Types of higher nervous activity
Each individual has predominantly genetically determined characteristics of functioning nervous system, which determine differences in the nature of the response to the same influences of the physical and social environment and, therefore, form the basis for the formation of behavior.
I. P. Pavlov identified three main properties of nervous processes: strength, balance and mobility.
The strength of nervous processes - This is the ability of nerve cells to maintain adequate performance under significant stress of excitatory and inhibitory processes. It is based on the severity of excitation and inhibition processes in the central nervous system. People with a stronger nervous system are more resilient and stress-resistant.
Balance of nervous processes – this is the balance of the processes of excitation and inhibition, creating the basis for more balanced behavior.
Mobility of nervous processes speaks of the ability to quickly transition from excitation to inhibition. People with a more mobile nervous system have greater behavioral flexibility; they adapt more quickly to new conditions.
Subsequently, additional properties of nervous processes were identified.
Dynamism – the ability of brain structures to quickly generate nervous processes during the formation of conditioned reactions. The dynamism of nervous processes underlies learning.
Lability – the rate of emergence and cessation of nervous processes. This property allows you to make movements with high frequency, quickly and clearly starting and finishing the movement.
Activation characterizes the individual level of activation of nervous processes and underlies the processes of memorization and reproduction.
Various combinations of these characteristics of nervous processes determine one or another type of temperament and, to some extent, character and personality traits. For example, the strength of the arousal process underlies endurance, energy, efficiency, ardor, courage, bravery, activity, boldness, ability to overcome difficulties, initiative, risk-taking, independence, determination, perseverance. And the power of braking determines such properties as caution, self-control, patience, secrecy, restraint, composure.
When the processes of excitation and inhibition are unbalanced, when excitation predominates over inhibition, a tendency towards increased excitability, a tendency to take risks, ardor, intolerance, and a predominance of persistence and compliance appear. Such a person is more of a man of action; waiting and patience are difficult for him. And such character traits as caution, restraint, restraint, calmness, lack of inclination towards excitement and risk are associated with the predominance of inhibition processes in the nervous system. Balance, i.e. the presence of a balance between inhibition and excitation presupposes moderation, prudence, dimensionality in activity, combined with the possibility of applying sufficient effort to achieve the goal, and, if necessary, risk. With pronounced mobility of excitatory processes, impulsivity and a tendency to quickly interrupt the work started when it ceases to arouse interest may arise. It is difficult for such a person to develop persistence in achieving a goal. When combined with the mobility of the inhibitory process, there may be a quick response to external stimuli, sociability, initiative - it is difficult for such people to be secretive, attached and constant.
Based on various combinations of the three main properties of nervous processes, various types of GNI are formed. In I. P. Pavlov’s classification, there are four main types of GNI, differing in adaptability to external conditions:
1) strong, unbalanced (“uncontrolled”) type characterized high strength processes of excitation, predominant by inhibition. This is a person with a high level of activity, quick-tempered, energetic, irritable, addicted, with strong, quickly arising emotions that are clearly reflected in speech, gestures and facial expressions;
2) strong, balanced, mobile (labile or "live") type characterized by strong, balanced processes of excitation and inhibition with the ability to easily replace one process with another. These are energetic people, with great self-control, decisive, able to quickly navigate a new environment, agile, impressionable, clearly expressing their emotions;
3) strong, balanced, inert (calm) type characterized by the presence of strong processes of excitation and inhibition, their balance, but at the same time low mobility of nervous processes. These are very efficient, able to restrain themselves, calm people, but slow, with weak expression of feelings, difficult to switch from one type of activity to another, committed to their habits;
4) weak type characterized by weak excitation processes and easily occurring inhibitory reactions. These are weak-willed, sad, sad people, with high emotional vulnerability, suspicious, prone to gloomy thoughts, to a depressed mood, they are timid, and often succumb to the influence of others.
These types of GNI correspond to the classical description of temperaments by Hippocrates, an ancient Greek physician who lived almost 2.5 millennia before I.P. Pavlov (Table 13.2).
Table 13.2
Correlation of types of higher nervous activity and temperaments according to Hippocrates
However, usually the combination of properties of the nervous system is more diverse, and therefore in life it is rarely possible to see such “pure” types of GNI. Even I.P. Pavlov noted that between the main types there are “intermediate, transitional types, and you need to know them in order to navigate human behavior.”
It is interesting to note that the main types of GNI are common to humans and animals. But along with them, I.P. Pavlov identified types that are unique to humans, based on the different ratio of the first and second signaling systems:
– artistic type - characterized by a slight predominance of the first signaling system over the second. Individuals belonging to this type are characterized by an objective, figurative perception of the surrounding world, a tendency to operate with sensory images in the process of thinking;
– thinking type - characterized by the predominance of the second signaling system over the first. Representatives of this type are characterized by the presence of pronounced abilities for abstraction, operating with abstract symbols in the process of thinking, and well-developed abilities for analysis;
– medium type – differs in the balance of signaling systems. Most people relate to him. Representatives of this type are characterized by both figurative impressions and abstract conclusions.
This classification is associated with the functional interhemispheric asymmetry of the brain, the peculiarities of their interaction: it is believed that the artistic type corresponds to right-hemispheric dominance and a predominantly simultaneous (holistic) way of processing information, and the thinking type corresponds to left-hemispheric dominance and a successive (sequential) way of processing information.
Definition of GNI, its types, connection of types with the temperament and character of children
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Introduction
The physiology of higher nervous activity (HNA) occupies an important place among biological disciplines and is essential for understanding the physiological mechanisms of certain mental phenomena and complex forms of adaptive behavior in animals and humans. This section of psychology was created by the outstanding Russian scientist I.P. Pavlov and his school. Also I.P. Pavlov made a major discovery - the discovery conditioned reflex as the main mechanism of cortex activity cerebral hemispheres.
The purpose of this work is to review General information regarding GNI. Detailed description types of higher nervous activity according to their division proposed by I.P. Pavlov, the connection between the types of GNI and the temperament and character of children.
Based on the goal, the following tasks can be identified:
Review general information about GNI;
Consider the types of GNI;
Consider the types of VNI in children
Consider the relationship between temperament, character and nervous system in children.
1. General information about higher nervous activity
According to the definition of I.P. Pavlova, higher nervous activity - complex shape vital activity, ensuring individual behavioral adaptation of humans and higher animals to changing environmental conditions (in contrast to lower nervous activity, aimed at the interaction of the organism “with itself”, that is, at the regulation internal processes, maintaining homeostasis and performing simple motor acts).
Currently, GND is defined as “the activity of the higher parts of the central nervous system, ensuring the most perfect adaptation of animals and humans to the environment.” In other words, GNI is “a set of unconditioned and conditioned reflexes, as well as higher mental functions that ensure adequate behavior in changing natural and social conditions.”
A full disclosure of the features of human higher nervous activity and the mechanisms of his brain activity belongs to the future.
GND is carried out due to the dominant influence of the cerebral cortex on all phylogenetically more ancient nervous structures, that is, the cerebral cortex is the highest coordination center. The main processes occurring in the nervous system are the processes of excitation and inhibition. Depending on the strength and predominance of the processes of excitation and inhibition, their dynamic alternation, certain reactions of the body are carried out. Pavlov considered the conditioned reflex to be the functional unit of GNI.
I.P. Pavlov and his school developed objective methods for studying the mechanisms of mental processes. Pavlov was the first to draw attention to the fact that an experimental animal can develop a reaction to a signal preceding a particular stimulus and give a response to it that would be given directly to the stimulus. It was this reaction to a signal preceding an unconditioned stimulus that Pavlov called a conditioned reflex and saw in it the highest form of reflex activity underlying complex adaptive behavior.
The Soviet physiologist P.K. also made a great contribution to the study of GNI. Anokhin, who showed that the main condition for the formation of goal-directed behavior is the ability to achieve a biologically important result of the action. A.A. also studied problems of higher nervous activity. Ukhtomsky, N.A. Bernstein, G.G. Shpet, I. Muller, C. Bell, G. Helmholtz, K. Ludwig, E. Dubois-Reymond and others.
2. Types of higher nervous activity
.1 Basics of typological features of higher nervous activity
The idea of the typological features of the nervous system of humans and animals is one of the defining ones in Pavlov’s doctrine of higher nervous activity. The relationship between strength, balance and mobility of the basic nervous processes determines the typology of the individual’s higher nervous activity.
