Cognitive processes. Features of human higher nervous activity. Teaching of I.P. Pavlova on signaling systems

1. I.M. Sechenov and I.P. Pavlov, the founders of the doctrine of GNI.

2. Unconditioned reflexes.

3. Conditioned reflexes.

4. Mechanism of formation of temporary connection.

5. Inhibition of conditioned reflexes.

6. Features of human GNI.

7. Functional system of behavioral act.

THEM. Sechenov and I.P. Pavlov, the founders of the doctrine of GNI. VND is the activity of the cortex cerebral hemispheres the brain and the subcortical formations closest to it, ensuring the most perfect adaptation of highly organized animals and humans in the environment.

The question of the reflex activity of the cortex was first presented by the founder of Russian physiology I.M. Sechenov in the book “Reflexes of the Brain” (1863). He believed that all human activity, including mental (mental), is carried out reflexively with the participation of the brain. The validity of Sechenov's views was subsequently confirmed by experimental research by I. P. Pavlov. He discovered conditioned reflexes - the basis of GNI.

All reflex reactions of the body to various stimuli I.P. Pavlov divided them into two groups: unconditional and conditional.

Unconditioned reflexes- these reflexes are innate and inherited. The most complex of them are called instincts (building honeycombs by bees, nests by birds). Unconditioned reflexes are characterized by great constancy. Such reflexes include sucking, swallowing, pupillary and various defensive reflexes. They are formed in response to various stimuli. Thus, the salivation reflex occurs when the taste buds of the tongue are irritated by food. The resulting excitation is transmitted along the sensory nerves to the medulla oblongata, where the center of salivation is located, from there it is carried through the motor nerves to the salivary glands, causing their secretion. The nerve centers of unconditioned reflexes lie in different parts of the brain and spinal cord. For their implementation, the participation of the cerebral cortex is not necessary. On the basis of unconditioned reflexes, the activity of different organs and systems is regulated and coordinated, and the very existence of the organism is maintained.

However, with the help of unconditioned reflexes, the body cannot adapt to changing environmental conditions. Preservation of vital functions and adaptation to environmental conditions is carried out due to the formation of conditioned reflexes in the cerebral cortex.

Conditioned reflexes. These are reflexes developed during an individual’s life, thanks to the formation of temporary nerve connections in the higher parts of the central nervous system (cerebral cortex).

For the formation of conditioned reflexes, the following conditions are necessary: ​​1) the presence of two stimuli - indifferent, i.e. one that they want to make conditional, and unconditional, causing some activity of the body, for example, the secretion of saliva (food); 2) an indifferent stimulus (light, sound, etc.) must precede the unconditional one (for example, you must first give light, and two seconds later food); 3) the unconditioned stimulus must be stronger than the conditioned one (for a well-fed dog with low excitability of the food center, the bell will not become a conditioned food stimulus); 4) absence of distracting, extraneous stimuli; 5) vigorous state of the cortex.

The mechanism of formation of a temporary connection. According to the ideas of I.P. Pavlova under the action of an unconditioned stimulus (food) and due to excitation of the food center of the cortex and the center of salivation medulla oblongata a salivary reaction occurs. When exposed to a visual stimulus, the focus of excitation arises in the visual area of ​​the cortex. When the action of the conditioned and unconditioned stimuli coincides in time, a temporary connection is established between the food and visual centers of the cortex.

When a conditioned reflex is developed, the excitation that arises in the visual center under the action of a light stimulus spreads to the food center, and from the food center along the afferent pathways it is sent to the salivary center and a salivary reaction occurs.

The reflex arc of a conditioned reflex contains the following sections: a receptor that responds to a conditioned stimulus; sensory nerve and its corresponding ascending pathway with subcortical formations; area of ​​the cortex that perceives the conditioned stimulus (for example, the visual center); a section of the cortex associated with the center of the unconditioned reflex (food center); motor nerve; working body

Inhibition of conditioned reflexes. Conditioned reflexes are not only developed, but also disappear or weaken when living conditions change as a result of inhibition. I.P. Pavlov distinguished two types of inhibition of conditioned reflexes: unconditioned (external) and conditioned (internal). Unconditioned inhibition occurs as a result of the action of a new stimulus of sufficient strength. In this case, a new focus of excitation appears in the cerebral cortex, which causes inhibition of the existing focus of excitation. For example, an employee has developed a conditioned reflex in a dog to the light of a light bulb and wants to show it at a lecture. The experiment fails - there is no reflex. The noise of a crowded audience, new signals completely turn off conditioned reflex activity / Conditioned inhibition is of four types: 1) extinction; 2) differentiation; 3) delay; 4) conditional brake.

