving within fractions of a second, but also contains an incomparably larger amount of information than can be used and is actually used at the subsequent stages of perception, fixation and reproduction of signals.

With a sufficient strength of the acting stimulus, iconic memory goes into the category of short-term (short-term) memory. Short-term memory - working memory, which ensures the performance of current behavioral and mental operations. The basis of short-term memory is the repeated multiple circulation of impulse discharges along circular closed circuits of nerve cells (Fig. 15.3) (Lorente de No, I. S. Beritov). Ring structures can also be formed within the same neuron by return signals formed by the terminal (or lateral, lateral) branches of the axonal process on the dendrites of the same neuron (I.S.Beritov). As a result of repeated passage of impulses along these ring structures, persistent changes gradually form in the latter, laying the foundation for the subsequent formation of long-term memory. Not only excitatory, but also inhibitory neurons can participate in these ring structures. The duration of short-term memory is seconds, minutes after the direct action of the corresponding message, phenomenon, object. The reverberation hypothesis of the nature of short-term memory admits the presence of closed circles of circulation of impulsive excitation both inside the cerebral cortex and between the cortex and subcortical formations (in particular, the thalamocortical nerve circles) containing both sensory and gnostic (learning, recognizing) nerve cells. Intracortical and thalamocortical reverberation circles as the structural basis of the neurophysiological mechanism of short-term memory are formed by cortical pyramidal cells of the V-VI layers, mainly of the frontal and parietal regions of the cerebral cortex.

The participation of the structures of the hippocampus and the limbic system of the brain in short-term memory is associated with the realization by these neural formations of the function of discriminating the novelty of signals and reading incoming afferent information at the input of the waking brain (OS Vinogradova). The realization of the phenomenon of short-term memory practically does not require and is not really associated with significant chemical and structural changes in neurons and synapses, since the corresponding changes in the synthesis of matrix (informational) RNAs require more time.

Despite the differences in hypotheses and theories about the nature of short-term memory, their initial prerequisite is the occurrence of short-term reversible changes in the physicochemical properties of the membrane, as well as the dynamics of mediators in synapses. Ionic currents across the membrane, combined with short-term metabolic shifts during synapse activation, can lead to changes in the efficiency of synaptic transmission lasting several seconds.

The transformation of short-term memory into long-term memory (memory consolidation) is generally due to the onset of persistent changes in synaptic conduction as a result of repeated excitation of nerve cells (learning populations, Hebb ensembles of neurons). The transition from short-term memory to long-term memory (memory consolidation) is caused by chemical and structural changes in the corresponding nerve formations. According to modern neurophysiology and neurochemistry, long-term (long-term) memory is based on complex chemical processes of the synthesis of protein molecules in the cells of the brain. At the heart of memory consolidation are many factors that lead to facilitating the transmission of impulses through synaptic structures (enhanced functioning of certain synapses, an increase in their conductivity for adequate impulse flows). One of these factors is the well-known the phenomenon of post-tetanic potentiation (see Chapter 4), supported by reverberant streams of impulses: stimulation of afferent nerve structures leads to a sufficiently long (tens of minutes) increase in the conduction of spinal motoneurons. This means that the physicochemical changes in the postsynaptic membranes that occur during a persistent shift of the membrane potential are likely to serve as the basis for the formation of memory traces, which are reflected in changes in the protein substrate of the nerve cell.

The changes observed in the mediator mechanisms that provide the process of chemical transfer of excitation from one nerve cell to another are also of some importance in the mechanisms of long-term memory. The basis of plastic chemical changes in synaptic structures is the interaction of mediators, for example, acetylcholine, with receptor proteins of the postsynaptic membrane and ions (Na +, K +, Ca 2+). The dynamics of the transmembrane currents of these ions makes the membrane more sensitive to the action of mediators. It was found that the learning process is accompanied by an increase in the activity of the enzyme cholinesterase, which destroys acetylcholine, and substances that suppress the effect of cholinesterase cause significant memory impairments.

One of the most widespread chemical theories of memory is Hyden's hypothesis about the protein nature of memory. According to the author, the information underlying long-term memory is encoded and recorded in the structure of the polynucleotide chain of the molecule. The different structure of impulse potentials, in which certain sensory information is encoded in the afferent nerve conductors, leads to different rearrangements of the RNA molecule, to the movements of nucleotides in their chains that are specific for each signal. Thus, each signal is fixed in the form of a specific imprint in the structure of the RNA molecule. Based on Hyden's hypothesis, it can be assumed that glial cells involved in the trophic support of neuron functions are included in the metabolic cycle of encoding incoming signals by changing the nucleotide composition of synthesizing RNAs. The entire set of probable rearrangements and combinations of nucleotide elements makes it possible to fix a huge amount of information in the structure of an RNA molecule: the theoretically calculated amount of this information is 10–10 20 bits, which significantly exceeds the real volume of human memory. The process of fixing information in a nerve cell is reflected in the synthesis of a protein, into the molecule of which the corresponding trace imprint of changes in the RNA molecule is introduced. In this case, the protein molecule becomes sensitive to a specific pattern of the impulse flow, thereby, as it were, it recognizes the afferent signal that is encoded in this impulse pattern. As a result, a transmitter is released in the corresponding synapse, leading to the transfer of information from one nerve cell to another in the system of neurons responsible for fixing, storing and reproducing information.

Some hormonal peptides, simple protein substances, and a specific S-100 protein are possible substrates for long-term memory. Some hormones (ACTH, growth hormone, vasopressin, etc.) belong to such peptides that stimulate, for example, the conditioned-reflex learning mechanism.

An interesting hypothesis about the immunochemical mechanism of memory formation was proposed by I.P. Ashmarin. The hypothesis is based on the recognition of the important role of an active immune response in consolidation and the formation of long-term memory. The essence of this concept is as follows: as a result of metabolic processes on synaptic membranes during excitation reverberation at the stage of short-term memory formation, substances are formed that play the role of an antigen for antibodies produced in glial cells. Binding of an antibody to an antigen occurs with the participation of stimulators of the formation of mediators or an inhibitor of enzymes that destroy and break down these stimulating substances (Fig. 15.4).

A significant place in providing neurophysiological mechanisms of long-term memory is given to glial cells (Galambus, A. I. Roitbak), the number of which in the central nervous formations is an order of magnitude greater than the number of nerve cells. The following mechanism of the participation of glial cells in the implementation of the conditioned reflex mechanism of learning is proposed. At the stage of formation and strengthening of the conditioned reflex in the glial cells adjacent to the nerve cell, the synthesis of myelin is enhanced, which envelops the terminal thin branches of the axonal process and thereby facilitates the conduction of nerve impulses along them, as a result of which the efficiency of synaptic transmission of excitation increases. In turn, the stimulation of myelin formation occurs as a result of depolarization of the membrane of the oligodendrocyte (glial cell) under the influence of the incoming nerve impulse. Thus, long-term memory may be based on conjugate changes in the neuroglial complex of the central nervous formations.

The ability to selectively turn off short-term memory without impairing long-term and selective effects on long-term memory in the absence of any impairment of short-term memory is usually considered as evidence of the different nature of the underlying neurophysiological mechanisms. Indirect evidence of the presence of certain differences in the mechanisms of short-term and long-term memory are the features of memory disorders with damage to brain structures. So, with some focal lesions of the brain (lesions of the temporal zones of the cortex, structures of the hippocampus), when it is shaken, memory disorders occur, expressed in the loss of the ability to remember current events or events of the recent past (that occurred shortly before the impact that caused this pathology) while preserving memory for the previous ones, events that happened long ago. However, a number of other influences have the same effect on both short-term and long-term memory. Apparently, despite some noticeable differences in physiological and biochemical mechanisms responsible for the formation and manifestation of short-term and long-term memory, their nature has much more in common than different; they can be considered as successive stages of a single mechanism of fixation and strengthening of trace processes occurring in nerve structures under the influence of repetitive or constantly acting signals.

21. Concept of functional systems (PK Anokhin). Systems approach in knowledge.

The concept of self-regulation of physiological functions found its fullest reflection in the theory of functional systems developed by academician P.K. Anokhin. According to this theory, the balancing of the organism with the environment is carried out by self-organizing functional systems.