The systematization of the types of higher nervous activity is based on an assessment of these three main features of the processes of excitation and inhibition: Force. Strength refers to the performance of cells in the cerebral cortex. When assessing the strength of the irritability process (excitability), measures are used that are aimed at increasing the excitability of the cells of the cerebral cortex. At the same time, it is assessed what degree of excitability the nervous system can withstand without falling into extreme inhibition;
Mobility. The mobility of the processes of excitation and inhibition is expressed in how quickly in the cells of the cerebral cortex the process of excitation is replaced by the process of inhibition and vice versa. The mobility of nervous processes can be determined by rapid replacement of the differentiation (inhibitory) stimulus.
Types of GNI act as a result of inherited and acquired individual qualities of the nervous system. The type is manifested in the peculiarities of the functioning of the physiological systems of the body and, above all, the nervous system itself, its higher “floors” that provide higher nervous activity.
Types of GNI are formed on the basis of both genotype and phenotype. The genotype is formed in the process of evolution under the influence of natural selection, ensuring the development of individuals most adapted to the environment. Under the influence of environmental conditions actually operating throughout an individual’s life, the genotype forms the phenotype of the organism.
2.2 Types of temperaments according to Hippocrates
The oldest description of temperaments belongs to the “father” of medicine, Hippocrates. He believed that a person's temperament is determined by which of the four body fluids predominates.
If blood predominates (“sanguis” in Latin), then the temperament will be sanguine, i.e. energetic, fast, cheerful, sociable, easily endures life's difficulties and failures. That is this type characterized by sufficient strength and mobility of excitatory and inhibitory processes (strong, balanced, mobile).
If bile (“chole”) predominates, then the person will be choleric - a bilious, irritable, excitable, unrestrained, very active person, Withrapid change of mood. We can say that the choleric type is characterized by a high strength of the excitatory process with a clear predominance over the inhibitory process and increased mobility, lability of the main nervous processes (strong, unbalanced, unrestrained). If mucus (“phlegm”) predominates, then the temperament is phlegmatic - a calm, slow, balanced person, slowly, Withhaving difficulty switching from one type of activity to another, poorly adapting to new conditions. In other words, the phlegmatic type is distinguished by sufficient strength of both nervous processes with relatively low rates of their mobility and lability (strong, balanced, inert). If black bile (“melanchole”) predominates, then the result is a melancholic person - a somewhat painfully shy and impressionable person, prone to sadness, timidity, isolation, he gets tired quickly, and is overly sensitive to adversity. That is, from a physiological point of view, we can say that the melancholic type is characterized by a clear predominance of the inhibitory process over the excitatory process and their low mobility (weak, unbalanced, inert). This theory of temperament can be called the humoral theory. 2.3 Types of GNI according to Pavlov
Strong, balanced, mobile - has equally strong processes of excitation and inhibition with good mobility, which ensures high adaptive capabilities and stability in difficult life situations. Strong, balanced, inert - with strong processes of excitation and inhibition and poor mobility, always experiencing difficulties when switching from one type of activity to another. Strong unbalanced - characterized by a strong irritability process and a lagging inhibitory process, therefore, a representative of this type in difficult situations is easily susceptible to violations of the IRR and is able to train and significantly improve insufficient inhibition. Weak - characterized by weakness of both nervous processes - excitation and inhibition, poorly adapts to environmental conditions, and is susceptible to neurotic disorders. Modern ideas about the types of higher nervous activity can be largely identified with four types of temperament (choleric, melancholic, phlegmatic, sanguine), identified by the ancient Greek physician Hippocrates (IV century BC). A complex combination of inherited characteristics combined with a wide variety of individually acquired behavior (in close connection with racial, national, climatic, socio-cultural living conditions modern man) allows only in the most general outline identify a certain type of higher nervous activity. In conditioned reflex activity, the strength of the excitation process is determined by the speed and strength of the development of conditioned reflexes, the strength of the inhibition process is reflected in the speed and strength of the development of differentiated and delayed inhibition. Lability and mobility of nervous processes are assessed in terms of the strength of alteration of the signal value of conditioned stimuli (from excitatory to inhibitory and vice versa). By connecting the classification of Hippocrates and Pavlov, one can see a clear connection between them, which can be easily expressed by the diagram presented in the figure. higher nervous temperament child It must be borne in mind that the types of higher nervous activity noted above represent extreme classical types, which in their pure form either do not occur at all or are extremely rare. Also I.P. Pavlov specifically identified types of higher nervous activity for humans, depending on the interaction and balance of signaling systems: Artistic type. Characterized by the predominance of the first signaling system over the second. This type includes people who directly perceive reality, widely use sensory images, and are characterized by figurative, objective thinking. Thinking type. These are people with a predominance of the second signaling system, “thinkers”, with a pronounced ability for abstract thinking. 3. Most people are of the average type with balanced activity of two signaling systems. They are characterized by both figurative impressions and speculative conclusions. 3. Relationship between types of GNI and the temperament and character of children
The main distinguishing feature of higher nervous activity in children is the fact of dynamic development and plasticity of its system itself. Despite the fact that the higher nervous activity of a child is extremely similar to the higher nervous activity and its types in an adult, we must not forget that, unlike an adult, the child’s psyche is not fully formed and the properties of the higher nervous activity, which subsequently form its types, are extremely depend on the age characteristics of the child. Thus, preschool children are characterized by weakness of the processes of excitation and inhibition and their imbalance towards the predominance of excitation, regardless of the type of their higher nervous activity. In this regard, in preschool children, a strong type of nervous system will also be characterized by weakness of nervous processes, but the degree of its severity will be less compared to a weak type, in other words, there is a kind of “overlap” of age-related characteristics of higher nervous activity with its typological properties. The basic properties of the nervous system reach their normal level, limited by the type of nervous system, only at the time of its full maturation, i.e. by 20-22 years. Academician N.I. Krasnogorsky concretized Pavlov's teaching about the types of higher nervous activity in relation to childhood. Children are sanguine. Strong, balanced, optimally excitable fast type. It is characterized by the rapid formation of unconditioned reflexes, the strength of these reflexes is significant. Such children have equally well expressed mental and emotional reactions. They are able to control their emotions and subordinate them to the requirements of the appropriate environment. Children of this type are capable of developing subtle differentiations. Their unconditioned reflex activity is regulated by a functionally strong cortex. The speech of sanguine people is well developed, loud, fast, correctly constructed, rich. Children adapt well to the school environment, cope successfully with school workloads, and are emotional in their behavior. Typical traits of sanguine children: cheerfulness, optimism, faith in one’s own strengths and capabilities, a critical attitude towards the shortcomings of others and one’s own. However, such children often overestimate their physical and intellectual capabilities. Children are phlegmatic. Strong, balanced, slow type. Conditioned connections are formed more slowly, extinct reflexes are also restored slowly. Children of this type are characterized by cortical control over unconditioned reflexes and emotions. They quickly learn to speak, are active and persistent when performing complex tasks. Rational activity clearly prevails over the emotional sphere. They control well, and, if necessary, suppress their emotions and desires, adapt to conditions without complications school life. Phlegmatic people behave smoothly, calmly, their speech is leisurely, measured, and is usually not accompanied by gestures. In a team, these guys are disciplined, restrained in relation to their own shortcomings and the shortcomings of others, calmly react to censure or approval of their actions, avoid conflicts, and are prone to solitude. To amuse or frighten a phlegmatic person, you need very strong stimuli and their rather long-term impact. Children are choleric. Strong, unbalanced, highly excitable, unrestrained type. It is characterized by insufficiency of the inhibitory process, strongly expressed subcortical activity, which is not always controlled at times. Conditioned reflexes in such children quickly fade, and the resulting differentiations are not stable. Speech in children of this type is rapid, with occasional shouting. Children with this temperament are characterized by pronounced emotional excitability and rapid mood swings. They weakly restrain their desires and emotions, their actions are often characterized by outbursts of excitement, sometimes aggressiveness. Cholerics do not always adapt to school life right away, as they are prone to conflicts with others, show intemperance in lessons, short temper, and impatience in response to the teacher’s comments. Such children are guided in their behavior more by feelings, desires and less by reason. They are inclined to study music, and react vividly to poetry and visual arts. In children with choleric temperament, vegetative reactions are exacerbated; with any emotional arousal, they easily turn pale or red. From birth, they have poorly developed inhibitory processes in the cerebral cortex, so it is difficult for them to overcome life's obstacles. If such a child’s desires do not coincide with the possibilities of their fulfillment, negativism and