ALARM SYSTEMS- a system of conditional connections, associations, with the help of which living organisms interact with environment.

The concept of " signal system» was introduced by I. P. Pavlov in 1932 to explain the physiol. regularities of the brain and is a reflection of the systemic principles of the organization of the functioning of the brain, as well as the features of higher nervous activity (see), allowing the body to provide best ratios with habitat.

S. s. play an important role in human and animal life. The principle of signaling is already realized at the level of protozoa, and all further complication and improvement of the adaptive capabilities of organisms is largely determined by the evolution of S. s. In particular, the possibility of a timely response to a signal that precedes the action of a biologically significant factor is equivalent to solving the question of further existence, since this factor can be beneficial or harmful to a given organism.

Signals of vital phenomena and objects that satisfy one or another need of the body can be any natural physical. or chem. agents - sounds, smells, visual images, etc. On their basis, the so-called. the first signaling system common to the entire animal world, including humans.

The concept "signal system" - one of the central in I. P. Pavlov's doctrine about conditioned reflexes (see). IP Pavlov, who considered conditioned reflexes as a type of association, believed that all animal behavior is determined by the level of organization in the animal. n. e. The first of them combines a system of unconditioned reflexes (see) - food, defensive, sexual, etc., including such complex forms as instincts (see), drives (see), etc. The functioning of these reflexes is based mechanisms genetic memory. Unconditioned reflexes are a way of adapting the body to the environment, but it is limited by the rigid framework of innate mechanisms.

The second level in n. e. is represented by a signaling system of vital factors by concomitant or related natural agents. Combining with the action of unconditioned stimuli, these agents, by the mechanism of conditional, or temporary, connection (stimulus - reinforcement) become their signals. The totality of such conditional connections also represents S. of page, edges at animals is unique, and at the person - the first S. of page. It provides the body with wide adaptive possibilities for orientation in the environment.

For a person, the value of the first S. s. is completely preserved. But its evolution, distinguished by such qualitatively new categories as social relations, required the development various forms communication. At first it was gestures, facial expressions, exclamations. Then the exclamations began to turn into words, continuous speech. Based on the ability to higher forms of generalization, abstraction, thinking was formed (see), which was enriched with knowledge, created science and art. Man began not only to adapt to nature, but also to adapt the natural environment for his needs.

Thus, the second S. characteristic of a person was formed, personifying a generalizing signaling in the form of speech (pronounced, audible), writing, drawing, gestures, etc. (see Speech). The word, combining the signals of the first S. with., becomes a signal of signals; words denote actions, relationships of various kinds.

Formation of the second S. with. well observed in observations of the development of children. In the first three years of life, the first S. is formed predominantly. and emotional sphere. The ability to a higher degree of generalization is developed on the 4-5th year of life, after which the second S. s. becomes decisive in the subsequent life of a person.

Structural and functional support of S. s. differs in complexity. The signal as a physical or chem. the factor is perceived by receptors (see) - input devices of analyzers (see). In receptors, information is encoded in the form of a sequence of nerve impulses (see Nerve impulse). The nerve code is subjected to primary analysis in the transmission relays (intermediate centers) of the sensory tract and enters the projection zones of the cerebral cortex (see). It is assumed that monosensory images corresponding to external influences are formed there, and in associative fields that differ in the presence of polysensory elements, polysensory associations are created on the basis of convergence: auditory and tactile, olfactory-gustatory, etc. For signaling activity, such associations are essential, in which one of the components of a complex image, it acts as a harbinger, a signal of another part, which is a vital factor for the body, for example, in the "smell - food" complex, the smell perceived as a harbinger of food acts as a natural signal.

Another important link in S. s. are centers of needs, excitation or inhibition of which determines the effectiveness or ineffectiveness of this signal, for example, the smell of food in a well-fed animal will not cause a food reflex, since the hypothalamic "hunger center" will be inhibited.

