Conditioned reflex activity of the cortex cerebral hemispheres Pavlov called the signaling activity of the brain, since stimuli external environment give the body signals about what is important to it in the world around it. Pavlov called the signals entering the brain that are caused by objects and phenomena acting on the senses (resulting in sensations, perceptions, ideas) the first signaling system; it is found in humans and animals. But man experienced, as Pavlov writes, an extraordinary increase in mechanisms nervous activity in progress labor activity And social life. This addition is human speech, and according to Pavlov’s theory, it is the second signaling system - verbal.
The first signaling system is visual, auditory and other sensory signals from which images are built outside world. 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.
The second signaling system is verbal, in which the word as a conditioned stimulus, a sign that has no real physical content, but is a symbol of objects and phenomena of the material world, becomes a strong stimulus. This signaling system consists of the perception of words - audible, spoken (aloud or silently) and visible (when reading and writing).
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 that serve as the basis for mental activity.
For the second signaling system to begin to function, the child needs to communicate with other people and acquire verbal and writing, which takes a number of years. If a child is born deaf or loses hearing before he begins to speak, then his inherent ability oral speech is not used and the child remains mute, although he can pronounce sounds. In the same way, if a person is not taught to read and write, then he will forever remain illiterate. All this testifies to the decisive influence environment for the development of a second signaling system. The latter is associated with the activity of the entire cerebral cortex, but some areas of it play a special role in speech. These areas of the cortex are the cores of speech analyzers.
Physiological basis speech. The activity of the second signaling system is ensured by the function of the motor, auditory and visual analyzers and the frontal parts 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).
Both signaling systems are in constant interaction. If the signals of the second signal system (words) do not have support in the first signal system (do not reflect what was received through it), then they become incomprehensible. Yes, word on foreign language, which we do not know, does not tell us anything, since this word has no specific content for us. But the first signals alone do not provide deep and complete knowledge about the world. Only with the help of the second signaling system (speech) did a person learn to expand his information, generalizing individual facts, establishing patterns that were important to him.
Thanks to the second signaling system, people deepen and retain their knowledge.
Pavlov considered the second signaling system to be the “highest regulator of human behavior”, which prevails over the first signaling system. But the latter, to a certain extent, controls the activity of the second signaling system. This allows a person to manage his unconditioned reflexes, restrain a significant part of the instinctive manifestations of the body and emotions. A person can consciously suppress defensive (even in response to painful stimuli), food and sexual reflexes. At the same time, the subcortical formations and nuclei of the brain stem, especially the reticular formation, are sources (generators) of impulses that maintain normal brain tone
1.1.First signal system 3
1.2. Second alarm system 4
1.3 Interaction of the first and second signal systems 7
References 10
1. Signaling activity of the brain
Pavlov called the conditioned reflex activity of the cerebral cortex the signal activity of the brain, since stimuli from the external environment give the body signals about what is important to it in the surrounding world. Pavlov called the signals entering the brain that are caused by objects and phenomena acting on the senses (resulting in sensations, perceptions, ideas) the first signaling system; it is found in humans and animals. But in humans, as Pavlov writes, an extraordinary increase in the mechanisms of nervous activity occurred in the process of work and social life. This addition is human speech, and according to Pavlov’s theory, it is the second signaling system - verbal.
According to Pavlov’s point of view, the regulation of the relationship of the organism with the environment is carried out in higher animals, including humans, through two interconnected instances of the brain: the nervous apparatus of unconditioned reflexes, caused by a few unconditioned (acting from birth) external stimuli, is concentrated in the subcortex; this apparatus, which constitutes the first instance, provides limited orientation in the environment and poor adaptation. The second instance is formed by the cerebral hemispheres, in which the nervous apparatus of conditioned reflexes is concentrated, providing signaling of a few unconditioned stimuli by a countless number of other stimuli, analyzed and synthesized; This device dramatically expands the body’s orientation capabilities and increases its adaptability.
