GND is the activity of the higher parts of the central nervous system, ensuring the most perfect adaptation of animals and humans to the environment. According to I.P. Pavlov, GNI is based on conditioned and unconditioned reflexes. In the process of evolution, conditioned reflexes begin to dominate behavior. The significance of higher nervous activity: 1. normal interactions between the body and the outside world are ensured. 2. the functioning of internal organs is regulated. 3. the existence of the organism as a single whole is ensured. In 1863, Ivan Mikhailovich Sechenov published a work entitled “Reflexes of the Brain.” A reflex is the action of some cause - a physiological stimulus. According to I.M. Sechenov, brain reflexes include three parts: 1. The first is excitation in the sense organs caused by external influences. 2. Second – the processes of excitation and inhibition occurring in the brain. 3. Third – human movements and actions, i.e. his behavior. All these links are interconnected and conditioned.

1. The difference between conditioned reflexes and unconditioned ones.

Reflex - This is the body’s response to irritation of receptors, carried out by the nervous system. The path along which a nerve impulse travels during a reflex is called a reflex arc.

Unconditional: present from birth; do not change or disappear during life; are the same in all organisms of the same species; adapt the body to constant conditions; The reflex arc passes through the spinal cord or brain stem.

Conditional : acquired during life, can change or disappear during life, each organism has its own, individual

Development of a conditioned reflex

Conditional (indifferent) stimulus must precede the unconditioned (causing an unconditioned reflex). For example: a lamp is lit, after 10 seconds the dog is given meat.

Braking: Conditional (non-reinforcement): the lamp is lit, but the dog is not given meat. Gradually, salivation when the lamp is turned on stops (the conditioned reflex fades).

Unconditional: During the action of a conditioned stimulus, a powerful unconditioned stimulus arises. For example, when the lamp is turned on, the bell rings loudly. No saliva is produced.

1. The mechanism of formation of conditioned reflexes.

When a conditioned stimulus is applied, a focus of excitation appears in the cortex. After excitation of unconditional irritation, 2 lesions appeared. A short circuit occurs between the foci (temporary connection).

Education occurs according to the dominant principle. The source of excitation from an unconditioned stimulus is always stronger than from a conditioned one. A stronger focus of excitation from unconditioned stimulation attracts excitation from the focus of conditioned stimulation. The degree of his excitement will increase. The dominant focus has the property of a long, stable existence. Consequently, conditioned and unconditioned excitation will interact with each other for a long time

1. Conditioned reflexes. Conditions necessary for their formation.

1. The action of the conditioned stimulus must precede the influence of the unconditioned one.

2. A repeated combination of conditioned and unconditioned stimuli is necessary.

3. unconditioned stimuli must be strong enough.

4. there is no extraneous external irritation.

5. presence of motivation.

1. Inhibition of conditioned reflexes: unconditioned and conditioned.

Unconditional braking – This is a rapid suppression of reflex activity. External - weakening or cessation of reflex conditions due to an extraneous stimulus. Fading – an extraneous signal that repeats. Transcendental - occurs under the action of conditioned irritation, being protective.

Conditioned inhibition- it develops slowly, consists in eliminating activities that are not necessary at a given time. Fading - occurs when a conditioned signal is re-attached and consolidated. Delayed - arose in the absence of reinforcement 2-3 minutes from the beginning of the unconditional signal. Differentiation - when additional stimulation is applied, it is close to conditioned and not reinforced. Conditioned inhibition occurs when another and not reinforced one is added to a conditioned stimulus.

1. Analysis and synthesis of stimuli.

Analysis lies in the fact that, with the help of emerging sensations, the body distinguishes between existing stimuli (qualitatively - light, sound, etc.) The central nervous system receives a huge amount of information from the peripheral parts of the analyzers, but a significant part of it is eliminated using inhibitory mechanisms - sensory relays .

Synthesis consists in the perception of an object, phenomenon and the formation of a response from the body. Perception is possible in two ways: when an object or phenomenon is encountered again or for the first time. Recognition (gnosis) is achieved as a result of comparison of currently incoming information with memory traces.

1. I and II signaling systems.

The first signaling system is present in humans and animals. The activity of this system is manifested in conditioned reflexes that are formed to any stimulation of the external environment (light, sound, mechanical stimulation, etc.), with the exception of words. In a person living in certain social conditions, the first signaling system has a social connotation. The first signaling system in animals and humans provides objective, specific thinking. The second signaling system arose and developed as a result of human labor activity and the appearance of speech. Work and speech contributed to the development of hands, brain and sensory organs. The activity of the second signaling system is manifested in speech conditioned reflexes. The second signaling system provides abstract thinking in the form of concepts, judgments, and conclusions.

1. Dynamic stereotype.

Dynamic stereotype- a stable sequence of conditioned reflexes developed and recorded in the cerebral cortex of a person or animal. In order for a dynamic stereotype to be formed, a complex of stimuli must act on the body in a certain order and at certain intervals of time (external stereotype). A stereotype is called dynamic because it can be destroyed and re-formed when conditions of existence change. The restructuring of the dynamic stereotype is observed in the life of every person at different age periods due to changes in living conditions: a child’s enrollment in school, a change of school to a special educational institution, the transition to independent work, etc. The dynamic stereotype underlies the development of various habits and skills , automatic processes in work activity. As a result, an experienced worker performs his usual work faster and with less fatigue than a beginner.

1. Types of human GNI.

I. P. Pavlov based the division of the nervous system into types on three properties of nervous processes: strength, balance and mobility (excitation and inhibition).

Strong unbalanced type. Characterized by strong unbalanced and mobile nervous processes. Weak braking type. Characterized by weak, unbalanced nervous processes. Strong balanced mobile type. Strong balanced inert type.

I. P. Pavlov identified four main types, using Hippocratic terminology to designate them: melancholic, choleric, sanguine, phlegmatic.

Choleric is a strong, unbalanced type. These are very energetic people, but excitable and hot-tempered. Melancholic is a weak type. Sanguine is a strong, balanced and agile type. Phlegmatic is a strong and balanced sedentary type.