Functional and organic defeats of c. n. With. cause various nervous and mental illnesses. Nek-ry forms of pathology have analogs at animals that allowed I. P. Pavlov to give them fiziol. analysis. He emphasized the importance of types of higher nervous activity (see). In dogs of the excitable type, a rapid change from excitation to inhibition, an overstrain of the inhibitory process, easily causes neurotic disorders (see Experimental neuroses). I. P. Pavlov called dogs of a weak inhibitory type the main "suppliers" of neuroses, since they cannot endure either intense excitation or intense inhibition. When the excitatory process is overstrained, such animals fall into a state similar to hysteria. In people, I. P. Pavlov believed, hysteria (see) is also characterized by a certain dissociation of the activity of the first and second S. of page. An important role in this is played by the development of phase, hypnotic states, in which the influence of the emotional “charge” of the subcortex often affects the concentration of nervous processes in the cortex and their extreme “fixation”.

IP Pavlov's assumptions about the violation of the correct interaction between the first and second S. s. with neuropsychiatric diseases further development in the works of A. G. Ivanov-Smolensky and other scientists. From these positions, the causes of such diseases as neuroses, psychoses (see Mental illnesses), schizophrenia (see) were considered.

It should be noted that dysfunction of the second S. page. is a very difficult problem. When analyzing diseases, it is necessary to take into account the interaction of various social factors with pathological ones; great importance have psychological indicators, to-rye not always manage to be explained from positions of physiology.

Research methods S. page. varied. This is, first of all, the classical method of conditioned reflexes in its various modifications with parallel recording of motor and vegetative reactions. Electrophysiological methods are widely used: electroencephalography (see), electromyography (see), microelectrode research method (see), allowing to study the activity of individual neurons and their populations in combination with machine mathematical analysis data (at the person neuronal activity is registered only in a wedge, conditions with the diagnostic purpose). Various types of associative verbal experiment, recording of the electrical activity of the muscles involved in the act of speech are also widely used. Along with this, data obtained from the study of sensory and other systems involved in the integrative-analytical activity of the brain are used.

Bibliography: Ivanov-Smolensky A. G. Essays pilot study higher nervous activity of a person, M., 1971; Koltsova M. M. Development of signal systems of reality in children, L., 1980, bibliogr.; Kratin Yu. G. Analysis of signals by the brain, L., 1977, bibliogr.; Krushinsky L. V. Biological bases of rational activity, M., 1977, bibliogr.; Orbeli L. A. Questions of higher nervous activity, M. - “ii., 1949; Pavlov IP Twenty-year experience of objective studying of higher nervous activity of animals, M., 1973; Penfield V. and Roberts L. Speech and brain mechanisms, trans. from English, L., 1964, bibliography; Sechenov I. M. Selected works, vol. 1, M., 1952; Firsov L. A. and Plotnikov V. IO. Voice behavior of anthropoids, L., 1981, bibliogr.

Lit.: Pavlov I.P., Poln. coll. soch., 2nd ed., vol. 3, book. 2, M.-L., 1951; Orbeli L. A., Izbr. works, vol. 3, M.-L., 1964.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what the "First Signaling System" is in other dictionaries:

first signaling system- see signaling systems. Brief psychological dictionary. Rostov-on-Don: PHOENIX. L.A. Karpenko, A.V. Petrovsky, M. G. Yaroshevsky. 1998 ... Great Psychological Encyclopedia

The system of reflection of reality in the form of sensations and perceptions, common to animals and humans; forms the basis of higher nervous activity and is reduced to a set of diverse (up to very complex) conditioned and unconditioned reflexes to ... ... Biological encyclopedic dictionary

A system of conditioned reflex connections that are formed in the cerebral cortex of animals and humans when exposed to specific stimuli (light, sound, pain, etc.). A form of direct reflection of reality in the form of sensations and ... Big Encyclopedic Dictionary

The concept introduced by I.P. Pavlov to designate the system of orientation of animals to direct stimuli, which can be visual, auditory, tactile signals associated with adaptive conditioned reflex ... ... Psychological Dictionary

A system of conditioned reflex connections formed in the cerebral cortex of animals and humans when exposed to specific stimuli (light, sound, pain, etc.). A form of direct reflection of reality in the form of sensations ... ... encyclopedic Dictionary

First signal system- the term of I.P. Pavlov, denotes sensory cognition, a system of analyzers, sense organs. * * * a system of conditioned reflex connections that are formed in the cerebral cortex of animals and humans when exposed to the receptors of the sense organs ... ... Encyclopedic Dictionary of Psychology and Pedagogy Natural science. encyclopedic Dictionary

See Signal Systems. Philosophical Encyclopedia. In 5 x t. M .: Soviet Encyclopedia. Edited by F. V. Konstantinov. 1960 1970 ... Philosophical Encyclopedia