Extinction inhibition occurs when the conditioned stimulus is not reinforced by the unconditioned stimulus several times (the light is turned on, and not reinforced with food).

Differential inhibition is developed if one signal stimulus, for example, the note “C,” is reinforced by an unconditioned stimulus, and the note “S” is not reinforced. After several repetitions, the “do” note will cause a positive conditioned reflex, and the “salt” note will cause an inhibitory reflex.

Delayed inhibition occurs when a conditioned stimulus is reinforced by an unconditioned stimulus after a certain time. For example, they turn on the light, and reinforce food only after 3 minutes. The separation of saliva after delayed inhibition has been developed begins at the end of the third minute.

A conditioned inhibition occurs in cases when some indifferent stimulus is added to the conditioned stimulus to which a conditioned reflex has been developed, and this new complex stimulus is not reinforced.

Features of higher nervous activity person. The behavior of any animal is simpler than human behavior. Features of human higher nervous activity are highly developed mental activity, consciousness, speech, and the ability for abstract logical thinking. The higher nervous activity of man was formed historically in the course of labor activity and the need for communication. Based on the characteristics of higher nervous activity in humans and animals, I.P. Pavlov developed the doctrine of the first and second signal systems. Animals and humans receive signals from the external world through the corresponding sense organs. Perception of the surrounding world, associated with the analysis and synthesis of direct signals that come from visual, auditory, olfactory and other receptors, constituting the first signaling system. The second signaling system arose and developed in humans in connection with the appearance of speech. It is absent in animals. The signal meaning of a word is associated not with a simple sound combination, but with its semantic content. The first and second signaling systems are in close interaction and interrelation in humans, since the excitation of the first signaling system is transmitted to the second signaling system.

Emotions. Emotions are reactions of animals and humans to the influence of external and internal stimuli that have a pronounced subjective coloring and cover all types of sensitivity. There are positive emotions: joy, pleasure, pleasure, and negative ones: sadness, sadness, displeasure. Different types emotions are accompanied by various physiological changes and mental manifestations in the body. For example, with sadness, embarrassment, and fear, the tone of the skeletal muscles decreases. Sadness is characterized by vasospasm, fear is characterized by relaxation of smooth muscles. Anger and joy are accompanied by an increase in the tone of skeletal muscles; with joy, in addition, blood vessels dilate; with anger, coordination of movements is upset, and the sugar level in the blood increases. Emotional arousal mobilizes all the body's reserves.

In the process of evolution, emotions were formed as a coping mechanism. Positive emotions play a huge role in a person’s life. They are important for maintaining human health and performance.

Memory. Accumulation, storage and processing of information is the most important property of the nervous system. There are two types of memory: short-term and long-term. Short-term memory is based on the circulation of nerve impulses along closed neural circuits. The material basis of long-term memory is various structural changes in neuron circuits caused by electrochemical excitation processes. Currently, peptides have been found that are produced by nerve cells and affect the memory process. Neurons of the cerebral cortex, the reticular formation of the brain stem, and the hypothalamic region are involved in the formation of memory. Visual, auditory, tactile, motor and mixed memory are distinguished depending on which of the analyzers plays the main role in this process.

Sleep and wakefulness. Alternation of sleep and wakefulness is a necessary condition of human life. The brain is kept awake by impulses from receptors. While awake, a person actively interacts with the external environment. When the flow of impulses into the brain ceases or is sharply limited, sleep develops. During sleep, the physiological activity of the body changes: muscles relax, skin sensitivity, vision, hearing, and smell decrease. Conditioned reflexes are inhibited, breathing is rare, metabolism, blood pressure, and heart rate are reduced.