nervousness appear in his behavior. To the choleric type (extreme in its severity) N.I. Krasnogorsky referred to the so-called difficult-to-educate children, whose behavior constantly shows indiscipline, unbridledness, a desire to enter into conflicts with adults and peers, and simplified thinking. Raising them requires a purely individual approach and is not an easy task. However, most children with choleric temperament respond very well to educational influences if they are built on the right pedagogical basis, taking into account the characteristics of their temperament. Children are melancholic. Weak type with reduced excitability. Conditioned reflexes are formed slowly, unstable, speech is often slow. Easily braked type. Characteristic is the weakness of internal inhibition with strongly pronounced external inhibition, which explains the difficulty of children getting used to new learning conditions and their changes. In melancholic children, the cortical and subcortical functions of the nervous system are weakened, and low mobility of nervous processes is observed. In other words, their thinking capabilities and emotional sphere are easily depleted. Melancholic children have difficulty adapting to the school environment; many of them are reluctant to attend school. If they are not raised correctly, they can easily develop neurotic conditions or diseases. It is in such children that one can observe inadequate reactions to positive influences: a new toy can first cause a negative attitude (crying, not wanting to play with it) and only later a normal positive reaction. The four main types of higher nervous activity of a child are the basis of the future character. Character is stable personality traits that are manifested in actions. The actions of young children are random, depend on circumstances and do not yet convey character traits. As we have already noted, a child’s character develops with age, which determines his behavior. Character traits express a person’s attitude towards people (collectivism, responsiveness, kindness, sociability, etc.), towards work (hard work, accuracy, initiative, frugality, etc.), towards himself (pride, self-esteem, self-criticism , modesty, conceit, selfishness, etc.). The type of higher nervous activity and character mutually influence each other, so some character traits develop quickly (for example, sociability in sanguine people), others slowly (for example, sociability in melancholic people), etc. Sometimes parents raise their children the same way, no matter how many there are. And then they are surprised that they grew up completely different. This is precisely the mistake parents make when they raise three children with different types of nervous activity in the same way. The most important thing is missing here - an individual approach, without which it is impossible to reveal best sides the child’s nature and on this basis form positive personality traits. Significant differences in the basic properties of nervous processes in children related to different types, determine their different functional capabilities in the process of training and education. The effectiveness of pedagogical influences is also largely determined by an individual approach to students, taking into account their typological characteristics. At the same time, we have already pointed out that one of the distinctive features types of higher nervous activity in humans is their plasticity. The plasticity of the cells of the cerebral cortex, their adaptability to changing environmental conditions is the morphofunctional basis for type transformation. Since the plasticity of nervous structures is especially great during the period of their intensive development, pedagogical influences that correct typological features are especially important to apply in childhood. I.P. Palov considered the plasticity of types to be the most important feature that allows one to educate, train and remake the character of people. Conclusion
Now, thanks to everything described above, we can conclude that Pavlov, in his works regarding higher nervous activity of a person and the classification of its types, made a serious step forward in the field of physiology, comparing the temperament and characteristics of the human nervous system, highlighting the properties of higher nervous activity, giving names to all of this. It allowed us to delve deeper into the study of the processes of physiology of the brain and nervous system. We also looked at various types of GNI, specifically taking into account the works of Hippocrates and N.I. Pavlov, since these types dominate in our time. The work revealed a strong connection between these two classifications. We also examined the distinctive features of a child’s GNI, revealing the main problem in classifying its types in children is the flexibility and instability of the nervous system due to age-related characteristics. However, despite this N.I. Krasnogorsky, relying on the reflex, speech and general mental reactions of the child, according to his age, was able to give a complete classification of the types of GNI of the child, outwardly, as already mentioned, similar to Pavlov’s classification. Next, the connections between the child’s GNI types, his character and temperament were described. References
1.Batuev A.S. Higher nervous activity. L.: graduate School, 1991. - 256 p. 2.Voronin L.G. Physiology of higher nervous activity. M.: Higher School, 1979. - 312 p. 3.Danilova N.N., Krylova A.L. Physiology of higher nervous activity. Rostov n/a, Phoenix publishing house, 2005. - 478 p. .Nemov R.S. Psychology: Textbook for students of higher pedagogical educational institutions: M.: Humanite. ed. VLADOS center, 3rd ed., 1997. - Book 1. General fundamentals of psychology. - 688 p. .Stolyarenko A.M. Physiology of higher nervous activity. Textbook for psychologists and teachers, M.: UNITI-DANA, 2009. - 463 p. .Stupina S.B., Filipiechev A.O. Physiology of higher nervous activity and sensory systems. Moscow, Higher Education, 2006. .Shulgovsky V.V. Physiology of higher nervous activity with the basics of neurobiology. Academy, 2003. - 464 p.
The concept of the type of higher nervous activity. Conditioned reflex activity depends on the individual properties of the nervous system. The individual properties of the nervous system are determined by the hereditary characteristics of the individual and his life experience. The combination of these properties is called the type of higher nervous activity.
Properties of nervous processes. I.P. Pavlov, based on many years of studying the characteristics of the formation and course of conditioned reflexes in animals, identified 4 main types of higher nervous activity. He based the division into types on three main indicators:
1)
force processes of excitation and inhibition;
2)
balance, etc. e. the ratio of the strength of the processes of excitation and inhibition;
3)
mobility processes of excitation and inhibition, i.e. the speed with which excitation can be replaced by inhibition, and vice versa.
Classification of types of higher nervous activity. Based on the manifestation of these three properties, I. P. Pavlov identified:
1)
the type is strong, but unbalanced, with a predominance of excitation over inhibition (“uncontrollable” type);
2)
the type is strong, balanced, with great mobility of nervous processes (“living”, mobile type);
3)
the type is strong, balanced, with low mobility of nervous processes (“calm”, sedentary, inert type);
4)
weak type with rapid depletion of nerve cells, leading to loss of performance.
I. P. Pavlov believed that the main types of higher nervous activity found in animals coincide with the four temperaments established in people by the Greek physician Hippocrates, who lived in the 4th century BC. e. The weak type corresponds to a melancholic temperament; strong unbalanced type - choleric temperament; strong, balanced, active type - sanguine temperament; strong, balanced, with low mobility of nervous processes - phlegmatic temperament.
However, it should be borne in mind that the hemispheres of the human brain, as a social being, have more advanced synthetic activity than those of animals. A person is characterized by a qualitatively special nervous activity associated with the presence of his speech function.
Depending on the interaction and balance of signaling systems, I. P. Pavlov, along with four types common to humans and animals, specially identified human types higher nervous activity:
1.
Artistic type. Characterized by the predominance of the first signaling system over the second. This type includes people who directly perceive reality, widely use sensory images, and are characterized by figurative, objective thinking.
2.
Thinking type. These are people with a predominance of the second signaling system, “thinkers”, with a pronounced ability for abstract thinking.
3.
Most people are of the average type with balanced activity of two signaling systems. They are characterized by both figurative impressions and speculative conclusions.
Plasticity of types of higher nervous activity. The innate properties of the nervous system are not immutable. They can change to one degree or another under the influence of upbringing due to the plasticity of the nervous system. The type of higher nervous activity consists of the interaction of the inherited properties of the nervous system and the influences that an individual experiences during life.
IP Pavlov called the plasticity of the nervous system the most important pedagogical factor. The strength and mobility of nervous processes can be trained, and children of the unbalanced type, under the influence of upbringing, can acquire traits that bring them closer to representatives of the balanced type. Prolonged overexertion of the inhibitory process in children of a weak type can lead to a “breakdown” of higher nervous activity and the emergence of neuroses. Such children have difficulty getting used to the new work schedule and need special attention.
Age characteristics conditioned reflexes. Types of higher nervous activity of a child. Adaptive reactions of a newborn child to external influences are ensured by orienting reflexes. Conditioned reflexes during the neonatal period are very limited in nature and are developed only in response to vital stimuli. Already In the first days of a child’s life, one can note the formation of a natural conditioned reflex during feeding, which is expressed in the awakening of children and increased motor activity. Sucking movements of the lips appear before the nipple is inserted into the mouth. It is clear that such a reflex manifests itself only with a strict feeding regime for children. With a strict feeding regimen on the 6th-7th day, infants experience a conditioned reflex increase in the number of leukocytes already 30 minutes before feeding, and their gas exchange increases before meals. By the end of the second week, a conditioned reflex appears in the form of sucking movements when the baby is positioned for feeding. Here the signal is a complex of stimuli acting from receptors of the skin, motor and vestibular apparatus, constantly combined with food reinforcement.
