The value of the higher nervous activity of man. Features of higher nervous activity of a person, thinking and speech

MOUSOSH №30

ABSTRACT ON BIOLOGY

"Higher nervous activity"

Pupils of the 8th "b" class

Aleksentseva Elena

Shakhty

2006-2007

1) "Unconditioned reflexes"

2) "Conditioned reflexes"

4) "Emotions"

5) "Memory"

7) "Forecast and suggestion"

Conclusion and Conclusion

Ι. "The significance of higher nervous activity in human life"

For many centuries, people have thought about the amazing adaptability of animal behavior and living conditions. In 1863, a book by I.M. Sechenov "Reflexes of the brain", which explained these phenomena. In this work, for the first time in the history of natural science, behavior and "spiritual" - mental activity of a person was explained by the reflex principle of the nervous system. "All mental acts without exception ... develop through a reflex," wrote I.M. Sechenov. He argued that the reflexes of the brain include three links: the first is excitation in the sense organs caused by external influences; the second - the processes of excitation and inhibition occurring in the brain, on their basis, mental phenomena arise (sensations, ideas, feelings, etc.); the third is the movements and actions of a person, i.e. his behavior. All these links are interconnected and condition each other.

The successor of the advanced ideas of I.M. Sechenov, was - I.P. Pavlov. The main goal of his work was to elucidate the nervous regulation of the work of organs, the logical conclusion of which was the study of the functions of the cortex hemispheres brain. I.P. Pavlov - founder general theory higher nervous activity. Under the higher nervous activity of I.P. Pavlov (understood) "an activity that ensures the normal complex relationship of the whole organism to the outside world." He singled out and studied the constituent parts, or (components) of higher nervous activity, on the basis of which any, even the most complex, human behavior is built. Such components of I.P. Pavlov considered hereditary - unconditioned reflexes, and acquired in the process of life - conditioned reflexes. I.P. Pavlov showed that the brain works on the principle of temporary connections. He revealed a constant change in the processes of excitation and inhibition in the cortex. These processes create coherence, the inner rhythm of the life of the brain. brain life - it is a bright mosaic of signals.

ΙΙ. "Anatomy, physiology and hygiene of higher nervous activity"

1) "Unconditioned reflexes"

Unconditioned reflexes are inherited by offspring from parents, and persist throughout the life of the organism. In response to the action of vital stimuli (for example, food or damage), reflexes arise. Such reflexes and the stimuli that cause them were called "unconditioned". Food, defensive, sexual and orienting reflexes are known. Much of the behavior of animals is due to instinct. For example, a duckling, seeing water, runs to it, swims and dives; a chicken from the first day of life pecks grains. (Examples of the most complex innate reflexes are: building nests, feeding chicks ...). Arcs of unconditioned reflexes pass through the brain stem or through the spinal cord; for their implementation, the participation of the cerebral cortex is not necessary. Thus, in extremely rare cases, children are born who are deprived of the large hemispheres of the brain. Such children cannot live long, but simple unconditioned reflexes can be observed in them. Thanks to unconditioned reflexes, the integrity of the body is maintained, constancy is maintained internal environment and reproduction takes place.

2) "Conditioned reflexes"

I.P. Pavlov proved that, along with hereditary, there are many reflexes that are acquired by the body during life. Popov called conditioned reflexes those reflexes that are acquired by the body during life and are formed as a result of a combination of indifferent stimuli with unconditioned ones. Temporary connections are quickly formed to biologically significant signals, for example, water coming from bathing ducks, crackling branches coming from beavers - easily cause the formation of conditioned reflexes.

The greater the mobility of the nervous processes of excitation and inhibition, the faster the extinction of old conditioned reflexes and the consolidation of new ones, the better the organism adapts to changing conditions.

Man can consciously control the behavior of animals. The domestication of animals is the development of conditioned reflexes. But conditioned reflexes are developed not only in animals, but also in humans, in life they are called habits: get up on time, without an alarm clock; turn on the light in your room without looking, etc. In mammals and in humans, the arcs of conditioned reflexes pass through the cortex of the cerebral hemispheres. A conditioned reflex wakes up strong if the conditioned stimulus is constantly reinforced by the unconditioned one. If the conditioned stimulus is not reinforced several times, the response weakens and then slows down. The conditioned reflex does not disappear. When you repeat the experience after a break, it is restored. New conditioned reflexes are connected with the old ones. Here is an interesting example: "in the laboratory of I.P. Pavlov, a dog could not develop a conditioned reflex to gurgling. Later it turned out that she had been in the kitchen for a long time, where food was being prepared. This sound was combined with the look and smell of food, and the dog was not given food "The sound of gurgling inhibited her salivation. Reflexes, both conditioned and unconditioned, are inhibited by the action of any unfamiliar stimulus." Thus, with the help of the formation of conditioned reflexes and their inhibition, a more flexible adaptation of the organism to specific conditions of existence is carried out.

3) "Features of the higher nervous activity of man"

I.P. Pavlov and V.M. Bekhterev established that the patterns of formation of conditioned reflexes and inhibition are basically the same in animals and humans. At the same time, I.P. Pavlov repeatedly pointed out that all the phenomena of higher nervous activity do not fit only into the concept of a conditioned reflex. The ability of animals to capture patterns that connect objects and phenomena environment, as well as to use the knowledge of these patterns in the new conditions was called rational activity. The more developed the nervous system, the higher the level of rational activity. It reaches its highest development in man and manifests itself in the form of thinking. Rational activity is the highest form of adaptation to environmental conditions. Thanks to it, the body not only adapts to rapidly changing environmental conditions, but can also anticipate these changes and take them into account in its behavior. In evolution, a person appeared, as I.P. Pavlov "An extraordinary increase in the mechanisms of the brain" - speech and words pronounced, meaningful and visible - these are signals, symbols of specific objects and environmental phenomena. "Word" - a person means everything that he perceives with the help of the senses. At the same time, the "word" has a generalizing function. The word, according to I.P. Pavlova is a signal of signals. Example: the child's brain gradually grows and develops, especially the frontal lobes of the hemispheres; speech is formed on the basis of conditioned reflexes: “the child first begins to understand words, and then to reproduce them independently. The “word” becomes a conditioned signal earlier than a conditioned reaction, an answer: the vocabulary grows, thought, consciousness develops. A person’s speech is characterized by a very high degree of generalization. A person generalizes not only concepts about objects, their properties and features, about natural phenomena, but also their sensations, feelings, experiences; A person thinks in words; Verbal thinking allows him to abstract himself from the specific circumstances of reality. A person’s speech becomes an apparatus of abstract thinking. A child learns to speak before the age of 5 or 6. If a child does not speak before this age, his mental development is delayed. Human speech functions are associated with many-sided brain structures. The formation of human oral speech is associated with the frontal lobe of the left hemisphere, written - with the temporal and parietal lobes.

4) "Emotions"

Man not only perceives the world, but also affects it. He has a certain relation to all objects and phenomena. Emotions are called - experiences in which the attitude of people to the world around them and to themselves is manifested. Human emotions are complex and varied. They can be divided into positive (joy, delight, love, etc.) and negative (anger, fear, horror, disgust, etc.). Any emotion is accompanied by activation of the nervous system and the appearance in the blood of biologically active substances that change activity. internal organs: blood circulation, respiration, digestion, etc. Changes in the activity of internal organs are the same with similar emotions in all people. The physiological significance of such reactions accompanying emotions is very great. They mobilize the forces of the body, bring it into a state of readiness for successful activity or protection.