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

There are several types of internal inhibition: extinction, differential, retarded and conditional brake. If an animal with a developed reflex to light is presented with a conditioned stimulus for a long time, without reinforcing it with an unconditioned stimulus (food), after a while salivation and juice secretion to light will no longer occur. This so-called fading internal inhibition conditioned reflex. In this case, the temporary connections between the centers of the analyzers and unconditioned reflexes are weakened or even disappear altogether. Differential braking

develops with non-reinforcement of stimuli close in parameters to the conditioned stimulus. For example, an animal has developed a salivary reflex to a certain sound signal. The presentation of another sound signal, not very different from the first one, without food reinforcement will lead to the fact that the animal will stop responding to the initial conditioned stimulus. delayed braking arises with a gradual increase in the interval between the conditioned stimulus and food reinforcement. In this case, the latter is preceded by an additional irritation. After some time, additional irritation causes the cessation of salivation and juice secretion to the conditioned stimulus.

16.2. The concept of the first and second signal systems

The higher nervous activity of man differs from that of animals. Animal behavior is much simpler than human behavior. Based on this, IP Pavlov developed the doctrine of the first and second signal systems.

First signal system found in both animals and humans. It provides concrete objective thinking, i.e. analysis and synthesis of specific signals from objects and phenomena of the external world entering the brain through the receptors of the sense organs.

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

stvii. The second signaling system appears in the child later than the first. Its development is associated with teaching speech and writing.

Speech is a unique human ability to sign-symbolic reflection of the objects of 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. that which can evoke an idea of ​​an object without presenting it. Speech makes learning possible without direct reference to the subjects being studied. It is the highest function of the central nervous system, primarily in the cerebral cortex.

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 substantive meaning. Written speech consists in the transmission of any information in the form of imprinted characters (letters, hieroglyphs and other signs) on a certain medium (paper, parchment, magnetic media, etc.). The development of speech in a child is a complex and lengthy process. Between the ages of 1 and 5, a child learns to communicate using words. By 5 - 7 years of age, it is possible to master the skills of writing and counting.

Thus, the first signaling system implies the acquisition of certain life skills through direct interaction with the environment without the conscious transfer of life experience gained from one generation to another. The second signaling system consists in the perception of the surrounding world both in direct contact with it and by means of comprehending various information received about it. This information can be passed 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 applied to the scalp, which perceive fluctuations in electrical potentials in the brain. In the future, these changes are amplified by 1 - 2 million times.

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

and amplitude. In a healthy person, predominateα-waves (alpha waves). Their frequency fluctuates within 8-12 oscillations per second, the amplitude is 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 the state of wakefulness; b - EEG in the state of slow-wave sleep;

in - EEG during REM sleep

have a frequency of 15 - 32 oscillations 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 mainly in the frontal regions. Slow δ waves (delta waves) and θ waves (theta waves) appear in healthy adults at the time 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, it is possible to establish the side of the brain lesion, the presumable localization of the pathological focus, to 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 the characteristics of the psyche. The psyche is a reflection inner world person. The basis of its existence is the brain. It is he who provides the totality of processes that form the psyche. The result of mental activity is a person's behavior, his reactions to certain situations.

Even Hippocrates noted the difference between people in their behavior. He associated this with the predominance in the body of one or another "Jew".

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, consequently, the type of higher nervous activity also depend on humoral factors - the level of hormones and biologically active substances in the blood.

Type of higher nervous activity - predominantly congenital individual properties of the functioning of the central nervous system. Should not be mixed this concept with the concept 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 more psychological. IP 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 to each other. Mobility is the ability to change the processes of excitation by processes of inhibition.

In terms of strength, higher nervous activity is divided into strong

and weak types, by balance - into balanced and unbalanced, by mobility - into mobile and inert.

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

How do different types higher nervous activity

and temperaments can be seen from Table. 16.2.

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

All patterns of conditioned reflex activity are common to higher animals and humans. And a person develops conditioned reflexes to various signals of the external world or internal state organism, if only various stimuli of the extero- or interoreceptors are combined with any stimuli that cause unconditioned or conditioned reflexes. And in a person, under appropriate conditions, external (unconditional) or internal (conditional) inhibition occurs. And in humans, irradiation and concentration of excitation and inhibition, induction, dynamic stereotypy and other characteristic manifestations of conditioned reflex activity are observed.