Taking into account the peculiarities of the interaction of the first and second signaling systems, I. P. Pavlov additionally identified three true human types. Artistic type . the first signaling system prevails over the second . Thinking type . the second signaling system significantly prevails over the first. Average type.

1. Childish nervousness.

In the nervous system of children in the first years of life, the resulting excitation easily radiates, leading to general motor restlessness, and prolonged or severe irritation leads to inhibition. As more and more conditioned connections are formed and higher nervous activity becomes more complex, the effect of excessive stimuli increasingly affects the child’s behavior. With a weak type of higher nervous activity, the child becomes fearful, touchy, often cries and trembles; with the excitable type - undisciplined, capricious, hot-tempered, excessively active, fussy. Such children are called nervous. Children of the other two types (balanced, active and balanced, slow) can also be nervous, but their nervousness, as a rule, manifests itself much weaker.

1. Memory, its types. Mechanisms of short- and long-term memory.

1. Neurophysiological bases of mental activity (perception, attention, motivation, thinking, consciousness).

Consciousness- it is an ideally subjective reflection using the brain of real activity. Feeling – a form of direct reflection in human consciousness, presets, properties. Perception is one of the forms of mental activity that consists in recognizing an object. Representation is an ideal image of an object, the appearance of which at a given moment does not affect the senses. Attention is a state of active wakefulness. Motivation is an incentive to action; a dynamic psychophysiological process that controls human behavior, determining its direction, organization, activity and stability; a person's ability to actively satisfy their needs.

1. The mechanism of sleep and wakefulness, dreams.

Sleep is a physiological need of the body. It takes up approximately 1/3 of a person's life.

Sleep phases: slow (75-80%), fast (10-25%). The need for sleep is related to age. Newborns sleep up to 20-23 hours a day; children 2-4 years old - 16 hours; 4-8 years - 12 hours; 8-12 years - 10 hours; 12-16 years old - 9 hours; Adults sleep 7-8 hours.

Mechanism: slow - drowsiness - falling asleep - shallow sleep - moderately deep - deep sleep. Rapid: signs of rapid eye movement, severe decrease in tone, convulsive movements, increased blood pressure.

1. Attention. Its physiological mechanisms and role in memory processes.

Attention is the direction and concentration of a person’s mental activity, expressing the activity of the individual at a given moment and under given conditions, including the regulation and control of mental processes and being their integral part, characterizing the dynamics of their processes. Types of attention.
1. Involuntary is the concentration of consciousness on an object due to the peculiarity of this object as a stimulus (strong, contrasting or significant and causing an emotional response).
2. Voluntary attention - activity; consciously aimed at controlling one’s behavior and maintaining the sustainability of electoral activity. The leading role in its mechanisms belongs to the second signaling system. Physiological mechanisms of attention. To understand the physiological basis of attention, the law of induction of neural processes is very important, according to which excitation processes arising in one area of ​​the cerebral cortex cause inhibition in other areas. At each moment in time, there is a focus of increased excitability in the cortex, characterized by the most favorable conditions for excitation.

1. Emotions. Their classification and neurophysiological mechanisms.

Emotions are mental reactions that reflect an individual’s subjective attitude to objective phenomena. Emotions arise as part of motivations and play an important role in shaping behavior. There are 3 types of emotional states: 1. Affects – strong, short-term emotions that arise in response to an existing situation. 2. Emotions themselves are long-term states that reflect the individual’s attitude to an existing or expected situation. Sadness, anxiety, joy.

3.Objective feelings - constant emotions associated with any object (feelings of love for a specific person, for the Motherland, etc.).

When the amygdala is irritated, a person experiences fear, rage, and anger. In humans, the frontal and temporal areas of the cortex play an important role in the formation of emotions. For example, when the frontal areas are damaged, emotional dullness occurs. The balance of neurotransmitters is important in the occurrence of emotions. For example, if the content of serotonin in the brain increases, mood improves; if it is deficient, depression occurs. The same picture is observed with a lack or excess of norepinephrine. It was found that suicides have significantly reduced levels of these neurotransmitters in the brain.

Higher nervous activity associated with the functions of the cerebral cortex. It ensures maximum human adaptability to environmental conditions. The doctrine of higher nervous activity is based on the works of I.M. Sechenov - “Reflexes of the brain”, I.P. Pavlova (theory of conditioned and unconditioned reflexes), P.K. Anokhin (theory of functional systems) and numerous other works.

Reflexes carried out by the body are divided according to I.P. Pavlova, on unconditional And conditional.

Unconditioned reflexes are inherited and reproduced from generation to generation. They are characteristic of all individuals of a certain species, i.e. group. For example, all seahorses build nests to breed and protect their young. Unconditioned reflexes have constant reflex arcs. A complex chain of unconditioned reflexes is called instinct. A mother feeds and protects her child, birds build nests - these are examples of instincts.

Conditioned reflexes are acquired by every person throughout his life. Each conditioned reflex is the result of a certain experience, habit. Reading, driving a car, salivating at the sight and smell of food are all examples of conditioned reflexes. They are individual, and certain conditions are necessary for their formation. These reflexes may disappear. So, without sufficient practice, a foreign language, a poem you once learned, the ability to skate, etc. are forgotten. This process is called conditional braking. Inhibition can also be unconditional (external). An example of unconditioned inhibition would be an attack by a dog whose food is taken away. External unconditional inhibition occurs in the digestive center, and excitation occurs in the “aggression” center. Conditioned reflexes are formed on the basis of unconditioned reflexes and are developed with the direct participation of the cerebral cortex. This is how the conditioned salivary reflex was formed in the laboratory of I.P. Pavlova when combining feeding and lighting a light bulb or sounding a bell. As a result, after several repetitions, saliva was released in response to the action of the unconditioned stimulus. This meant that a new, temporary connection had formed in the cerebral cortex between the salivary centers and the visual (auditory) center. New conditioned reflexes are formed on the basis of old conditioned reflexes.

The features of human higher nervous activity are the following:

– developed mental activity;

– ability for abstract logical thinking.

I.P. Pavlov developed the doctrine about the first and second signaling systems.