Each emotion can be accompanied by expressive movements. They release the tension created by emotion; moreover, it is the language of emotions. Watching the expression of feelings, we not only understand what the other person feels, but also become infected with his condition. Thus, expressive movements can control the emotions of many. However, expressive movements lend themselves to arbitrary reaction. The appearance of emotional reactions is associated with the work of the cerebral hemispheres and divisions of the diencephalon. Of great importance for the formation of emotions are the temporal and frontal lobes of the cortex. The frontal lobe inhibits or activates emotions, i.e. manages them.

5) "Memory"

Memory is a complex of processes that take place in the central nervous system and ensure the accumulation, storage and reproduction of individual experience. THEM. Sechenov wrote that a person without memory would remain forever in the position of a newborn. According to modern concepts, the brain regions related to memory (cortex, frontal and temporal lobes of the cortex) are interconnected by closed chains of neurons. Nerve impulses circulating in these chains change the processes of biosynthesis in nerve cells. As a result, substances are formed - material carriers of "memory traces". Violation of the synthesis of certain biologically active substances interferes with the formation of "memory traces" and, consequently, the learning process. In order for information to be deposited in memory, it is necessary to repeat it for some time. There are 4 types of memory.

Motor memory underlies the training of movements, everyday, sports and labor skills, writing.

Figurative memory helps to remember and reproduce people's faces, smells, sounds, musical melodies, pictures of nature.

Emotional memory stores feelings experienced by a person. It has been proven that memorization is facilitated by biologically active substances released during emotional arousal. Memorization, preservation, reproduction of read, heard or spoken words - verbal memory. All types of memory are interconnected. The same information is stored in several types of memory. Memory may not be arbitrary, when memorization proceeds effortlessly, as if by itself. Memory can be arbitrary; in this case, a person sets a goal: "to memorize the material, makes strong-willed efforts, uses special techniques."

6) "Dream"

Sleep is as essential to a person as water or food. A person spends more than 20 years out of 60 in a dream. Without sleep, life is impossible. In experiments, dogs lived without food for 20–25 days and lost 50% of their weight, while those deprived of sleep died after 10–12 days, although their weight decreased by only 5–13%. Insomnia is very painful, and it is no coincidence that Ancient China sentenced to death by sleep deprivation.

The nature of sleep was explained by I.P. Popov: Sleep is a general inhibition; it extends to the entire cerebral cortex and even affects the midbrain. Sleep occurs when brain cells need rest. Sleep protects the brain from overexertion. Therefore, I.P. Popov called sleep protective inhibition. In the process of sleep, brain cells restore their efficiency, they actively absorb nutrients, accumulate energy. Sleep restores mental strength, creating a feeling of freshness, vigor, readiness to work. Rhythmic stimuli can induce sleep: measured drops of drops, the sound of carriage wheels, the ticking of a clock, a monotonous song.

The causes of sleep are even more deeply revealed by modern science. The change of sleep and wakefulness is associated with the activity of the network substance of the brain stem. The cerebral cortex can serve or maintain a state of wakefulness. Awakening occurs only when the excitation through the network substance reaches the cortex. Sleep is not interrupted if the signals are not significant. The inhibitory cells of the reticular formation cause sleep, and their active influence on the cells of the cortex causes wakefulness. Why, for example, is it difficult to fall asleep after intense mental work or unrest? This can be explained in the following way: The air condition of the cortex affects the reticular formation, increasing or inhibiting its activity. Sleep disorder is associated with impaired activity of the reticular formation. In sleep, we lose touch with external stimuli. Most quickly, we lose the ability to see and smell, in a dream the ability to perceive tactile and auditory stimuli is partially preserved, many life processes change, gas exchange decreases, energy is spent less, blood pressure drops, breathing is less frequent, heartbeats are calmer and weaker, muscles relax. Biocurrents of the cerebral cortex were recorded with precise instruments. In sleep, their rhythm changes, but they do not disappear at all. In some cases, entire areas of the brain continue intense activity during sleep. The content of dreams is always related to the past or present, but not as not to the future. A person cannot dream what was not perceived in the waking state. Both animals and humans experience partial sleep. In the sleeping brain, as it were, a duty post is set up to capture a certain signal from the environment. Under the influence of accidental stimuli, traces of old impressions can combine with each other in the most bizarre combinations. In life, we experience many joys and anxieties. Dreams reflect our feelings, thoughts, actions. “An example from life: a man had a terrible dream: he was bitten in the chest by a snake. A few days later, an abscess formed on his chest. “Scientists wondered: how to explain this?” The disease developed gradually, and weak signals did not reach the cerebral cortex during wakefulness. that the sleeping brain is sensitive even to weak signals.Most often, "prophetic" dreams are caused by stimuli that come from the external environment during sleep.

Several thousand people were examined with the help of sensitive electronic sensors, recording the biocurrents of the sleeping people. It turns out that several phases of sleep can be distinguished according to the recording curve of brain biocurrents: the first light sleep; normal sleep; first deep sleep, etc.

Modern data have shown that brain activity during sleep often exceeds daytime levels. It became clear that sleep is not a frozen unconscious state. It has been found that the movement of the eyeball under the eyelids occurs in connection with dreams. During this period, increased brain activity is distinguished, blood pressure rises, the pulse quickens, oxygen consumption rises, breathing quickens, and there is an increased metabolism. This state is repeated every 80 - 90 minutes, it was decided to call it the phase of paradoxical sleep. 4 - 5 times it interrupts not deep sleep and lasts 10 - 30 minutes. Dreams occur during this phase. What is the meaning of "paradoxical" sleep, which combines a deep loss of consciousness with increased brain activity, an accelerated metabolism with a general relaxation of the body? As a result of experiments, it was proved that dreams serve as a kind of "valves" for a person to release unused nervous energy. Scientists have not yet been able to figure out which processes directly cause sleep and control its rhythm. Adequate sleep is vital for the body. However, its violations are common. The cause of insomnia can be a decrease in physical activity, changes in the traditional daily rhythm, information overload, etc. In order for sleep to be normal, you need to remember the daily rhythm of the body: do the most interesting work in the morning and afternoon hours, sleep at least 7 - 8 ocloc'k.

7) "Forecast and suggestion"

For a long time, there were many superstitions and prejudices in the concept of hypnosis. Science has revealed the essence of hypnotism. I.P. Pavlov considered hypnosis in the light of the theory of inhibition. Just as in shallow sleep, individual "watch points" of the cortex are preserved, so in hypnosis, contact is established through non-inhibited areas, or, as they say, a report from the hypnotized to the hypnotizer. Scientists have established that hypnosis is a specially induced partial sleep. During hypnosis, the process of inhibition of brain cells is uneven and not deep. The nature of sleep and hypnosis are one. So, a hypnotic sleep can turn into a normal sleep, and then an independent awakening occurs under the influence of noise, light, etc. It is possible, and vice versa, to translate an ordinary dream into a hypnotic one. Conditioned reflexes formed during hypnosis are "torn out", isolated from others. They are durable and hard to fade. In 98% of adults, hypnosis can be induced, but not in every person it comes easily; it depends on the characteristics of the nervous system. It is known, for example, that different people respond differently to the same stimuli. In a hypnotic state, through suggestion, the functions of many organs can be changed. To inspire the most hypnotized various activities and he fulfills them, while the work of the internal organs changes. There are so-called post-hypnotic suggestions. The suggested action is accurately performed after several days, months and even years. It is impossible for a person to inspire what he cannot do due to natural data; for example - make him sing if he has no voice. Hypnosis and suggestion are closely related phenomena. Hypnosis is possible without suggestion, and vice versa. Unlike hypnosis, suggestion is dominated by excitation of a certain area of ​​the cerebral cortex.