Functional systems (FS) are a dynamically folding self-regulating complex of central and peripheral formations, providing the achievement of useful adaptive results.

The result of the action of any FS is a vital adaptive indicator necessary for the normal functioning of the organism in biological and social terms. Hence follows the system-forming role of the result of action. It is to achieve a certain adaptive result that FS are formed, the complexity of the organization of which is determined by the nature of this result.

The variety of adaptive results useful for the body can be reduced to several groups: 1) metabolic results resulting from metabolic processes at the molecular (biochemical) level, creating substrates or end products necessary for vital activity; 2) homeopathic results, which are the leading indicators of body fluids: blood, lymph, interstitial fluid (osmotic pressure, pH, content of nutrients, oxygen, hormones, etc.), providing various aspects of normal metabolism; 3) the results of the behavioral activity of animals and humans, satisfying the basic metabolic, biological needs: food, drinking, sexual, etc .; 4) the results of a person's social activities that satisfy social (creation of a social product of labor, environmental protection, protection of the fatherland, arrangement of everyday life) and spiritual (acquisition of knowledge, creativity) needs.

Each FS includes various organs and tissues. The unification of the latter in the FS is carried out by the result, for the achievement of which the FS is created. This principle of the organization of the FS was called the principle of selective mobilization of the activity of organs and tissues into an integral system. For example, in order to provide an optimal blood gas composition for metabolism, selective mobilization of the activity of the lungs, heart, blood vessels, kidneys, hematopoietic organs, and blood occurs in the respiratory system.

The inclusion of individual organs and tissues in the FS is carried out according to the principle of interaction, which provides for the active participation of each element of the system in achieving a useful adaptive result.

In the given example, each element actively contributes to the maintenance of the gas composition of the blood: the lungs provide gas exchange, the blood binds and transports O 2 and CO 2, the heart and blood vessels provide the necessary blood speed and value.

To achieve results of various levels, multilevel FS are formed. FS at any level of the organization has a fundamentally similar structure, which includes 5 main components: 1) useful adaptive result; 2) result acceptors (control devices); 3) reverse afferentation, which supplies information from receptors to the central link of the FS; 4) central architectonics - selective unification of nerve elements of various levels into special nodal mechanisms (control devices); 5) executive components (reaction apparatus) - somatic, vegetative, endocrine, behavioral.

22. Central mechanisms of functional systems that form behavioral acts: motivation, stage of afferent synthesis (situational afferentation, triggering afferentation, memory), stage of decision making. Formation of an acceptor of action results, reverse afferentation.

The state of the internal environment is constantly monitored by the corresponding receptors. The source of changes in the parameters of the internal environment of the body is the metabolic process (metabolism) continuously flowing in the cells, accompanied by the consumption of the initial and the formation of final products. Any deviation of the parameters from the parameters optimal for metabolism, as well as changes in the results of a different level, is perceived by the receptors. From the latter, information is transmitted by a feedback link to the corresponding nerve centers. On the basis of the incoming information, the structures of various levels of the central nervous system are selectively involved in this FS to mobilize the executive organs and systems (reaction apparatus). The activity of the latter leads to the restoration of the result necessary for metabolism or social adaptation.

The organization of various FS in the body is fundamentally the same. This is isomorphism principle FS.

At the same time, there are differences in their organization, which are due to the nature of the result. FS, which determine various indicators of the internal environment of the organism, are genetically determined, often include only internal (vegetative, humoral) mechanisms of self-regulation. These include PS, which determine the optimal level for tissue metabolism, the level of blood mass, formed elements, the reaction of the medium (pH), and blood pressure. Other FS of the homeostatic level also include the external link of self-regulation, which provides for the interaction of the organism with the external environment. In the work of some PSs, the external link plays a relatively passive role as a source of necessary substrates (for example, oxygen for the PS of respiration), in others, the external link of self-regulation is active and includes purposeful human behavior in the environment, aimed at transforming it. These include PS, which provides the optimal level of nutrients for the body, osmotic pressure, and body temperature.

FS of the behavioral and social level are extremely dynamic in their organization and are formed as the corresponding needs arise. In such FS, the external link of self-regulation plays a leading role. At the same time, human behavior is determined and corrected genetically, by individually acquired experience, as well as by numerous disturbing influences. An example of such FS is the production activity of a person to achieve a socially significant result for society and the individual: the work of scientists, artists, writers.

FS control devices. The central architectonics (control apparatus) of the FS, which consists of several stages, is also built on the principle of isomorphism (see Fig. 3.1). The initial stage is the stage of afferent synthesis. It is based on dominant motivation, arising on the basis of the body's most significant needs at the moment. Arousal generated by dominant motivation mobilizes genetic and individually acquired experience (memory) to meet this need. Habitat status information supplied situational afferentation, allows in a specific situation to assess the possibility and, if necessary, adjust the past experience of satisfying the need. The interaction of excitations created by the dominant motivation, memory mechanisms and environmental afferentation creates a state of readiness (prestarting integration) necessary to obtain an adaptive result. Start-up afferentation transfers the system from a state of readiness to a state of activity. At the stage of afferent synthesis, the dominant motivation determines what to do, memory - how to do it, situational and triggering afferentation - when to do it in order to achieve the desired result.

The stage of afferent synthesis ends with the adoption of a decision. At this stage, out of many possible ones, the only way is chosen to satisfy the leading needs of the organism. There is a limitation of the degrees of freedom of the FS activity.

Following the decision, an acceptor of the result of the action and the program of action are formed. IN the acceptor of the results of action all the main features of the future result of the action are programmed. This programming takes place on the basis of dominant motivation, which extracts from memory mechanisms the necessary information about the characteristics of the result and the ways to achieve it. Thus, the acceptor of action results is an apparatus for foresight, forecasting, modeling of the results of the FS activity, where the parameters of the result are modeled and compared with the afferent model. Information about the parameters of the result is supplied using reverse afferentation.

The program of action (efferent synthesis) is a coordinated interaction of somatic, vegetative and humoral components in order to successfully achieve a useful adaptive result. The program of action forms a necessary adaptive act in the form of a certain complex of excitations in the central nervous system before its implementation in the form of specific actions. This program determines the inclusion of efferent structures necessary to obtain a useful result.

The necessary link in the work of the FS is reverse afferentation. With its help, individual stages and the final result of the systems' activity are assessed. Information from the receptors goes through the afferent nerves and humoral communication channels to the structures that make up the acceptor of the result of the action. The coincidence of the parameters of the real result and the properties of the model prepared in the acceptor means the satisfaction of the initial needs of the body. FS activity ends there. Its components can be used in other filesystems. If the parameters of the result and the properties of the model, prepared on the basis of afferent synthesis in the acceptor of the results of action, do not coincide, an orientation-research reaction arises. It leads to a restructuring of afferent synthesis, making a new decision, clarifying the characteristics of the model in the acceptor of the results of an action and the program for achieving them. The activities of the FS are carried out in a new direction, necessary to meet the leading needs.

Principles of FS interaction. Several functional systems work simultaneously in the body, which provides for their interaction, which is based on certain principles.

The principle of systems genesis presupposes selective maturation and involution of functional systems. Thus, PSs of blood circulation, respiration, nutrition and their individual components in the process of ontogenesis mature and develop earlier than other PSs.

The principle of multiparameter (multiply connected) interactions defines the generalized activity of various FS, aimed at achieving a multicomponent result. For example, the parameters of homeostasis (osmotic pressure, KOS, etc.) are provided by independent FS, which are combined into a single generalized FS of homeostasis. It determines the unity of the internal environment of the organism, as well as its changes due to metabolic processes and the active activity of the organism in the external environment. In this case, the deviation of one indicator of the internal environment causes a redistribution in certain ratios of other parameters of the result of the generalized FS of homeostasis.

Hierarchy principle assumes that the FS of the organism is arranged in a certain series in accordance with the biological or social significance. For example, in biological terms, the dominant position is occupied by the FS, which ensures the preservation of the integrity of tissues, then - the FS of nutrition, reproduction, etc. The activity of the organism in each time period is determined by the dominant FS in terms of survival or adaptation of the organism to the conditions of existence. After the satisfaction of one leading need, the dominant position is occupied by another need, which is most important in terms of social or biological significance.