According to electroencephalography (EEG), in a person's sleep there is an alternation of two main phases of sleep: the phase of slow-wave sleep - a period of deep sleep, during which slow activity (delta waves) can be recorded on the EEG, and the phase of paradoxical, or fast-wave, sleep, during which the EEG records rhythms characteristic of a state of wakefulness. In this phase, rapid eye movements are observed, pulse and breathing rates increase; a person dreams. This phase occurs approximately every 80-90 minutes, its duration is on average 20 minutes.

Sleep is a protective device of the body, protecting it from excessive irritation and making it possible to restore efficiency. During sleep, the higher parts of the brain process information received during the waking period. According to the reticular theory of sleep and wakefulness, the onset of sleep is associated with the inhibition of the ascending influences of the reticular formation, activating the higher parts of the brain. In the regulation of the sleep-wake cycle big role mediators play - serotonin and norepinephrine.

Functional system of behavioral act.Functional system as an integrative formation of the brain. The most advanced model of the structure of behavior is set out in the concept of the functional system by P.K. Anokhina. Functional system– this is a unit of integrative activity of the body that carries out selective involvement and integration of structures and processes aimed at performing any behavioral act or function of the body.

The functional system is dynamic, capable of restructuring, and selectively involving brain structures to carry out behavioral reactions. There are two types of functional systems of the body: 1. Functional systems of the homeostatic level of regulation ensure the constancy of the constants of the internal environment of the body (body temperature, blood pressure, etc.); 2. Functional systems of the behavioral level of regulation ensure adaptation of the body through changes in behavior.

Stages of a behavioral act. According to the ideas of P.K. Anokhin, the physiological architecture of a behavioral act is built from successively successive stages: afferent synthesis, decision-making, acceptor of action results, efferent synthesis (action program), formation of the action itself and evaluation of the achieved results.

Afferent synthesis consists in processing and comparing all information that is used by the body to make decisions and form the most adequate adaptive behavior. Excitation in the central nervous system caused by an external stimulus does not act in isolation. It interacts with other afferent excitations that have a different functional meaning. The brain synthesizes all signals arriving through various channels. And only as a result of this, conditions are created for the implementation of purposeful behavior. In turn, afferent synthesis is determined by the influence of several factors: motivational arousal, environmental afferentation, memory and triggering afferentation.

Motivational arousal arises in the central nervous system with the appearance of any need in humans and animals; it has a dominant character, i.e. suppresses other motivations and directs the body's behavior to achieve a useful adaptive result. The basis of dominant motivation is the mechanism of dominance A.A. Ukhtomsky.

Situational afferentation represents the integration of excitations under the influence of the environment on the organism. It can promote or, on the contrary, hinder the implementation of motivation. For example, a feeling of hunger that arises at home causes actions aimed at satisfying it, but if this feeling arises at a lecture, then behavioral reactions related to the satisfaction of this need do not occur.

Trigger afferentation associated with the action of a signal, which is a direct stimulus for triggering a particular behavioral reaction. An adequate reaction can only occur through the interaction of situational and trigger afferentation, which creates pre-trigger integration of nervous processes.

Usage memory device occurs when incoming information is evaluated by comparison with memory traces related to a given dominant motivation. Completion of the afferent synthesis stage is accompanied by a transition to the decision-making stage.

Under decision making understand the selective involvement of a complex of neurons, which ensures the emergence of a single reaction aimed at satisfying a dominant need. The body has many degrees of freedom in choosing its response. When making a decision, one is chosen behavioral response, all other degrees of freedom are inhibited. The decision-making stage is implemented through the stage of forming an acceptor of action results.

Acceptor of action results – this is a neural model of the expected result. It is formed in the cerebral cortex and subcortical structures due to the involvement of neural and synaptic formations in the activity, determining the architecture of the distribution of excitations. Excitation, once in a network of interneurons with ring connections, can circulate in it for a long time, ensuring retention of the goal of behavior.

Then develops stage of the action program (efferent synthesis). At this stage, the integration of somatic and vegetative arousals into a holistic behavioral act occurs. This stage is characterized by the fact that the action has already been formed as a central process, but externally it is not realized.

