The human nervous system (NS) supports homeostasis– stability and constancy of the internal environment of the body in changing external conditions, and also ensures functional interaction and integration of all structures of the body.

Thanks to the nervous system, the body adequately adapts to environment. This is achieved based on the perception of current stimuli, subsequent analysis and synthesis of this information, as well as action based on it.

The process of processing incoming stimuli and the reaction to them depend on the properties nervous system. Pavlov I.P. identified 3 main properties of nervous processes: strength, mobility and balance, the combination of which forms 4 different types temperament

Table 1. Scheme of combining the properties of the nervous system and the corresponding type of temperament according to Pavlov.

NS strength (or strength of basic neural processes in the central nervous system)– this is the individual’s ability to withstand intense or prolonged stimulation without entering a state of protective inhibition, i.e. fatigue.

People with strong nervous system Unlike people with a weak nervous system, they are more efficient and resistant to interference, can better concentrate and distribute attention, and are able to work longer and more intensely without signs of fatigue.

In turn, people with weak nervous system They get tired faster and are not able to maintain excitement for as long. At the same time, they are distinguished by greater sensitivity to the action of stimuli of various modalities (visual, auditory, etc.), and are able to respond even to weak environmental signals.

In conditions of monotonous, slow-paced activity, inhibitory processes and associated changes develop in the central nervous system. mental state, defined as monotony. The state of monotony develops faster in people with a strong nervous system, so they are less suitable for monotonous work, unlike people with a weak nervous system.

At the same time, in activities where a specialist is forced to work in a long-term mode of waiting for a signal to act, in persons with strong NA, the state of monotony is observed much later than in persons with weak NA.

The strength of the nervous system is closely related to such an additional property of nervous processes as endurance.

Endurance NS- this is the ability to perform any activity for a long time without reducing its effectiveness.

Nervous system mobility in Pavlov’s understanding, it is a rather ambiguous property that B.M. Teplov divided NS into two narrower ones: mobility and lability of NS.

Mobility in a narrow sense, according to Teplov, this is the ease of alteration of the signal meaning of stimuli (positive to negative and vice versa). In situations where it is necessary to react differently to various stimuli, for example, to react to positive ones, to inhibit the emerging reaction to negative ones, the speed of response depends precisely on the mobility of nervous processes, that is, on how long traces of previous reactions persist and have an impact for the next ones. The mobility of the nervous system determines workability - how easy it is for a person to get involved in new activity, and the ease of remaking stereotypes - the extent to which a person can easily move from one way of performing an activity to another.

People with a flexible nervous system easily get involved in work, switch well to new techniques and methods of activity, both in the motor and intellectual spheres, and easily establish contacts with different people. People with inert nervous system they need more time to optimally engage in work, it is difficult for them to quickly leave one task and move on to a new one, while they are more patient, establish stronger conditioned reflex connections and have better voluntary memory.

Lability of NS– these are the speed characteristics of the emergence and cessation of nervous processes. Lability determines the pace of activity (high or low), as well as the speed of information processing and decision making. This property is also the basis of learning ability, positively influencing success in various fields of activity. In a narrow sense, they often talk about intellectual and emotional lability.

Balance of the NS- This is the balance of the excitation force and the inhibitory force. This balance is related to the level of activation at rest. It is higher in balanced people and lower in people with a pronounced predominance of excitation over inhibition or inhibition over excitation.

As part of professional selection, the most important properties of the nervous system for us are lability and endurance, which reflect, respectively, how quickly a person can get involved in performing a new task, at what speed he can perform it, and also how long he can maintain this speed without getting tired . We may also be interested in the strength or weakness of the basic nervous processes in the central nervous system if the operating conditions impose specific requirements on this (for example, the chief of guard at a fire department).

By the strength of nervous processes, I.P. Pavlov understood the performance of nerve cells, their ability to withstand strong stress without falling into an inhibitory state (exorbitant inhibition). The strength of nervous processes depends on the supply of reactive, or functional, substance in nerve cells. Depending on the strength of the nervous processes, the nervous system can be strong or weak. A strong nervous system is characterized by great strength of nervous processes - excitation and inhibition; the latter is due to a large supply of the reactive substance in nerve cells.

A weak nervous system is associated with a small supply of reactive substances in nerve cells; it is characterized by weakness of the basic nervous processes - excitation and inhibition. A strong nervous system can withstand great stress, but a weak nervous system cannot withstand such stress.

The strength of the nervous system is a property of the nervous system that reflects the limit of performance of the cells of the cerebral cortex, i.e. their ability to withstand, without going into an inhibitory state, either very strong or long-acting (albeit not strong) impact.