The principle of consistent dynamic interaction provides for a clear sequence of changes in the activities of several interrelated FS. The factor that determines the beginning of the activity of each subsequent FS is the result of the activity of the previous system. Another principle of organizing the interaction of the FS is the principle of systemic quantization of life. For example, in the process of breathing, the following systemic "quanta" with their final results can be distinguished: inhalation and the flow of a certain amount of air into the alveoli; diffusion of О 2 from the alveoli to the pulmonary capillaries and the binding of O 2 to hemoglobin; transport of O 2 to tissues; diffusion of O 2 from blood into tissues and CO 2 in the opposite direction; CO2 transport to the lungs; diffusion of CO 2 from the blood into the alveolar air; exhalation. The principle of systemic quantization applies to human behavior.

Thus, the management of the body's vital activity by organizing the FS of homeostatic and behavioral levels has a number of properties that allow the body to adequately adapt to the changing external environment. FS allows you to react to the disturbing influences of the external environment and, on the basis of reverse affectation, to rebuild the activity of the organism when the parameters of the internal environment are deviated. In addition, in the central mechanisms of the FS, an apparatus for predicting future results is formed - an acceptor of the result of an action, on the basis of which the organization and initiation of adaptive acts anticipating actual events occurs, which significantly expands the adaptive capabilities of the organism. Comparison of the parameters of the achieved result with the afferent model in the acceptor of the results of action serves as the basis for correcting the body's activity in terms of obtaining exactly those results that best ensure the adaptation process.

23. Physiological nature of sleep. Sleep theories.

Sleep is a vital, periodically occurring special functional state, characterized by specific electrophysiological, somatic and vegetative manifestations.

It is known that the periodic alternation of natural sleep and wakefulness refers to the so-called circadian rhythms and is largely determined by the daily change in illumination. A person spends about a third of his life in a dream, which led to a long-standing and keen interest among researchers in this state.

Theories of sleep mechanisms.According to concepts of 3. Freud, sleep is a state in which a person interrupts conscious interaction with the external world in the name of deepening into the internal world, while external irritations are blocked. According to 3. Freud, the biological purpose of sleep is rest.

Humoral concept the main reason for the onset of sleep is explained by the accumulation of metabolic products during the waking period. According to current data, specific peptides, for example, the "delta sleep" peptide, play an important role in inducing sleep.

Information deficit theory the main reason for the onset of sleep is believed to be the limitation of sensory influx. Indeed, in observations on volunteers in preparation for space flight, it was revealed that sensory deprivation (a sharp restriction or cessation of the flow of sensory information) leads to the onset of sleep.

According to the definition of I.P. Pavlov and many of his followers, natural sleep is a diffuse inhibition of cortical and subcortical structures, cessation of contact with the outside world, extinction of afferent and efferent activity, disconnection of conditioned and unconditioned reflexes during sleep, as well as the development of general and private relaxation. Modern physiological studies have not confirmed the presence of diffuse inhibition. Thus, microelectrode studies revealed a high degree of neuronal activity during sleep in almost all parts of the cerebral cortex. From the analysis of the pattern of these discharges, it was concluded that the state of natural sleep represents a different organization of brain activity, different from the activity of the brain in the waking state.

24. Phases of sleep: "slow" and "fast" (paradoxical) according to EEG indicators. Brain structures involved in the regulation of sleep and wakefulness.

The most interesting results were obtained during polygraphic research during night sleep. During such studies throughout the night, the electrical activity of the brain is continuously recorded on a multichannel recorder - an electroencephalogram (EEG) at various points (most often in the frontal, occipital and parietal lobes) synchronously with the registration of rapid (REM) and slow (MDG) eye movements and electromyograms of skeletal muscles, as well as a number of vegetative indicators - the activity of the heart, digestive tract, respiration, temperature, etc.

EEG during sleep. The discovery by E. Azerinsky and N. Kleitman of the phenomenon of "fast", or "paradoxical" sleep, during which rapid eye movements (REM) with closed eyelids and general complete muscle relaxation were discovered, served as the basis for modern studies of the physiology of sleep. It turned out that sleep is a combination of two alternating phases: "slow" or "orthodox" sleep and "fast" or "paradoxical" sleep. These sleep phases are named after characteristic features EEG: during "slow" sleep, mainly slow waves are recorded, and during "REM" sleep - a fast beta rhythm, characteristic of a person's wakefulness, which gave reason to call this phase of sleep "paradoxical" sleep. On the basis of the electroencephalographic picture, the phase of "slow" sleep, in turn, is divided into several stages. The following main stages of sleep are distinguished:

stage I - nap, the process of falling asleep. This stage is characterized by polymorphic EEG, the disappearance of the alpha rhythm. During a night's sleep, this stage is usually short (1-7 minutes). Sometimes you can observe slow movements of the eyeballs (MDG), while their rapid movements (REM) are completely absent;

stage II is characterized by the appearance on the EEG of so-called sleep spindles (12-18 per second) and vertex potentials, two-phase waves with an amplitude of about 200 μV against a general background of electrical activity with an amplitude of 50-75 μV, as well as K-complexes (vertex potential with the subsequent "sleepy spindle"). This stage is the longest of all; it can take about 50 % the entire night's sleep. No eye movements are observed;

stage III is characterized by the presence of K-complexes and rhythmic activity (5-9 per second) and the appearance of slow, or delta-waves (0.5-4 per second) with an amplitude above 75 μV. The total duration of delta waves in this stage takes from 20 to 50% of the entire III stage. No eye movements. Quite often, this stage of sleep is called delta sleep.

Stage IV - the stage of "fast" or "paradoxical" sleep is characterized by the presence of desynchronized mixed activity on the EEG: fast low-amplitude rhythms (in these manifestations it resembles stage I and active wakefulness - beta rhythm), which can alternate with low-amplitude slow and short flashes of alpha rhythm, sawtooth discharges, REM with closed eyelids.

Night sleep usually consists of 4-5 cycles, each of which begins with the first stages of "slow" sleep and ends with "REM" sleep. The cycle duration in a healthy adult is relatively stable and is 90-100 minutes. In the first two cycles, "slow" sleep prevails, in the last - "fast", and the "delta" -sleep is sharply reduced and may even be absent.

The duration of "slow" sleep is 75-85%, and "paradoxical" - 15-25 % from the total duration of a night's sleep.

Muscle tone during sleep. Throughout all stages of "slow" sleep, the tone of skeletal muscles progressively decreases, in "REM" sleep muscle tone is absent.

Vegetative shifts during sleep. During "slow" sleep, the work of the heart slows down, the respiratory rate decreases, the occurrence of Cheyne-Stokes respiration is possible, as the "slow" sleep deepens, there may be partial obstruction of the upper respiratory tract and the appearance of snoring. The secretory and motor functions of the digestive tract decrease with the deepening of "slow" sleep. The body temperature before falling asleep decreases and as NREM sleep deepens, this decrease progresses. It is believed that a decrease in body temperature may be one of the reasons for the onset of sleep. Awakening is accompanied by an increase in body temperature.

In REM sleep, the heart rate can exceed the heart rate in wakefulness, various forms of arrhythmias and significant changes in blood pressure may occur. It is believed that a combination of these factors can lead to sudden death during sleep.

Breathing is irregular, often prolonged apnea occurs. Thermoregulation is impaired. The secretory and motor activity of the digestive tract is practically absent.

The stage of "REM" sleep is very characteristic of the presence of an erection of the penis and clitoris, which is observed from the moment of birth.

It is believed that the lack of an erection in adults indicates organic brain damage, and in children it will lead to a violation of normal sexual behavior in adulthood.

The functional significance of the individual stages of sleep is different. At present, sleep is generally considered as an active state, as a phase of the circadian (circadian) biorhythm that performs an adaptive function. In a dream, the volume of short-term memory, emotional balance, and a disturbed system of psychological defenses are restored.

During delta sleep, the information received during the waking period is organized, taking into account the degree of its significance. It is assumed that during delta sleep, physical and mental performance is restored, which is accompanied by muscle relaxation and pleasant experiences; an important component of this compensatory function is the synthesis of protein macromolecules during delta sleep, including in the central nervous system, which are further used during REM sleep.