From the middle of the first month of life, conditioned reflexes arise to various primary signal stimuli: light, sound, olfactory stimulation.
The rate of formation of conditioned reflexes in the first month of life is very low and increases rapidly with age. Thus, a protective reflex to light occurs only after 200 combinations, if its development began on the 15th day after birth, and less than 40 combinations are required if the development of the same reflex began in a one and a half month old child. From the first days of a child’s life, unconditional (external) inhibition appears. The baby stops sucking if a sharp sound is suddenly heard. Conditioned (internal) inhibition is developed later. Its appearance and strengthening are determined by the maturation of the nervous elements of the cerebral cortex. The first manifestations of differentiation of motor conditioned reflexes are noted by the 20th day of life, when the child begins to differentiate the feeding position from the changing procedure. A clear differentiation of visual and auditory conditioned stimuli is observed at 3-4 months. Other types of internal inhibition are formed later than differentiation. Thus, the development of delayed inhibition becomes possible from the age of 5 months (M. M. Koltsova).
The development of internal inhibition in a child is an important factor in education. In the first year of life, it is advisable to cultivate inhibition, attracting facial expressions and gestures that characterize the negative attitude of adults, or stimuli that distract the child’s attention, i.e., they are an external inhibitor. For the proper development of a child in the first year of life, a strict regime is very important - a certain sequence of alternating sleep, wakefulness, feeding, and walks. This is determined by the significance of the stereotype of interoceptive conditioned reflexes at this age. By the end of the first year, complexes of external exteroceptive stimuli that characterize the situation as a whole become important. The word becomes one of the important components of the complex of stimuli.
The first signs of the development of the second signaling system appear in the child in the second half of the first year of life. During the development of a child, the sensory mechanisms of speech, which determine the possibility of perceiving a word, are formed earlier than the motor ones, with which the ability to speak is associated. The period of formation of the function is especially sensitive to formative influences, so you need to talk with the child from the first days of his life. When caring for a child, you need to name all your actions, name the surrounding objects. This is very important, since in order to form connections of the second signal system, it is necessary to combine the verbal designation of objects, phenomena, surrounding people with their specific image - to combine primary-signal irritations with secondary-signal stimuli.
By the end of the first year of life, the word becomes a significant irritant. However, during this period, children’s reaction to a word does not have an independent meaning; it is determined by a complex of stimuli, and only later does the word acquire the meaning of an independent signal (M. M. Koltsova). During the first year of life, the child actively trains in pronunciation first individual sounds, then syllables and finally words. The formation of speech function requires a certain maturity of the peripheral apparatus - the tongue, muscles of the larynx, lips, and their coordinated activity.
The mechanism of speech reproduction is associated with the complex coordinated work of the nerve centers of the cortex, the formation of certain connections between speech centers and motor areas. A close connection between speech function and motor activity has been shown, especially with finely coordinated movements of the fingers. By developing finely coordinated actions, you can accelerate the formation of speech skills.
A child’s speech develops especially intensively between the ages of 1 and 3 years. At this age, the child’s behavior is characterized by pronounced research activities. The child reaches out to each object, feels it, looks inside, tries to pick it up, and puts it in his mouth. At this age, injuries easily occur due to curiosity and lack of experience, and the frequency of acute infections increases due to the child’s increased contact with other children and his environment.
The conditioned reflex activity of children of this age changes significantly. In the second year of life, individual objects begin to be isolated from the generalized undifferentiated world surrounding the child as separate complexes of irritations. This is made possible by manipulating objects. Therefore, you should not limit the movements of children: let them dress, wash, and eat themselves.
Thanks to actions with objects, children begin to develop a generalization function. Extensive use of objects develops a child’s motor analyzer.
In the second year of life, the child develops large number conditioned reflexes to the relationship between the size, severity, and distance of objects (identification of faster and slower stimuli, larger or smaller in comparison with others). Of particular importance is the development of systems of conditioned connections to stereotypes of exteroceptive stimulation. In early childhood, dynamic stereotypes are especially important. With insufficient strength and mobility of nervous processes, stereotypes facilitate children’s adaptation to the environment; they are the basis for the formation of habits and skills. Noteworthy is the great strength of the system of conditioned connections developed in children under 3 years of age, and the associated pain due to the violation of the stereotype: children are capricious, cry if you stay with them for a long time; They do not fall asleep for a long time if they are placed in a new place. For children under the age of 3, the development of a large number of different stereotypes not only does not present difficulties, but each subsequent stereotype is developed more and more easily. However, changing the order of stimuli in one stereotype is an extremely difficult task. Systems of conditioned connections developed at this time retain their significance throughout the subsequent life of a person, therefore the formation of stereotypes that are appropriate for health and have educational value, is especially important at this age.
In the second year, increased development of speech begins, the child’s assimilation of the grammatical structure of the language, with a major role played by imitative reflex. An adult, when communicating with a child, must pay special attention to the correctness of his speech.
At this stage of development, mastery of actions with objects has decisive influence and on the formation of generalization of objects with words, i.e. the formation of a second signaling system.
In the process of child development in the development of new reactions, everything higher value acquires the use of previously formed connections. Systems of conditional connections developed in the early and to school age(up to 5 years), are especially durable and retain their value throughout life. This fact is important for teaching practice. The habits and skills developed at this age, which arose on the basis of strong conditioned reflex connections, largely determine a person’s behavior.
In preschool age, the role of the imitative and play reflex is very important. Children copy adults, their gestures, words, manners.
By the end of the preschool period, significant changes occur in the interaction of excitatory and inhibitory processes. As the cerebral cortex develops, the generalization of the excitatory process is gradually removed. Internal, conditioned inhibition is formed and becomes increasingly important. Differentiations are better developed, and periods of inhibition retention become longer. All this contributes to a more selective and adequate response of the child to external influences. At this age, the generalizing function of the word increases, the ability to generalize with words not only specific objects, but also many objects of the external world, categories of objects. So, the child begins to understand that a doll, a bear, a car are all toys, and toys, furniture, dishes, clothes are things. In older preschool age, the reflection of reality is already based on the development of complex systems of connections, including the interaction of the first and second signaling systems.
By the age of 6-7 years, reactivity to verbal stimuli improves. The nature of the interaction between the first and second signaling systems changes. In 3-4 year old children the first signaling system prevails and has an inhibitory effect on the second. At 6-7 years of age, the increasing activity of the second signaling system has an overwhelming effect on the first signaling system. The development of the second signaling system is one of the important indicators of a child’s readiness for school.
At primary school age, as the cerebral cortex progressively matures, the strength, balance and mobility of nervous processes improve. The development of cortical inhibition processes creates conditions for the rapid and differentiated formation of conditioned connections. The formation of connections in the higher parts of the central nervous system is facilitated by the intensive maturation at this age of intracortical associative pathways that unite various nerve centers. In the process of learning to write and read, the generalizing function of the word continues to develop intensively. The importance of the second signaling system is increasing.
Some changes in conditioned reflex activity are noted in adolescence. The onset of puberty is characterized by increased activity of the hypothalamus. This causes a change in the balance of cortical-subcortical interaction, resulting in an increase in generalized excitation and a weakening of internal inhibition. Compared to the previous one age group During adolescence, the formation of temporary connections becomes more difficult. The rate of formation of conditioned reflexes to both primary and secondary signal stimuli decreases. The peculiarities of the higher nervous activity of adolescents require an attentive attitude towards them and a thoughtful organization of the educational process.
Typological features of the child’s higher nervous activity. The formation of individual typological characteristics in the process of ontogenesis is determined by the gradual maturation of higher nerve centers. As will be shown below, during the development of a child, a change occurs in the relationship between the cerebral cortex and subcortical structures. This determines the characteristics of excitatory and inhibitory processes in childhood, and, consequently, the specificity of the manifestation of typological features.
N.I. Krasnogorsky, studying the higher nervous activity of a child on the basis of strength, balance, mobility of nervous processes, relationships between the cortex and subcortical formations, and the relationship between signaling systems, identified 4 types of nervous activity in childhood.
1.
Strong, balanced, optimally excitable, fast type. It is characterized by the rapid formation of conditioned reflexes, the strength of these reflexes is significant. Children of this type are capable of developing subtle differentiations. Their unconditioned reflex activity is regulated by a functionally strong cortex. Children of this type have well-developed speech with a rich vocabulary.