First signaling system provides perception of the surrounding world through the senses. With the help of this signaling system, conditioned reflexes are developed to a variety of signals. Second signaling system appeared in humans in connection with the development of speech. A word for a person is not a combination of sounds, but an expression of the meaning of a word, a concept. The development of speech has made it possible to abstract, generalize, and operate with concepts. The first and second signaling systems are closely interconnected. Signals from the first signaling system enter the second. It begins to develop in children by 5-7 months of the first year of life.

I.P. Pavlov formulated the idea of ​​individual types of the nervous system. He assessed the strength, balance and dynamism of basic nervous processes (excitation and inhibition). Based on the data obtained, four types of nervous system or temperament were identified: choleric, sanguine, phlegmatic, melancholic.

Usually a person combines traits of different temperaments, but one of them dominates. Assessing temperament is important when choosing the nature of professional activity.

Emotions– these are subjective reactions of humans and other animals to the influence of external and internal stimuli. Emotions happen positive And negative. Different types of emotions cause corresponding physiological changes in the body. Emotions such as joy, anger, and pre-race excitement increase muscle tone, the release of adrenaline, and increased cardiovascular activity. Fear and despondency may be accompanied by decreased muscle tone and vascular spasms. With the help of emotions, a person changes his behavior.

Memory is the ability of the brain to store information and reproduce it at certain intervals. Depending on how long it takes to store information, memory can be short-term or long-term. The temporal lobes of the brain, the reticular formation of the brain stem, and the hypothalamus are involved in the formation of memory. The following types of memory are distinguished:

– motor;

– visual;

– auditory;

– tactile;

– mixed.

Thinking– a set of mental processes associated with cognition. In the process of thinking, concepts are formed. The more active and deeper the process of cognition, the deeper the concepts formed, their content and meaning.

The concept of “cell,” formed by a 6th grade student, has been developing over several years. As a result, a school graduate has a much deeper understanding of the cell as a biological system than a sixth grader.

Dream– a state of depression of consciousness and weakening of a person’s connections with the environment. The onset of sleep is associated with inhibition of the ascending influences of the reticular formation. Normal sleep duration is 7-8 hours.

Sleep and wakefulness are manifestations of circadian rhythms. Sleep ensures restoration of performance, processing and assimilation of information received during wakefulness.

In accordance with these functions of sleep, deep (slow wave) and superficial (fast wave) sleep are distinguished.

A person dreams during REM sleep. At this time, you can observe increased brain activity, movements of the eyeballs, and sometimes the sleeper begins to speak. This phase occurs approximately every hour and a half and lasts 15-20 minutes. During deep, slow-wave sleep, the rhythmic activity of the brain decreases. Breathing and heart rate slow down. Thus, sleep is a periodic change in various functional states of the brain. The hormones norepinephrine and serotonin play an important role in the regulation of sleep.

Dreams are a kind of reflection of received information in the form of visual images.

Behavior is a human activity aimed at satisfying biological, physiological, psychological and social needs.

Human behavior is determined by the neurohumoral activity of the body and the social conditions of its life.

Aspects cerebral (nervous) activities: each hemisphere has its own function.

Right hemisphere - creative thinking, perception of images, music, emotions, feelings, functionality of the left hand; left hemisphere - logic, strategic thinking, reading, counting, functionality of the right hand. A person's right- or left-handedness is laid down in the embryo - the hand whose finger he sucks will be functional when he is born and matures.

The cortex is responsible for the higher nervous (psychological) activity of a person; its areas are usually divided into lobes of the brain:

The human nervous system operates on the principle of excitation - the main functions of the neuron and nervous tissue are excitability and conductivity. However, there is an opposite mechanism, inhibition, blocking of impulses entering the cerebral cortex. This allows the nervous tissue to rest and recover.

The most striking example of inhibition is sleep. At this moment, the nervous system does not stop working, it adapts to a different mode of operation - rest, bringing all functions back to normal, relaxation.

During sleep, the brain rests, but is not inactive, while cells that are active during the day rest. Many scientists suggest that during sleep, a kind of processing of information accumulated during the day occurs, but the person is not aware of this, because the corresponding functional systems of the cortex that provide awareness are inhibited.

External braking it's the same physiological, it's the same unconditional- by name and essence - this is some kind of strong impact on the nervous system from the outside, for example, a sharp sound, a painful effect, etc. It turns out that a new nerve impulse, a new “signal” suppresses and interrupts the previous one.

Internal inhibition comes from within, i.e. from directly from the cerebral cortex, manifests itself during a conditioned reflex, when the body adapts to external stimuli, and therefore excitation occurs under the action of only strictly defined stimuli, while others, even slightly different from the first, cause an inhibitory effect.

The set of nervous processes occurring in the higher parts of the central nervous system and ensuring the implementation of human behavioral reactions form – higher nervous activity (HNA).

It has long been noted that mental phenomena are closely related to the functioning of the human brain. Hippocrates (5th century BC) first spoke about this; this position developed and deepened.

In 1863, I.M. Sechenov published the book “Reflexes of the Brain,” in which human behavior was explained by the reflex principle of the GM. The general principles of his ideas are as follows:

1. External influences cause stimulation in the senses.

2. This leads to excitation or inhibition of GM neurons, on the basis of which mental effects arise (sensations, ideas, feelings, etc.)

3. Excitation of GM neurons is realized in human movements (facial expressions, speech, gestures), which is expressed by his behavior.

4. All these phenomena are interconnected and determine each other.

The main differences between conditioned and unconditioned reflexes.

Unconditioned reflexes	Conditioned reflexes
1. Congenital and inherited.	Acquired during life.
2. Universal, characteristic of all people.	They are individual, the result of their own experience.
3. They close at the level of the spinal cord and brainstem.	They close at the level of the KBP and subcortex.
4. They are carried out through an anatomically expressed reflex arc.	Carried out through functional temporary connections.
5. Stable, as a rule, persist throughout life.	Changeable, constantly forming and fading away.

I.P. Pavlov developed these ideas and created the doctrine of conditioned and unconditioned reflexes - physiology of behavior.

Subsequently, other ways of acquiring life experience were discovered and described. . However, to this day Pavlovian teaching remainsgenerally recognized. V.M. Bekhterev, P.K. Anokhin, B. Skinner ( learning through trial and error), W. Köhler ( insight - “comprehension”), K. Lorenz ( imprinting - imprinting) and other scientists.