In early studies of REM sleep, it was found that significant mental changes occur with prolonged REM sleep deprivation. Emotional and behavioral disinhibition appears, hallucinations, paranoid ideas and other psychotic phenomena appear. Later, these data were not confirmed, but the effect of REM sleep deprivation on emotional status, resistance to stress and mechanisms of psychological defense was proved. Moreover, analysis of many studies shows that REM sleep deprivation has a beneficial therapeutic effect in the case of endogenous depression. REM sleep plays a large role in reducing unproductive anxiety stress.

Sleep and mental activity, dreams. When falling asleep, volitional control over thoughts is lost, contact with reality is broken and so-called regressive thinking is formed. It arises with a decrease in sensory influx and is characterized by the presence of fantastic representations, dissociation of thoughts and images, fragmentary scenes. Hypnagogic hallucinations appear, which are a series of frozen visual images (such as slides), while subjectively time flows much faster than in the real world. In "delta" -sleep, conversations in a dream are possible. Strenuous creative activity dramatically increases the duration of "REM" sleep.

It was initially found that dreams occur in REM sleep. Later it was shown that dreams are also characteristic of "slow" sleep, especially for the stage of "delta" -sleep. The causes of occurrence, the nature of the content, the physiological significance of dreams have long attracted the attention of researchers. In ancient peoples, dreams were surrounded by mystical ideas about the afterlife and were identified with communication with the dead. The content of dreams was attributed to the function of interpretation, predictions, or prescriptions for subsequent actions or events. Many historical monuments testify to the significant influence of the content of dreams on the everyday and socio-political life of people of almost all ancient cultures.

In the ancient era of human history, dreams were also interpreted in their connection with active wakefulness and emotional needs. Sleep, as Aristotle defined, is a continuation of the mental life that a person lives in a waking state. Long before Z. Freud's psychoanalysis, Aristotle believed that sensory function is reduced in sleep, yielding to the sensitivity of dreams to emotional subjective distortions.

I.M.Sechenov called dreams unprecedented combinations of experienced impressions.

All people see dreams, but many do not remember them. It is believed that in some cases this is due to the peculiarities of memory mechanisms in a particular person, while in other cases it is a kind of psychological defense mechanism. There is a sort of repression of dreams that are unacceptable in content, that is, we “try to forget”.

Physiological significance of dreams. It lies in the fact that dreams use the mechanism of figurative thinking to solve problems that could not be solved in wakefulness with the help of logical thinking. A striking example is the famous case of D. I. Mendeleev, who "saw" the structure of his famous periodic table of elements in a dream.

Dreams are a kind of psychological defense mechanism - reconciliation of unresolved conflicts in wakefulness, relieving tension and anxiety. Suffice it to recall the proverb "the morning is wiser than the evening." When resolving a conflict during sleep, dreams are remembered, otherwise dreams are displaced or dreams of a frightening nature arise - "one has nightmares."

Dreams differ between men and women. As a rule, men are more aggressive in dreams, while in women, sexual components occupy a large place in the content of dreams.

Sleep and emotional stress. Studies have shown that emotional stress significantly affects night sleep, changing the duration of its stages, that is, disrupting the structure of night sleep, and altering the content of dreams. Most often, during emotional stress, a decrease in the period of "REM" sleep and an increase in the latent period of falling asleep are noted. Before the exam, the subjects had a reduction in the total duration of sleep and its individual stages. For parachutists, before difficult jumps, the period of falling asleep and the first stage of "slow" sleep increase.

Introduction

The basic principles and patterns of higher nervous activity are common to both animals and humans. However, the higher nervous activity of man differs significantly from the higher nervous activity of animals. A fundamentally new signaling system arises in a person in the process of his social labor activity and reaches a high level of development.

The first signaling system of reality is a system of our immediate sensations, perceptions, impressions from specific objects and phenomena of the surrounding world. Word (speech) is the second signaling system (signaling signals). It arose and developed on the basis of the first signaling system and is significant only in close connection with it.

Thanks to the second signaling system (word), temporary connections are formed in humans more quickly than in animals, for the word carries the socially developed meaning of the object. Human temporary nerve connections are more stable and persist without reinforcement for many years.

The word is a means of cognition of the surrounding reality, a generalized and indirect reflection of its essential properties. With the word "a new principle of nervous activity is introduced - distraction and at the same time the generalization of countless signals - a principle that determines unlimited orientation in the world around and creates the highest human adaptation - science."

§ 1. Word as a signal of signals

The patterns of conditioned reflex activity established for animals are also characteristic of humans. However, human behavior is so different from that of animals that it must have additional neurophysiological mechanisms that determine the characteristics of its higher nervous activity.

I.P. Pavlov believed that the specificity of human higher nervous activity arose as a result of a new way of interacting with the outside world, which became possible during the labor activity of people and which was expressed in speech. Speech arose as a means of communication between people in the labor process. Its development led to the emergence of language. IP Pavlov wrote that "the word made us people ...". With the emergence of language, a new system of stimuli appeared in man in the form of words denoting various objects, phenomena of the surrounding world and their relationships. Thus, in humans, unlike animals, there are two systems of signal stimuli: the first signal system, consisting of direct effects of the internal and external environment on sensory inputs, and the second signal system, consisting mainly of words designating these effects.

A word for an object is not the result of a simple word-object association.

The connections of a word with an object are qualitatively different from the first signal connections. Although the word is a real physical stimulus (auditory, visual, kinesthetic), it is fundamentally different in that it reflects not specific, but the most essential, basic properties and relationships of objects and phenomena. It provides an opportunity for generalized and abstract reflection of reality. This function of the word clearly reveals itself in the study of deaf-dumbness. According to A.R. Luria, a deaf-mute who is not trained in speech, is not able to abstract a quality or action from a real object. He cannot form abstract concepts and systematize the phenomena of the external world according to abstract signs.

Thus, the first signaling system is understood as the work of the brain, which conditions the transformation of direct stimuli into signals of various types of body activity. This is a system of concrete, directly sensory images of reality, fixed by the brain of humans and animals. The second signaling system refers to the function of the human brain, which deals with verbal symbols ("signaling signals"). This is a system of generalized reflection of the surrounding reality in the form of concepts, the content of which is fixed in words, mathematical symbols, images of works of art.

The integrative activity of the human nervous system is carried out not only on the basis of direct sensations and impressions, but also by operating with words. Moreover, the word acts not only as a means of expressing thoughts. The word reconstructs the thinking and intellectual functions of a person, since the thought itself is accomplished and formed with the help of the word.

The essence of thinking is in performing some internal operations with images in the internal picture of the world. These operations make it possible to build and complete a changing model of the world. Thanks to the word, the picture of the world becomes more perfect, on the one hand, more generalized, on the other, more differentiated. Joining the immediate image of an object, the word highlights its essential features, introduces into it forms of analysis and synthesis that are not directly accessible to the subject. The word translates the subjective meaning of the image into a system of meanings, which makes it more understandable for both the subject and any listener.

§ 2. Speech and its functions

Researchers identify three main functions of speech: communicative, regulatory and programming. The communicative function is the implementation of communication between people using language. In the communicative function, the function of the message and the function of motivation to action are distinguished. When communicating, a person points to a subject or expresses his judgments on any issue. The incentive power of speech depends on its emotional expressiveness.

Through the word, a person gains knowledge about objects and phenomena of the surrounding world without direct contact with them. The system of verbal symbols expands the possibilities of human adaptation to the environment, the possibilities of his orientation in the natural and social world. Through the knowledge accumulated by humanity and recorded in oral and written speech, a person is connected with the past and future.

The human ability to communicate with the help of words-symbols has its origins in the communicative abilities of the higher apes.