2.
Strong, balanced, slow type. In children of this type, conditioned connections are formed more slowly, and extinct reflexes are also restored slowly. Children of this type are characterized by pronounced control of the cortex over unconditioned reflexes and emotions. They quickly learn to speak, but their speech is somewhat slow. They are active and persistent when performing complex tasks.
3.
Strong, unbalanced, highly excitable, unrestrained type. It is characterized by insufficiency of the inhibitory process, strongly expressed subcortical activity, not always controlled by the cortex. Conditioned reflexes in such children quickly fade, and the resulting differentiations are unstable. Children of this type are characterized by high emotional excitability, temper, and affect. Speech in children of this type is rapid with occasional shouting.
4.
Weak type with reduced excitability. Conditioned reflexes are formed slowly, unstable, speech is often slow. Easy to brake type. Characteristic is the weakness of internal inhibition with strongly pronounced external inhibition, which explains the difficulty of children getting used to new learning conditions and their changes. Children of this type cannot tolerate strong and prolonged irritation and get tired easily.
Significant differences in the basic properties of nervous processes in children belonging to different types determine their different functional capabilities in the process of learning and upbringing. The effectiveness of pedagogical influences is largely determined by an individual approach to students, taking into account their typological characteristics. At the same time, we have already pointed out that one of the distinguishing features of the types of higher nervous activity in humans is their plasticity. The plasticity of the cells of the cerebral cortex, their adaptability to changing environmental conditions is the morphofunctional basis for type transformation. Since the plasticity of nervous structures is especially great during the period of their intensive development, pedagogical influences that correct typological features are especially important to apply in childhood. I. P. Pavlov considered the plasticity of types to be the most important feature that allows one to educate, train and remake the character of people.
Higher nervous activity is a set of unconditioned and conditioned reflexes, as well as higher mental functions that ensure adequate behavior in changing natural and social conditions. For the first time, the assumption about the reflex nature of the activity of the higher parts of the brain was made by I.M. Sechenov, which made it possible to extend the reflex principle to human mental activity. The ideas of I.M. Sechenov received experimental confirmation in the works of I.P. Pavlov, who developed a method for objective assessment of the functions of the higher parts of the brain - the method of conditioned reflexes.
I.P. Pavlov showed that all reflex reactions can be divided into two groups: unconditional and conditional.
CLASSIFICATION OF TYPES OF HIGHER NERVOUS ACTIVITY.
Unconditioned reflexes : 1. Congenital, hereditary reactions, most of them begin to function immediately after birth. 2. They are specific, i.e. characteristic of all representatives of this species. 3. Permanent and maintained throughout life. 4. Carried out by the lower parts of the central nervous system (subcortical nuclei, brain stem, spinal cord). 5. They arise in response to adequate stimulation acting on a specific receptive field.
Conditioned reflexes: 1. Reactions acquired in the process of individual life. 2. Individual. 3. Impermanent - they can appear and disappear. 4. They are primarily a function of the cerebral cortex. 5. Occurs in response to any stimuli acting on different receptive fields.
Unconditioned reflexes can be simple or complex. Complex innate unconditional reflex reactions are called instincts. Their characteristic feature is the chain nature of the reactions.
According to the teachings of I.P. Pavlov, individual behavioral characteristics and the dynamics of mental activity depend on individual differences in the activity of the nervous system. The basis of individual differences in nervous activity is the manifestation and correlation of the properties of two main nervous processes - excitation and inhibition.
Three properties of the processes of excitation and inhibition have been established:
1) the strength of the processes of excitation and inhibition,
2) balance of excitation and inhibition processes,
3) mobility (changeability) of the processes of excitation and inhibition.
Based on these basic features, I.P. Pavlov, as a result of his research using the method of conditioned reflexes, came to the definition of four main types of the nervous system.
Combinations of these properties of nervous processes of excitation and inhibition were used as the basis for determining the type of higher nervous activity. Depending on the combination of strength, mobility and balance of the processes of excitation and inhibition, four main types of higher nervous activity are distinguished. The classification of types of higher nervous activity is presented in Figure 1.
Weak type. Representatives of a weak type of nervous system cannot withstand strong, prolonged and concentrated stimuli, because their processes of inhibition and excitation are weak. When exposed to strong stimuli, the development of conditioned reflexes is delayed. Along with this, there is a high sensitivity (i.e., a low threshold) to the actions of stimuli.
Strong unbalanced type. Distinguished by a strong nervous system, it is characterized by an imbalance of the basic nervous processes - the predominance of excitation processes over inhibition processes.
Strong balanced mobile type. The processes of inhibition and excitation are strong and balanced, but their speed, mobility, and rapid turnover of nervous processes lead to relative instability of nerve connections.
Strong balanced inert type. Strong and balanced nervous processes are characterized by low mobility. Representatives of this type are always outwardly calm, even, and difficult to excite.
The type of higher nervous activity refers to natural higher data; this is an innate property of the nervous system, since the property of nervous processes is encoded in the gene of a typical human apparatus and is therefore inherited - passed on from parents to descendants. On this physiological basis, various systems of conditional connections can be formed, i.e., during the course of life, these conditional connections will be formed differently in different people, influencing the individual nature of behavior and activity. This is where the type of higher nervous activity will manifest itself.
The type of HNA (higher nervous activity) is the physiological foundation for the formation of temperament, which demonstrates the manifestation of the type of higher nervous activity in human activity and behavior.
Rice. 2. Scheme of types of GNI according to I.V. Pavlov.
Types of higher nervous activity and their relationship with temperament.
I.P. Pavlov proposed to distinguish human types of higher nervous activity based on the degree of development of the first and second signaling systems. He highlighted:
1. Artistic type, which is characterized by specific thinking, the predominance of the first signaling system, that is, sensory perception of reality. This type includes people with well-developed sensory perception, expressed affects on everything that happens. They are inclined to professions of the sensory-emotional circle. This type is often noted among actors, artists, and musicians. During a neurotic breakdown, people of the artistic type tend to give reactions of the hysterical circle.
2. Thinking type when abstraction from reality and abstract thinking are well expressed. This type includes individuals with well-developed abstract thinking and abstract concepts. They are inclined to study mathematics and theoretical sciences. With a neurotic breakdown, they are prone to a psychasthenic type of reaction.
3. Medium type when there is no predominance of one way of thinking or another. Pavlov believed that extreme types are rare, and most people belong to the average type, that is, this classification also does not reflect the entire variety of forms of human GNI.
Many scientists note that the significance of I.P. Pavlov’s work on the problem of temperaments lies primarily in elucidating the role of the properties of the nervous system as the primary and deepest parameters of the psychological organization of the individual.
Types of temperaments according to Hippocrates:
Melancholic- a person with a weak nervous system, who has increased sensitivity even to weak stimuli, and a strong stimulus can already cause a “breakdown”, “stopper”, confusion, “rabbit stress”, therefore in stressful situations (exams, competitions, danger, etc. .) the results of a melancholic person’s activity may worsen compared to a calm, familiar situation. Increased sensitivity leads to rapid fatigue and decreased performance (longer rest is required). A minor reason can cause resentment and tears. The mood is very changeable, but usually a melancholic person tries to hide, not show his feelings outwardly, does not talk about his experiences, although he is very inclined to give himself up to emotions, is often sad, depressed, unsure of himself, anxious, and may experience neurotic disorders. However, having a highly sensitive nervous system, they often have pronounced artistic and intellectual abilities.
Sanguine- a person with a strong, balanced, mobile nervous system, has a quick reaction speed, his actions are thoughtful, he is cheerful, due to which he is characterized by high resistance to the difficulties of life. The mobility of his nervous system determines the variability of feelings, attachments, interests, views, and high adaptability to new conditions. This is a sociable person, he easily gets along with new people and therefore he has wide circle acquaintances, although he is not distinguished by constancy in communication and affection. He is a productive worker, but only when there are a lot of interesting things to do, that is, with constant excitement, otherwise he becomes boring, lethargic, and distracted. In a stressful situation, he exhibits a “lion reaction,” i.e., he actively, thoughtfully defends himself and fights to normalize the situation.