The strength of nervous processes is characterized by the efficiency and endurance of the nervous system and means its ability to withstand prolonged or short-term, but very strong excitation or inhibition. Weakness of nervous processes is the inability of nerve cells to withstand prolonged and concentrated excitation or inhibition. When they act, nerve cells quickly go into a state of protective inhibition. However, a weak nervous system is highly sensitive.

Temperament is indicative of the strength of mental processes. In this case, not only their absolute strength at one moment or another is significant, but also how constant it remains, i.e. degree of dynamic stabilityOsti.
With significant stability, the strength of reactions in each individual case depends on the changing conditions in which a person finds himself, and is adequate to them: stronger external irritation causes a stronger reaction, weaker irritation causes a weaker reaction. In individuals with greater instability, on the contrary, strong irritation can - depending on the very variable state of the personality - cause either a very strong or a very weak reaction; in the same way, the weakest irritation can sometimes cause a very strong reaction; a very significant event, fraught with the most serious consequences, can leave a person indifferent, and in another case, an insignificant reason will give a violent outbreak: the reaction in this sense is not at all adequate to the stimulus.

Factors acting on the development of conditioned reflexes:

1. frequency of occurrence of conditioned reflexes;
2. strength of conditioned reflexes;
3. ability to differentiate stimuli;
4. ability to generalize stimuli.

All these factors depend on the type of nervous system.

The type of nervous system is a set of nervous processes determined genetically and acquired during life.

The concept of “type of nervous system” includes 3 properties of nervous processes:

1. strength of nervous processes;
2. balance of nervous processes;
3. mobility of nervous processes.

The power of nervous processes- the ability to develop an adequate reaction to a strong and super-strong stimulus. It is based on the severity of excitation and inhibition processes in the central nervous system. Nervous processes are divided (by strength) into strong (the predominance of excitation processes in the central nervous system) and weak (the predominance of inhibition processes in the central nervous system).

Balance of nervous processes- balance of excitation and inhibition processes.

Strong nervous processes (by balance) are divided into:

1. balanced (the excitation process is balanced by inhibitory processes);
2. unbalanced (a sharp predominance of excitation processes, they are not compensated by inhibition - “uncontrolled type”).

Mobility of nervous processes- the ability to quickly change the processes of excitation and inhibition.

Strong balanced nervous processes (based on mobility) are divided into:

1. mobile (excitation and inhibition easily replace each other)
2. motionless (inert: processes change with difficulty).

Methods for studying types of nervous systems

In animals- experiments in special conditions with special stimuli. In humans, the type of nervous system is determined by observation and special tests.

The strength of nervous processes is determined by:

1. by the ability to develop a conditioned reflex to a strong and super-strong stimulus. If a conditioned reflex is developed, then the nervous processes are strong; if not, then the nervous processes are weak, because in response to the action of the stimulus, extreme inhibition occurs in the central nervous system;
2. by “stitching” conditioned reflexes. A conditioned reflex is developed to a stimulus of a certain frequency and another conditioned reflex to a stimulus of a different frequency. By swapping the frequencies, preservation of conditioned reflexes is observed in animals with a strong type of nervous system. In animals with a weak type of nervous system, a pathological condition arises - “experimental neurosis”;
3. With using tests, which are based on determining the speed of inhibition in the central nervous system.

The balance of nervous processes is determined by the ability to develop delayed inhibition (an increase in the time between the action of the conditioned signal and the unconditioned stimulus):

1. if the conditioned reflex is quickly inhibited, and a new conditioned reflex does not arise, then inhibition predominates in the central nervous system;
2. if the old conditioned reflex is inhibited and a new conditioned reflex is developed, then excitation and inhibition are balanced;
3. if the old reflex is not inhibited for a long time, and a new one has already been developed, then excitation predominates in the central nervous system, which is not balanced by inhibition.

The mobility of nervous processes is determined by the speed at which two conditioned reflexes replace each other. 2 conditioned reflexes are developed, and then the conditioned stimuli change places. The speed of change of conditioned reflexes is used to judge the mobility of processes.

Types of nervous systems in animals

Animals have 2 extreme and 1 central type of nervous system:

1. strong unbalanced type- excitation prevails over inhibition: an aggressive animal that gives a pronounced reaction to any stimulus;
2. weak type- processes of inhibition over excitation predominate in the central nervous system: a cowardly animal;
3. strong balanced type- central type.

There are 2 subgroups:

1. with moving nervous processes- friendly, inquisitive, interested in changing conditions;
2. with sedentary nervous processes- a calmer type. Most efficient in the laboratory.