GNI (according to Pavlov) is an activity that ensures normal complex relationships of the whole organism with the outside world, i.e. GNI = human mental activity

Groups of unconditioned reflexes.

1. Food reflexes– salivation, chewing, swallowing, etc.

2. Defensive (protective) reflexes– coughing, blinking, withdrawing the hand when irritated by pain.

3. Life-sustaining reflexes– thermoregulation, breathing and other reflexes supporting homeostasis.

4. Approximate reflexes– figuratively speaking the reflex “What is it?”

5. Gaming reflexes– during the game, models of future life situations are created.

6. Sexual and parental reflexes– from sexual intercourse to reflexes of caring for offspring.

Unconditioned reflexes ensure the organism's adaptation only to those environmental changes that have often been encountered by many generations. Their significance is that thanks to them the integrity of the body is preserved, homeostasis and prolongation of the species are maintained.

More complex unconditionally reflexive, activities are instincts, their biological nature remains unclear in detail. In a simplified form, instincts can be represented as a complex interconnected series of simple innate reflexes.

Conditioned reflexes .

They are relatively easy to acquire and are also easily lost by the body if the need for them is no longer necessary.

Physiological mechanisms of formation of conditioned reflexes:

To understand these mechanisms, let us consider the mechanism of formation of a simple natural conditioned reflex - increased salivation at the sight of a lemon. For a person who has never tried lemon, it arouses simple curiosity ( orientation reflex).

Excitation at the sight of a lemon arises in the visual receptors and is sent to the visual zone of the KBP (occipital region) - a focus of excitation arises here. Following this, the person tastes the lemon - a focus of excitation appears in the center of salivation (this is the subcortical center). He, as a stronger one, will “attract” excitement from the visual center. As a result, a nervous temporary connection arises between two never connected nerve centers. After several repetitions, it is consolidated and now the excitement that arises in the visual center quickly moves to the subcortical center, causing salivation at the sight of a lemon.

Thus, for the formation of a conditioned reflex, the following most important conditions are necessary:

The presence of a conditioned stimulus (in this example, the type of lemon). It must precede unconditional reinforcement and be somewhat weaker than it.

Unconditional reinforcement (taste and the process of salivation that begins under its influence).

The normal functional state of the nervous system and, above all, the GM is a necessary condition for the emergence of a temporary connection.

A conditioned stimulus can be any change in the surrounding and internal environment of the body: sound, light, tactile stimulation, etc.

The most suitable reinforcements are food and pain. With such reinforcement, the development of the reflex occurs most quickly. In other words, powerful incentives are - reward and punishment.

Conditioned reflexes of higher orders .

When developing new conditioned reflexes, conditioned reflexes developed earlier can also be used as reinforcement. For example, if a conditioned reflex has been developed - salivation when setting the table. If we now introduce a new conditioned stimulus, say a time signal on the radio and reinforce it with table setting, then this radio signal will cause salivation. Such reflexes are called reflexes of the second order; there are also reflexes of the third, fourth, fifth and higher orders.

Classification of conditioned reflexes.

Difficult due to their large number. But still they distinguish:

1. By the type of irritated receptors - exteroceptive, interoceptive, propriceptive conditioned reflexes.

2. Natural (formed by the action of natural unconditioned stimuli on the receptors) and artificial (by the action of indifferent stimuli).

3. Positive – associated with motor and secretory reactions. 4. Reflexes without external motor and secretory effects - negative or inhibitory.

5. Conditioned reflexes for time - associated with regularly repeated stimuli. They are also called trace reflexes.

6. Imitation reflexes. The “viewer” also forms temporary connections, primarily in children.

7. Extrapolation reflexes – consist in a person’s ability to correctly determine the direction of movement of a useful and dangerous object, i.e. foresee favorable and unfavorable situations for life.

In life, a person has to encounter many stimuli and their components. In order to select from this infinite variety of stimuli only those that are biologically and socially significant for us. It is necessary that the brain has the ability to analyze various effects on the body, i.e., the ability to differentiate them.

For a subsequent adequate reaction, synthesis processes are required, i.e. the ability of the brain to connect and generalize, to combine individual stimuli into a single whole.

Both of these processes are inextricably linked and are carried out by the nervous system constantly in the process of VND.

An example of the most complex analytical and synthetic processes of KBP is education dynamicstereotype. This is a stable system for the implementation of individual conditioned reflexes. It is developed and consolidated due to the emergence of a connection between the trace action from the previous stimulus and subsequent excitation. It is autonomous - it is carried out not only on the stimulus, but on its place in the system of influences. Plays a big role in the formation of various (work, sports, gaming, etc.) skills. In principle, the common name for a dynamic stereotype is “habit.”

Inhibition of conditioned reflexes .

If you do not reinforce a conditioned stimulus with an unconditioned stimulus, then it becomes inhibited. This is an active nervous process, the result of which is a weakening or suppression of the process of excitation and temporary communication. Various stimuli cause inhibition of some reflexes and stimulation and formation of others. The formation of new reflexes and their inhibition leads to a flexible adaptation of the body to specific conditions of existence.

Types of inhibition of conditioned reflexes:

1. External (unconditional) inhibition– is caused by inhibition by an unconditioned stimulus, which appears simultaneously with the developed one (for example, an orienting reflex). A new focus of excitation, unrelated to this reflex, appears in the CPB. He draws off the excitement.

2. Internal (conditioned) inhibition. Caused by inhibition when not reinforced by an unconditioned stimulus.

3. Protective inhibition. Protects nerve centers from excessive irritation or overwork.

4. Disinhibition. Occurs when the braking process is inhibited.

Age characteristics of GNI.

A child is born with a set of unconditioned reflexes; their reflex arcs begin to form in the 3rd month of prenatal development. By the time of birth, the child has formed most of the innate reflexes that ensure his vegetative sphere. Despite the morphological and functional immaturity of the brain, simple food conditioned reactions are possible already on the first or second day.