I.P. Pavlov considered suggestion as a simplified typical human conditioned reflex. After all, one description of a lemon is enough to cause the separation of saliva in almost every person. The outstanding Russian scientist V.M. Bekhterev believed that suggestibility is a normal property of every healthy person, although it manifests itself in different people to varying degrees. Suggestion, mutual suggestion and self-hypnosis are very common in Everyday life. The power of suggestion is great, it heals or disturbs the normal functions of the organs. natural healing power Modern medicine uses sleep as one of the methods of treatment. Prolonged inhibition of the cerebral cortex in combination with sedatives gives a favorable outcome in case of nervous shocks, severe fatigue, peptic ulcer. Recent times electric sleep began to be used.

They also treat with suggestion. The influence of the word on the human condition is great. Through the word, you can influence the activity of internal organs. Under the influence of dreams, a person may turn pale or blush. He may change the rhythm of breathing and heartbeat. A doctor with only one soothing conversation with a patient often lowers blood pressure, moderates the patient's pulse. Based on the influence of the word, psychotherapy and hypnosis treatment have been developed. Suggestion is now being used more and more widely in hypnotic sleep for medicinal purposes.

8) "Disorders of higher nervous activity"

Higher nervous activity is exclusively dependent on the conditions of both the external and internal environment of the body. Insufficient nutrition, irregular rest, general illness, lack of movement can disrupt the functions of the cortex and higher nervous activity. A greater influence on the higher nervous activity of a person is exerted by mental and emotional overstrain, caused by the need to process more information in short periods of time, the environment in which a person lives and works also affects his behavior and well-being. Unfavorable environmental factors can both short-term and permanently disrupt the processes of higher nervous activity. These disorders are not always associated with damage to nerve cells; more often it is their excessive functional overvoltage. At the same time, the processes of excitation and inhibition in the cerebral cortex are disrupted, which leads to disruption in the formation of conditioned reflexes, memory impairment, and causes insomnia. Violation of higher nervous activity is accompanied by painful changes in the activity of internal organs. Disrupted processes are restored if the causes that caused them are eliminated. Alcohol is a poison, primarily the cells of the cerebral hemispheres suffer from it.

The conditioned reflex activity of a person worsens, the formation of complex movements slows down, the ratio of the processes of excitation and inhibition of the central nervous system changes. Under the influence of alcohol, voluntary movements are disturbed, a person loses the ability to control himself. Penetration of alcohol to the cells of the frontal lobe of the cortex "liberates" a person's emotions, unjustified joy, stupid laughter, lightness in judgments appear. Following the increasing excitation in the cortex of the diseased hemispheres of the brain, a sharp weakening of the processes of inhibition occurs. The cortex ceases to control the work of the lower parts of the brain. A person loses restraint, modesty, he says and does what he did not say, and would not have done in a sober state. Each new portion of alcohol paralyzes the higher nerve centers more and more. Impaired coordination of movements; for example, eye movement; a clumsy staggering gait appears, the tongue is tangled.

Violation of the functioning of the nervous system and internal organs is observed with any use of alcohol: one-time episodic and systematic. Alcoholism is not a habit, but a disease. The habit is controlled by consciousness, it can be eliminated. Addiction to alcohol is more difficult to overcome because of the poisoning of the body. About 10% of people who drink alcohol become alcoholics. Alcoholism is a disease characterized by mental and physical changes in the body.

higher nervous activity reflex

Conclusion and Conclusion

The structure of the nervous system corresponds to the functions it performs (management of individual organs and the entire human body). Normal life activity and human health are completely dependent on the work of the nervous system, therefore, the hygiene of the nervous system allows you to maintain human health. main feature The highest nervous activity of a person lies in the ability to think abstractly, speak articulately and work. All this is achieved through the upbringing of the child, i.e. outside human society he cannot become a man.

Bibliography

one). A.M. Zuzmer, O.L. Petrishina. Biology "Man and his health".

2). I.D. Zverev. "A Reading Book on Human Anatomy, Physiology and Hygiene".

The cerebral cortex and the subcortical nuclei closest to it form the higher parts of the central nervous system, which implement the formation of temporary connections and the formation of complex purposeful behavioral acts.

For the first time, the idea of ​​the reflex principle of the work of the higher parts of the central nervous system was put forward and substantiated by I.M. Sechenov in the book “Reflexes of the Brain” (1863). The ideas of I.M. Sechenov were developed by I.P. Pavlov (1849-1936), who created a fundamentally new objective method of physiological research - the method of conditioned reflex, with the help of which the foundations of the doctrine of higher nervous activity (HNV) were developed.

According to I.P. Pavlov, all reflexes are divided into two groups - congenital (unconditioned reflexes) and acquired (conditioned reflexes). A conditioned reflex is an organism's reaction to a stimulus acquired in ontogenesis, previously indifferent to this reaction. In accordance with this approach, a distinction is made between lower and higher nervous activity. Lower nervous activity is a set of neurophysiological processes that ensure the implementation of unconditioned reflexes and instincts. I.P. Pavlov proposed to use the term higher nervous activity instead of the term mental activity, but these concepts are not equivalent. The term higher nervous activity should be understood as a set of neurophysiological processes that provide consciousness, subconscious assimilation of information and adaptive behavior of the body. Mental activity is an ideal, subjectively perceived activity of the body, carried out with the help of neurophysiological processes. Thus, mental activity is realized with the help of VIE (such is the ratio of these concepts).

Physiological basis of behavior

Behavior refers to all activities of an organism in the environment. For a person, this is a set of actions through which he takes possession of the environment, transforms it; for animals, this is a motor activity that ensures survival, adaptation to environmental changes. Human Physiology: Textbook / Ed. V.M. Smirnova. M.: Medicine, 2002. - S. 502

Forms of learning

There are several classifications of learning. It is advisable to combine all of them into four main groups mainly according to the criterion of the activity of an animal or a person in the course of learning: a) passive (reactive) learning, b) active (operant) learning (operatio - action), c) learning through observation, d) insight . Human Physiology: Textbook / Ed. V.M. Smirnova. M.: Medicine, 2002. - S. 507

Analytical-synthetic activity of the brain

The survival of an organism depends on the degree of its adaptation to the environment. It is the higher, the more perfect the property of analysis and synthesis. “The property of analysis and synthesis is understood as the ability of the nervous system to analyze, i.e. isolate from the external environment a greater or lesser amount of stimuli acting on the body, and synthesize, i.e. combine those that are this moment coincide with any of his activities” (I.P. Pavlov).

In addition to external signals, this property also applies to excitations coming from internal organs; especially great importance have signals from the organs of speech.