Types of nervous systems in humans

The types of nervous systems in humans are more difficult to determine than in animals. When dividing the nervous system into types, it is necessary to consider:

1. strength, mobility and balance of nervous processes;
2. the relationship between the cerebral cortex and subcortical formations;
3. ratio and predominance of 1 and 2 signaling systems.

Education and training have a great influence on the type of nervous system.

4 types of the nervous system in humans (based on the Hippocratic classification).

Type 1 - choleric- “bilious” type, strong unbalanced nervous processes, aggressive type;

Type 2 - melancholic- “black bile”, weak nervous processes, predominance of inhibition, sad type;

Type 3 - sanguine- “blood”, strong balanced mobile nervous processes, cheerful, strong, a change of environment is very important;

Type 4 - phlegmatic- “lymph”, strong balanced sedentary nervous processes, strong, active, hardworking, patient.

Based on the severity of signaling systems, there are 4 types:

1. art- 1 signal system predominates - emotional, with concrete thinking;
2. mental- signal system 2 predominates - abstract thinking;
3. balanced- 1 signal system is approximately equal to 2 signal system;
4. brilliant- both signaling systems are identical and significantly expressed.

Introduction

The topic of my test reveals the basic concepts of higher nervous activity and its typology. It is known that higher nervous activity is provided by the cerebral cortex. This means that our memory, speech, attention, thinking and many other types of mental processes directly depend on the correct functioning of the cortex, its adequate perception and analysis of all kinds of stimuli.

Nervous processes occurring in the cortex have certain properties (strength, ratio, mobility), which form the individual characteristics of higher nervous activity, and therefore emphasize the individuality of each person.

The typology of higher nervous activity indicates in what unique way an individual perceives the world around him.

1. Basic properties of nervous processes that determine behavior

Long-term study of conditioned reflexes allowed Pavlov to identify three main properties of nervous processes that determine the individual characteristics of animal behavior and their temperaments. The first property is the strength of the processes of excitation and inhibition, which characterizes the performance of cortical cells. This property is determined by the maximum strength of stimulation to which positive and negative conditioned reflexes can be formed. Some dogs easily form conditioned reflexes to both weak and strong stimuli. For other dogs, strong stimuli (a sharp bell or rattle) turn out to be excessive and cause extreme inhibition at the corresponding point, easily radiating throughout the entire cortex. In such dogs, conditioned reflexes are formed only to weak or moderately strong stimuli.

The second property is the ratio, or balance, of the forces of the processes of excitation and inhibition, in other words, their balance. In some dogs, both positive and negative conditioned reflexes are equally easily formed; in others, the strength of the processes of excitation and inhibition is not the same. If the process of excitation prevails over the process of inhibition, then, along with the rapid formation of positive conditioned reflexes, there is a difficulty in developing differentiations, especially subtle ones; already existing differentiations are easily disinhibited. In such excitable dogs, overstrain of the inhibitory process leads to the disappearance of all previously developed differentiations. If, on the contrary, the process of excitation turns out to be weaker than the process of inhibition, then the dog’s behavior approaches those in whom strong stimuli cause general cortical inhibition. The third property is the mobility of the processes of excitation and inhibition, i.e. the speed with which they can replace each other. In some dogs, the resulting excitation or inhibition appears to be of a stagnant nature, slowly giving way to the opposite process. Converting a positive reflex into a negative one, and a negative one into a positive one, is difficult for them. A rapid change of positive and negative stimuli can sometimes even lead to disruption of cortical activity. in other dogs, on the contrary, cortical cells easily cope with a task that requires a rapid change in the processes of excitation and inhibition; in an experiment it is not difficult to achieve mutual alteration of positive and negative reflexes. This property acquires significant, decisive significance when the processes of excitation and inhibition are sufficiently strong and balanced and recedes into the background when both processes or one of them are weak.