Phlegmatic person- a person with a strong, balanced, but inert nervous system, as a result of which he reacts slowly, is taciturn, emotions appear slowly (it is difficult to anger or cheer); has a high performance capacity, resists strong and prolonged stimuli and difficulties well, but is not able to react quickly in unexpected new situations. He firmly remembers everything he has learned, is unable to give up acquired skills and stereotypes, does not like to change habits, routine, work, friends, and adapts to new conditions with difficulty and slowly. The mood is stable and even. In case of serious troubles, the phlegmatic person remains outwardly calm.
Choleric- this is a person whose nervous system is determined by the predominance of excitation over inhibition, as a result of which he reacts very quickly, often thoughtlessly, does not have time to slow down or restrain himself, shows impatience, impetuosity, abruptness of movements, hot temper, unbridledness, lack of restraint. The imbalance of his nervous system predetermines the cyclical change in his activity and vigor: having become carried away by some task, he works passionately with full dedication, but he does not have enough strength for long, and as soon as they are depleted, he works himself to the point that everything is unbearable for him. An irritated state appears Bad mood, loss of strength and lethargy (“everything falls out of hand”). The alternation of positive cycles of uplifting mood and energy with negative cycles of decline and depression causes uneven behavior and well-being, and an increased susceptibility to neurotic breakdowns and conflicts with people.
Each of the presented types of temperament in itself is neither good nor bad (if you do not connect temperament and character). Manifesting itself in the dynamic characteristics of the human psyche and behavior, each type of temperament can have advantages and disadvantages. People of sanguine temperament have a quick reaction, easily and quickly adapt to changing living conditions, have increased performance, especially in the initial period of work, but in the end they reduce performance due to rapid fatigue and loss of interest. On the contrary, those who are characterized by a melancholic type of temperament are distinguished by their slow entry into work, but also by greater endurance. Their performance is usually higher in the middle or towards the end of work, rather than at the beginning. In general, the productivity and quality of work of sanguine people and melancholic people are approximately the same, and the differences relate mainly only to the dynamics of work in different periods.
The choleric temperament has the advantage that it allows one to concentrate significant efforts in a short period of time. But when working for a long time, a person with such a temperament does not always have enough endurance. Phlegmatic people, on the contrary, are not able to quickly gather and concentrate their efforts, but in return they have the valuable ability to work long and hard to achieve their goal. The type of person’s temperament must be taken into account where the work makes special demands on the specified dynamic features of the activity.
Hippocrates' classification of temperaments refers to humoral theories. Later, this line was proposed by the German philosopher I. Kant, who also considered blood characteristics to be the natural basis of temperament.
The characteristics of a person’s mental activity, which determine his actions, behavior, habits, interests, knowledge, are formed in the process of a person’s individual life, in the process of upbringing. The type of higher nervous activity gives originality to a person’s behavior, leaves a characteristic imprint on the entire appearance of a person, i.e. determines the mobility of his mental processes, their stability, but does not determine the overall behavior, actions of a person, his beliefs, moral principles, since they form in the process of ontogenesis (individual development) on the basis of consciousness.
PROPERTIES OF THE NERVOUS SYSTEM.
The properties of the nervous processes underlying the types of GNI determine the properties of the nervous system. These are her stable qualities that are innate. These properties include:
1. The strength of the nervous system in relation to excitation, i.e. its ability to withstand intense and frequently repeated loads for a long time without detecting excessive braking.
2. The strength of the nervous system in relation to inhibition, i.e. ability to withstand prolonged and frequently repeated inhibitory influences.
3. Balance of the nervous system in relation to excitation and inhibition, which is manifested in the equal reactivity of the nervous system in response to excitatory and inhibitory influences.
4. Lability (mobility) of the nervous system, assessed by the speed of onset and cessation of the nervous process of excitation or inhibition.
The weakness of nervous processes is characterized by the inability of nerve cells to withstand prolonged and concentrated excitation and inhibition. When exposed to very strong stimuli, nerve cells quickly go into a state of protective inhibition. Thus, in a weak nervous system, nerve cells are characterized by low efficiency, their energy is quickly depleted. But a weak nervous system has great sensitivity: even to weak stimuli it gives an appropriate reaction.
Currently, differential psychology has developed a 12-dimensional classification of the properties of the human nervous system (V.D. Nebylitsyn). It includes 8 primary properties (strength, mobility, dynamism and lability in relation to excitation and inhibition) and four secondary properties (balance in these basic properties). It is shown that these properties can relate to the entire nervous system (its general properties) and to individual analyzers (partial properties).
Classification of the properties of the nervous system according to V.D. Nebylitsyn:
The strength of the nervous system is understood as endurance, the performance of nerve cells, resistance either to the long-term action of a stimulus that produces concentrated excitation, concentrated in the same nerve centers and accumulating in them, or to the short-term action of super-strong stimuli. The weaker the nervous system, the sooner the nerve centers enter a state of fatigue and protective inhibition;
The dynamism of the nervous system is the speed of formation of conditioned reflexes or the ability of the nervous system to learn in in a broad sense words. The main content of dynamism is the ease and speed with which nervous processes are generated in brain structures during the formation of excitatory and inhibitory conditioned reflexes;
Lability, a property of the nervous system associated with the speed of occurrence, course and termination of the nervous process;
The mobility of the nervous system, the speed of movement, the spread of nervous processes, their irradiation and concentration, as well as mutual transformation.
1. General, or systemic, properties that cover the entire human brain and characterize the dynamics of its work as a whole.
2. Complex properties, manifested in the peculiarities of the work of individual “blocks” of the brain (hemispheres, frontal lobes, analyzers, anatomically and functionally separated subcortical structures, etc.).
3. The simplest, or elementary, properties correlated with the work of individual neurons.
As B.M. wrote Teplev, the properties of the nervous system “form the soil on which some forms of behavior are easier to form, and others more difficult.”
For example, in monotonous work, the best results are shown by people with a weak type of nervous system, and when moving to work associated with large and unexpected loads, on the contrary, people with a strong nervous system.
A person’s complex of individual-typological properties of his nervous system primarily determines temperament, on which the individual style of activity further depends.
1. Innate forms of behavior (instincts and innate reflexes), their significance in the adaptive activity of the body.
Unconditioned reflexes- these are congenital reflexes, carried out along constant reflex arcs existing from birth. An example of an unconditioned reflex is the activity of the salivary gland during the act of eating, blinking when a speck enters the eye, defensive movements during painful stimuli, and many other reactions of this type. Unconditioned reflexes in humans and higher animals are carried out through the subcortical sections of the central nervous system (dorsal, medulla oblongata, midbrain, diencephalon and basal ganglia). At the same time, the center of any unconditioned reflex (UR) is connected by nerve connections with certain areas of the cortex, i.e. there is a so-called cortical representation of BR. Different BRs (food, defensive, sexual, etc.) can have different complexity. In particular, BR includes such complex innate forms of animal behavior as instincts.
BRs undoubtedly play a major role in the adaptation of the organism to the environment. Thus, the presence of innate reflex sucking movements in mammals provides them with the opportunity to feed on mother’s milk in the early stages of ontogenesis. The presence of innate protective reactions (blinking, coughing, sneezing, etc.) protects the body from foreign bodies entering the respiratory tract. Even more obvious is the exceptional importance for the life of animals of various kinds of innate instinctive reactions (building nests, burrows, shelters, caring for offspring, etc.).
It should be borne in mind that BRs are not absolutely constant, as some believe. Within certain limits, the nature of the innate, unconditioned reflex can change depending on the functional state of the reflex apparatus. For example, in a spinal frog, irritation of the skin of the foot can cause an unconditional reflex reaction of a different nature depending on the initial state of the irritated paw: when the paw is extended, this irritation causes it to flex, and when it is bent, it causes it to extend.
Unconditioned reflexes ensure adaptation of the body only under relatively constant conditions. Their variability is extremely limited. Therefore, to adapt to continuously and dramatically changing conditions of existence, unconditioned reflexes alone are not enough. This is confirmed by the often encountered cases when instinctive behavior, so striking in its “reasonableness” under normal conditions, not only does not provide adaptation in a dramatically changed situation, but even becomes completely meaningless.
For a more complete and subtle adaptation of the body to constantly changing living conditions, animals in the process of evolution have developed more advanced forms of interaction with the environment in the form of the so-called. conditioned reflexes.
2. The meaning of the teachings of I.P. Pavlova on higher nervous activity for medicine, philosophy and psychology.
1 - strong unbalanced
;
4 - weak type.