2. First signaling system
In the first signaling system, all forms of behavior, including methods and means of mutual communication, are based solely on the direct perception of reality and reactions to natural stimuli. The first signaling system provides forms of concrete sensory reflection. In this case, the body first develops a sensation of individual properties, objects, and phenomena perceived by the corresponding receptor formations. At the next stage, the nervous mechanisms of sensations become more complex, and on their basis other, more complex forms of reflection - perception - arise. And only with the emergence and development of the second signaling system does it become possible to implement an abstract form of reflection - the formation of concepts and ideas.
Unlike the conditioned reflexes of animals, which reflect the surrounding reality with the help of specific auditory, visual and other sensory signals, stimuli of the second signaling system reflect the surrounding reality with the help of generalizing, abstract concepts expressed in words. While animals operate only with images formed on the basis of directly perceived signal stimuli, a person with his developed second signal system operates not only with images, but also with thoughts associated with them, meaningful images containing semantic (notional) information. Stimuli of the second signaling system are largely mediated by human mental activity.
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.
The first signaling system, a system of conditioned reflex connections formed in the cerebral cortex of animals and humans when receptors are exposed to stimuli coming from the external and internal environment. It is the basis for the direct reflection of reality in the form of sensations and perceptions.
The term first signaling system was introduced in 1932 by I. P. Pavlov while studying the physiological mechanism of speech. According to Pavlov, for an animal, reality is signaled mainly by irritations (and their traces in the cerebral hemispheres), which are perceived directly by the 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 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 first signaling system provides forms of concrete sensory reflection. In this case, the body first develops a sensation of individual properties, objects, and phenomena perceived by the corresponding receptor formations. At the next stage, the nervous mechanisms of sensations become more complex, and on their basis other, more complex forms of reflection - perception - arise. And only with the emergence and development of the second signaling system does it become possible to implement an abstract form of reflection - the formation of concepts and ideas.
The first and second signaling systems - one of them makes us similar to animals, the other distinguishes us from them. The concept of the first and second signal systems was introduced by the famous academician Pavlov.
If the first includes various processes occurring in the brain in response to environmental stimuli, and it is the sensory basis for a person’s construction of the subjective world, then the second includes all processes associated with the perception of speech and verbal signals. Thus, the signaling system is responsible for the perception and emergence of a reaction to external stimuli, which allows a person to adapt to the environment and behave adequately depending on the conditions.
The development of the second signaling system is associated with difficulty and the growing importance of society for humans. The 1st signaling system performs the function of directly reflecting the world through signals from the senses, the 2nd - through abstract ones, general concepts. In the process of reading and speaking, it is the second system that leads to the emergence of associations with words. It is the basis for abstractions, and therefore for .
The dependence of the two systems can be easily observed using the example of deaf children. Without the ability to hear the sounds made and imitate those around them, they do not develop speech. Both systems influence and control each other, the second system is able to control.
Left and right
Rubinstein emphasizes that the second signaling system should include formations in the brain that are activated in response to speech signals. You cannot call it language, speech or thinking, but it is correct to understand it as the principle of activity of the cerebral cortex. It is impossible to say in which area of the brain it “lives”; all structures are involved. But we can highlight the most related areas:
- Broca's speech center (damage results in absence of oral speech).
- Wernicke's center (damage to this area affects the ability to understand meaning).
- Optical center (damage here leads to degradation of the perception of what is written).
The listed centers are concentrated in the left hemisphere, which is apparently associated with right-handedness. The left hemisphere is often called responsible for the second signaling system. If the functioning of the left hemisphere is affected, then, as a rule, problems arise with speech processing, pronouncing words, understanding texts, and solving puzzles, but the first signaling system does not suffer in any way.
On the contrary, when the right hemisphere is suppressed, the emotional side of music, sounds, and the appearance of objects are disrupted, but all mental and speech functions remain normal. The division by hemisphere is also confirmed by tests for addressing people in different forms(verbal or non-verbal).
Socialization
Speech function is acquired through training. A child will not develop the ability to speak if he is deprived of communication. The word becomes an irritant already in the first year of life, namely in the second half of the year.
The beginning of the second year marks the transition of the word from minor roles to the main ones. It becomes an independent and leading irritant. An important factor in achieving this result is a change in scenery and conditions while keeping the word unchanged during the child’s education.
