awakening suppresses all others and determines the nature of the body's response.

There are several types of internal inhibition: extinction, differentiation, delayed and conditioned inhibition. If an animal with a developed reflex to light for a long time presenting a conditioned stimulus without reinforcing it with an unconditioned stimulus (food) - after some time, salivation and secretion of juice into the light will no longer occur. This is the so called extinction internal inhibition conditioned reflex. Temporary connections between the analyzer centers and unconditioned reflexes weaken or even disappear completely. Differential braking

develops when stimuli that are close in parameters to the conditioned stimulus are not reinforced. For example, an animal has developed a salivary reflex to a certain sound signal. Presentation of another sound signal, not very different from the first one, without food reinforcement will lead to the animal stopping responding to the original conditioned stimulus. Delayed braking occurs with a gradual increase in the interval between the conditioned stimulus and the reinforcement with food. A conditioned inhibitor is produced by the alternating presentation of a reinforced and non-reinforced conditioned stimulus. In this case, the latter is preceded by additional irritation. After some time, additional irritation causes the cessation of salivation and juice secretion to the conditioned stimulus.

16.2. The concept of first and second signaling systems Oh

The higher nervous activity of humans differs from that of animals. Animal behavior is significant simpler behavior people Based on this, I.P. Pavlov developed the doctrine of the first and second signal systems.

First signaling system exists in both animals and humans. It provides specific objective thinking, i.e. analysis and synthesis of specific signals from objects and phenomena of the external world entering the brain through sensory organ receptors.

Second signaling system only available to humans. Its occurrence is associated with the development of speech. When pronouncing words are perceived by the organ of hearing or when reading, an association arises with some object or action that the word denotes. Thus the word is a symbol. The second signaling system is associated with the assimilation of information that comes in the form of symbols, primarily words. It makes abstract thinking possible. The first and second signaling systems are in close and constant interaction in humans.

sti. The second signaling system appears in the child later than the first. Its development is associated with learning to speak and write.

Speech - unique ability of a person to the sign-symbolic reflection of objects in the surrounding world. It is speech that forms, in the words of I. P. Pavlov, “specially human higher thinking.” It is the word that is the “signal of signals”, i.e. in that it can evoke an idea of ​​an object without its presentation. Speech makes possible training without direct reference to the subjects being studied. She is highest function central nervous system, primarily the cortex cerebral hemispheres brain.

Speech is divided into oral and written. Each of them has its own cortical centers. Oral speech is understood as the pronunciation of certain words or other sound signals that have a certain subject meaning. Written speech consists of transmitting any information in the form of printed symbols (letters, hieroglyphs and other signs) on a certain medium (paper, parchment, magnetic media, etc.). Speech development in a child is complex and long process. Between the ages of 1 and 5 years, a child learns to communicate using words. By the age of 5 - 7 years, it is possible to master writing and counting skills.

Thus, the first signaling system implies the acquisition of certain life skills through direct interaction with the environment without conscious transfer of what was received. life experience from one generation to another. The second signaling system is the perception of the surrounding world, both in direct contact with it and through comprehension various information received about him. This information can be transmitted from one individual to another, from generation to generation.

16.3. Electroencephalography

Electroencephalography (EEG) is a method of recording the bioelectrical activity of the brain. When performing this study, electrodes are placed on the scalp that sense vibrations. electrical potentials in the brain. Subsequently, these changes intensify by 1 - 2 million times

And are registered using special devices on a medium (for example, paper). The bioelectrical activity of the brain recorded using EEG, as a rule, has a wave character (Fig. 16.1). These waves have different shapes, frequencies

And amplitude. U healthy person prevailα waves (alpha waves). Their frequency fluctuates between 8-12 oscillations per second, amplitude 10 - 50 µV (up to 100 µV). β-Waves (beta waves)

Rice. 16.1. Electroencephalogram of a person during periods of wakefulness and sleep:

A - EEG in a state of wakefulness; b - EEG in a state of slow-wave sleep;

V - EEG in a state of fast-wave sleep

have a frequency of 15 - 32 vibrations per second, but their amplitude is several times less than that of a-waves. At rest, α waves predominate in the posterior regions of the brain, while P waves are localized primarily in the frontal regions. Slow δ waves (delta waves) and θ waves (theta waves) appear in healthy adults at the moment of falling asleep. Their frequency is 0.5 - 3 oscillations per second for 8-waves and 4-7 oscillations per second for θ-waves. The amplitude of slow rhythms is 100 - 300 µV.