1. Animals with strong, unbalanced
People of this type (cholerics)
2. Dogs strong, balanced, mobile
People of this type ( sanguine people
3. For dogs
People of this type (phlegmatic
4. In dog behavior weak
melancholic people
1. Art
2. Thinking type
3. Medium type
3. Rules for the development of conditioned reflexes. Law of force. Classification of conditioned reflexes.
Conditioned reflexes are not innate, they are formed in the process of individual life of animals and humans on the basis of unconditional ones. A conditioned reflex is formed due to the emergence of a new nervous connection (temporary connection according to Pavlov) between the center of the unconditioned reflex and the center that perceives the accompanying conditioned stimulation. In humans and higher animals, these temporary connections are formed in the cerebral cortex, and in animals that do not have a cortex, in the corresponding higher parts of the central nervous system.
Unconditioned reflexes can be combined with a wide variety of changes in the external or internal environment of the body, and therefore, on the basis of one unconditioned reflex, many conditioned reflexes can be formed. This significantly expands the possibilities of adaptation of an animal organism to living conditions, since an adaptive reaction can be caused not only by those factors that directly cause changes in the functions of the body, and sometimes threaten its very life, but also by those that only signal the former. Thanks to this, the adaptive reaction occurs in advance.
Conditioned reflexes are characterized by extreme variability depending on the situation and the state of the nervous system.
So, in difficult conditions of interaction with the environment, the adaptive activity of the organism is carried out both by unconditional reflex and conditioned reflex ways, most often in the form of complex systems of conditioned and unconditioned reflexes. Consequently, the higher nervous activity of humans and animals represents an inextricable unity of innate and individually acquired forms of adaptation, and is the result of the joint activity of the cerebral cortex and subcortical formations. However, the leading role in this activity belongs to the cortex.
A conditioned reflex in animals or humans can be developed on the basis of any unconditioned reflex, subject to the following basic rules (conditions). Actually, this type of reflexes was called “conditional”, since it requires certain conditions for its formation.
1. It is necessary to coincide in time (combination) of two stimuli - unconditional and some indifferent (conditional).
2. It is necessary that the action of the conditioned stimulus somewhat precede the action of the unconditioned.
3. The conditioned stimulus must be physiologically weaker compared to the unconditioned one, and possibly more indifferent, i.e. not causing a significant reaction.
4. A normal, active state of the higher parts of the central nervous system is necessary.
5. During the formation of a conditioned reflex (CR), the cerebral cortex should be free from other types of activity. In other words, during the development of the UR, the animal must be protected from the action of extraneous stimuli.
6. A more or less long-term (depending on the evolutionary advancement of the animal) repetition of such combinations of a conditioned signal and an unconditioned stimulus is necessary.
If these rules are not observed, SDs are not formed at all, or are formed with difficulty and quickly fade away.
To produce UR in various animals and humans, various techniques(registration of salivation is a classic Pavlovian technique, registration of motor-defensive reactions, food-procuring reflexes, labyrinth methods, etc.). The mechanism of formation of a conditioned reflex. A conditioned reflex is formed when a BR is combined with an indifferent stimulus.
The simultaneous excitation of two points of the central nervous system ultimately leads to the emergence of a temporary connection between them, due to which an indifferent stimulus, previously never associated with a combined unconditioned reflex, acquires the ability to cause this reflex (becomes a conditioned stimulus). Thus, the physiological mechanism of UR formation is based on the process of closing a temporary connection.
The process of formation of the UR is a complex act, characterized by certain sequential changes in the functional relationships between the cortical and subcortical nervous structures participating in this process.
At the very beginning of combinations of indifferent and unconditioned stimuli, an indicative reaction occurs in the animal under the influence of the factor of novelty. This innate, unconditioned reaction is expressed in the inhibition of general motor activity, in the rotation of the torso, head and eyes towards stimuli, in the pricking of the ears, olfactory movements, as well as in changes in breathing and cardiac activity. It plays a significant role in the process of formation of the UR, increasing the activity of cortical cells due to the tonic influences of the subcortical formations (in particular, the reticular formation). Maintaining the required level of excitability in cortical points that perceive conditioned and unconditioned stimuli creates favorable conditions for closing the connection between these points. A gradual increase in excitability in these zones is observed from the very beginning of the development of Ur. And when it reaches a certain level, reactions to the conditioned stimulus begin to appear.
In the formation of UR, the emotional state of the animal caused by the action of stimuli is of no small importance. The emotional tone of the sensation (pain, disgust, pleasure, etc.) immediately determines the most general assessment of the operating factors - whether they are useful or harmful, and immediately activate the corresponding compensatory mechanisms, contributing to the urgent formation of an adaptive reaction.
The appearance of the first reactions to a conditioned stimulus marks only the initial stage of the formation of the UR. At this time, it is still fragile (it does not appear for every application of a conditioned signal) and is of a generalized, generalized nature (a reaction is caused not only by a specific conditioned signal, but also by stimuli similar to it). Simplification and specialization of SD occurs only after additional combinations.
In the process of developing the SD, its relationship with the indicative reaction changes. Sharply expressed at the beginning of development of the SD, as the SD becomes stronger, the indicative reaction weakens and disappears.
Based on the relationship of the conditioned stimulus to the reaction it signals, natural and artificial conditioned reflexes are distinguished.
Natural called conditioned reflexes, which are formed in response to stimuli that are natural, necessarily accompanying signs, properties of the unconditional stimulus on the basis of which they are produced (for example, the smell of meat when feeding it). Natural conditioned reflexes, compared to artificial ones, are easier to form and more durable.
Artificial called conditioned reflexes, formed in response to stimuli that are usually not directly related to the unconditioned stimulus that reinforces them (for example, a light stimulus reinforced by food).
Depending on the nature of the receptor structures on which conditioned stimuli act, exteroceptive, interoceptive and proprioceptive conditioned reflexes are distinguished.
Exteroceptive conditioned reflexes, formed in response to stimuli perceived by the external external receptors of the body, constitute the bulk of conditioned reflex reactions that ensure adaptive (adaptive) behavior of animals and humans in conditions of a changing external environment.
Interoceptive conditioned reflexes, produced in response to physical and chemical stimulation of interoreceptors, provide physiological processes of homeostatic regulation of the function of internal organs.
Proprioceptive conditioned reflexes, formed by irritation of the own receptors of the striated muscles of the trunk and limbs, form the basis of all motor skills of animals and humans.
Depending on the structure of the used conditioned stimulus, simple and complex (complex) conditioned reflexes are distinguished.
In case simple conditioned reflex a simple stimulus (light, sound, etc.) is used as a conditioned stimulus. In real conditions of the functioning of the body, as a rule, the conditioned signals are not individual, single stimuli, but their temporal and spatial complexes.
In this case, either the entire environment surrounding the animal or parts of it in the form of a complex of signals acts as a conditioned stimulus.
One of the varieties of such a complex conditioned reflex is stereotypical conditioned reflex, formed for a certain temporal or spatial “pattern”, a complex of stimuli.
There are also conditioned reflexes produced to simultaneous and sequential complexes of stimuli, to a sequential chain of conditioned stimuli separated by a certain time interval.
Trace conditioned reflexes are formed in the case when an unconditioned reinforcing stimulus is presented only after the end of the conditioned stimulus.
Finally, conditioned reflexes of the first, second, third, etc. order are distinguished. If a conditioned stimulus (light) is reinforced by an unconditioned stimulus (food), a conditioned reflex of the first order. Conditioned reflex of the second order is formed if a conditioned stimulus (for example, light) is reinforced not by an unconditioned, but by a conditioned stimulus to which a conditioned reflex was previously formed. Conditioned reflexes of the second and more complex order are more difficult to form and are less durable.
Conditioned reflexes of the second and higher order include conditioned reflexes produced in response to a verbal signal (the word here represents a signal to which a conditioned reflex was previously formed when reinforced by an unconditioned stimulus).
4. Conditioned reflexes are a factor in the body’s adaptation to changing conditions of existence. Methodology for the formation of a conditioned reflex. Differences between conditioned reflexes and unconditioned ones. Principles of the theory of I.P. Pavlova.
One of the main elementary acts of higher nervous activity is the conditioned reflex. The biological significance of conditioned reflexes lies in a sharp expansion in the number of signal stimuli that are significant for the body, which ensures an incomparably higher level of adaptive behavior.
The conditioned reflex mechanism underlies the formation of any acquired skill, the basis of the learning process. The structural and functional basis of the conditioned reflex is the cortex and subcortical formations of the brain.