Types of higher nervous activity

A. Criteria for assessing GNI. The type of GNI is a combination of congenital and acquired properties of the nervous system that determine the nature of the interaction of the organism with the environment and are reflected in all functions of the organism. The criteria for the typological properties of the nervous system are the strength of the processes of excitation and inhibition, their balance and mobility (I.P. Pavlov). Various combinations of three

the basic properties of the nervous system made it possible to distinguish certain types that differ in adaptive abilities and resistance to neurotic agents. I.P. Pavlov's doctrine of the types of GNI is a doctrine of the reactivity of the nervous system, especially its higher sections - the cerebral cortex. The same diseases proceed differently in patients depending on the type of HNA and require a different approach in drug treatment.

The concepts of the type of the nervous system and the type of GNA are most often used as identical, interchangeable, although not everyone agrees with this, believing that with the help of conditioned reflex techniques, the features of the cerebral cortex are more revealed and, to a lesser extent, the features of the nervous system as a whole. The study of the types of GNA shows that through the study of the characteristics of cortical conditioned reflex activity, we are approaching an understanding of the true types of the nervous system as a whole.

B. Characterization of the properties of nervous processes. The strength of nervous processes is understood as the performance of cortical cells, determined by the duration nervous tension, expressed in the processes of excitation and inhibition. The balance of nervous processes is understood as the ratio of the processes of excitation and inhibition in terms of their strength. The mobility of nervous processes is understood as the ability of cortical cells, at the request of the external environment, to quickly "give way", to give an advantage to one process over another: excitation before inhibition and vice versa.

An experimental study of the typological characteristics of dogs made it possible to distinguish among them four main types of GNI: 1) a strong and unbalanced animal (“unrestrained type”); 2) the animal is strong, balanced, mobile (“live type”); 3) the animal is strong, balanced, inert ("calm type"); 4) the animal is weak ("greenhouse type") (see Fig. 19.8). In reality, there are much more types of VND. Animals of the weak (“greenhouse”) type were characterized by the following features: 1) difficult development of conditioned reflexes to signals of ordinary strength, with their weakening, development is often facilitated; 2) facilitated emergence of passive-defensive reactions to extraneous new stimuli; 3) a tendency to develop translimiting inhibition due to the weakness of the cortical cells (dogs constantly freeze, as if frozen with a slight increase in conditioned signals).

The "unrestrained" type of animals is characterized by a fast rate of development of conditioned reflexes and a slow rate of their inhibition.

They have strong excitatory and inhibitory processes, but the inhibitory one is relatively weaker than the irritable one, so hard work often ends with a “breakdown” of the GNI (neurosis). Animals of the "living" type easily develop conditioned reflexes, they quickly cope with changes in the stereotype of conditioned reflexes. The “calm” (inert) type is characterized by the slow development of conditioned reflexes and the difficult change in the stereotype of conditioned reflexes, which can lead to neurotic states. In these animals, both processes are strong, but the mobility of the nervous processes is low.

B. Types of GNI and temperaments. The ancient Greek physician, the founder of medicine, Hippocrates (460-377 BC) explained the unequal course of the same disease in different people due to the different state of the “body juices” in the human body: blood, mucus, bile, and black bile. This is how the empirical doctrine of temperaments arose (from Latin proportionality, proper ratio). This was the first attempt to understand the different reactivity of the human body. According to Hippocrates, four temperaments are distinguished: sanguine (from Latin sangius - blood), choleric (from Latin chole - bile), phlegmatic (from Latin phlegma - mucus, phlegm), melancholic (from Greek melanos + chole - black bile ).

A sanguine person is a decisive, energetic person, with quick excitability, mobile, impressionable, with a bright outward expression of emotions, their easy turnover; phlegmatic - calm, slow, with a weak manifestation of feelings, it is difficult to switch from one activity to another; choleric - quick-tempered, with a high level of activity, irritable, energetic, with strong, quickly emerging emotions, clearly reflected in speech, gestures, facial expressions; melancholic - a low level of neuropsychic activity, dull, dreary, with high emotional vulnerability, suspicious, prone to gloomy thoughts and with a depressed mood, withdrawn, shy. In life, such "pure" temperaments are rare; usually we are dealing with a more diverse combination of properties. The doctrine of the types of GNI is common to animals and humans.

Higher nervous activity I

integrative activity of the brain, which ensures the individual adaptation of higher animals and humans to changing environmental conditions. Scientific ideas about V. n. were developed by the school of Academician I.P. Pavlova on the basis of the doctrine of the conditioned reflex (Conditioned reflexes) . At the heart of V. n. The physiological mechanisms of unconditioned reflexes (Unconditioned reflexes) and the conditioned reflexes that are formed on their basis in the process of ontogenesis lie. genetically determined, inherent in a certain type of organisms and form, ensuring their survival in a relatively constant conditions environment. Individually acquired forms of behavior that ensure the adaptation of humans and animals to changing environmental conditions are possible only through training, which is based on the neurophysiological mechanisms of memory (Memory) .

The main patterns of V. n. are based on the physiological mechanisms of the formation and disappearance of conditioned reflexes. For the formation of conditioned reflexes, the appearance of a c.n.s. in the structures is necessary. temporal connection between neurons that perceive the conditioned, and neurons that are part of the structure of unconditioned reflexes. A conditioned reflex occurs when some (conditional) is reinforced by an unconditioned one. Due to temporary connections of varying complexity, previously indifferent stimuli that precede this or that activity become a signal of this activity. Acquiring a signal value, the conditioned stimulus leads to the appearance in the central nervous system. excitation, advancing the structures of the brain, providing the formation of future behavior. Such anticipatory excitation not only provides a biologically expedient adaptation of the organism to the environment, but also underlies the active influence on this environment.

In the mechanisms of V.'s formation, n. d. animals and humans, along with conditioned reflex excitation in the central nervous system. braking processes are always involved. There are two types of inhibition: external (unconditional) and internal (conditional). The external arises in the case of the sudden appearance of an extraneous stimulus and is manifested by the fact that the conditioned stimulus is not formed at all or, having begun, stops. A variation of external inhibition is transmarginal inhibition, which is noted with an excessive increase in the strength of the conditioned stimulus. Internal inhibition occurs when the conditioned stimulus is not reinforced by the unconditioned stimulus. Depending on the conditions for the formation of internal inhibition, the following types of it are distinguished: extinction, differential, conditional brake, retarded (see Braking) . The interaction of the processes of conditioned reflex excitation and internal inhibition makes it possible for animals and humans to navigate in the most difficult situations. At the same time, if he constantly performs approximately the same and sequential actions in time, then various stimuli, which are conditional in relation to the ongoing actions, create a stereotype of their performance. The sequence of excitations that occurs in this case in the cerebral cortex and leads to a certain sequence of behavioral acts performed is called a dynamic stereotype. A sharp violation of the dynamic stereotype that has developed throughout a person’s life can cause the development of various diseases and premature aging.

The higher nervous activity of an individual animal (of the same species) and a person has individual characteristics associated primarily with the innate properties of c.n.s. (his genotype). Individual development, the possibility of learning skills are determined by differences in the speed and strength of the resulting conditioned reflexes, the intensity of external and internal inhibition, the speed of irradiation and the concentration of nervous processes (i.e., the phenotype). The totality of the genotypic and phenotypic features of an organism determines its V. n. There are four main types of V. n. in animals, which in terms of the main indicators (strength, mobility and balance of the processes of excitation and inhibition) are similar to the classical idea of ​​temperaments in humans. strong, unbalanced with a predominance of excitation coincides with the choleric temperament; strong, balanced, sedentary type - with phlegmatic; strong, balanced, mobile - with sanguine; weak, quickly exhausted, inactive - with melancholic.