Formation stage result of action characterized by the implementation of a behavioral program. Efferent excitation reaches the actuators and the action is carried out. Thanks to the acceptor of action results, in which the goal and methods of behavior are programmed, the body can compare them with afferent information about the results and parameters of the action performed.

If the signal about the completed action fully corresponds to the programmed information contained in the action results acceptor, then the search behavior ends, the need is satisfied, the person and animal calm down. In the case when the results of an action do not coincide with the acceptor of the action and their mismatch occurs, then the afferent synthesis is rebuilt, a new acceptor of the results of the action is created, and a new program actions. This happens until the results of the behavior coincide with the new acceptor of the action. Then the behavioral act ends.

The doctrine of I. P. Pavlov about two signal systems of reality. Higher nervous activity in humans, as well as in animals, is of a reflex nature. And a person develops conditioned reflexes to various signals from the external world or develops internal inhibition.

Common to both animals and humans are the analysis and synthesis of specific signals, objects and phenomena of the external world that make up the first signaling system.

The higher nervous activity of man has its own qualitative characteristics that place it above the entire animal world.

The collective labor activity of people contributed to the emergence and development of articulate speech, which introduced new things into the activity of the cerebral hemispheres. Only humans have a highly developed consciousness and abstract thinking. In the process of human development, an “extraordinary increase” in the mechanisms of brain function appeared. This is the second signal system of reality. In humans, signals of the second system appeared, developed and extremely improved in the form of words spoken, heard and read. Words and speech signals can not only replace direct signals, but also generalize them, highlight individual characteristics of objects and phenomena, and establish their connections.

The emergence of the second signaling system introduced a new principle into the activity of the cerebral hemispheres of the human brain. I. P. Pavlov wrote that if our sensations and ideas related to the world around us are the first signals of reality, concrete signals, then the signals going to the cortex from the speech organs are the second signals, “signals of signals.” They represent an abstraction from reality and allow for generalization, which is what constitutes our specifically human thinking. The development of verbal signaling has made generalization and distraction possible, which is expressed in concepts.

The second signaling system is socially conditioned. Outside of society, without communication with other people, it does not develop.

The first and second signaling systems are inseparable from each other; they function together. The higher nervous activity of man in this sense is united.

§3. Types of higher nervous activity

The concept of the type of higher nervous activity. Conditioned reflex activity depends on the individual properties of the nervous system. The individual properties of the nervous system are determined by the hereditary characteristics of the individual and his life experience. The combination of these properties is called the type of higher nervous activity.

Properties of nervous processes. I.P. Pavlov, based on many years of studying the characteristics of the formation and course of conditioned reflexes in animals, identified 4 main types of higher nervous activity. He based the division into types on three main indicators:

1) the strength of the processes of excitation and inhibition;

2) balance, i.e. the ratio of the strength of the processes of excitation and inhibition;

3) the mobility of the processes of excitation and inhibition, that is, the speed with which excitation can be replaced by inhibition, and vice versa.

Classification of types of higher nervous activity. Based on the manifestation of these three properties, I. P. Pavlov identified:

1) the type is strong, but unbalanced, with a predominance of excitation over inhibition (“uncontrollable” type);

2) the type is strong, balanced, with great mobility of nervous processes (“living”, mobile type);

3) a strong, balanced type, with low mobility of nervous processes (“calm”, sedentary, inert type);

4) weak type with rapid depletion of nerve cells, leading to loss of performance.

I. P. Pavlov believed that the main types of higher nervous activity found in animals coincide with the four temperaments established in people by the Greek physician Hippocrates, who lived in the 4th century BC. e. The weak type corresponds to a melancholic temperament; strong unbalanced type - choleric temperament; strong, balanced, active type - sanguine temperament; strong, balanced, with low mobility of nervous processes - phlegmatic temperament.

However, it should be borne in mind that the hemispheres of the human brain, as a social being, have more advanced synthetic activity than those of animals. A person is characterized by a qualitatively special nervous activity associated with the presence of his speech function.