2. Types of higher nervous activity

The individual characteristics of the higher nervous activity of dogs are extremely diverse, since the gradations of strength, balance and mobility of nervous processes can be very different. Pavlov managed to identify four main types - one weak and three strong (add. No. 1). Pavlov divides dogs whose cortical cells have sufficient strength of excitation and inhibition processes into unbalanced and balanced, and the latter, in turn, into animals with a mobile and inert nature of cortical processes. Ultimately, Pavlov distinguishes, based on the above characteristics, the following types of higher nervous activity: weak; unbalanced; alive or moving; calm or inert. The weak type is characterized by very low physiological lability of the nerve cells of the cerebral cortex, and, consequently, the ease of their transition to a state of inhibition under the influence of incoming impulses. Excessive inhibition of cells determines the low limit of their performance. Animals with a weak type of higher nervous activity are cowardly, and in response to strong or unusual stimuli they often give a passive defensive reaction. Animals with an unbalanced type of higher nervous activity have sufficient strength of nervous processes and, at the same time, a clear predominance of excitation over inhibition. Excitation of cortical cells can reach great strength and easily radiate throughout the cortex, overcoming inhibition, which leads to a disruption of the normal relationship between the processes of excitation and inhibition. Such dogs are overly excitable, aggressive, uncontrollable in their aggression and are difficult to educate (train) due to the easily occurring breakdown of inhibitory processes, in particular differentiation. The living or mobile type is characterized by great mobility of nervous processes and at the same time their sufficient strength and balance. Well-defined phenomena of positive and negative induction prevent excessive irradiation of nervous processes and ensure speed and ease of transition from one process to another. To maintain an active state, cortical cells require an influx of a large number of afferent impulses, without which their excitability decreases and inhibition develops, easily radiating throughout the cortex. Animals with a living type of higher nervous activity are mobile, sociable, easily oriented in a new environment, and react quickly to every new stimulus without showing excessive aggression; in a monotonous, monotonous environment they easily fall asleep. Characteristic calm or inert type - low mobility, stagnation of nervous processes with sufficient strength and balance. The process of excitation or inhibition that arises in the cortical cell persists for some time, without showing a tendency to rapid and significant irradiation. Animals with a calm type of higher nervous activity are unsociable, react weakly to new stimuli, as if ignoring everything that is happening around them. The above classification of types is a diagram that only to some approximation reflects reality. In life one can observe various variations of these types. The described types of higher nervous activity can also be found in humans. Pavlov rightfully draws an analogy between these types and the temperaments once described by Hippocrates: the weak type corresponds to a melancholic temperament, the unbalanced one to choleric, the lively type to sanguine, and the calm type to phlegmatic.

3. Analytical and synthetic activity of the cerebral cortex

The mechanisms of higher nervous activity in higher animals and humans are associated with the activity of a number of parts of the brain. The main role in these mechanisms belongs to the cerebral cortex (I.P. Pavlov). It has been experimentally shown that in the highest representatives of the animal world, after complete surgical removal cortex, higher nervous activity deteriorates sharply. They lose the ability to subtly adapt to the external environment and exist independently in it. In humans, the cerebral cortex plays the role of “manager and distributor” of all life functions (I.P. Pavlov). This is due to the fact that during phylogenetic development a process of corticalization of functions occurs. It is expressed in the increasing subordination of the somatic and vegetative functions of the body to the regulatory influences of the cerebral cortex. In the event of the death of nerve cells in a significant part of the human cerebral cortex, it turns out to be non-viable and quickly dies with a noticeable disruption of the homeostasis of the most important autonomic functions. A feature of the cerebral cortex is its ability to isolate individual elements from the mass of incoming signals, to distinguish them from each other, i.e. she has the ability to analyze. Of all the perceived signals, the animal selects only those that are directly related to one or another function of the body: obtaining food, maintaining the integrity of the body, reproduction, etc. in response to these stimuli, impulses are transmitted to the corresponding effector organs (motor or secretory). The analysis and synthesis of stimuli in the simplest form can also be carried out by the peripheral parts of the analyzers - the receptors. Since receptors are specialized in the perception of certain stimuli, therefore, they produce their qualitative separation, i.e. analysis of certain signals from the external environment. With a complex structure of the receptor apparatus, for example the organ of hearing, its structural elements may differ in sounds of unequal pitch. At the same time, a complex perception of sounds is also produced, which leads to their synthesis into one whole. Analysis and synthesis carried out by the peripheral ends of the analyzers are called elementary analysis and synthesis. But excitation from the receptors also reaches the central cortical ends of the analyzers, where more complex forms of analysis and synthesis occur. Here, excitation, in the process of forming a conditioned reflex, comes into contact with numerous foci of excitation in other areas of the cortex, which contributes to the unification of numerous stimuli into a single complex, and also makes it possible to more subtly distinguish between elementary stimuli. Analysis and synthesis carried out by the cortical ends of the analyzers are called higher analysis and synthesis. The analytical activity of the cortex is based on the process of inhibition, which limits the irradiation of excitation. As a result of the analysis of perceived irritations, their differentiation is possible. The environment is constantly changing biological significance its individual elements with others. In this regard, in the cerebral cortex the relationship between analysis and synthesis is constantly changing. Both processes are constantly interconnected, and therefore they are considered as a single analytical-synthetic process, a single analytical-synthetic activity of the cerebral cortex.