The main patterns of V. n. are common in animals and humans. and synthesis of stimuli (signals) from outside world in ts.n.s. constitute the first signaling system. In humans, unlike animals, along with the first, there is a second signal associated with speech. The word for a person is not only a sound, but also a semantic signal. for example, the word "forward" for a dog only serves as a start signal. For a person, this word can mean the manifestation of a wide variety of forms of activity. The development of verbal signaling made it possible to distract a person from this particular life situation and at the same time generalize many surrounding phenomena. The first and second signaling systems in humans are inseparable from each other. Only in a child before mastering speech, and in an adult in cases of pathology, there can be a separate functioning of the first signaling system.

At the same time, there are differences in the ratio of the development of the first and second signaling systems in different people, which allowed I.P. Pavlov to allocate particular types of V. n. (artistic, mental and intermediate, or average).

With the artistic type of V. n. e. manifestations of the first signal system predominate. Such people are distinguished by a pronounced figurative-emotional type of thinking, extraordinary sharpness, brightness and completeness of direct perception of reality. Most often this type of V. n. e. inherent in artists, writers, musicians, artists; thinking type V. n. d. is characteristic of a person with a tendency to abstract verbal thinking, i.e. with the predominance of the second signal system. People of the thinking type are most often found among scientists, public figures, and lawyers. With the average type of V. n. e. the first and second signaling systems are equally significant for human perception of the environment. To this type V. n. applies to most people.

The complexity and versatility of V. n. in various animals and humans are closely related to the development of the cerebral cortex. Modern methods research V. n. (, stereotactic and microelectrode technique, irritation and self-irritation of brain structures) showed a different degree of participation of brain structures in the formation of V. n. e. Intracerebral processes during the formation of V. n. is considered not as a local mechanism for establishing a temporary connection between the foci of conditioned and unconditioned excitation in the cerebral cortex, but as an interaction of excitations associated with the formation of motivations (Motivation) , with memory mechanisms and the work of analyzers (Analyzers) . Within the framework of the theory functional systems Academician P.K. Anokhin, the interaction of excitations begins at the stage of afferent synthesis, which is a systemic process of comparison, integration and selection in the structures of the central nervous system. varied in functional value for an organism of numerous streams of excitations (see. Functional systems) . This can be carried out not only in individual brain structures, but also at the level of individual nerve cells, based on the convergence of multimodal excitations. The subsequent interaction between cells is determined by the mechanisms of functional relationships between individual structures of the brain. First of all, these are the mechanisms of ascending activating influences of subcortical formations on the cerebral cortex (see Subcortical functions) . The unification of the cerebral cortex and subcortical structures is also facilitated by corticofugal influences, which activate the reticular formation of the brain stem and create flows of recurrent generalized influences on the cortex. On this basis, cortical-subcortical reverberation (circulation) of excitations and centrifugal tuning of peripheral receptors can occur, which makes it possible to eliminate excess information. Elimination of redundant information in the CNS there is, in essence, a transition to the next stage of the systemic organization of intracerebral processes - the decision-making stage. As a result of afferent synthesis, it has the ability to perform an infinite number of behavioral acts, the decision-making stage contributes to the formation of an action program. At this stage, a dynamic combination of somatic and vegetative functions is carried out into a holistic behavioral act aimed at obtaining a result useful for the body. Simultaneously with the formation of the program of action in the senior researcher. formed physiological foresight and evaluation of the results of action - . It "anticipates" the afferent properties of the result that should be obtained in accordance with decision and, therefore, ahead of the course of events in the relationship between the organism and the external world. Comparison of the parameters of the result of the action in the form of excitations going to the c.n.s. from peripheral receptors, with an “afferent model” of the result presented in the apparatus of the acceptor of the results of action, is carried out on the basis of the receipt of reverse afferentation in the brain structures ( feedback). If the inverse does not correspond to the parameters of the programmed result of behavior, an orienting-exploratory organism arises, accompanied by a search for new forms of adaptive behavior. Such a discrepancy, called mismatch, is the basis for the occurrence of V.'s violations of n. manifested by neurosis, emotional stress. This is confirmed by the so-called experimental studies studied in the laboratories of I.P. Pavlova. The discrepancy between the formed goals of behavior and the physiological possibilities of achieving them, determined by the type of higher nervous activity in each person, is often the cause of diseases. On this basis, medical tactics in treatment can be developed using not only pharmacological drugs, but also non-drug methods of therapy.

Bibliography: Anokhin P.K. System mechanisms of higher nervous activity, M., 1979; Asratyan E.A. reflex theory higher nervous activity, M., 1983; Simonov P.F. Higher nervous activity of a person, M., 1975.

1. Small medical encyclopedia. - M.: Medical Encyclopedia. 1991-96 2. First health care. - M.: Bolshaya Russian Encyclopedia. 1994 3. Encyclopedic dictionary of medical terms. - M.: Soviet Encyclopedia. - 1982-1984.

See what "Higher nervous activity" is in other dictionaries:

Higher nervous activity is the processes occurring in the higher parts of the central nervous system of animals and humans. These processes include a set of conditioned and unconditioned reflexes, as well as "higher" mental functions, which ... ... Wikipedia

higher nervous activity- Category. Neurophysiological processes that take place in the cerebral cortex and the subcortex closest to it and determine the implementation of mental functions. Specificity. As a unit of analysis of higher nervous activity ... ... Great Psychological Encyclopedia

The activity of the higher parts of the central nervous system, which ensures the most perfect adaptation of animals and humans to the environment. Structural basis of V. n. in mammals, the cerebral cortex along with the subcortical nuclei ... ... Biological encyclopedic dictionary

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Modern Encyclopedia

The activity of the higher parts of the central nervous system (the cerebral cortex and subcortical centers), which ensures the most perfect adaptation of animals and humans to the environment. The basis of higher nervous activity are conditional ... Big Encyclopedic Dictionary

Higher nervous activity- HIGHER NERVOUS ACTIVITY, the activity of the higher parts of the central nervous system (the cerebral cortex and subcortical centers), providing the most perfect adaptation of animals and humans to the environment. At the core of the higher... Illustrated Encyclopedic Dictionary

Neurophysiological processes that take place in the cerebral cortex and the subcortex closest to it and determine the implementation of mental functions. As the main theoretical model for… Psychological Dictionary

higher nervous activity- provides behavioral adaptation of higher animals to environmental conditions. ↓ psyche ... Ideographic Dictionary of the Russian Language

HIGHER NERVOUS ACTIVITY- HIGH NERVOUS ACTIVITY. 1. Processes occurring in the cerebral cortex and the subcortex closest to it during the formation, functioning and extinction of conditioned reflexes in animals and humans. 2. The science of the mechanisms of brain activity, ... ... New dictionary methodological terms and concepts (theory and practice of teaching languages)

Books

• Physiology and ethology of animals in 3 parts. Part 3. Endocrine and central nervous systems, higher nervous activity, analyzers, ethology. Textbook and workshop for SPO, Skopichev VG This textbook is a presentation of the basic physiological functions of the body. Focusing on modern scientific data, the authors revealed the essence of the mechanisms of the nervous, humoral and ...

Higher nervous activity- this is the activity of the higher parts of the central nervous system, providing 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 organism is the crowning result 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 of the reflex principle of brain activity and created the doctrine of the physiology of higher nervous activity in animals and humans.