By the end of the first month of life, (some) conditioned reflexes are formed - motor and temporary. They form slowly and are easily inhibited, probably due to the immaturity of cortical neurons.

From the second month of life, reflexes are formed - auditory, visual and tactile. By the 5th month of development, the child has formed all the main types of conditioned inhibition. The learning process (i.e., the development of conditioned reflexes) plays an important role. The earlier it starts, the faster their formation goes.

By the end of the first year of development, the child can distinguish relatively well the taste of food, smells, shape and color of objects, and distinguishes voices and faces. Movements are significantly improved (up to the formation of walking skills). The child tries to pronounce individual words, and conditioned reflexes to verbal stimuli are formed, i.e. The development of the second signaling system is in full swing.

In the second year of development, the child improves all types of conditioned reflex activity, and the formation of the second signaling system continues, it acquires signaling significance). The vocabulary increases significantly (250 - 300 words), stimuli cause verbal reactions. Communication with adults (i.e. the surrounding social environment and learning) plays a decisive role in these processes.

The second and third years of life are distinguished by lively orientation and research activities. The child is no longer limited to the question “what is this?”, but to the question “what can be done about it?”

The period up to three years is also characterized by the extraordinary ease of formation of conditioned reflexes to a wide variety of stimuli.

The age from three to five years is characterized by further development of speech and improvement of nervous processes (their strength, mobility and balance increase). Dynamic stereotypes are easily developed, the orientation reflex is still longer and more intense than in schoolchildren. Conditional connections and dynamic stereotypes that arose at this time are exceptionally strong and carry a person throughout his life. Although they may not constantly appear, they are easily restored under certain conditions.

By the age of five to seven years, the role of the second signaling system increases even more, because children can already speak freely.

Junior school age (from 7 to 12 years) is a period of relatively “quiet” development of GNI. Emotions begin to become more connected with thinking and lose connection with reflexes.

Adolescence (from 11 – 12 to 15 – 17 years). Endocrine transformations and the formation of secondary sexual characteristics also affect the properties of GNI. The balance of nervous processes is disturbed, excitation becomes more powerful, the increase in the mobility of nervous processes slows down, etc. The activity of the KBP is weakened (this period is figuratively called “mountain gorge” by physiologists). These functional changes lead to mental imbalance in adolescents and frequent conflicts.

Senior school age (15–18 years) coincides with the final morphofunctional maturation of all body systems. The role of cortical processes in the regulation of mental activity and physiological functions of the body increases significantly; the leading role in IRR is played by cortical processes and the second signaling system. All properties of nervous processes reach the level of an adult.

Types of higher nervous activity.

In reality, there is a complex of basic congenital and acquired individual properties of the human nervous system that determine differences in behavior and attitude to the same environmental influences.

I.P. Pavlov in 1929 according to those indicators of excitation processes and braking:

A) The power of these processes.

b) Their mutual balance.

V) Mobility (speed of their change).

Based on this, four types of GNI were identified.

1. Strong unbalanced (“uncontrolled”)– characterized by a strong nervous system and a predominance of excitation over inhibition (imbalance of these processes). He is called - "choleric".

2. Strong, balanced, mobile (labile)– characterized by high mobility of nervous processes, their strength and balance – "sanguine"

3. Strong balanced inert type - has a significant strength of nervous processes, their low mobility - “phlegmatic.”

4. Weak fast-draining type– characterized by low performance of neurons and, consequently, weakness of nervous processes – "melancholic"

It should be noted that the names of the types are taken from the classification of temperaments of Hippocrates (5th century BC).

This classification is far from practical reality; in life, people with pronounced types are extremely rare. In modern research, the types of IRR are determined using more than 30 physiological indicators.

In addition, in humans, I.P. Pavlov identified types of GNI in relation to signaling systems.

1. Artistic type. Slight predominance of the first signaling system. People of this type are characterized by imaginative perception of the world around them, operating with sensory images in the process of thinking (visual-figurative thinking).

2. Thinking type. Slight predominance of the second signaling system. This type is characterized by abstraction from reality. In the process of thinking, people of this type operate with abstract symbols and have the ability to finely analyze and synthesize stimuli from the surrounding world.

3. Average type. Characterized by the balance of signaling systems. The majority of people belong to this type.

Unfortunately, we have to admit the fact that this problem still remains unresolved in physiology. Although psychology and pedagogy in this matter need the help of physiology.

The doctrine of signaling systems.

Human behavior is much more complex than animal behavior. Although the patterns of formation of conditioned reflexes are similar. But a person has the highest form of adaptation to environmental conditions - rational activity. This is the ability to grasp patterns connecting objects and environmental phenomena and use this knowledge in new conditions. As a result, the organism not only adapts (like animals), but is also able to anticipate changes in the environment and take them into account in its behavior. Taking this into account, I.P. Pavlov developed the doctrine of two signaling systems.

I. First signaling system– analyzes signals coming from all analyzers. Valid in all animals.

II. Second signaling system– this is verbal signaling (i.e. speech). A unique feature of humans, in the process of ontogenesis the stock of words from which the child constructs sentences gradually increases. words begin to lose their narrow specific meaning, a broader generalizing meaning is embedded in them - concepts arise (i.e., it is no longer necessary to obtain information about an object using the first signal system). The word begins to mean different concepts and requires clarification; not only words meaning objects, but also our sensations, experiences, and actions are subject to generalization. This is how abstract concepts arise, and with them abstract thinking. Thus, thanks to the second signaling system, the brain receives information in the form of symbols (words, signs, images). The word plays the role of not just a conditioned stimulus, but its signal, i.e. the word is the signal of the signal.

For example, a man with a dog crosses the road. Both, seeing a car quickly approaching them, will be saved together (the car is a specific danger signal, well understood by both). But after all, a person who hears a danger signal (the cry of another passerby “Beware of the car!”) without seeing it yet, will be saved. The dog needs to see the danger; the speech signal does not tell it anything about it.

The presence of a system of verbal signals denoting specific signals of reality is an important evolutionary acquisition for humans. Now the analysis and synthesis of the surrounding world is carried out not only as a result of the action of direct stimuli on the analyzers and their operation, but also as a result of operation with words. It is this ability of the human brain that forms the basis of human thinking.