Gradually, words, while remaining associated with complexes of phenomena, turn from sound stimuli into speech signals. Physiology explains this by the activity of different foci in the brain. Excitation associated with the stimulus-object becomes synchronized with excitation from the word. This creates a single mesh that includes both areas.
Only by the time of admission to primary school in the child, the system responsible for speech reflexes becomes the leading one, but the first one does not completely lose its influence. To develop effective patterns of behavior, it is useful to combine words and actions to activate the first system.
Features of reactions
1. If a person has developed a conditioned reflex, then a reflexive reaction will also occur to words similar in meaning to it.
2. Rapid formation and restructuring. It takes many repetitions for the first one to create/undo/change the stimulus-response link; it takes seconds to connect words and object—or, more accurately, meaning and object.
3. The second and first are displayed within each other. If a reflex action to the sound of a bell has already been created, then the word “bell”, written or spoken, will cause the same reaction. Thus, everything that relates directly to the first in a person will be connected with the second through words, since the signal is also imprinted verbally. The same thing happens when a reaction is developed directly to a word - it is repeated on phenomena related to it.
5. Reflexes of the second system are subject to external influences and are more prone to high fatigue, which is explained by their youth. The schoolchildren had a strong motor reflex to the bell throughout the day, and to the word “bell” the reaction decreased towards the end of the day. Examples of high sensitivity are states of alcoholic intoxication: first problems with rational judgment begin, and only then the reflexes of the first system fail.
Typology
When the first one works more intensively and more often, a person is classified as artistic type, when the second - to the thinking. Short description two extremes:
- The artistic type is specific. He is attracted to everything bright, imaginative, filled with sounds and colors. Artists cannot do without smells and touches.
- The thinking type is characterized by a penchant for abstractions and analytics. Bright pictures as if they elude the thinker’s gaze; he presents everything in the form of generalizations and verbal definitions.
The first signaling system, as already mentioned, is responsible for that part of the reflected reality that is perceived by the senses. The second signaling system provides meaning. Neither the first nor the second are isolated, which is easy to notice when studying the reflexes of the latter.
In a person, it is the second that prevails due to the characteristics of his life (society, culture). At the same time, thanks to the mutual influence of the first and second systems, it is possible to produce better learning using words and reinforcement. Author: Ekaterina Volkova
All patterns of conditioned reflex activity are common to higher animals and humans. And a person develops conditioned reflexes to various signals from the external world or the internal state of the body, if only various irritations of extero- or interoreceptors are combined with any irritations that cause unconditioned or conditioned reflexes. And in a person, under appropriate conditions, external (unconditional) or internal (conditional) inhibition occurs. And in humans there is irradiation and concentration of excitation and inhibition, induction, dynamic stereotypy and other characteristic manifestations of conditioned reflex activity.
Common to both animals and humans are the analysis and synthesis of direct signals from the external world, which constitute first signaling system reality.
On this occasion, I.P. Pavlov said: “For an animal, reality is signaled almost exclusively only by irritations and their traces in the cerebral hemispheres, directly arriving in 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 surrounding external environment, both natural and social, excluding the word, audible and visible. This - first signaling system reality, we have in common with animals.”
A person is in the process of social development, as a result of work activity, an extraordinary increase in the mechanisms of brain function appeared. She became second signaling system, associated with verbal signaling, with speech. This highly sophisticated signaling system consists of the perception of words - spoken (aloud or silently), heard or visible (reading). The development of the second signaling system has incredibly expanded and qualitatively changed the higher nervous activity of humans.
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 the speech organs, are the second signals , signals signals. They represent an abstraction from reality and allow for generalization, which constitutes our superfluous specifically human higher thinking, which creates first universal human empiricism, and finally science - a tool for man’s highest orientation in the world around him and in himself.”
A person uses verbal signals to designate everything that he perceives with the help of his receptors. The word “signal of signals” makes it possible to escape 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 generalizes.
Feelings show reality; thought and word are common.” Second signaling system is inextricably linked with human social life, is the result of complex relationships in which the individual finds himself with his environment social environment. Verbal signaling, speech, language are means of communication between people; they developed among people in the process of collective work. Thus, the second signaling system is socially determined.