4. Reality signaling systems

In 6935, Pavlov wrote about the “extraordinary increase in the mechanisms of nervous activity” that occurred in the developing animal world during the process of human development. In an animal, afferent impulses signal phenomena and events that directly affect the body's receptors. Such a direct signaling system of reality is also inherent in humans. However, there is another, specifically our, human signaling system of reality. In humans, “signals of the second degree appeared, developed and were extremely improved, the signals of these primary signals - in the form of words, spoken, audible and visible” (Pavlov). Thus, a person is characterized by a double signaling of reality: 1. A common system of direct signals of reality with animals; 2. A special system of indirect, speech signals. Speech signals underlie a special principle, a special form of reflection of reality. They can not only replace direct signals, but also generalize them, highlight and abstract individual features and qualities of objects and phenomena, establish their connections and mutual dependence, as well as the processes of their formation and change. It is this system of signals that determines the most important features of human higher nervous activity and makes possible “specially human, higher thinking” (Pavlov), leading to unlimited orientation in the surrounding world, to the development of science and its practical reflection - technology. A remarkable feature of the second signaling system is the speed of formation of conditioned connections: it is enough for a person to hear something once or read something in a book for new conditioned connections to appear in the cerebral cortex. Sometimes they are so strong that they last for many years without needing reinforcement. The second signaling system, associated in its development with mental activity, has characteristics in each person that depend on individual life experience, and is not inherited. An illustration of this is the case where children grow up among animals and are deprived of influence human society . Such people experience a sharp decline in intelligence and an inability to develop abstract, abstract thinking. Many people ask the question: do the mind, speech, and human psyche develop if a child grows up in isolation from human society? Nature itself answered this question. Such children were physically strong, ran quickly on all fours, saw and heard well, but were devoid of intelligence."In 1920, in India, Dr. Singh discovered two girls in a wolf's den along with a litter of wolf cubs. One of them looked 7-8 years old , another year 2. The girls were sent to an orphanage. At first they walked and ran only on all fours, and only at night, and during the day they slept, huddled in a corner and huddled together like puppies. The youngest girl soon died, and the eldest, they named her Kamala, lived for about 10 years. All these years, Singh kept a detailed diary of observations of Kamala. She walked on all fours for a long time, leaning on her hands and feet. She drank by lapping, and only ate meat from the floor, and did not take it from her hands. ". When they approached her while eating, she bared her teeth like a wolf and growled. Kamala saw well in the dark and was afraid of strong light and fire. During the day she slept, squatting in the corner, facing the wall. She tore off her clothes and even in cold weather she threw off the blanket.After 2 years, Kamala learned to stand, but poorly. After 6 years, she began to walk, but still ran on all fours. Within 4 years she had learned only 6 words, and after 7 years she had learned 45 words. Kamala's vocabulary subsequently expanded to 100 words. By this time, she fell in love with the company of people, stopped being afraid of light, and learned to eat with her hands and drink from a glass. Having reached approximately 17 years of age, Kamala, in terms of mental development, resembled a 4-year-old child" (Kuznetsov O.N., Lebedev V.I. "Psychology and psychopathy of loneliness" 1972). There are cases when children were deliberately isolated from the team "Growing up, they were no different from children who grew up among animals. "About 350 years ago, the Indian padishah Akbar argued with his court sages, who argued that every child would speak the language of his parents, even if no one taught him this. Akbar doubted the validity of this opinion and conducted an experiment worthy of the cruelty of the eastern feudal lords of the Middle Ages. Small children of various nationalities were seized and placed one at a time in separate rooms. The children were served by dumb servants. During the 7 years of this “experiment,” the children never heard a human voice. When people came to them 7 years later, instead of human speech they heard incoherent screams, howls, meows" (Kuznetsov O.N., Lebedev V.I. "Psychology and psychopathy of loneliness" 1972)

These examples convince us that the process of human mental development depends on learning, starting from early childhood. A child isolated from human society does not develop a second signaling system. The influence of human society on the formation of a child’s mental sphere is very important for proper education. The more adequate stimuli a child receives, the better abstract thinking and consciousness develops. This is better perceived in childhood, when a certain morphological restructuring of the nervous system occurs, which has huge hereditary reserves. Isolation from the social environment of an adult also causes known functional disorders and mental illnesses.