The electroencephalography method is widely used in clinical practice. With its help, you can establish the side of the brain lesion, the presumable localization of the pathological focus, and distinguish a diffuse pathological process from a focal one. The value of the method in the diagnosis of epilepsy is invaluable.

16.4. Types of higher nervous activity

Each person is individual. All people differ from each other not only in physical qualities, but also in mental characteristics. Psyche - reflection inner world person. The basis of its existence is the brain. It is he who ensures the totality of processes that form the psyche. The result of mental activity is a person’s behavior, his reactions to certain situations.

Hippocrates also noted the differences between people in their behavior. He associated this with the predominance of one or another “liquid” in the body

bones": blood, mucus, bile and black bile. It has now been established that these differences in behavior are due to the types of higher nervous activity. However, it should be noted that the functioning of the nervous system, and therefore the type of higher nervous activity, also depends on humoral factors - the level of hormones and biologically active substances in the blood.

Type of higher nervous activity - mostly congenital individual properties functioning of the central nervous system. Should not be mixed this concept with understanding temperament , which is a manifestation in human behavior of the type of his higher nervous activity. Moreover, the first concept is a physiological concept, and the second is to a greater extent psychological. I.P. Pavlov believed that the main types of higher nervous activity coincide with the four types of temperament established by Hippocrates.

Features of nervous processes, properties of higher nervous activity determine such concepts as strength, balance and mobility. Strength is determined by the intensity of the processes of excitation and inhibition in the brain. Equilibrium characterized by their relationship with each other. Mobility is the possibility of changing excitation processes by inhibition processes.

Based on strength, higher nervous activity is divided into strong

And weak types, according to balance - into balanced and unbalanced, according to mobility - into mobile and inert.

IN Depending on the characteristics of nervous processes, four main types of higher nervous activity and four types of temperament are distinguished.

How do they relate various types higher nervous activity

And temperaments can be seen from the table. 16.2.

What traits characterize each of the types of temperament identified here? Cholerics are explosive, very emotional people with slight mood swings, extremely active, energetic, characterized by rapid response to various stimuli. Sangvi-

The relationship of the body with the environment is carried out on the basis of signals entering the nervous system as a result of the direct influence of objects and phenomena of the external world on the receptors. I.P. Pavlov called this type of signaling the first signaling system. In the animal world, the first signaling system is the body's only channel of information about the state of the environment. Various items the outside world, their physical and chemical properties (sound, color, shape, chemical composition etc.) acquire the meaning of conditioned signals, notifying the body about the phenomena occurring after them, thereby causing adaptive reactions. For example, a dormant herbivore flees at the sound of footsteps or the smell of a predator, since these stimuli signal danger.

The first signaling system of higher animals provides fairly perfect reflection outside world and in connection with this, their rapid and precise adaptation to the environment. I.P. Pavlov considered the first signaling system as a system of perception, impressions from all influences of the external and internal world, signaling biologically useful or harmful stimuli for the body. He wrote: “For an animal, reality is signaled almost exclusively only by irritations and their traces in the cerebral hemispheres, directly arriving by special cells of visual, auditory and other receptors of the body. This is what we have in ourselves as impressions, sensations and ideas from the surrounding external environment, both natural and our social, excluding the word, audible and visible. This is the first signaling system of reality that we have in common with animals.”

The signals of the first signaling system are specific and relate to a specific subject.

The formation of conditioned reflexes through the first signaling system constitutes in higher animals the physiological basis of their elementary concrete, or objective, thinking. The first signaling system is the same in humans and animals. In conditions ordinary life in humans, it functions in isolation only in the first six months of life.

When a person is raised, he develops second alarm system, characteristic only of humans. This transfers the higher nervous activity of a person to a higher level. It acquires new qualities that contribute to the expansion of opportunities for communication with the outside world and the versatility of its manifestations. I. P. Pavlov called the second signaling system an “extraordinary addition” to the mechanisms of higher nervous activity in humans. The second signaling system is speech, the word, visible, audible, spoken mentally. This is the highest alarm system for the surrounding world. It consists of verbal designation of all its signals and verbal communication. The second signaling system developed in humans under the influence of the social environment during the labor process. A large role in this was played by kinesthetic irritations of the brain arising as a result of labor processes. The word for a person serves as the same physiological irritant as objects and phenomena of the surrounding world.