L.A. Firsov and his co-workers propose to divide languages \u200b\u200binto primary and secondary. They refer to the primary language as the very behavior of an animal and a person, various reactions: a change in the shape, size and color of certain parts of the body, changes in feather and hair, as well as innate communicative (voice, facial expressions, posture, gestures, etc.) signals. Thus, the primary language corresponds to the pre-conceptual level of reflection of reality in the form of sensations, perceptions and representations. Secondary language represents the conceptual level of reflection. It distinguishes stage A, common for humans and animals (pre-verbal concepts). The complex forms of generalization that anthropoids and some lower monkeys reveal correspond to stage A. At stage B of the secondary language (verbal concepts), the speech apparatus is used. Thus, the primary language corresponds to the first signaling system, according to I.P. Pavlov, and stage B of the secondary language - the second signaling system. According to L.A. Orbeli, the evolutionary continuity of the nervous regulation of behavior is expressed in the "intermediate stages" of the development of the first signaling system into the second. They correspond to stage A of the secondary language.

Language is a certain system of signs and rules for their formation. A person learns the language during life as a result of learning. What language he learns as a native depends on the environment in which he lives and the conditions of upbringing. There is a critical period for language acquisition. After 10 years, the ability to develop neural networks necessary to build a speech center is lost. Mowgli is one of the literary examples of the loss of speech function.

A person can master different languages. This means that he uses the opportunity to designate the same object with different symbols, both orally and in writing. When studying the second and subsequent languages, the same neural networks are used that were previously formed when mastering the native language. More than 2,500 living developing languages \u200b\u200bare currently known.

Language knowledge is not inherited. However, a person has genetic prerequisites for communication through speech and language acquisition. They are embedded in the features of both the central nervous system and the speech motor apparatus, the larynx.

The regulating function of speech realizes itself in higher mental functions - conscious forms of mental activity. The concept of higher mental function was introduced by L.S. Vygotsky and developed by A.R. Luria and other Russian psychologists. A distinctive feature of higher mental functions is their voluntary nature.

Initially, the highest mental function is, as it were, divided between two people. One person regulates the behavior of another person with the help of special stimuli ("signs"), among which speech is of the greatest importance. Learning to apply to one's own behavior the stimuli that were originally used to regulate the behavior of other people, a person comes to master his own behavior. As a result of the process of interiorization, inner speech becomes the mechanism by which a person masters his own personal skills in the works of A.R. Luria, E.D. Chomskoy shows the relationship of the regulatory function of speech with the anterior hemispheres. They established the important role of the convexital parts of the prefrontal cortex in the regulation of voluntary movements and actions, constructive activity, and various intellectual processes.

The programming function of speech is expressed in the construction of semantic schemes of a speech utterance, grammatical structures of sentences, in the transition from a concept to an external expanded utterance. At the heart of this process is internal programming, carried out using internal speech. As clinical data show, it is necessary not only for speech utterance, but also for the construction of a wide variety of movements and actions. The programming function of speech suffers with lesions in the anterior sections of the speech zones - the posterior and premotor sections of the left hemisphere.

§ 3. Development of speech in a child

In a child, a word does not immediately become a signal of signals. This quality is acquired gradually as the brain matures and new and increasingly complex temporary connections are formed. In an infant, the first conditioned reflexes are unstable and appear from the second, sometimes third month of life. First of all, conditioned food reflexes are formed to taste and odor stimuli, then to vestibular (swaying) and later to sound and visual. A weakness of the processes of excitation and inhibition is characteristic of an infant. He easily develops protective inhibition. This is indicated by the almost continuous sleep of the newborn (about 20 hours).

Conditioned reflexes to verbal stimuli appear only in the second half of the year of life. When an adult communicates with a child, the word is usually combined with other immediate stimuli. As a result, it becomes one of the components of the complex. For example, the words "Where is mom?" the child reacts by turning his head towards the mother only in combination with other stimuli: kinesthetic (from the position of the body), visual (familiar environment, the face of the person asking the question), sound (voice, intonation). It is necessary to change one of the components of the complex, and the reaction to the word disappears. Gradually, the word begins to acquire a leading meaning, displacing other components of the complex. First, the kinesthetic component drops out, then visual and sound stimuli lose their meaning. And just one word causes a reaction.

The presentation of a certain object while simultaneously naming it leads to the fact that the word begins to replace the object it designates. This ability appears in a child by the end of the first year of life or the beginning of the second. However, the word first replaces only a specific object, for example a given doll, and not a doll in general. That is, the word acts at this stage of development as a first-order integrator.

The transformation of a word into a second-order integrator or "signal of signals" occurs at the end of the second year of life. To do this, it is necessary that at least 15 different conditional connections (a bundle of connections) were developed for it. The child must learn to operate with various objects, designated by one word. If the number of conditioned connections developed is less, then the word remains a symbol that replaces only a specific object.

Between 3 and 4 years of life, words appear - integrators of the third order. The child begins to understand words such as "toy", "flowers", "animals". By the fifth year of life, a child has more complex concepts. So, the word "thing" he refers to toys, and dishes, and furniture, etc.

The development of the second signaling system proceeds in close connection with the first. In the process of ontogenesis, several phases of the development of the joint activity of two signaling systems are distinguished.

Initially, the conditioned reflexes of the child are carried out at the level of the first signaling system. That is, a direct stimulus comes into contact with direct vegetative and somatic reactions. According to the terminology of A.G. Ivanov-Smolensky, these are connections type H-H ("Immediate stimulus - immediate reaction"). In the second half of the year, the child begins to respond to verbal stimuli with direct autonomic and somatic reactions. Thus, conditional links are added type C-H ("Verbal stimulus is an immediate reaction"). By the end of the first year of life (after 8 months), the child begins to imitate the speech of an adult in the same way as primates do, with the help of separate sounds denoting something outside or some state of his own. Then the child begins to speak the words. At first, they are also not associated with any events in the outside world. At the same time, at the age of 1.5-2 years, one word often denotes not only an object, but also actions, experiences associated with it. Later, there is a differentiation of words denoting objects, actions, feelings. Thus, a new type of N-S connections is added ("immediate stimulus - verbal reaction"). In the second year of life, the child's vocabulary increases to 200 or more words. He begins to combine words into the simplest speech chains, and then build sentences. By the end of the third year, the vocabulary reaches 500-700 words. Verbal reactions are caused not only by immediate stimuli, but also by words. The child learns to speak. Thus, a new type of C-C connections appears ("verbal stimulus - verbal reaction").

With the development of speech and the formation of a generalizing action of a word in a child aged 2-3 years, the integrative activity of the brain becomes more complicated: conditioned reflexes appear on the relationship of quantities, weight, distance, color of objects. Children aged 3-4 years develop various motor stereotypes. However, among conditioned reflexes, direct temporary connections predominate. Feedbacks arise later and the power relations between them level out by 5-6 years of age.

§ 4. The relationship of the first and second signaling systems

The phenomenon of elective (or selective) irradiation of nervous processes between the two systems belongs to the laws of interaction between two signaling systems. It is due to the presence of nerve connections formed in the process of ontogenesis between the immediate stimuli and the words designating them. The phenomenon of elective irradiation from the first signal system to the second was first described in 1927 by O.P. Skit. In children, a conditioned motor reflex was developed in response to a call with food reinforcement. Then the conditioned stimulus was replaced with different words. It turned out that only when pronouncing the words "bell" or "ringing", as well as showing a card on which "bell" is written, a conditioned motor reaction occurs. Elective irradiation of excitation was also obtained for the autonomic reaction after the elaboration of a conditioned defensive reflex to the call. Replacing the call with the phrase: "I give the call" causes the same vascular defensive reaction: vasoconstriction of the arm and head, like the call itself. Other words do not cause that reaction. In adults, the transition of excitation from the first signaling system to the second is less pronounced than in children. It is more easily detected by vegetative indicators than by motor indicators. Selective irradiation of excitation also occurs from the second signaling system to the first.

There is a brake irradiation between the two signaling systems. The development of differentiation for the first signal stimuli can be reproduced by replacing them with the corresponding words. In most cases, elective irradiation between two signaling systems occurs as a short-term phenomenon after the development of conditioned connections.

Another feature of the interaction of two signaling systems is their mutual inhibition (or mutual induction). The development of a conditioned reflex within the first signaling system (for example, a blinking conditioned reflex) is delayed under conditions of activation of the second signaling system (for example, when solving an arithmetic problem orally). The presence of inductive relationships between signaling systems creates favorable conditions for the distraction of a word from the specific phenomenon that it designates, which leads to the relative independence of their impact. Automation of motor skills also indicates the relative independence of the functioning of each of the signaling systems.