This allows a person to gain knowledge and experience without direct contact with reality. For example, to find out about the requirements for an exam, it is enough to ask about it from a person who has already taken it, and it is not at all necessary to be there yourself.

Physiological basis of speech .

Speech is one of the most complex human functions. It is associated with intense work of the organs of vision, hearing and peripheral speech apparatus. Complex coordination of their activities is carried out by neurons of different zones of the BSC. Of particular importance are - Wernicke Center(located in the left temporal lobe of the brain) and Broca's center(lower left frontal lobe of the brain). If damaged Broca's center(this is the motor center of speech) a person understands everything he hears, but he himself is not able to utter a single word. If damaged Wernicke Center(also called auditory) a person hears everything, but does not understand speech, including his own. Written speech is associated with many departments of the KBP: regulating hand movements, visual, Broca's and Wernicke's centers and others.

Thus, the human speech-producing apparatus is an extremely complex multicomponent functional system controlled by various zones of the CBP.

Physiological mechanisms of sleep and dreams .

Sleep is a physiological state of the brain and the body as a whole, characterized by significant immobility, an almost complete absence of reactions to external stimuli and, at the same time, a special organization of the activity of brain neurons.

A person spends 1/3 of his life sleeping. When deprived of sleep, attention and memory are impaired, emotions are dulled, work ability decreases, inadequate reactions and hallucinations are observed. Thus, sleep is a necessity. Healthy, normal sleep is the key to a person’s daily activity, a high level of performance, and the normal functioning of his organs and systems.

Sleep phases.

Normal sleep consists of 4 – 5 cycles, replacing each other. Cycles consist of two phases:

I. NREM sleep phase– accompanied by slower breathing and pulse; muscle relaxation; decreased metabolism and temperature. It occurs immediately after falling asleep and lasts 1 – 1.5 hours.

II. REM sleep phase. The activity of internal organs is activated in it: pulse and breathing become more frequent; temperature rises; various muscle groups contract (limbs, facial muscles); eyes move under closed eyelids (as when reading). This phase lasts 10–15 minutes, increasing to 30 minutes in the morning. Dreams in this phase are realistic and emotional (because the neurons of the optic lobes are excited).

Theories of sleep.

There are several theories about sleep.

1.Humoral– sleep occurs when specific chemicals – hypnotoxins – accumulate in the blood. However, it is likely that humoral factors play a minor role.

2.Sleep center theory– periodic changes in the activity of the subcortical centers of sleep and wakefulness (they are located in the hypothalamus).

3.Cortical theory of sleep– irradiation along the cortex of an inhibitory process that can descend to the subcortex. Those. sleep represents a “protective inhibition” and protects the neurons of the CBP from excessive fatigue. In addition, sleep may also occur when the flow of nerve impulses in the BSC is sharply limited (for example, a sleepy state occurs when a person is placed in a dark, soundproofed room).

The reasons for the change in sleep and wakefulness are automatic (circadian) rhythms; fatigue of GM neurons; conditioned reflexes associated with falling asleep accelerate the onset of sleep.

Reasons for awakening– external signals; signals from internal organs (for example, hunger or a full bladder).

Dreams.

Sleep does not mean peace for the GM, because... During sleep, brain activity does not decrease, but is rebuilt. GM neurons begin to work in a different mode, analyze what they collect during wakefulness and draw conclusions (i.e., they try to “foresee” the future, as it were). Thus, so-called “prophetic dreams” foreshadow unpleasant events based on unconscious harbingers of these events. Most often, dreams do not come true and are quickly forgotten (all people see dreams, but do not always remember them). The likelihood of a dream coinciding with future reality is low, but if it coincides, it is interpreted as a supernatural phenomenon.

An important influence is exerted by external and internal stimuli, which are unconsciously registered by the brain and included in the plot of dreams. For example, thunderclaps - cannon fire, a full stomach - a feeling of suffocation, etc. In addition, sometimes the brain continues creative work during sleep. For example, after a long day's work on a problem, D.I. Mendeleev saw in a dream the first version of the periodic table of chemical elements, and G. Kekule saw the formula for benzene in an allegorical form.

The highest forms of GNI - memory, attention, motivation and the emotional-volitional sphere - are the subject of psychology. Modern physiology is still far from a complete knowledge of the biological mechanisms of these processes. However, it is worth considering what is already known.

Physiological mechanisms of memory.

Memory is a complex of processes occurring in the KBP that ensures the accumulation, storage and reproduction of individual experience. Memory can be divided into three main components - the process of recording information, the process of storage and the process of reproduction.

Memory hypotheses:

1. Neural hypothesis– the processes of memorization and storage are associated with the circulation of impulses along closed circuits of neurons. This mechanism probably underlies short-term memory. Good memory is characterized by a wealth of synaptic connections in the brain.

2. Biochemical hypothesis– impulses change metabolism in neurons, which causes structural changes in RNA. It is stored until the right moment, then causing the excitation of neurons (long-term memory).

Most likely, both mechanisms form a single whole.

Physiology of attention.

The highest nervous and mental activity of a person is always characterized by a certain selectivity and direction. It is important for VND to maintain the focus of its activities on essential elements while abstracting from everything unimportant. This selectivity of processes is called attention.

The physiological basis of attention is the processes of excitation and inhibition, the features of their movement and interaction in the CBP. Directionality is always associated with the excitation of some cortical areas and the inhibition of others (according to induction). Among the excited zones of the BSC, the dominant one always stands out - according to the theory of dominance. This ensures the selectivity of our activities and exercises control over its progress.

The mechanism of attention is based on the activation of the GM, associated with the activity of the frontal lobes of the GBP.

Physiology of emotions.

Emotions (emovere – shock, excite) are a person’s subjective reactions to the influence of internal and external stimuli, manifested in the form of positive or negative manifestations.

Emotions are active states of specialized brain structures that prompt a person to weaken or strengthen these states. The nature of emotions is determined by the current need and the prediction of the likelihood of its satisfaction. A low probability of need satisfaction makes emotions negative (fear, rage, etc.); An increase in the probability of satisfaction compared to the previously available forecast gives emotions a positive connotation (pleasure, joy, etc.).