Common for both animals and humans are the analysis and synthesis of direct signals from the outside world, which make up first signal system reality.

On this occasion, I. P. Pavlov said: “For an animal, reality is signaled almost exclusively only by stimuli and their traces in the cerebral hemispheres, which directly come to special cells of the visual, auditory and other receptors of the body. This is what we also have in ourselves as impressions, sensations and ideas from the environment. external environment both general natural and from our social, excluding the word, audible and visible. It - first signaling system reality that we have in common with animals.

A person in the process of his social development, as a result of labor activity, has an extraordinary increase in the mechanisms of the brain. She became second signal system associated with verbal signaling, with speech. This highly sophisticated signaling system consists in the perception of words - spoken (aloud or to oneself), heard or seen (while reading). The development of the second signaling system incredibly expanded and qualitatively changed the higher nervous activity of man.

The emergence of speech signaling introduced a new principle into the activity of the cerebral hemispheres. “If our sensations and ideas,” said I. P. Pavlov, “relating to the world around us, are for us the first signals of reality, concrete signals, then speech, especially especially kinesthetic stimuli coming to the cortex from speech organs, there are second signals, signal signals. They represent a distraction from reality and allow for generalization, which is our superfluous specially human higher thinking, which first creates universal human empiricism, and finally, science - a tool for the highest orientation of man in the world around him and in himself.

With verbal signals, a person denotes everything that he perceives with the help of his receptors. The word as a “signal of signals” makes it possible to abstract from specific objects and phenomena. The development of verbal signaling made possible generalization and abstraction, which find their expression in human concepts. “Every word (speech) already generalises.

Feelings show reality; thought and word are common. Second signal system is inextricably linked with the social life of a person, is the result of a complex relationship in which the individual is located with the social environment surrounding him. Verbal signaling, speech, language are the means of communication between people, they have developed in people in the process of collective labor. Thus, the second signaling system is socially determined.

Outside of society - without communication with other people - the second signaling system does not develop. Cases are described when children carried away by wild animals remained alive and grew up in an animal den. They did not understand speech and did not know how to speak. It is also known that people, at a young age, isolated for decades from the society of other people, forgot speech; their second signaling system ceased to function.

The doctrine of higher nervous activity made it possible to reveal the patterns of functioning of the second signaling system. It turned out that the basic laws of excitation and inhibition are common to both the first and second signal systems. The excitation of any point of the cerebral cortex in a person is connected with the zones of perception of speech and its expression, i.e. with the sensory and motor centers of speech. Evidence for this is given in the experiments of A. G. Ivanov-Smolensky and his collaborators on children.

After the formation of a conditioned reflex to any sound or light signal, for example, to the sound of a bell or the flashing of a red lamp, the verbal designation of the conditioned signal, i.e. the words “call”, “red”, is immediately evoked without prior combination with an unconditioned stimulus conditioned reflex. Under the reverse conditions of the experiment, when the conditioned reflex was developed to a verbal signal, i.e., when the words “bell” or “red lamp” were the conditioned stimulus, the conditioned reflex was observed at the very first use of the sound of a bell or the flashing of a red lamp as a stimulus, which have never been combined with unconditioned irritation before.

In some experiments of L. I. Kotlyarevsky, the unconditioned stimulus was the dimming of the eye, which caused the pupil to dilate. The conditioned stimulus was the bell. After the development of a conditioned reflex to the sound of a bell, it was enough to pronounce the word "bell", as a conditioned reflex appeared. Moreover, if the subject himself uttered this word, then a conditioned reflex of constriction or expansion of the pupil also arose. The same phenomena were observed if the unconditioned stimulus was pressure on the eyeball, which caused a reflex decrease in cardiac activity.

The mechanism of such conditioned reflex reactions is related to the fact that in the process of teaching speech, long before the experiments, temporary connections arose between the cortical points that receive signals from various objects and the centers of speech that perceive the verbal designations of objects. Thus, speech centers are included in the formation of temporary connections in the human cerebral cortex. In all the experiments described, we encounter the phenomenon of elective irradiation, which consists in the fact that excitations are transmitted from the first signal system to the second and vice versa. Elective irradiation is an essentially new physiological principle that manifests itself in the activity of the second signaling system and characterizes its relationship with the first.