In terms of the conceptual reflex arc, E.N. Sokolov's verbal stimuli act on the basis of a system of connections formed during a person's life. When a conditioned reflex is developed to a word, whole bundles, groups of verbal stimuli, come into connection with the reaction. The strength of the connection is determined by the semantic closeness to the conditioned verbal stimulus. These verbal stimuli, by analogy with sensory stimuli, which form the receptive field of the command neuron, create a semantic field for command neurons that initiate defensive, orientation, and other reflexes.

The connection between the two signaling systems, which is designated as "verbal stimulus - immediate reaction", is the most widespread. All cases of controlling behavior, movement with the help of the word refer to this type of connection. In this case, speech regulation is carried out not only with the help of external speech signals, but also through internal speech.

Another important form of relationship between the first and second signaling systems is designated as "immediate stimulus - verbal response" or the function of naming.

Verbal responses to immediate stimuli within the conceptual reflex arc can be represented as responses of command neurons with a special structure of connections with detectors. Command neurons responsible for speech responses have potentially wide receptive fields. Since the connections of these neurons with detectors are plastic, their specific form depends on the formation of speech in ontogenesis. Connections and disconnections of detectors in relation to command neurons of speech reactions can also occur with the help of a speech instruction, i.e., through other verbal signals.

From this point of view, the basis of the naming function is the choice of the command neuron, which controls the program for constructing the corresponding word.

§ 5. Speech functions of the hemispheres

Understanding of verbal stimuli and the implementation of verbal reactions are associated with the function of the dominant, speech hemisphere. Clinical data obtained from the study of brain lesions, as well as the results of electrical stimulation of brain structures during brain surgery, made it possible to identify those critical structures of the cortex that are important for the ability to speak and understand speech. A technique that allows you to map brain areas associated with speech using direct electrical stimulation of the brain was developed in the 30s. W. Penfil-dom in Montreal at the Institute of Neurology regarding the surgical removal of brain areas with epileptic foci. During the procedure, which was carried out without anesthesia, the patient had to name the pictures shown to him. Speech centers were identified by aphasic stop (loss of the ability to speak), when stimulation with a current hit them.

The most important data on the organization of speech processes have been obtained in neuropsychology in the study of local brain lesions. According to the views of A.R. Luria, there are two groups of brain structures with different functions in relation to speech activity. Their defeat causes two categories of aphasias: syntagmatic and paradigmatic. The first are associated with the difficulties of the dynamic organization of speech utterance and are observed with damage to the anterior sections of the left hemisphere. The latter arise when the posterior parts of the left hemisphere are damaged and are associated with a violation of speech codes (phonemic, articulatory, semantic, etc.).

Broca's center also belongs to the anterior sections of the speech zones of the cortex. It is located in the lower parts of the third frontal gyrus, in most people in the left hemisphere. This zone controls the implementation of speech reactions. Its defeat causes efferent motor aphasia, in which the patient's own speech is disturbed, and the understanding of someone else's speech is basically preserved. With efferent motor aphasia, the kinetic melody of words is disturbed due to the impossibility of smooth switching from one element of the utterance to another. Patients with Broca's aphasia are aware of most of their mistakes. They speak with great difficulty and little.

The defeat of the other part of the anterior speech zones (in the lower parts of the premotor cortex) is accompanied by the so-called dynamic aphasia, when the patient loses the ability to formulate statements, translate his thoughts into detailed speech (violation of the programming function of speech). It proceeds against the background of the relative safety of repeated and automated speech, reading and writing under dictation.

The Wernicke center refers to the posterior parts of the speech cortex. It is located in the temporal lobe and provides speech comprehension. With its defeat, phonemic hearing disorders occur, difficulties appear in understanding oral speech, in writing under dictation (sensory aphasia). The speech of such a patient is rather fluent, but usually meaningless, since the patient does not notice his defects. Acoustic-mnestic, optical-mnestic aphasias, which are based on memory impairment, and semantic aphasia, a violation of understanding of logical-grammatical structures reflecting the spatial relationships of objects, are also associated with the defeat of the posterior parts of the speech zones of the cortex.

New data on the speech functions of the hemispheres were obtained in the experiments of R. Sperry on patients "with a split brain." After dissection of the commissural connections of the two hemispheres in such patients, each hemisphere functions independently, receiving information only from the right or left.

If a patient "with a split brain" is presented with an object in the right half of the visual field, he can name it and select it with his right hand. The same is with the word: he can read or write it, and also select the corresponding object with his right hand; i.e. if the left hemisphere is used, then such a patient does not differ from normal person... The defect appears when stimuli arise on the left side of the body or in the left half of the visual field. The patient cannot name the object, the image of which is projected into the right hemisphere. However, he correctly chooses him among others, although after that he still cannot name him. That is, the right hemisphere cannot provide the function of naming an object, but it is able to recognize it.

Although the left hemisphere is associated with linguistic ability, nevertheless the right hemisphere also has some linguistic functions. So, if you present the name of the object, then the patient does not experience difficulties in finding the appropriate object with his left hand among several others hidden from sight. That is, the right hemisphere can understand written language.

In the experiments of J. Ledum. Gazzaniganabolny S.P. (see), who underwent commissurotomy, in which the right hemisphere had significantly greater linguistic abilities than usual, it was shown that the right hemisphere can not only read questions, but also answer them with the help of the left hand, making words from letters applied on cards. In the same way, the patient S.P. could name objects presented to him visually in the right hemisphere, or rather "write" with the help of the right hemisphere.

Normally, both hemispheres work closely together, complementing each other. The difference between the left and right hemispheres can be studied in healthy people, without resorting to surgical intervention - the dissection of the commissures connecting both hemispheres. For this, the Jun Wada method can be used - the method of "anesthesia of the hemispheres". It was created in the clinic to identify the speech hemisphere. In this method, a thin tube is inserted into the carotid artery on one side of the neck for subsequent administration of a solution of barbiturates (amytal sodium). Since each carotid artery supplies blood to only one hemisphere, the hypnotic injected into it enters one hemisphere and has a narcotic effect on it. During the test, the patient lies on his back with his arms raised and counts from 100 in the reverse order.

A few seconds after the injection of the drug, one can see how powerlessly one arm of the patient falls, the one that is opposite the side of the injection. Then there is a violation in the account. If the substance enters the speech hemisphere, then the stopping of counting, depending on the administered dose, lasts 2-5 minutes. If to the other hemisphere, then the delay is only a few seconds. Thus, this method made it possible to temporarily turn off any hemisphere and explore the isolated work of the remaining one.

The use of techniques that make it possible to selectively present information to only one hemisphere has enabled researchers to demonstrate significant differences in the abilities of the two hemispheres. It was found that the left hemisphere is involved mainly in analytical processes, it is the basis for logical thinking. The left hemisphere provides speech activity: its understanding and construction, work with verbal symbols. The processing of input signals is carried out in it, apparently, in a sequential manner. The right hemisphere provides concrete-figurative thinking, deals with non-verbal material, is responsible for certain skills in handling spatial signals, for structural-spatial transformations, the ability to visual and tactile recognition of objects. The information coming to it is processed simultaneously and in a holistic manner. Musical ability is associated with the right hemisphere.

In recent years, the point of view has been strenuously defended that different ways of cognition are reflected in the functions of different hemispheres. The functions of the left hemisphere are identified with analytical thinking. The right hemisphere function is intuitive thinking. According to R. Ornstein, the adopted education system is based solely on the development of the abilities of the left hemisphere, that is, linguistic and logical thinking, and the functions of the right hemisphere are not specially developed. Non-verbal intelligence is overlooked.

The study of the functional asymmetry of the brain in children showed that initially the processing of speech signals is carried out by both hemispheres and the dominance of the left is formed later. If a child who has learned to speak has a lesion of the speech area of \u200b\u200bthe left hemisphere, then he develops aphasia. However, after about a year, speech is restored. In this case, the center of speech moves to the area of \u200b\u200bthe right hemisphere. Such a transfer of speech function from the left hemisphere to the right is possible only up to 10 years. The specialization of the right hemisphere in the function of orientation in space also does not appear immediately: in boys at the age of 6 years, and in girls after 13 years.