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

With an unconditioned reflex, the behavioral reaction of the organism is innate, formed in the process of 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 through reflex arc into 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 organism, 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. The conditioned reflex is formed on the basis of the 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 an indifferent stimulus must act first, and then an unconditioned one. A certain time interval is necessary between 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, a multiple combination of exposure to both stimuli is necessary. IP 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 organism to a wide variety of conditions.

Conditioned reflexes form the basis of training, education, development of speech and thinking in a child, skills of labor, social and creative human activity. Only a person is characterized by a highly developed mental activity, consciousness, the ability for abstract-logical thinking, which developed in the course of his labor 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 signal system exists in both humans and animals. Any external stimuli, including conditioned ones, which are signals of unconditioned stimuli, form the first signal system. The centers of this system are located in the cerebral cortex and through receptors perceive direct, specific stimuli (signals) of the outside world - objects or phenomena. For a person, they create a material basis for sensations, ideas, perceptions, impressions about the natural environment and the social environment, and this forms the basis of concrete thinking.

From the first days of life, an infant develops a variety of conditioned reflexes to the position of the body, the appearance of the mother, the time, etc. Gradually, there are more and more of them. The child hears the words of the mother, 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 signaling system.

Gradually, the child's vocabulary increases, from which he builds sentences. Words begin to lose their narrow concrete meaning, a broader generalizing meaning is laid in them, concepts arise. At first, the word "porridge" for a child meant only a certain, for example, semolina, porridge. Gradually, with the acquisition of experience and as it was generalized, this word began to mean the concepts of different cereals, and for clarification it was necessary to use additional words(buckwheat, semolina). Not only words that meant objects, natural phenomena, but also our sensations, experiences, actions were subject to generalization. This is how abstract concepts 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 signal system.

Second signal 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 heard (speech) and visible (writing). Signals about specific stimuli are transmitted through the word, and in this case the word serves as a fundamentally new stimulus - a signal of signals.

For example, a person has a protective conditioned reflex, which manifests itself in pulling the hand away from the electrodes with electric shock when the bell is sounded, it arises not only in response to the bell itself, but also when the experimenter pronounces the word "bell".

In animals, just like in humans, conditioned reflexes to words can be developed (for example, a dog follows the orders of the owner). 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 signal 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 signal system dominates, figurative thinking
• mental - the predominance of the second signal system, verbal thinking, a pronounced ability to abstract
• middle type - characterized by the mutual balance of two signal 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, while the right hemisphere is responsible for figurative perception and thinking, emotionality of mental processes.

For neurological diagnostics importance has a study of the features of higher nervous activity, tk. 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 defeat of any part of this complex system accompanied by the appearance of certain clinical symptoms, which reflect violations of this system.

It must be emphasized that the localization of a symptom of a lesion and the localization of a function are far from the same thing. Functions such as speech, for example, are associated with the work not only of the cortex, but also of many parts of the brain (subcortical, stem), 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 with a focus in the area of ​​​​the angular gyrus (gyrus angularis) of the left hemisphere (field 39).

The writing process involves:

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

The defeat of each of these five zones can cause a writing disorder, but this disorder each time has a peculiar character.

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

Higher nervous activity is the integrative ability of the higher parts of the brain to provide individual behavioral adaptation of a person to changing conditions of the internal and external environment. The theory of higher nervous activity is built on the following basic basis:

1. on the concepts of reflex theory,

2. on the theory of reflection,

3. on the theory of systemic activity of the brain.

The physiological basis of the processes of higher nervous activity is the analytical and synthetic activity of the cerebral cortex.

Analytical activity of the cortex of the brain lies in its ability to separate, isolate and distinguish between individual stimuli, that is, to differentiate them.

Synthetic activity of the cortex of the cerebral hemispheres is manifested in the unification, generalization of the excitation that occurs in its various parts from the action of various stimuli.

Analysis and synthesis of specific signals are first signal system man and animals. Second signal system- these are nervous processes that occur in the hemispheres of the human brain as a result of the perception of signals from the surrounding world in the form of speech designations. The second signaling system is the basis of human thinking, it is socially conditioned. Outside of society, without communication with other people, it does not develop. The first and second signal systems are inseparable from each other, they function together and determine the unity of the higher nervous activity of a person.

Methods for studying GNI

1. Method of conditioned reflexes.

2. Electroencephalography - registration of the total electrical activity of the brain from the surface of the head. Four main physiological rhythms are recorded on the EEG: ά-, β-, θ- and δ- rhythms.

3. The method of evoked potentials - registration of fluctuations in electrical activity on the EEG during a single stimulation of peripheral receptors.

4. Computed tomography - X-ray image of each part of the brain from different points.

5. Nuclear magnetic resonance– registration of the appearance and attenuation of the electromagnetic resonance radiation of the nuclei of hydrogen atoms.

6. Magnetoencephalography - recording the voltage of magnetic fields.

7. Rheoencephalography - registration of changes in the resistance of brain tissue to high-frequency alternating current, depending on blood supply.

8. Galvanic skin response - measurement of changes in skin resistance under the action of an irritant.

Human Behavioral Responses

Forms of behavior of the human body are usually divided into congenital and acquired in the process of ontogenesis. Innate forms of behavior are based on unconditioned reflexes and instincts.

instincts- this is a genetically formed form of behavior, carried out under the influence of basic biological needs. The instinctive activity of a person is based on the innate connections of the subcortical centers with the cerebral cortex.

Unconditioned reflex- this is an innate response of the body that occurs constantly in individuals of a given species and age with an adequate impact of vital stimuli on certain receptors. Thanks to unconditioned reflexes, the integrity of the body is maintained, the constancy of the internal environment is maintained, and reproduction occurs. Unconditioned reflexes are

food reflexes (chewing, swallowing, sucking, separation of saliva, gastric juice);

defensive reflexes (coughing, sneezing, blinking when a foreign object gets into the eye, pulling the hand away from a hot object);

Sexual reflexes (reflexes associated with sexual intercourse, feeding and caring for offspring);

thermoregulation reflexes;

breath reflexes

cardiac reflexes;

vascular reflexes;

reflexes of homeostasis.

The acquired forms of behavior are based on conditioned reflex reactions.

Conditioned reflex- this is the response of the body, acquired during life as a result of a combination of an indifferent (indifferent) stimulus with an unconditioned one.

Indifferent stimulus(signal) - this is the stimulus that does not cause any changes in the body.

unconditioned stimulus(signal) is a stimulus that represents biologically significant signals. In their presence, an unconditioned reflex occurs.

Conditioned reflexes provide a perfect adaptation of the organism to changing conditions of life and make behavior plastic. Under action conditional signal(a signal that causes the corresponding conditioned reflex) the cerebral cortex provides the body with preliminary preparation for responding to those environmental stimuli that will have their effect in the future.

The main differences between conditioned reflexes and unconditioned reflexes

The following conditions are necessary for the formation of a conditioned reflex

1. an indifferent signal (stimulus) must precede the unconditional,

2. the strength of the indifferent stimulus should be of medium strength (with low and high strength, the reflex may not be developed),

3. there must be a sufficiently large strength of the unconditioned stimulus,

4. there must be sufficient excitability of the cells of the cerebral cortex,

5. the absence of extraneous stimuli during the development of the reflex is necessary.