Depending on the interaction and balance of signaling systems, I. P. Pavlov, along with four types common to humans and animals, specially identified human types higher nervous activity:

1. Artistic type. Characterized by the predominance of the first signaling system over the second. This type includes people who directly perceive reality, widely use sensory images, and are characterized by figurative, objective thinking.

2. Thinking type. These are people with a predominance of the second signaling system, “thinkers”, with a pronounced ability for abstract thinking.

3. Most people belong to the average type with balanced activity of two signaling systems. They are characterized by both figurative impressions and speculative conclusions.

Plasticity of types of higher nervous activity. The innate properties of the nervous system are not immutable. They can change to one degree or another under the influence of upbringing due to the plasticity of the nervous system. The type of higher nervous activity consists of the interaction of the inherited properties of the nervous system and the influences that an individual experiences during life.

IP Pavlov called the plasticity of the nervous system the most important pedagogical factor. The strength and mobility of nervous processes can be trained, and children of the unbalanced type, under the influence of upbringing, can acquire traits that bring them closer to representatives of the balanced type. Prolonged overexertion of the inhibitory process in children of a weak type can lead to a “breakdown” of higher nervous activity and the emergence of neuroses. Such children have difficulty getting used to the new work schedule and need special attention.

Age-related characteristics of conditioned reflexes. Types of higher nervous activity of a child. Adaptive reactions of a newborn child to external influences are ensured by orienting reflexes. Conditioned reflexes during the neonatal period are very limited in nature and are developed only to vital stimuli. Already in the first days of a child’s life, one can note the formation of a natural conditioned reflex during feeding, which is expressed in the awakening of children and increased motor activity. Sucking movements of the lips appear before the nipple is inserted into the mouth. It is clear that such a reflex manifests itself only with a strict feeding regime for children. With a strict feeding regimen on the 6th-7th day, infants experience a conditioned reflex increase in the number of leukocytes already 30 minutes before feeding, and their gas exchange increases before meals. By the end of the second week, a conditioned reflex appears in the form of sucking movements when the baby is positioned for feeding. Here the signal is a complex of stimuli acting from receptors of the skin, motor and vestibular apparatus, constantly combined with food reinforcement.

From the middle of the first month of life, conditioned reflexes arise to various primary signal stimuli: light, sound, olfactory stimulation.

The rate of formation of conditioned reflexes in the first month of life is very low and increases rapidly with age. Thus, a protective reflex to light occurs only after 200 combinations, if its development began on the 15th day after birth, and less than 40 combinations are required if the development of the same reflex began in a one and a half month old child. From the first days of a child’s life, unconditional (external) inhibition appears. The baby stops sucking if a sharp sound is suddenly heard. Conditioned (internal) inhibition is developed later. Its appearance and strengthening are determined by the maturation of the nervous elements of the cerebral cortex. The first manifestations of differentiation of motor conditioned reflexes are noted by the 20th day of life, when the child begins to differentiate the feeding position from the changing procedure. A clear differentiation of visual and auditory conditioned stimuli is observed at 3-4 months. Other types of internal inhibition are formed later than differentiation. Thus, the development of delayed inhibition becomes possible from the age of 5 months (M. M. Koltsova).

The development of internal inhibition in a child is an important factor in education. In the first year of life, it is advisable to cultivate inhibition, attracting facial expressions and gestures that characterize the negative attitude of adults, or stimuli that distract the child’s attention, i.e., they are an external inhibitor. For proper development For a child in the first year of life, a strict regime is very important - a certain sequence of alternating sleep, wakefulness, feeding, and walks. This is determined by the significance of the stereotype of interoceptive conditioned reflexes at this age. By the end of the first year, complexes of external exteroceptive stimuli that characterize the situation as a whole become important. The word becomes one of the important components of the complex of stimuli.

The first signs of the development of the second signaling system appear in the child in the second half of the first year of life. During the development of a child, the sensory mechanisms of speech, which determine the possibility of perceiving a word, are formed earlier than the motor ones, with which the ability to speak is associated. The period of formation of the function is especially sensitive to formative influences, so you need to talk with the child from the first days of his life. When caring for a child, you need to name all your actions, name the surrounding objects. This is very important, since in order to form connections of the second signal system, it is necessary to combine the verbal designation of objects, phenomena, surrounding people with their specific image - to combine primary-signal irritations with secondary-signal stimuli.