5. Particular types of human higher nervous activity

A person can think about various objects without reproducing their real image. However, when thinking about an object, for example a lemon, it is good to imagine its appearance, smell and taste. In this case, the cortical process will more strongly affect the primary signal activity, and as a result, such a specific idea of ​​​​a lemon may arise that salivation will immediately appear. If the thinking process is more abstract in nature, without reproducing real images, then such a reaction does not occur. In individual people, thinking can occur with varying degrees of participation of primary-signal activity, although in all cases, secondary-signal activity, of course, retains a leading role. This gave Pavlov the basis to distinguish between types of higher nervous activity, not only common to animals and people, but also specific to human ones. He distinguished three types of people, which were designated as “artistic”, “mental” and “average”. The relative predominance of signals of the first signaling system in a person’s mental activity characterizes the artistic type, the relative predominance of the signal signals - the thinking type, their equal representation - the average type of people. The artistic type is characterized by the brightness of images that arise as a result of direct influence, living impressions, and emotions. The thinking type is characterized by a predominance of abstractions, logical constructions, and theorizing. It must be emphasized that classifying a person as an artistic type does not mean weakness of intellectual activity, lack of intelligence. We are talking here about the relative predominance of figurative components of the psyche over mental ones. In general, the second signaling system in humans predominates over the first, and this predominance is absolute, since the role of language and thinking in people’s activities is decisive and the processes of a person’s reflection of the world are mediated by his thoughts expressed verbally. Therefore, we encounter an absolute preponderance of the first signaling system only in dreams, with their violent emotionality and chaotic imagery, which is in no way ordered or regulated by thinking.

What does the relative predominance of one of the signaling systems mean? If we express the absolute predominance of the second signaling system mathematically, denoting it C2, and the first signaling system by C1, then the dependence would have the following form: C2>C1.

The relative predominance of the first signaling system over the second can be denoted by C2>C1 + m (where m are those structural features of emotional and figurative comprehension of the world that distinguish representatives of this type). In turn, the thinking type of a person can be designated as follows: C2 + n > C1 (where n are the structural features of the abstracting attitude towards the world that distinguish representatives of this type from the rest). These mathematical relationships make it possible to see that the relative dominance of one system over another should not be confused with absolute dominance.

6. The appearance of the first conditioned reflexes

At the core higher manifestations nervous activity lies in the formation of conditioned connections that ensure the flow of positive and negative conditioned reflexes. Without conditioned connections there is no higher nervous activity. its appearance in the process of ontogenesis should be attributed to the moment of formation of the first conditioned reflexes. In a premature baby, it is possible to form food and defensive conditioned reflexes during that period of his life when he should not yet be born. This suggests that several weeks before birth, cortical cells are morphologically mature enough to exhibit their specific function. However, during intrauterine development the environment surrounding the fetal body is extremely stable, and therefore there are no conditions that are necessary for the manifestation of a specific cortical function. These conditions appear from the moment of birth, when various new stimuli begin to act on the body, which, repeatedly combined with the action of unconditioned stimuli, can acquire a signal value. However, the first conditioned reflexes are formed slowly and are initially characterized by low stability, which can be explained by the pronounced irradiation of excitation and inhibition. By the beginning of the second month of life, food and defensive conditioned reflexes become stronger and are formed in response to irritation of any receptors; it is possible to develop rough differentiations, i.e. to stimuli that differ significantly from each other. In the process of the emergence of more and more new positive and negative conditioned reflexes, the rate of their formation and strengthening increases. However, in individual children, the rate of formation of reflexes to various irritations varies greatly. These individual characteristics primarily depend on previously formed conditioned reflexes. The child more easily and quickly distinguishes those stimuli that played a large role in his previous life, in other words, took a greater part in the formation of the available fund of conditioned connections. Consequently, new positive and negative conditioned reflexes are developed faster and easier, the more similar (or similar) reflexes were formed earlier. This is one of the patterns of development of higher nervous activity, which underlies its qualitative age-related characteristics. In children 3-4 months old, some conditioned reflexes (in particular, food and defensive ones) arise after several combinations; at the same time, both the strength and fineness of the differentiations begin to increase. By this time, the conditioned reflex activity of the cerebral cortex becomes significantly more complicated. A sufficient number of previously formed connections to simple stimuli makes it possible to develop not only positive, but also negative conditioned reflexes to more complex, for example complex, stimuli. The simplest unconditioned orientation reflexes are present in children already in the first days after birth. Conditioned orienting reflexes appear much later, usually from the third or fourth month of life. In the future, they form very easily and begin to play a significant role in the child’s behavior. The most important conditioned stimulus that causes an orienting reflex is auditory speech, signaling the presence of a person.