Data on the linguistic abilities of the right hemisphere, as well as the similarity of the functions of both hemispheres at the early stages of ontogenesis, rather indicate that in the course of evolution, both hemispheres, having initially similar, symmetric functions, gradually specialized, which led to the emergence of the dominant and subdominant hemispheres.

Little else is known about the reasons that led to the specialization of the hemispheres. The most interesting and reasonable is the explanation of this process by Doreen Kimura and her colleagues. Based on the fact that the speech function of the left hemisphere is associated with the movements of the leading right hand, it suggests that the specialization of the left hemisphere for speech is not so much a consequence of the asymmetric development of symbolic functions, but the development of certain motor skills that help in communication. Language appeared because the left hemisphere was adapted for certain types of physical activity.

The relationship of the left hemisphere with certain types of movement is well known in the clinic. The hand corresponding to the hemisphere with the speech center (more often the right one) exhibits greater ability for fine movements than the hand associated with the non-dominant hemisphere. Patients with damage to the left hemisphere and without right-sided paralysis nevertheless have difficulty in reproducing the complex sequence of hand movements and complex finger positions. In the deaf and dumb, the defeat of the left hemisphere is accompanied by the decay of sign language, which is similar to the decay of speech in normally speaking people.

D. Kimura believes that in evolutionary terms it was the development of the hand as an organ of sign language and its manipulative abilities that led to the development of the left hemisphere. Later, this function in the hand was transferred to the vocal muscles.

The left hemisphere also surpasses the right in the ability to understand speech, although these differences are less pronounced. According to the motor theory of perception, the main component of speech sound recognition is kinesthetic signals arising from the muscles of the speech apparatus during the perception of speech signals. The motor systems of the left hemisphere play a special role in this.

Speech functions in right-handers are predominantly located in the left hemisphere. And only 5% of individuals have speech centers in the right hemisphere. In 70% of left-handed people, the center of speech, as well as in right-handed people, is in the left hemisphere. 15% of left-handed people have a speech center in the right hemisphere.

Functional brain asymmetry is not found in all people. In about one third, it is not expressed, that is, the hemispheres do not have a clear functional specialization. There is a mutual inhibition relationship between the specialized hemispheres. This is evident from the enhancement of the corresponding functions in a one-hemispheric person in comparison with a normal person.

The ratio of the activity of the two hemispheres can be very different. On this basis, I.P. Pavlov identified specifically human types of higher nervous activity: artistic, mental and average.

The artistic type is characterized by the predominance of the activity of the first signaling system over the second. People of the artistic type have predominantly "right-brain" imaginative thinking. They embrace reality in its entirety, without dividing it into parts.

The thinking type is characterized by the predominance of the second signal system over the first, ie, "left-hemispheric" abstract thinking. The middle type is characterized by a balanced functioning of the two signaling systems. Most people are of this type.

§ 6. The brain and consciousness

A feature of the human psyche is the awareness of many processes of his inner life. Consciousness is a function of the human brain. It is often defined as "the highest level of mental reflection of reality, inherent only in man as a social-historical being." Specifying this definition, D.I. Dubrovsky emphasizes that consciousness involves not only awareness of external objects, but also awareness of oneself as a person and one's mental activity. In the definition proposed by P.V. Simonov, emphasizes the communicative function of consciousness. Consciousness is defined by him "... as knowledge that can be transmitted with the help of words, mathematical symbols and generalizing images of works of art, can become the property of other members of society." To realize is to be able to communicate, to transfer your knowledge to another. And everything that cannot be communicated to people is unconscious. From this definition it follows that the emergence of consciousness is associated with the development of special means of transmission, among which the leading role belongs to speech.

Most researchers are supporters of the verbal theory of consciousness. They talk about the decisive role of speech activity in the phenomenon of consciousness. These views are supported by neurophysiological data. Lack of verbal reporting of a conditioned reaction means a lack of awareness of it. Inadequate verbalization is inadequate awareness of a real stimulus and a perfect response. Recovery of consciousness after a prolonged coma in persons who have suffered a traumatic brain injury goes through several stages. The first sign of the return of consciousness is opening the eyes, then fixing the gaze on close faces, understanding speech, and, finally, own speech. The study of intra-hemispheric connections based on EEG in the process of consciousness restoration indicates the decisive role of speech structures. Only at the stage when the patient's ability to understand speech returns, are the connections characteristic of a person at the frequency of the alpha rhythm restored between the motor-speech zones of the left hemisphere and other areas of the cortex.

to be aware of any external stimulus, activation of connections between the perceiving area of \u200b\u200bthe cerebral cortex and the motor speech area is of decisive importance. An essential role in this process belongs to the mechanism of nonspecific activation. The importance of activation reactions for the awareness of the stimuli that cause it has been shown in many works.

The difference between EPs into conscious and unconscious verbal stimuli indicates that the activation of nonspecific systems is carried out through corticofugal pathways from semantic mechanisms. Upon awareness of the stimulus, local activation occurs in the cortical structures that perceive this stimulus, due to the cortical-thalamo-cortical mechanism. An unconscious stimulus causes a more diffuse and weaker activation of the cortex.

The optimal conditions for conscious perception are provided by the inclusion of the selective attention mechanism.

G.V. Gershuni described the so-called subsensory zone, that is, the zone of subthreshold stimuli, to which conditioned reflexes can be developed, but which, however, will not be realized by the subject. In his experiments, an imperceptible sound (3-6 db below the auditory threshold) was reinforced by painful stimulation causing CTE. After 25-35 such combinations, GSR began to appear on the isolated presentation of subthreshold sound. A conditioned reflex blockade of the alpha rhythm to a subthreshold sound (6-12 dB below the hearing threshold), accompanied by light, causing depression of the alpha rhythm, was also developed. Thus, at an unconscious level, conditioned reflex activity is possible, although in a rather narrow zone, near subjective thresholds.

The dominant hemisphere normally keeps the functions of the subdominant under control. Split-brain studies have shown that each hemisphere can make independent judgments, which in some cases may not coincide. So, the patient when projecting a question into the right hemisphere: “What kind of work would he like to do? "Answered -" auto racing ", and when presenting the same question to the left hemisphere -" draftsman ". A person's mood depends on the consistency of assessments made by the hemispheres. When judgments coincide, the patient is calm, easy to communicate, pleasant. If the assessments differ, the patient's behavior becomes difficult to control, hyperactivity and aggressiveness appear.

In view of the fact that each hemisphere can have its own independent system of assessing the significance of events, we can talk about a doubling of consciousness in such patients. However, in a normal person, the leading role in making judgments belongs to the speech, dominant hemisphere. Although certain linguistic abilities are inherent in the subdominant hemisphere. Consciousness is associated with linguistic mechanisms that are represented differently in the left and right hemispheres.

Unconscious mental processes cover a wide range of phenomena. P.V. Simonov proposes to single out at least two groups among them. The first group is the subconscious. It includes everything that was previously realized and can again become conscious under certain conditions. These are various automated skills, norms of behavior deeply assimilated by a person, motivational conflicts, displaced from the sphere of consciousness. The subconscious mind protects a person from excessive energy expenditure, protects against stress.

Another group of unconscious mental phenomena - superconsciousness or intuition, is associated with creative processes that are not controlled by consciousness. Superconsciousness is a source of new information, hypotheses, discoveries. Its neurophysiological basis is the transformation of memory traces and the generation of new combinations from them, the creation of new temporary connections, the generation of analogies. Consciousness is left with the function of selecting hypotheses based on their logical analysis. The direction of development of superconsciousness is determined by the dominant need. Superconsciousness plays an essential role in the emergence of scientific discoveries and the creation of works of art, masterpieces of art.

Conclusion

The action of a word as a conditioned stimulus can have the same force as a direct primary signal stimulus. Under the influence of the word are not only mental, but also physiological processes (this is the basis of suggestion and self-hypnosis). The second signal system has two functions - communicative (it provides communication between people) and the function of reflecting objective laws. The word not only gives a name to the object, but also contains a generalization.

The second signal system includes the word audible, visible (written) and pronounced.

Typological features of higher nervous activity are common in humans and higher animals (four types). But people have specific typological features associated with the second signaling system. In all people, the second signaling system prevails over the first. The degree of this predominance is not the same. This gives grounds to divide the higher nervous activity of a person into three types: 1) mental; 2) artistic; 3) medium (mixed).