The brain structures responsible for the implementation of lower elementary emotions are located in diencephalon(hypothalamus) and in the ancient parts of the cerebral hemispheres - fear, aggression, feelings of hunger and thirst, a feeling of satiety and many others. Higher specifically human (cortical) emotions are associated with the activity of the CBP zones - for example, a person’s moral feelings.

Emotions play a decisive role in the learning process, in reinforcing newly formed conditioned reflexes. They change perception thresholds, activate memory, and serve as an additional means of communication (facial expressions, voice intonations, etc.). The desire to re-experience positive emotions encourages a person to actively look for dissatisfied emotions and new ways to satisfy them. Negative emotions serve self-preservation, positive emotions promote self-development in the process of mastering new areas of activity.

Physiology of motivation.

These are active states of brain structures that encourage a person to perform acts of behavior aimed at satisfying his needs. Motivations make behavior purposeful, orienting it either hereditarily (unconditioned reflexes) or thanks to the accumulated early conditioned reflex experience.

Biochemical changes (when homeostasis is disturbed) and external stimuli are transformed into the process of excitation, this activates the structures of the hypothalamus. It transmits a signal to the KBP, where a behavior program is formed that helps satisfy the corresponding needs.

Literature:

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Green N., Stout W., Taylor D. Biology – 3 volumes, - M.: Mir, 1990.

Ermolaev Yu.A. Age physiology. – M.; Higher school, 1985.

Kazmin V.D. Directory of a family doctor, 2 vols., - M.: AST, 1999.

Kemp P., Arms K. Introduction to biology. – M.; World, 1988.

Markosyan A.A. Physiology. – M.; Medicine, 1968.

Nemov R.S. Psychology, 2 vols., - M.: Education, 1994.

Sapin M.R., Bryksina Z.G. Human Anatomy - M.: Education, 1995.

Sidorov E.P. Human anatomy and physiology (structured abstract) - M.: Young Guard, 1996.

Sytkin K.M. Handbook of biology - Kyiv: Naukova Dumka, 1985.

Fenish H. Pocket atlas of human anatomy - Minsk: Higher School, 1997.

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Higher nervous activity

Definition 1

The higher nervous system is the work of the cerebral cortex and all subcortical formations.

This concept also includes the psychological activity and behavioral characteristics of the individual.

Since each person has his own distinctive abilities, views, habits, beliefs and behavioral characteristics, which are formed throughout life. All these features depend on the system of conditioned reflexes, which, in turn, are formed under the influence of the environment and the heredity of the nervous system.

Properties of higher nervous activity

The properties of higher nervous activity include:

• Mobility;
• Equilibrium;
• The strength of nervous processes.

The most important property is considered to be the strength of nervous processes, which is characterized directly by the ability of the nervous system to withstand the effects of stimulating factors for a long time.

People's nervous systems can be strong or weak. A strong nervous system is divided into balanced and unbalanced. Balance has a high speed in the development of conditioned reflexes.

Mobility depends on the change in the processes of inhibition and excitation. People with a mobile nervous system easily switch from one activity to another.

Types of higher nervous activity

Behavioral reactions and mental processes have their own individual characteristics for each person. The combination of balance, mobility and strength characterizes the type of higher nervous activity. Based on these characteristics, the following types are distinguished:

1. Balanced, agile and strong;
2. Unbalanced and strong;
3. Balanced, inert and strong;
4. Weak.

There are also types of higher nervous activity associated with the interaction of the first and second signaling systems:

1. Thoughtful;
2. Art;
3. Thoughtful and artistic.

Distinctive features of human higher nervous activity

The physiology of higher nervous activity is capable of developing and nurturing all the qualities and characteristics of an individual necessary for society, regardless of his temperament.

Behavior and mental processes are complicated by the presence of a second signaling system in a person. Also, higher nervous activity is characterized by the presence of conditioned reflex activity acquired by a person throughout his life. In contrast to animals, humans develop mental activity and become aware of the internal processes of life.

The higher nervous activity of people is of a social nature. The speech that people have makes it possible to think abstractly, which leaves a significant imprint on the activities and behavior of people.

The diversity of higher nervous activity in people is of great practical importance. It has been scientifically proven that diseases of the central nervous system are directly related to the peculiarities of the course of nervous processes.

Example 1

For example, people with a weak type of higher nervous activity are clients of the neurosis clinic. Many diseases occur with greater complexity in people with a weak nervous system. If a person has a strong nervous system, illnesses are tolerated more easily and recovery occurs faster.

Also, the effect of drugs on the human body depends on the individual characteristics of higher nervous activity, so they are taken into account when prescribing treatment.

A person’s behavior, in addition to his temperament, is influenced by the condition of his life in society. The type of higher nervous activity and temperament are a prerequisite for the development of the necessary personality qualities.

Higher nervous activity- this is the activity of the higher parts of the central nervous system, ensuring the most perfect adaptation of animals and humans to the environment. Higher nervous activity includes gnosis (cognition), praxis (action), speech, memory and thinking, consciousness, etc. The behavior of the body is the crowning achievement of higher nervous activity.

The structural basis of higher nervous activity in humans is the cerebral cortex together with the subcortical formations of the forebrain and diencephalon.

The term “higher nervous activity” was introduced into science by I. P. Pavlov, who creatively developed and expanded the theoretical principles about the reflex principle of brain activity and created the doctrine of the physiology of higher nervous activity in animals and humans.

Higher nervous activity ensures individual behavioral adaptation of humans and mammals to changing environmental conditions; it is of a reflex nature, carried out by unconditioned and conditioned reflexes.

With an unconditioned reflex, the behavioral reaction of the body is innate, formed during the evolution of the species, genetically fixed and carried out with the help of the nervous system. In this case, excitation from the receptor is transmitted along a reflex arc to the central nervous system (spinal cord, brain stem, etc.) and back to the working organ (Fig. A).

Complex forms of animal behavior are provided by a set of unconditioned reflexes and are called instinct. However, unconditioned reflexes alone are not enough for the body to adapt to changing environmental conditions. This requires the development of conditioned reflexes.