Verbal signals generalize the stimuli of the first signaling system. The same word “table” signals not only a specific table, but also many other tables, different in size, shape, color, etc. This fact expresses not only a generalization, but also an abstraction from specific objects of reality, i.e. e. the transition of a person from objective thinking to abstract thinking. In order for the word “table” to indicate a specific table, a clarification is necessary - “this table”. Within the second signaling system, stimuli not only from the first, but also from the second signaling system itself are generalized. For example, the word with a narrow meaning “aspen” generalizes specific stimuli of the first signal system, and the word with a broader meaning “tree” generalizes the stimuli of the second signal system.

Thus, the second signaling system is comprehensive, capable of replacing, abstracting and generalizing all the stimuli of the first signaling system. Thanks to the entire previous life of an adult, the word is connected with all external and internal irritations coming into the nervous system, it signals all of them and replaces them all, causing the same actions as them.

Other exclusively important The second signaling system is that it dramatically increases the volume of information - through the use of not only individual, but also the collective experience of all humanity. The verbal information a person receives from other persons - oral and especially written - has an extremely wide range (this can be information not only from living persons, but also from many previous generations). Thus, an athlete’s improvement only partially occurs due to his personal experience; through verbal information, he widely uses the experience of his coach and huge number other persons set out in methodological manuals, textbooks, articles, etc.

The first and second signaling systems are functionally interconnected. Signals of the first signaling system coming from various parts body and environment, continuously interact with the signals of the second signaling system. In this case, conditioned reflexes second and higher orders, functionally linking signaling systems into a single whole. In addition, the connection between two signal systems, based on the elective (selective) irradiation of excitation, makes it possible to reproduce conditioned reflexes developed on the basis of the first signal system through the second signal system (A. G. Ivanov-Smolensky).

The second signaling system constitutes the physiological basis of abstract verbal thinking, which is unique to humans. Afferent signals entering the central nervous system from the speech organs, through the auditory and visual analyzers, form complex reflexes in a person that determine sound and written speech.

The localization of the functions of the second signaling system in the cerebral cortex has not yet been fully elucidated. The structures of the right and left hemispheres participate in its implementation. The dominant role in most people (right-handed) belongs to the left hemisphere. Relatively large areas of it perform complex functions related to understanding the meaning of words, coordinating the speech-motor apparatus when pronouncing them, and other processes.

Introduced the concepts of the first and second signaling systems, expressing various ways mental reflection of reality. The first signaling system is present in both animals and humans.

The activity of this system is manifested in reflexes that are formed in response to any irritation of external and internal environment, with the exception of the semantic content of the word. The signals of the 1st signal system are smell, color, shape, temperature, taste of objects, etc. These signals affect the receptors of the analyzers, from which the brain receives nerve impulses. Both humans and animals, as a result of the activity of the 1st signaling system, carry out the analysis and synthesis of these nerve impulses.

The first signaling system provides a concrete sensory reflection of the surrounding reality.

The characteristic features of conditioned reflexes of the 1st signal system are:

1) specificity of the signal (this or that phenomenon of the surrounding reality);

2) reinforcement with an unconditioned stimulus (food, defensive, sexual);

3) biological nature the adaptation achieved (to the best nutrition, defense, reproduction).

A person is in the process of social development, as a result of collective labor activity appeared, according to I.P. Pavlova, “extraordinary increase” in the mechanisms of brain function. She became 2nd signaling system, ensuring the formation of a generalized idea of ​​the surrounding reality with the help of words and speech. The second signaling system is closely related to human consciousness and abstract thinking.

The signals of the 2nd signal system are words spoken and writing, as well as formulas and symbols, drawings, gestures, facial expressions. The activity of the 2nd signal system is manifested mainly in speech conditioned reflexes. The signal meaning of a word for a person lies not in a simple sound combination, but in its semantic content(unlike trained animals. Moreover semantic meaning words, for example orange, does not depend on the sound of this concept in different languages.

For a person, the word is the same and even stronger physiological irritant as objects and phenomena of the surrounding world. The second signaling system is comprehensive, capable of replacing and generalizing all stimuli of the 1st signaling system. Signals from the 1st signaling system, coming from various parts of the body and the environment, continuously interact with signals from the 2nd signaling system. In this case, conditioned reflexes of the second and higher orders are formed.