The thinking type includes persons with a significant predominance of the second signal system over the first. They have more developed abstract thinking (mathematicians, philosophers); direct reflection of reality occurs in them in insufficiently vivid images.

The artistic type includes people with less predominance of the second signal system over the first. They are characterized by liveliness, brightness of specific images (artists, writers, actors, designers, inventors, etc.).

The average, or mixed, type of people occupies an intermediate position between the first two.

Excessive dominance of the second signaling system, bordering on its separation from the first signaling system, is an undesirable quality of a person.

“You need to remember, - said I.P. Pavlov, - that the second signaling system matters through the first signaling system and in connection with the latter, and if it breaks away from the first signaling system, then you turn out to be an idle talker, a chatterbox and will not find a place for yourself in life. "

People with an excessive predominance of the first signaling system, as a rule, have a less developed tendency to abstraction and theorization.

Modern research of higher nervous activity is characterized by the development of an integral approach to the study of the integral work of the brain.

The general patterns of GNI in humans and animals are the same, but human GNI has significant differences.

AND. Purposeful planned work activity actively changes the world around in accordance with the needs of society: the creation of products of labor, housing, tools of production, etc. Human labor is qualitatively different from the adaptive behavior of animals - it is aimed only at adapting to nature.

B. Man has the first and second signaling systems, animals only the first. The idea of \u200b\u200bthe signaling systems of humans and animals was substantiated by I.P. Pavlov. Since the existing definitions of signaling systems differ from each other, we offer our version. The first signaling system - it is a system of the organism that ensures the formation of a concrete (direct) idea of \u200b\u200bthe surrounding reality and adaptive reactions through conditional connections.The signals of the first signal system are objects, phenomena and their individual properties (smell, color, shape, etc.). Second signaling system is a system of the body that provides the formation of a generalized idea of \u200b\u200bthe surrounding reality with the help of the human language.

Human language -means of communication of people with each other, the main form of which is written and oral speech, as well as formulas and symbols, drawings, gestures, facial expressions.

Speech -a form of communication of people with each other using signals (words) and providing human thinking. Speech can be internal, which is a necessary form of the thinking process, and external (written and oral), with the help of which a person communicates his thoughts to other people. Speech is one of the forms of language.

Although the first signaling system is characteristic of animals and humans, however, in humans, due to its close interaction with the second signaling system, the first human signaling system is qualitatively different from that in animals and bears the imprint of cultural and historical influences.

IN. A person has figurative (concrete) and abstract thinking, in animals, only the concrete. The first signaling system provides figurative (concrete) thinking in both humans and animals, the second - abstract thinking, only in humans. A striking example, testifying to the absence of abstract thinking in animals, is the behavior of a monkey in the laboratory of I.P. Pavlov. To achieve a useful result (getting food), the monkey learned to extinguish the fire by pouring it with water from a tank that stood on the shore, and the monkey; Yana was sitting on the raft, where she had to put out the fire. Each time she jumped from a raft into the water and went to the shore to fetch water. Although the raft was surrounded on all sides by water, the monkey did not suspect that the water from the lake had the same fire extinguishing properties as the water from the tank.

G. A person has specific types of species inherent only to him. I.P. Pavlov's concept of two signaling systems of reality led him to the idea of special human types of GNI.Their division is based on the relationship between the first and second signaling systems. The predominance of the first signal system over the second characterizes art type,with the opposite ratio - thinking type,if they are equal - medium type.The artistic type (mainly writers, artists, musicians) is characterized by an integral perception of reality. The thinking type (mainly philosophers, mathematicians) perceives the surrounding reality through verbal signals, i.e. splits it up. The middle type (intermediate) is characterized by certain properties of the mental and artistic types.

D. In humans, unlike animals, functional asymmetry of the hemispheres is observed (literalization of the functional

tions),that at the end of the 60s of the twentieth century, the English psychiatrist S. Kennicott showed with the help of a one-sided shutdown in mental patients of one of the hemispheres with an electric current. Based on the observations obtained, he formulated the position about the left-hemisphere and right-hemisphere people.

Left-handedness and right-handedness -one of the facts indicating the lateralization of functions; most people are right-handed.

As a rule, speech centersare located only in the left hemisphere. In some left-handers, they are in the same place, and in other cases, either in the right or in both hemispheres. The left hemisphere specializes in not only speech, but also motor acts(since the left premotor cortex is involved in developing a strategy for any movement, regardless of whether it is performed by the right or left side of the body).

An example of lateralization of functions is that the left hemisphere is the basic basis of logical thinking, and the right hemisphere is figurative (concrete) thinking.

More and more evidence is accumulating that the right hemisphere does better at certain tasks than the left. Thus, it is more correct to speak not about the dominance of the hemispheres in general, but about their complementary specialization with a predominance of speech functions (as a rule) in the left (R. Schmidt, G. Tevs, 1996).

E. Socio-determined human consciousness.

Consciousness is the ideal subjective reflection of reality with the help of the brain.Consciousness is the highest function of the brain. It reflects real reality in various forms of human mental activity, which are: sensation, perception, representation, thinking, attention, feelings (emotions) and will. The neurophysiological foundations of consciousness are as follows.

1. Connection of consciousness is usually achieved by activating a large number of structures, where the cerebral cortex with the nearest subcortex, the limbic system, and their interaction are of prime importance. The most important role is played by the ascending activating influences of the reticular formation.

2. Consciousness requires a certain level of activity of the central nervous system, corresponding to the desynchronized EEG during wakefulness; too low neural activity (for example, with anesthesia or coma) is incompatible with it. On the other hand, consciousness is impossible even with excessive activity of neurons - for example, with epileptic seizures (characterized by peaks

and waves on the EEG), it can turn off in a state of rage (a state of passion).

3. The minimum period of time of activation of brain structures for conscious perception of the signal is 100-300 ms.

4. It is believed that the frontal lobes are of leading importance for the manifestation of higher mental functions. The defeat of the frontal lobes in humans is accompanied by mental instability, euphoria, irritability. The absence of firm plans based on forecasting, the presence of frivolity and rudeness are noted. Often there are persistent repetitions of actions, conflicts with others.

The basis of higher nervous activity is conditioned reflexes that arise during the vital activity of the organism, and which allow it to respond expediently to external stimuli and thereby adapt to constantly changing environmental conditions. The conditioned reflexes developed earlier are capable of damping and disappearing due to inhibition when the environment changes.
The stimuli for the formation of conditioned reflexes in humans are not only environmental factors (heat, cold, light, smell), but also words denoting a particular object, phenomenon. The exceptional ability of man (as opposed to animals) to perceive the meaning of a word, properties of objects, phenomena, human experiences, to think in general terms, to communicate with each other using speech. Outside of society, a person cannot learn to speak, perceive written and oral speech, study the experience accumulated over the long years of human existence, and pass it on to descendants.
A feature of human higher nervous activity is the high development of mental activity and its manifestation in the form of thinking. The level of mental activity directly depends on the level of development of the nervous system. Man has the most developed nervous system. A feature of human higher nervous activity is the awareness of many internal processes of his life. Consciousness is a function of the human brain.
The higher nervous activity of man differs significantly from the higher nervous activity of animals. A fundamentally new signaling system arises in a person in the process of his social labor activity and reaches a high level of development.
The first signaling system of reality is a system of our immediate sensations, perceptions, impressions from specific objects and phenomena of the surrounding world. Word (speech) is the second signaling system (signaling signals). It arose and developed on the basis of the first signaling system and is significant only in close connection with it.
Thanks to the second signaling system (word), temporary connections are formed in humans more quickly than in animals, for the word carries the socially developed meaning of the object. Human temporary nerve connections are more stable and persist without reinforcement for many years.
The second signaling system has two functions - communicative (it provides communication between people) and the function of reflecting objective laws. The word not only gives a name to the object, but also contains a generalization.
The second signal system includes the word audible, visible (written) and pronounced.
The first signaling system is understood as the work of the brain, which causes the transformation of direct stimuli into signals of various types of body activity. The second signaling system refers to the function of the human brain, which deals with verbal symbols.