Conditioned reflexes are individual acquired systemic adaptive reactions of the body, formed on the basis of the formation of a temporary connection between a conditioned stimulus and an unconditioned reflex act. The term “conditioned reflexes” was first proposed by I.P. Pavlov in 1903 while studying the functioning of the brain. A conditioned reflex is formed on the basis of an unconditioned one (Fig. B). For the formation of a conditioned reflex, the presence of two stimuli is necessary - an unconditioned (for example, meat) and an indifferent (light or sound), and the indifferent stimulus must act first, and then the unconditioned. A certain time interval is required between the indifferent and unconditioned stimuli. The strength of both stimuli must be optimal, the conditioned stimulus must be weaker than the unconditioned stimulus in its activity.

To develop a conditioned reflex, repeated combinations of exposure to both stimuli are necessary. I.P. Pavlov called the conditioned reflex a temporary connection, since it manifests itself only under the conditions under which it was formed. Its biological role is to expand the range of adaptive capabilities of the body to a wide variety of conditions.

Conditioned reflexes form the basis of training, education, development of speech and thinking in a child, skills in labor, social and creative activities of a person. Only humans are characterized by highly developed mental activity, consciousness, and the ability for abstract logical thinking, which developed in the course of their work activity and the need for communication.

The formation of conditioned reflexes is possible due to a special property of the brain - memory.

Based on the development of speech function in humans, I.P. Pavlov created the doctrine of the first and second signal systems.

First signaling system exists in both humans and animals. Any external stimuli, including conditioned ones, which are signals of unconditioned stimuli, form the first signaling system. The centers of this system are located in the cerebral cortex and through receptors perceive direct, specific stimuli (signals) of the external world - objects or phenomena. In humans, they create the material basis for sensations, ideas, perceptions, impressions about the surrounding nature and social environment, and this forms the basis of concrete thinking.

From the first days of life, a baby develops various conditioned reflexes to the position of the body, the appearance of the mother, time, etc. Gradually, their number increases. The child hears the mother’s words, and they are combined with certain procedures - feeding, bathing, etc. Conditioned reflexes are also developed to these words. These conditioned reflexes are no different from the conditioned reflexes of animals and are components of the first signal system.

Gradually, the child’s vocabulary increases, and he builds sentences from them. Words begin to lose their narrow, specific meaning, they acquire a broader general meaning, and concepts emerge. At first, the word “porridge” for a child meant only a certain type of porridge, for example semolina. Gradually, with the acquisition of experience and as it was generalized, this word began to mean the concepts of different porridges, and for clarification it was necessary to use additional words (buckwheat, semolina). Not only words that meant objects and natural phenomena, but also our sensations, experiences, and actions were subject to generalization. This is how abstract concepts arose, and with them abstract thinking.

When a person begins to understand the meaning of words, when they begin to mean certain concepts, generalizations, then words create a second signaling system.

Second signaling system exists only in humans. It arose as a result of the joint labor activity of people and is associated with the function of speech: with the word audible (speech) and visible (writing). Through the word, signals about specific stimuli are transmitted, and in this case the word serves as a fundamentally new stimulus - a signal of signals.

For example, in a person, a protective conditioned reflex, which manifests itself in withdrawing the hand from electrodes with electric current when a bell sounds, occurs not only in response to the action of the bell itself, but also when the experimenter says the word “bell.”

Animals, just like humans, can develop conditioned reflexes to words (for example, a dog follows the owner’s orders). But these reflexes are reactions to a sound stimulus, to a combination of sounds, and not to the meaning of a word that the animal does not understand.

Speech is a means of communication between people. A person thinks in words, therefore thinking is inextricably linked with the second signaling system and is the result of the function of the entire cerebral cortex.

Depending on the predominance of the first or second signaling systems, people are divided into types:

• artistic - the first signaling system dominates, imaginative thinking
• mental - predominance of the second signaling system, verbal thinking, pronounced ability to abstract
• middle type - characterized by mutual balance of two signaling systems and which most people belong to

These differences in human types of higher nervous activity are associated with the phenomenon of functional asymmetry of the brain, which manifests itself in the fact that the right and left hemispheres of the brain perform different functions. The left hemisphere is more responsible for logical, abstract thinking, verbal perception, and the right hemisphere is more responsible for figurative perception and thinking, emotionality of mental processes.

For neurological diagnostics, it is important to study the characteristics of higher nervous activity, because A person’s ability to implement it is provided primarily by the nervous system: the cerebral cortex and the activity of the structures of the brain stem and subcortical formations. Local damage to any part of this complex system is accompanied by the appearance of certain clinical symptoms, which reflect violations of this system.

It must be emphasized that the localization of a lesion symptom and the localization of a function are far from the same thing. Functions such as speech, for example, are associated with the work of not only the cortex, but also many parts of the brain (subcortical, brainstem), so they cannot be localized in narrow cortical “centers.”

For example, the functions of reading and writing are closely related to the function of speech.

Reading disorder (Alexia) is detected in the area of ​​the angular gyrus (gyrus angularis) of the left hemisphere (field 39).

The writing process involves:

1. Wernicke speech-auditory analyzer;
2. a zone of general sensitivity (in particular, muscle feeling) in the left parietal lobe, which allows kinesthetic differentiation of articulations necessary for the pronunciation of the word to be written;
3. the parietal-occipital region of the cortex, with the help of which acoustic images of sounds are re-encrypted into optical images of letters and the necessary spatial arrangement of their elements is preserved;
4. Broca's speech-motor analyzer;
5. the frontal lobes of the cortex, which control the execution of the act of writing.

Damage to each of these five zones can cause a writing disorder, but this disorder has a unique character each time.

In the lower part of the inferior parietal lobule, which belongs to the so-called specific human formations of the brain, has no homolog in animals in its architectonics and is associated with the complex function of expedient systematic action, in the region of the supramarginal gyrus (Gyrus supramarginalis) of the left hemisphere there is field 40, associated with praxia function. A lesion in Gyrus supramarginalis results in apraxia, i.e., loss, despite the absence of paralysis, of the ability to systematically perform habitual motor acts that the subject has learned throughout life. Lesions in the left Gyrus supramarginalis lead to bilateral apraxia.