7. Speech development

From the middle of the first year of life, the child develops conditioned reflexes to speech stimuli. He begins to respond to words spoken by others, which turn into signals of various unconditioned, and later conditioned stimuli. Gradually, words become signals of certain actions, phenomena and relationships between them. Due to the imitative reflex, clearly expressed already in the first months of life, the child begins to repeat the facial movements of those around him and the sounds of their speech. The first speech noises appear - pharyngeal, laryngeal, palatal, labial, etc., which then gradually differentiate, leading to the formation of phonemes, i.e. speech sounds. Every sound a child pronounces evokes afferent impulses from both the hearing organ (he hears the word he pronounces) and the speech organs (vocal cords, tongue and the entire speech apparatus). These impulses, reaching the cortex, become signals that acquire critical importance in establishing speech conditional connections. The child’s speech begins from the moment when the phonemes he pronounces or their combinations acquire the meaning of conditioned stimuli, becoming the same signals of immediate stimuli as the words spoken by others. Towards the end of the first and beginning of the second year of life, the child, often not yet having formed the pronunciation of individual words, begins to combine two and then three words in his speech reactions, thus forming the first simple combinations of words. The child learns ready-made speech stereotypes, soon creating new combinations of words. Mastering the grammar of a language and the rules for combining words into sentences begins very early, already in the second year of life. By the end of it, the vocabulary of children's speech reaches 200-400 words. Subsequently, the development of children's speech, i.e. Giving the language a coherent, grammatically correct and meaningful character largely depends on the correct construction of the speech of others.

8. The role of Sechenov and Pavlov in the development of the doctrine of higher nervous activity

I. P. Pavlov (1849-1936) I. M. Sechenov (1849-1936)

The first attempt to analyze mental activity as the physiological work of the higher part of the brain was made by Sechenov. In his remarkable article “Reflexes of the Brain” (1863) and a number of subsequent works, he proved with great skill that the external manifestation of brain activity always “reduces finally to just one phenomenon - muscle movement” and that reflexes underlie all manifestations of human mental activity . The phenomena of inhibition discovered by Sechenov in the central nervous system served as the basis for distinguishing cases with increased and delayed (inhibited) reflex reactions of the brain. He considered states of passion and affect as an intensification of a motor reaction, and imagined an unspoken thought as an unfinished reflex, the last link of which, i.e. movement is slowed down. Sechenov repeatedly emphasized that “the first reason for every human action lies outside of him” and that “under the same internal and external conditions of a person, his activity should be the same.” In other words, Sechenov recognized the determinism of all acts of conscious life. In his works, he gave a deeply materialistic physiological interpretation of human mental activity, thereby laying the foundation for future experimental physiology of the brain. I. Sechenov’s studies on the reflex nature of the psyche were developed by I. Pavlov (1849-1936) in his doctrine of higher nervous activity. The theory of reflex activity is based on three basic principles of scientific research: 1. Determinism - causation any action. 2. Analysis and synthesis - decomposition of the whole into parts and then composing a new whole from elements. 3. Structurality. In his studies, I. Pavlov proved that the cerebral hemispheres have great importance in the life activity of the entire organism. The cerebral cortex, together with the nearest subcortical centers, carries out complex analytical and synthetic activities. Complex temporary nerve connections are formed in it, with the help of which the relationship between the organism and the external environment, as well as the activity of the organism itself, is regulated. I. Pavlov calls this activity of the cerebral hemispheres higher nervous activity. There are two types of reflexes: conditioned and unconditioned. Unconditioned reflexes are innate, they are inherited and characterized by great constancy. Any unconditioned reflex, like an innate one, appears immediately upon the first application of the corresponding irritation, if the central nervous system has reached the required degree of maturity. Conditioned reflexes are acquired throughout life, are not inherited and are much less constant. Conditioned reflexes do not appear immediately: they are developed gradually, under certain conditions. This is due to the fact that the unconditioned reflex flows through ready-made reflex arcs, and for the implementation of a conditioned reflex it is necessary that new connections between nerve cells, called conditioned connections, be established in the cortex, and thereby a new, previously non-existent reflex arc is closed. Unconditioned reflexes can be considered as specific, i.e. characteristic of all representatives of a given species, and conditional - as individual, i.e. acquired by an individual during its life.