The second signaling system forms the physiological basis abstract verbal thinking, inherent only to man. Abstract thinking allows a person to be distracted from specific items and phenomena of the surrounding world, think in words that replace these objects, verbally compare and generalize them in the form of concepts and conclusions. The structures of the right and left hemispheres of the brain take part in the implementation of the functions of the 2nd signaling system.

Man, like animals, is born only with unconditioned reflexes. During the process of growth and development in both humans and animals, the formation of conditioned reflexes of the 1st signaling system occurs. In humans, the process of development of GNI does not end here and on the basis of the 1st signal system, conditioned reflexes of the 2nd signal system are formed. They begin to form when the child begins to speak and learn the world around us. Conditioned reflexes to verbal stimuli appear only in the second half of the first year of life. Consequently, human behavior consists of unconditioned reflexes, conditioned reflexes of the 1st signal system and conditioned reflexes of the 2nd signal system.

IN physiological conditions The 2nd signaling system somewhat slows down the activity of the 1st signaling system. With the advent of the 2nd signaling system, new form nervous activity - distraction and generalization many signals entering the brain. This determines high degree human adaptation to environment. The second signaling system is the highest regulator various forms human behavior in the surrounding world.

The characteristic features of conditioned reflexes of the 2nd signal system are:

1) extension of the signal meaning of words to all related, similar facts and phenomena, i.e. an increasingly broad generalization of concepts and abstraction from specific details (a person is walking, a train is also walking, a clock is running, it is raining, etc.);

2) the simultaneous formation and restructuring of temporary nerve connections. For example, you can explain to a visitor how to find the house he needs, and a person who has never been to this city will directly come to the Animal’s destination to find the right way in the maze, will make a lot of trial and error.

3) Display in the second signal system of temporary connections formed in the first, and vice versa. For example, if a person develops a conditioned reflex of standing up at the sound of a bell, and then instead of turning on the bell, say the word “bell,” then the person will get up. Or, if you describe in words the look and taste of a person’s favorite food, then the person will begin to salivate.

4) The more abstract and abstract the concept, expressed in words, those weaker connection this verbal signal with a specific signal of the 1st signal system.

5) Higher fatigue and susceptibility external influences reflexes of the second signaling system compared to the first.

The interaction of two signaling systems is expressed in the phenomenon of selective irradiation of nervous processes between the two systems. It is due to the presence of connections between the sensory areas of the cerebral cortex that perceive stimuli and nerve structures, denoting these stimuli with words. There is also braking irradiation between the two signal systems. The development of differentiation to a signal stimulus can also be reproduced by replacing the differentiation stimulus with its verbal designation.

During ontogenesis, the interaction of two signaling systems goes through several stages. Initially, the child's conditioned reflexes are realized at the level of the first signal system: the immediate stimulus comes into contact with immediate vegetative and motor reactions. In the second half of the year, the child begins to respond to verbal stimuli with immediate vegetative and somatic reactions, therefore, additional conditional connections“verbal stimulus is an immediate reaction.” By the end of the first year of life (after 8 months), the child already begins to imitate the speech of an adult in the same way as primates do, using individual sounds to designate objects, ongoing events, as well as one’s condition.

Later the child begins to say individual words. At first they are not associated with any subject. At the age of 1.5-2 years, one word often denotes not only an object, but also actions and experiences associated with it. Only later does the differentiation of words into categories denoting objects, actions, and feelings occur. Appears new type connections: direct stimulus - verbal reaction.

In the second year of life vocabulary child increases to 200 words or more. He can already combine words into simple speech chains and construct sentences. By the end of the third year, the vocabulary reaches 500-700 words. Verbal reactions are caused not only by direct stimuli, but also by words. A new type of connection appears: verbal stimulus - verbal reaction.

With the development of speech in a child aged 2-3 years, it becomes more difficult integrative activities brain: conditioned reflexes appear on the relationships between quantities, weights, distances, and colors of objects. At the age of 3-4 years, various motor and some speech stereotypes are developed.