By the end of the first year of life, the word becomes a significant irritant. However, during this period, children’s reaction to a word does not have an independent meaning; it is determined by a complex of stimuli, and only later does the word acquire the meaning of an independent signal (M. M. Koltsova). During the first year of life, the child actively trains in pronunciation, first of individual sounds, then of syllables and finally of words. The formation of speech function requires a certain maturity of the peripheral apparatus - the tongue, muscles of the larynx, lips, and their coordinated activity.

The mechanism of speech reproduction is associated with the complex coordinated work of the nerve centers of the cortex, the formation of certain connections between speech centers and motor areas. A close connection between speech function and motor activity has been shown, especially with finely coordinated movements of the fingers. By developing finely coordinated actions, you can accelerate the formation of speech skills.

A child’s speech develops especially intensively between the ages of 1 and 3 years. At this age, the child’s behavior is characterized by pronounced exploratory activity. The child reaches out to each object, feels it, looks inside, tries to pick it up, and puts it in his mouth. At this age, injuries easily occur due to curiosity and lack of experience, and the frequency of acute infections increases due to the child’s increased contact with other children and his environment.

The conditioned reflex activity of children of this age changes significantly. In the second year of life, individual objects begin to be isolated from the generalized undifferentiated world surrounding the child as separate complexes of irritations. This is made possible by manipulating objects. Therefore, you should not limit the movements of children: let them dress, wash, and eat themselves.

Thanks to actions with objects, children begin to develop a generalization function. Extensive use of objects develops a child's motor analyzer.

In the second year of life, a child develops a large number of conditioned reflexes to the relationship between the size, severity, and distance of objects (identification of faster and slower stimuli, larger or smaller in comparison with others). Of particular importance is the development of systems of conditioned connections to stereotypes of exteroceptive stimulation. In the early childhood dynamic stereotypes are especially important. With insufficient strength and mobility of nervous processes, stereotypes facilitate children’s adaptation to the environment; they are the basis for the formation of habits and skills. Noteworthy is the great strength of the system of conditioned connections developed in children under 3 years of age, and the associated pain due to the violation of the stereotype: children are capricious, cry if you stay with them for a long time; They do not fall asleep for a long time if they are placed in a new place. For children under the age of 3, the development of a large number of different stereotypes not only does not present difficulties, but each subsequent stereotype is developed more and more easily. However, changing the order of stimuli in one stereotype is an extremely difficult task. Systems of conditioned connections developed at this time retain their significance throughout a person’s subsequent life, therefore the formation of stereotypes that are beneficial for health and have educational significance is especially important at this age.

In the second year, increased development of speech begins, the child masters the grammatical structure of the language, with a large role played by the imitative reflex. An adult, when communicating with a child, must pay special attention to the correctness of his speech.

At this stage of development, mastery of actions with objects also has a decisive influence on the formation of the generalization of objects into words, i.e., the formation of the second signaling system.

In the process of child development in the development of new reactions, everything higher value acquires the use of previously formed connections. Systems of conditioned connections developed in early and preschool age (up to 5 years) are especially strong and retain their significance throughout life. This fact is important for teaching practice. The habits and skills developed at this age, which arose on the basis of strong conditioned reflex connections, largely determine a person’s behavior.

In preschool age, the role of the imitative and play reflex is very important. Children copy adults, their gestures, words, manners.

By the end of the preschool period, significant changes occur in the interaction of excitatory and inhibitory processes. As the cerebral cortex develops, the generalization of the excitatory process is gradually removed. Internal, conditioned inhibition is formed and becomes increasingly important. Differentiations are better developed, and periods of inhibition retention become longer. All this contributes to a more selective and adequate response of the child to external influences. At this age, the generalizing function of the word increases, the ability to generalize with words not only specific objects, but also many objects of the external world, categories of objects. So, the child begins to understand that a doll, a bear, a car are all toys, and toys, furniture, dishes, clothes are things. In older preschool age, the reflection of reality is already based on the development of complex systems of connections, including the interaction of the first and second signaling systems.