The mechanism of formation of a conditioned reflex is associated with the establishment of a temporary connection

1. between two or more excited foci in the cerebral cortex;

2. between the center of conditioned stimulation in the subcortical structures of the brain and the center of unconditioned stimulation in the cortex;

3. between the cortical center of the unconditioned stimulus and the subcortical conditioned stimulus;

4. and at the level of subcortical formations.

There are three stages in the formation of a conditioned reflex:

1. stage of pregeneralization - characterized by a concentration of excitation in the projection zones of the cortex of conditioned and unconditioned stimuli and the absence of conditioned behavioral reactions;

2. the stage of generalization - this stage is based on the process of irradiation of excitation;

3. stage of specialization of the conditioned reflex - characterized by the extinction of intersignal reactions and the appearance of a conditioned response to signal stimuli.

A necessary prerequisite for the formation of a conditioned reflex is the emergence of an orienting reflex. Orienting reflex- this is, of course, reflex, involuntary sensory attention, caused by an unexpected or new stimulus for the body. The orienting reaction precedes the formation of a conditioned reflex and consists of three main phases

the first - the phase of preventive inhibition, which consists in the termination of the current activity with the fixation of the posture;

· the second - the phase of general activation, which manifests itself in the form of a multicomponent reaction, including the rotation of the head and eyes in the direction of the stimulus;

· third - the phase of the analysis of external signals and decision-making about the body's response.

The value of the conditioned reflex:

· the conditioned reflex mechanism underlies the formation of any acquired skill, at the heart of the learning process;

On the basis of a number of conditioned reflexes, a dynamic stereotype is formed, which is the basis of a person's habits, the basis of his professional skills;

Conditioned reflexes dramatically expand the number of signal stimuli that are significant for the body, which ensures a higher level of adaptive behavior.

The functioning of the conditioned reflex mechanism is based on two nervous processes: excitation and inhibition.

Braking- this is the activation of inhibitory neurons, which leads to a decrease in excitation in the centers of an already developed conditioned reflex. Inhibition of conditioned reflex activity is manifested in the form external, or unconditional, braking and in shape internal, or conditional, braking.

External unconditional inhibition of conditioned reflexes- this is an innate genetically programmed inhibition of one conditioned reflex by other conditioned or unconditioned ones. There are two types of external braking: transcendental and induction.

1. Transmarginal inhibition of UR develops either with a strong stimulus, or with a weak functioning of the nervous system. Outrageous braking has a protective value.

2. Inductive inhibition of UR is observed when a new stimulus is applied after the development of UR or together with a known stimulus.

biological significance external braking consists in the fact that the body delays its reaction to secondary events and focuses its activity on the most important at the moment.

Internal, or conditional, inhibition- this is inhibition that occurs within the reflex arc in case of non-reinforcement of the conditioned reflex. The biological significance of internal inhibition lies in the fact that if the conditioned reflex reactions to the generated signals cannot provide the adaptive behavior necessary in a given situation, especially when the situation changes, then such signals are gradually canceled while preserving those that turn out to be more valuable.

There are three types of internal inhibition of the conditioned reflex: differential, fading and delayed inhibition.

1. As a result of differential inhibition, a person begins to distinguish stimuli that are similar in their parameters, and reacts only to biologically significant ones.

2. Fading inhibition occurs when, with a developed conditioned reflex, the impact on the body of a conditioned stimulus is not reinforced by the impact of an unconditioned stimulus. Due to extinction, the body stops responding to signals that have lost their meaning. Fading helps to get rid of unnecessary unnecessary movements.

3. Delayed inhibition occurs if the developed conditioned reflex is moved away in time from the unconditioned stimulus that reinforces it. Delay in children is developed with great difficulty under the influence of education and training. Delay is the basis of endurance, willpower, the ability to restrain one's desires.

dynamic stereotype is the highest manifestation of the analytical and synthetic activity of the cerebral cortex. A dynamic stereotype is a system of conditioned reflex acts in which each subsequent reflex is caused by the completion of the previous reflex. It is the basis of human habits, the basis of his professional skills.

Motivations and emotions

Motivation is an impetus to purposeful action caused by a need. The motivation formation mechanism consists of five steps:

1. Change in metabolic state - the emergence of a need;

2. Activation of the hypothalamic centers in the neurohumoral way;

3. Activation of other brain structures, including the cortex, by excited hypothalamic centers;

4. Excitatory and inhibitory influence of the limbic system and the cerebral cortex on the hypothalamic motivational centers;

5. Cellular and molecular integration of cortical-subcortical structures.

Emotions are the subjective reactions of a person to internal and external stimuli. From a physiological point of view, emotions are an active state of specialized brain structures that prompt changes in behavior in the direction of strengthening or weakening a certain state. The anatomical and physiological substrate of emotions is the limbic system of the brain. Emotions have the following functions:

1. evaluation function (reflective) - consists in a generalized assessment of external and internal events;

2. motivating function - consists in calling an action aimed at satisfying a need;

3. switching function - provides a choice of competing motivations;

4. communicative function - is to transfer the state to other people with the help of facial expressions and gestures;

5. reinforcing function - consists in the fact that a positive emotion arising as a result of an action performed is a reward for learning (development of reflexes), and negative emotions contribute to the development of internal inhibition.

Motivations and emotions do not have a sharp distinction between themselves and reflect different shades the same process.

Stress

Under emotional stress understand the overall systemic response of the body to stress factors. The reason for the emotional stress reaction is not the impact itself, but the attitude towards it. The following neurohumoral structures are involved in stress reactions: hypothalamus, pituitary gland, limbic system, basal ganglia, cerebral cortex and adrenal glands.

Memory

biological memory- this is the ability of living organisms to perceive information about irritation, fix and store it for subsequent use of the stored information in the organization of behavior. Distinguish between genetic memory and acquired.

Under genetic (species) memory understands all the information received from parents through gametes. This memory contains information about the development of the organism. The carrier of genetic memory are DNA molecules.

Acquired (individual) memory arises in ontogenesis on the basis of life experience. It is associated with the adaptation of the organism to a changing environment. Individual memory is formed in the process of learning and includes several processes:

· receiving the information;

imprinting information in the form of the formation of a memory trace - an engram;

preservation of the engram;

reproduction of previously received information.

There are several types of individual memory:

motor memory - memorization and reproduction of movements;

figurative memory - the basis is the memorization of objects and their properties;

verbal-logical memory - memorization, recognition and reproduction of thoughts and concepts;

Emotional memory - memorization and reproduction of sensory perceptions together with the objects that cause them.

According to the mechanism of formation, short-term and long-term memory are distinguished.

At the core short-term memory are the processes of reverberation of nerve impulses along closed circuits of neurons in the III and IV layers of the cortex of the frontal and parietal lobes.

Long term memory is based on structural and chemical transformations at the cellular, synaptic and systemic levels of the brain.

The activity of many brain structures is associated with memory: the reticular formation, the hippocampus, the amygdala, and the hypothalamus. For example, the hippocampus has a regulatory effect on the neurons of the new cortex, creating in them fluctuations in excitability coordinated in time. The temporal cortex is involved in the imprinting and storage of figurative information. The frontal cortex forms general behavioral programs and commands for the nearest subcortex. The thalamocortical system contributes to the organization of short-term memory. The reticular formation activates the structures involved in the fixation and reproduction of engrams and itself participates in the processes of engram formation.