Outside society - without communication with other people - the second signaling system does not develop. Cases have been described in which children carried away by wild animals remained alive and grew up in an animal den. They did not understand speech and could not speak. It is also known that people who, at a young age, were isolated for decades from the society of other people, forgot their speech; their second alarm system stopped functioning.
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. Excitation of any point in the cerebral cortex in humans is brought into connection with the areas of speech perception and its expression, i.e., with the sensory and motor centers of speech. Evidence of this is given in the experiments of A.G. Ivanov-Smolensky and his colleagues 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 “bell”, “red color”, is immediately evoked without prior combination with an unconditioned stimulus conditioned reflex. Under the opposite conditions of the experiment, when a conditioned reflex was developed in response to a verbal signal, i.e., when the conditioned stimulus was the words “bell” or “red lamp,” the conditioned reflex was observed at the very first use as a stimulus of the sound of a bell or the flashing of a red lamp, which have never been combined with unconditional irritation before.
In some experiments by L.I. Kotlyarevsky, the unconditioned stimulus was the darkening of the eye, which caused dilation of the pupil. The conditioned stimulus was the bell. After developing a conditioned reflex about the sound of a bell, it was enough to say the word “bell”, and the conditioned reflex appeared. Moreover, if the subject himself uttered this word, then a conditioned reflex of constriction or dilation 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 due to the fact that in the process of learning speech, long before the experiments, temporary connections arose between cortical points that receive signals from various items, and speech centers that perceive verbal designations of objects. Thus, speech centers are involved 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 from the first signal system are transmitted to the second and back. Selective irradiation is an essentially new physiological principle, manifested in the activity of the second signaling system and characterizing 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 specific concept, that is, its semantic meaning is perceived. This is proven 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 synonymous word evoked exactly the same conditioned reflex reaction as the word for which the conditioned reflex was developed. A similar phenomenon was observed when replacing a Russian word, which served as a conditioned stimulus, with a word of the same meaning in a foreign language familiar to the subject. It is essential that “neutral” words, i.e. those for which a conditioned reflex was not formed, did not evoke reactions. A word that sounded similar, for example, the word “smoke” during a conditioned reflex to the word “house,” evoked the 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 areas of the cerebral cortex and centers involved in the acts of reading and writing during 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 experiments on humans can be successfully used as reinforcement 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”, “stand up”, “pull your hand away”, etc. As a result of a number of combinations of the conditioned stimulus with verbal instructions, (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 reinforcer, on the basis of which very strong conditioned reflexes can be formed.
First and second signaling systems inseparable from each other. In humans, all perceptions and ideas and most of the sensations are verbally designated. It follows from this that the 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 (except in cases of pathology) is possible only in a child before he has mastered speech.
First and second signaling systems
The types of GNI discussed above are common to animals and humans. It is possible to identify special ones that are unique to humans typological features. 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. Separate elements of a more complex signaling system begin to appear in social species of animals (highly organized mammals and birds), which use sounds (signal codes) to warn of danger, that a given territory is occupied, etc.
But only in the process of work and social life does a person develop a second signaling system - a verbal one, in which the word as a conditioned stimulus, a sign that has no real physical content, but is a symbol of objects and phenomena of the material world, becomes a strong stimulus. 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 appears in the brain on the basis of neural mechanisms when decoding information and comparing it with really existing material objects. With the emergence and development of the second signaling system, it becomes possible to implement an abstract form of reflection - 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 for 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 of internal organs, the intensity of metabolic processes, and affect the muscular 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 of speech. The activity of the second signaling system is ensured by the function of the motor, auditory and visual analyzers and the frontal parts 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. Arose fundamentally new form mental activity - drawing conclusions based on the use of multivalued (probabilistic) logic. The constant use of language has led to the fact that the 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 classified it as an artistic type (representatives of this type have a predominant imaginative type of 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 are dominated by the logical type of thinking, the ability to construct abstract concepts (scientists, philosophers). In cases where the first and second signaling systems create nervous processes of equal strength, then such people belong to the average (mixed type), which is the majority of people. But there is another extremely rare typological variant, which includes very rare people who have particularly strong development of both the first and second signaling systems. These people are capable of both artistic and scientific creativity; I.P. Pavlov included Leonardo da Vinci among such brilliant personalities.