A word is perceived by a person not only as a separate sound or a sum of sounds, but as a definite concept, that is, its semantic meaning is perceived. This is proved by the experiments of L. A. Schwartz, who, having developed a conditioned reflex to a word, for example, “path”, then replaced it with a synonym, for example, the word “path”. The word-synonym evoked exactly the same conditioned reflex reaction as the word to which the conditioned reflex was developed. A similar phenomenon was observed when the Russian word, which served as a conditioned stimulus, was replaced by the same word in meaning to foreign language familiar to the subject. It is essential that "neutral" words, i.e., those to which no conditioned reflex was formed, did not evoke reactions. A word close in sound, for example, the word "smoke" in the conditioned reflex to the word "house", evoked a reflex only at first. Very quickly, differentiation was formed in response to such words, and they ceased to evoke conditioned reflexes.

Connections are also formed between different parts of the cerebral cortex and the centers involved in the acts of reading and writing in the learning process. That is why, after developing a conditioned reflex to the sound of a bell, the inscription “bell” evokes a conditioned reflex reaction in a person who can read.

Speech signals in human experiments can be successfully used as a reinforcer of a conditioned stimulus. For this purpose, a conditioned stimulus, for example, the sound of a bell, is accompanied by a verbal instruction - an order: “press the key”, “get up”, “pull your hand away”, etc. As a result of a number of combinations of a conditioned stimulus with a verbal instruction, a (in our example - to the sound of a bell) is a conditioned reflex, the nature of which corresponds to the instructions. The word is a powerful reinforcement, on the basis of which very strong conditioned reflexes can be formed.

First and second signal systems are inseparable from each other. A person has all the perceptions and ideas and most of sensations are verbally indicated. It follows from this that excitations of the first signal system, caused by specific signals from objects and phenomena of the surrounding world, are transmitted to the second signal system.

Separate functioning of the first signaling system without the participation of the second (with the exception of cases of pathology) is possible only in a child before he masters speech.

FEATURES OF THE HIGHER NERVOUS ACTIVITY OF THE HUMAN.

Distinguish between the first and second signal systems.

First signal system found in humans and animals. The activity of this system is manifested in conditioned reflexes that are formed to any stimuli of the external environment (light, sound, mechanical irritation, etc.), with the exception of the word. In a person living in certain social conditions, the first signaling system has a social connotation.

Conditioned reflexes of the first signaling system are formed as a result of the activity of the cells of the cerebral cortex, except for the frontal region and the region of the brain section of the speech-motor analyzer. The first signaling system in animals and humans provides subject-specific thinking.

The second signal system arose and developed as a result of human labor activity and the appearance of speech. Labor and speech contributed to the development of hands, brain and sense organs.

Activity of the second signaling system manifested in speech conditioned reflexes. We can in this moment not to see some object, but its verbal designation is enough for us to clearly imagine it. The second signaling system provides abstract thinking in the form of concepts, judgments, conclusions.

Speech reflexes of the second signaling system are formed due to the activity of neurons in the frontal areas and the area of ​​the speech motor analyzer. The peripheral section of this analyzer is represented by receptors that are located in the word-pronouncing organs (receptors of the larynx, soft palate, tongue, etc.). From the receptors, the impulses arrive along the corresponding afferent pathways to the brain section of the motor speech analyzer, which is a complex structure that includes several zones of the cerebral cortex. The function of the speech-motor analyzer is especially closely connected with the activity of the motor, visual and sound analyzers. Speech reflexes, like ordinary conditioned reflexes, obey the same laws. However, the word differs from the stimuli of the first signaling system in that it is multi-comprehensive. A kind word said in time contributes good mood, increases working capacity, but a word can seriously injure a person. This is especially true for the relationship between sick people and medical workers. A carelessly spoken word in the presence of a patient about his illness can significantly worsen his condition.

Animals and humans are born only with unconditioned reflexes. In the process of growth and development, the formation of conditioned reflex connections of the first signal system, the only one in animals, takes place. In a person, on the basis of the first signal system, connections of the second signal system are gradually formed when the child begins to speak and learn about the surrounding reality.

The second signaling system is the highest regulator of various forms of human behavior in the natural and social environment surrounding him.

However, the second signal system correctly reflects the external objective world only if its coordinated interaction with the first signal system is constantly preserved.