Sleep is an active state of the body, different in its characteristics from wakefulness. The sleep state has the following features:

Loss of active connection of the body with external environment;

Change in muscle tone

a drop in blood pressure

a decrease in heart rate;

redistribution of blood in the vessels: greater filling of the vessels of the abdominal cavity with blood;

The minimum level of metabolism;

a decrease in body temperature;

Changes in the electroencephalogram.

Human sleep can be monophasic (night sleep), that is, once a day, and polyphasic (day and night), which is typical for children of the first seven years of life. Night sleep has a duration of 7-8 hours and consists of 4-5 cycles. Each cycle begins with a phase of "slow" sleep and ends with "REM" sleep. The duration of the cycle in an adult is approximately 60-100 minutes. In the first two cycles, "slow" sleep prevails, and in the last - "REM" sleep. In an adult, the share of "slow" sleep accounts for approximately 6.5 hours, and the phase of "REM" sleep - 1.5 hours. At the newborn - on a share REM sleep accounts for 50-60% of the total duration of sleep.

During slow sleep

1. recovery processes occur in the tissues, organs and systems of the body;

2. there is a restoration of the functions of organs, physical and mental performance;

3. growth processes are carried out;

4. in the cerebral cortex there are processes of ordering information;

5. transfer of information from blocks of short-term memory to blocks of long-term memory;

6. part of the information that has no biological significance is forced out of the central nervous system, which leads to a decrease in information and emotional overload.

During REM sleep, the functions of brain neurons and synapses are restored. It performs a watchdog function and prepares the body for the transition to a state of wakefulness.

Sleep mechanisms

Sleep arises due to the excitation of inhibitory (hypnogenic) structures and the inhibition of activating brain structures. It is assumed that the orbitofrontal cortex and preoptic nuclei of the hypothalamus activate the raphe nuclei, which begin to exert an inhibitory effect on the reticular formation of the brainstem. When the reticular formation of the trunk is inhibited, its inhibitory effect on the nonspecific nuclei of the thalamus weakens, due to which the cortex is inhibited and "slow" sleep develops. On the other hand, the inhibition of the reticular formation of the trunk leads to the fact that its activating effect on the cerebral cortex is completely removed. This period corresponds to the appearance of REM sleep. The change from "slow" sleep to "fast" is carried out using two types of neurons of the reticular formation of the bridge:

cholinergic - neurons of the "rapid" sleep phase, which contribute to an increase in the secretion of serotonin and a decrease in the secretion of norepinephrine. In this case, sleep occurs.

noradrenergic - neurons of the phase of "slow" sleep, which contribute to the reverse process, after which the state of wakefulness occurs.

Age features of human higher nervous activity

Development of conditioned reflexes. A child is born with a certain set of innate, unconditioned reflex reactions. From the second day of life, he begins to develop conditioned connections. For example, on the 2-5th day, a reaction to the position for feeding is formed, an orienting reflex occurs. From the 6th day, a leukocyte conditioned reflex reaction to food intake appears. On the 7-15th day of a child's life, conditioned reflexes to sound and vestibular stimuli appear. At 2 months, reflexes can be developed from any analyzer. In the second year of life, a child develops a large number of conditioned reflexes to the ratio of the size, severity, and distance of objects. In the process of formation of a conditioned reflex, four stages are distinguished:

The stage of a non-specific reaction, which is characterized by the appearance of an orienting reaction to a stimulus;

the stage of inhibition, at which the child's activity is inhibited under the action of a conditioned signal;

The stage of an unstable conditioned reflex, when conditioned stimuli do not always cause a response;

stage of a stable conditioned reflex.

With age, the rate of development of conditioned reflexes increases. The systems of conditional connections developed in the early and preschool age(up to 5 years), are especially durable and retain their value throughout life.

External unconditional inhibition. External unconditional inhibition appears in a child from the first days of life. At 6-7 years of age, the importance of external inhibition for higher nervous activity decreases and the role of internal inhibition increases.

internal inhibition. Internal inhibition appears in a child approximately from the 20th day after birth in the form of a primitive form of differential inhibition. Fading inhibition appears at 2-2.5 months, conditioned inhibition is observed at 2.5-3 months, and delayed inhibition - from 5 months.

dynamic stereotype. In early childhood, stereotypes are of particular importance. They facilitate the adaptation of children to the environment, are the basis for the formation of habits and skills. In children under three years of age, stereotypes are easily developed and help the child to develop the conditioned reflexes necessary for life with their help.

The development of speech. The development of speech is the process of development of the second signal system. The terms of development of sensory and motor speech do not coincide. The development of sensory speech precedes the development of motor speech. Even before the child begins to speak, he already understands the meaning of the words. In the formation of speech, the following stages are distinguished:

1. Preparatory stage, or the stage of pronunciation of individual sounds and syllables (from 2-4 to 6 months);

2. The stage of the emergence of sensory speech, that is, the manifestation of the first signs of a conditioned reflex to a word, to its meaning (6-8 months);

3. The stage of the emergence of motor speech, that is, the pronunciation of meaningful words (10-12 months).

Up to 2 months vocabulary the child is 10-12 words, by 18 months - 30-40 words, by 24 months - 200-300 words, by 36 months - 500-700, in some cases - up to 1500 words. By the age of 6-7, the ability to internal (semantic) speech appears.

Development of thinking. Visual-effective thinking is formed in preschool and primary school age. Verbal-logical thinking manifests itself by the age of 8-9, reaching development by the age of 14-18.

Development of behavior. The behavioral act is carried out according to two principles:

on the principle of reflex, that is, from stimulus to action;

· according to the principle of self-regulation – when one or another physiological indicator deviates from the level that ensures normal life activity, a behavioral reaction is activated, which restores homeostasis.

Sensory, motor, central and some neurohumoral mechanisms are involved in the organization of behavior. Sensor systems provide recognition of stimuli of the external and internal environment. Motor systems implement the motor program in accordance with sensory information. Central systems connect sensory and propulsion systems to ensure the adaptive behavior of the whole organism in accordance with changing environmental conditions and on the basis of dominant motivation.

For a person, the most important behavior is communicative behavior. The formation of communicative behavior requires visual, acoustic, olfactory and tactile information.

Eye contact for a child is very important for establishing relationships with others. A child aged 1-1.5 weeks distinguishes well common features presented objects, and it is they, and not their form, that are the most essential for him.

Acoustic contact is carried out in the form of a speech dialogue. It is believed that the child responds to the sounds of speech from birth. In infants 4-5 months old, an “revitalization complex” of maximum strength and duration, including “cooing”, is observed in the speech of an adult.

· Tactile sensitivity provides perception of external stimuli in a wide range, so for newborns and young children it is of great cognitive importance. Particularly effective tactile contacts in the first trimester of life.

With age, the role of vision and hearing in ensuring communicative behavior increases. The first communicative interactions occur even before the birth of a child in the "mother-fetus" system. The connection between the mother and the fetus is carried out through tissue contacts. After birth, the mother-child relationship continues in the mother-child system. Already from the 3rd day after birth, a newborn is able to distinguish the smell of milk and the body of his mother from the smell of other people. After the 3rd month of life, the child switches to interactions with other family members. Starting from 2-2.5 years old, children can create groups of 3-4 people. Moreover, boys interact more often than girls. In the presence of mothers, children prefer interaction with adults.

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