First and second signaling systems

The types of GNI discussed above are common to animals and humans. It is possible to identify special typological features inherent only to humans. According to I.P. Pavlov, they are based on the degree of development of the first and second signaling systems. The first signaling system is visual, auditory and other sensory signals from which images of the external world are built. The perception of direct signals from objects and phenomena of the surrounding world and signals from the internal environment of the body, coming from visual, auditory, tactile and other receptors, constitutes the first signaling system that animals and humans have. Individual elements more complex signaling systems begin to appear in social species animals (highly organized mammals and birds) that use sounds (signal codes) to warn of danger, that this territory busy, etc.

But only in a person in the process of labor activity and social life a second signaling system develops - verbal, in which the word is a conditioned stimulus, a sign that has no real physical content, but is a symbol of objects and phenomena material world, becomes a strong incentive. This signaling system consists of the perception of words - audible, spoken (aloud or silently) and visible (when reading and writing). One and the same phenomenon, object on different languages denoted by words that have different sound and writing, abstract concepts are created from these verbal signals. The ability to understand and then pronounce words arises in a child as a result of the association of certain sounds (words) with visual, tactile and other impressions of external objects. A subjective image arises in the brain on the basis of neural mechanisms when decoding information and comparing it with what actually exists material objects. With the emergence and development of the second signaling system, it becomes possible to implement abstract form reflections - the formation of concepts and ideas. Stimuli of the second signaling system reflect the surrounding reality with the help of generalizing, abstract concepts expressed in words. A person can operate not only with images, but also with thoughts associated with them, meaningful images containing semantic (semantic) information. With the help of a word, a transition is made from the sensory image of the first signaling system to the concept, representation of the second signaling system. The ability to operate with abstract concepts expressed in words serves as the basis mental activity.

Language- is a means of expressing thoughts and a form of existence of thoughts. Language consolidates the results of thinking in sentences and makes it possible to exchange thoughts. Speech makes it possible to create scientific concepts, formulate laws.

Speech can participate in the regulation of the activities of various organs with the help of words. Verbal stimuli are physiologically active factors; they change the function internal organs, the intensity of metabolic processes, affect muscle and sensory systems. What was said in time kind word can improve performance, promote good mood. A carelessly spoken word in the presence of a patient can significantly worsen his condition.

Physiological basis speeches. The activity of the second signaling system is ensured by the function of motor, auditory and visual analyzers and frontal regions of the brain. The regulation of speech is associated with the triggering and regulatory role of the cortex, which receives afferent impulses from the receptors of the muscles, tendons and ligaments of the vocal apparatus and respiratory muscles. The cortical nucleus of the speech motor analyzer is located in the area of ​​the second and third frontal gyri - Broca's speech motor center. Speech perception occurs with the help of speech-motor and speech-auditory analyzers (Wernicke's center).

To decode speech perceived in acoustic form, the most important condition is the retention of all its elements in speech memory, and in optical form - the participation of complex search eye movements. Speech decoding processes are carried out by the temporo-parietal-occipital regions of the left hemisphere (in right-handed people). When these parts of the cortex are damaged, the understanding of logical-grammatical structures and counting operations is impaired.

The second signaling system allows for ambiguous relationships between a phenomenon, an object and its designation (word), which allowed a person to act intelligently in conditions of a probabilistic event environment (information uncertainty). This greatly contributed to the development of intuitive thinking abilities. A fundamentally new form of mental activity has emerged - the construction of inferences based on the use of multivalued (probabilistic) logic. Constant use language has led to human brain, as a rule, operates with imprecise concepts, qualitative assessments easier than quantitative categories, numbers.

Taking into account the relationship between the first and second signaling systems in a particular individual, I.P. Pavlov identified specific human types IRR depending on the predominance of the first or second signal system in the perception of reality.

People with a predominance of the functions of cortical projections responsible for primary signal stimuli, I.P. Pavlov attributed to artistic type(representatives of this type predominate figurative type thinking). These are people who are characterized by vivid visual and auditory perceptions of events in the surrounding world (artists and musicians). If the second signaling system turns out to be stronger, then such people are classified as the thinking type. Representatives of this type predominate boolean type thinking, ability to build abstract concepts(scientists, philosophers). In cases where the first and second signaling systems create nervous processes equal strength, then such people belong to the average ( mixed type) to which most people belong. But there is another extremely rare typological option, which is very rare people, having special strong development both the first and second signaling systems. These people are capable of both artistic and scientific creativity, among these genius personalities I.P. Pavlov attributed it to Leonardo da Vinci.