By the age of 6-7 years, reactivity to verbal stimuli improves. The nature of the interaction between the first and second signaling systems changes. In 3-4 year old children, the first signaling system prevails and has an inhibitory effect on the second. At 6-7 years of age, the increasing activity of the second signaling system has an overwhelming effect on the first signaling system. The development of the second signaling system is one of the important indicators of a child’s readiness for school.

At primary school age, as the cerebral cortex progressively matures, the strength, balance and mobility of nervous processes improve. The development of cortical inhibition processes creates conditions for the rapid and differentiated formation of conditioned connections. The formation of connections in the higher parts of the central nervous system is facilitated by the intensive maturation at this age of intracortical associative pathways that unite various nerve centers. In the process of learning to write and read, the generalizing function of the word continues to develop intensively. The importance of the second signaling system is increasing.

Some changes in conditioned reflex activity are noted in adolescence. The onset of puberty is characterized by increased activity of the hypothalamus. This causes a change in the balance of cortical-subcortical interaction, resulting in an increase in generalized excitation and a weakening of internal inhibition. Compared to the previous age group, the formation of temporary connections becomes more difficult in adolescence. The rate of formation of conditioned reflexes to both primary and secondary signal stimuli decreases. The peculiarities of the higher nervous activity of adolescents require an attentive attitude towards them and a thoughtful organization of the educational process.

Typological features of the child’s higher nervous activity. The formation of individual typological characteristics in the process of ontogenesis is determined by the gradual maturation of higher nerve centers. As will be shown below, during the development of a child, a change occurs in the relationship between the cerebral cortex and subcortical structures. This determines the characteristics of excitatory and inhibitory processes in childhood, and, consequently, the specificity of the manifestation of typological features.

N.I. Krasnogorsky, studying the higher nervous activity of a child on the basis of strength, balance, mobility of nervous processes, relationships between the cortex and subcortical formations, and the relationship between signaling systems, identified 4 types of nervous activity in childhood.

1. Strong, balanced, optimally excitable, fast type. Characterized by the rapid formation of conditioned reflexes, the strength of these reflexes is significant. Children of this type are capable of developing subtle differentiations. Their unconditioned reflex activity is regulated by a functionally strong cortex. Children of this type have well-developed speech with a rich vocabulary.

2. Strong, balanced, slow type. In children of this type, conditioned connections are formed more slowly, and extinct reflexes are also restored slowly. Children of this type are characterized by pronounced control of the cortex over unconditioned reflexes and emotions. They quickly learn to speak, but their speech is somewhat slow. They are active and persistent when performing complex tasks.

3. Strong, unbalanced, highly excitable, unrestrained type. It is characterized by insufficiency of the inhibitory process, strongly expressed subcortical activity, not always controlled by the cortex. Conditioned reflexes in such children quickly fade, and the resulting differentiations are unstable. Children of this type are characterized by high emotional excitability, temper, and affect. Speech in children of this type is rapid with occasional shouting.

4. Weak type with reduced excitability. Conditioned reflexes are formed slowly, unstable, speech is often slow. Easy to brake type. Characteristic is the weakness of internal inhibition with strongly pronounced external inhibition, which explains the difficulty of children getting used to new learning conditions and their changes. Children of this type cannot tolerate strong and prolonged irritation and get tired easily.

Significant differences in the basic properties of nervous processes in children belonging to different types determine their different functional capabilities in the process of learning and upbringing. The effectiveness of pedagogical influences is largely determined by an individual approach to students, taking into account their typological characteristics. At the same time, we have already pointed out that one of the distinguishing features of the types of higher nervous activity in humans is their plasticity. The plasticity of the cells of the cerebral cortex, their adaptability to changing environmental conditions is the morphofunctional basis for type transformation. Since the plasticity of nervous structures is especially great during the period of their intensive development, pedagogical influences that correct typological features are especially important to apply in childhood. I. P. Pavlov considered the plasticity of types to be the most important feature that allows one to educate, train and remake the character of people.