Conclusion

The higher nervous activity of a person is of a reflex nature. The main qualitative feature of the functions of the higher part of the human brain is consciousness as the highest stage of mental development. Both man and animal in their mental activity reflect the phenomena of the surrounding world. However, a person, reflecting the world in his consciousness, generalizes the observed phenomena and establishes the patterns of their occurrence. This gives a person the opportunity to subjugate nature and remake the world in the process of work. Conscious thinking, which determines the main qualitative difference between the human brain and the brain of any animal, is manifested in speech activity. “Of course,” wrote Pavlov, “the word for a person is the same real conditioned stimulus as all the others he has in common with animals, but together with thus, it is so comprehensive as no other, and in this respect does not come into any quantitative or qualitative comparison with the conditioned stimuli of an animal." Nervous processes occurring in the body have three main properties: strength, correlation and mobility. They determine the individual characteristics of a person’s behavior and his temperament. Based on this, four types of higher nervous activity are distinguished. This classification reflects reality only to some approximation. Various variations of these types can be observed in life, since weakness and imbalance of the nervous system can be expressed to varying degrees.

Literature

Anokhin P.K. Essays on the physiology of functional systems. - M.: Medicine, 1975

Batuev A.V. Higher nervous activity. - M.: Higher. school, 1991

Kostyuk P. G. Physiology of the central nervous system. - K.: Higher. school, 1971

Nebylitsin V.D. Basic properties of the human nervous system. - M.: Education, 1966

Plakhtiy P. D. Physiology of humans. - Kamyanets-Podilsky: Osvita, 2000

Starushenko L. I. Anatomy and physiology of people. - K.: Health, 2003

Tkachuk V. G., Khapko V. B. Anatomy and evolution of the nervous system: Brief lecture notes. - 2nd ed. stereotype. - K.: MAUP, 2003

Balance of nervous processes

A property of the nervous system that expresses the relationship between excitation and inhibition. The concept of U. n. p., introduced by I.P. Pavlov, was considered by him as one of the independent properties of the nervous system, forming in combination with others (with the strength and mobility of the nervous system). In the research of the school of B. M. Teplov -V. D. Nebylitsyna U. n. n. began to be considered as a set of secondary (derived) properties of the nervous system, determined by the ratio of excitation and inhibition indicators for each of its primary properties (strength, dynamism of the nervous system). Along with the new interpretation of U. n. a new term was also proposed - the balance of nervous processes.

Brief psychological dictionary. - Rostov-on-Don: “PHOENIX”. L.A. Karpenko, A.V. Petrovsky, M. G. Yaroshevsky. 1998 .

See what “balance of nervous processes” is in other dictionaries:

Balance of nervous processes- a concept proposed by I.P. Pavlov and reflecting the relationship between excitation and inhibition. In connection with the research of the school of B. M. Teplov and V. D. Nebylitsyn, the content of this concept was revised and a new term was proposed - “balance of nervous... ... Trainer's Dictionary

balance of nervous processes- a property of the nervous system that expresses the relationship between excitation and inhibition. The concept of U.n.p introduced by I.P. Pavlov, was considered by him as one of the independent properties of the nervous system, forming in combination with others (with strength, and... ... encyclopedic Dictionary in psychology and pedagogy

Nervous process: balance is a property of the nervous system, expressing the relationship between excitation and inhibition. The concept was introduced by I.P. Pavlov, was considered by him as one of the independent properties of the nervous system, forming in... ...

See nervous process: poise. Dictionary of a practical psychologist. M.: AST, Harvest. S. Yu. Golovin. 1998 ... Great psychological encyclopedia

A property of the nervous system that expresses the relationship between excitation and inhibition. The concept was introduced by I.P. Pavlov, was considered by him as one of the independent properties of the nervous system, forming, in combination with other strength and mobility, a type... ... Great psychological encyclopedia

See nervous process: poise Dictionary of a practical psychologist. M.: AST, Harvest. S. Yu. Golovin. 1998 ... Great psychological encyclopedia

- (from the Greek dynamis force) a property of the nervous system, characterized by the ease of excitation and inhibition during the development of conditioned reflexes. The relationship between the indicators of the dynamics of excitation and inhibition is defined as the balance... Great psychological encyclopedia

Neuroendocrine system- The effect of physical activity on the neuroendocrine system is not as pronounced externally as, for example, in the case of growth muscle mass. For this reason, we sometimes have to deal with the statement that physical activity is detrimental... ... Pedagogical encyclopedia "Education" healthy image students' lives"

Stable features of the nervous system that, ceteris paribus, influence individual psychological characteristics person. Without predetermining its social value, without directly determining the substantive side of the psyche, S. science. With … Great psychological encyclopedia

CONDITIONED REFLEXES- CONDITIONED REFLEXES. The conditioned reflex is now a separate physiol. a term denoting a certain nervous phenomenon, a detailed study of which led to the formation of a new department in animal physiology, the physiology of higher nervous activity as... ... Great Medical Encyclopedia