The essence of the conditioned reflex activity of the body comes down to the transformation of an indifferent stimulus into a signal, meaningful one, due to the repeated reinforcement of the irritation with an unconditioned stimulus. Due to the reinforcement of a conditioned stimulus by an unconditioned stimulus, a previously indifferent stimulus is associated in the life of the organism with a biological important event and thereby signals the onset of this event. In this case, any innervated organ can act as an effector link in the reflex arc of a conditioned reflex. There is no organ in the human or animal body whose functioning could not change under the influence of a conditioned reflex. Any function of the body as a whole or of its individual physiological systems can be modified (strengthened or suppressed) as a result of the formation of a corresponding conditioned reflex.
In the zone of the cortical representation of the conditioned stimulus and the cortical (or subcortical) representation of the unconditioned stimulus, two foci of excitation are formed. The focus of excitation caused by an unconditional stimulus of the external or internal environment of the body, as a stronger (dominant) one, attracts to itself excitation from the focus of weaker excitation caused by the conditioned stimulus. After several repeated presentations of the conditioned and unconditioned stimuli, a stable path of excitation movement is “trodden” between these two zones: from the focus caused by the conditioned stimulus to the focus caused by the unconditioned stimulus. As a result, the isolated presentation of only the conditioned stimulus now leads to the response caused by the previously unconditioned stimulus.
The main cellular elements of the central mechanism for the formation of a conditioned reflex are intercalary and associative neurons of the cortex big brain.
For the formation of a conditioned reflex, the following rules must be observed: 1) an indifferent stimulus (which must become a conditioned, signal) must have sufficient strength to excite certain receptors; 2) it is necessary that the indifferent stimulus be reinforced by an unconditioned stimulus, and the indifferent stimulus must either slightly precede or be presented simultaneously with the unconditioned one; 3) it is necessary that the stimulus used as a conditional stimulus be weaker than the unconditional one. To develop a conditioned reflex, it is also necessary to have a normal physiological state of the cortical and subcortical structures that form the central representation of the corresponding conditioned and unconditioned stimuli, the absence of strong extraneous stimuli, and the absence of significant pathological processes in the body.
If the specified conditions are met, a conditioned reflex can be developed to almost any stimulus.
I. P. Pavlov, the author of the doctrine of conditioned reflexes as the basis of higher nervous activity, initially assumed that the conditioned reflex is formed at the level of the cortex - subcortical formations (a temporary connection is made between the cortical neurons in the zone of representation of the indifferent conditioned stimulus and the subcortical nerve cells that make up the central representation unconditional stimulus). In more later works IP Pavlov explained the formation of a conditioned reflex connection by the formation of a connection at the level of the cortical zones of the representation of conditioned and unconditioned stimuli.
Subsequent neurophysiological studies led to the development, experimental and theoretical substantiation of several different hypotheses about the formation of a conditioned reflex. Data from modern neurophysiology indicate the possibility different levels closure, the formation of a conditioned reflex connection (cortex - cortex, cortex - subcortical formations, subcortical formations - subcortical formations) with a dominant role in this process of cortical structures. Obviously, the physiological mechanism for the formation of a conditioned reflex is a complex dynamic organization of cortical and subcortical structures of the brain (L. G. Voronin, E. A. Asratyan, P. K. Anokhin, A. B. Kogan).
Despite certain individual differences, conditioned reflexes are characterized by the following general properties (features):
1. All conditioned reflexes represent one of the forms of adaptive reactions of the body to changing environmental conditions.
2. Conditioned reflexes belong to the category of reflex reactions acquired during individual life and are distinguished by individual specificity.
3. All types of conditioned reflex activity are of a warning signal nature.
4. Conditioned reflex reactions are formed on the basis of unconditioned reflexes; Without reinforcement, conditioned reflexes are weakened and suppressed over time.
5. Active forms of learning. Instrumental reflexes.
6. Stages of formation of conditioned reflexes (generalization, directed irradiation and concentration).
In the formation and strengthening of a conditioned reflex, two stages are distinguished: the initial stage (generalization of conditioned excitation) and the final stage of a strengthened conditioned reflex (concentration of conditioned excitation).
Initial stage of generalized conditioned excitation in essence, it is a continuation of a more general universal reaction of the body to any new stimulus, represented by an unconditioned orienting reflex. The orienting reflex is a generalized multicomponent complex reaction of the body to a fairly strong external stimulus, covering many of its physiological systems, including autonomic ones. The biological significance of the orienting reflex lies in the mobilization of the functional systems of the body for better perception of the stimulus, i.e. the orienting reflex is adaptive (adaptive) in nature. An externally indicative reaction, called by I.P. Pavlov the “what is this?” reflex, manifests itself in the animal in alertness, listening, sniffing, turning the eyes and head towards the stimulus. This reaction is the result of a wide spread of the excitatory process from the source of initial excitation caused by the active agent to the surrounding central nervous structures. The orienting reflex, unlike other unconditioned reflexes, is quickly inhibited and suppressed with repeated application of the stimulus.
The initial stage of the formation of a conditioned reflex consists of the formation of a temporary connection not only to this specific conditioned stimulus, but also to all stimuli related to it in nature. The neurophysiological mechanism is irradiation of excitation from the center of the projection of the conditioned stimulus onto the nerve cells of the surrounding projection zones, which are functionally close to the cells of the central representation of the conditioned stimulus to which the conditioned reflex is formed. The farther from the initial initial focus caused by the main stimulus, reinforced by the unconditioned stimulus, the zone covered by the irradiation of excitation is located, the less likely it is to activate this zone. Therefore, at the initial stages of generalization of conditioned excitation, characterized by a generalized generalized reaction, a conditioned reflex response is observed to similar, close in meaning stimuli as a result of the spread of excitation from the projection zone of the main conditioned stimulus.
As the conditioned reflex strengthens, the processes of excitation irradiation are replaced by concentration processes, limiting the focus of excitation only to the zone of representation of the main stimulus. As a result, clarification and specialization of the conditioned reflex occurs. At the final stage of a strengthened conditioned reflex, concentration of conditioned excitation: a conditioned reflex reaction is observed only to a given stimulus; to secondary stimuli that are close in meaning, it stops. At the stage of concentration of conditioned excitation, the excitatory process is localized only in the zone of the central representation of the conditioned stimulus (a reaction is realized only to the main stimulus), accompanied by inhibition of the reaction to side stimuli. The external manifestation of this stage is the differentiation of the parameters of the current conditioned stimulus - the specialization of the conditioned reflex.
7. Inhibition in the cerebral cortex. Types of inhibition: unconditional (external) and conditional (internal).
The formation of a conditioned reflex is based on the processes of interaction of excitations in the cerebral cortex. However, for the successful completion of the process of closing a temporary connection, it is necessary not only to activate the neurons involved in this process, but also to suppress the activity of those cortical and subcortical formations that interfere with this process. Such inhibition is carried out due to the participation of the inhibition process.
In its external manifestation, inhibition is the opposite of excitation. When it occurs, a weakening or cessation of neuronal activity is observed, or possible excitation is prevented.
Cortical inhibition is usually divided into unconditional and conditional, acquired. Unconditional forms of inhibition include external, arising in the center as a result of its interaction with other active centers of the cortex or subcortex, and transcendental, which occurs in cortical cells with excessively strong irritations. These types (forms) of inhibition are congenital and appear already in newborns.
8. Unconditional (external) inhibition. Fading and constant brake.
External unconditional inhibition manifests itself in the weakening or cessation of conditioned reflex reactions under the influence of any extraneous stimuli. If you call the dog's UR and then apply a strong foreign irritant (pain, smell), then the salivation that has begun will stop. Unconditioned reflexes are also inhibited (Türk’s reflex in a frog when pinching the second paw).
Cases of external inhibition of conditioned reflex activity occur at every step and in the natural life of animals and humans. This includes a constantly observed decrease in activity and hesitancy to act in a new, unusual environment, a decrease in the effect or even the complete impossibility of activity in the presence of extraneous stimuli (noise, pain, hunger, etc.).
External inhibition of conditioned reflex activity is associated with the appearance of a reaction to an extraneous stimulus. It comes the easier and is more powerful, the stronger the extraneous stimulus and the less strong the conditioned reflex. External inhibition of the conditioned reflex occurs immediately upon the first application of an extraneous stimulus. Consequently, the ability of cortical cells to fall into a state of external inhibition is an innate property of the nervous system. This is one of the manifestations of the so-called. negative induction.
9. Conditioned (internal) inhibition, its significance (limitation of conditioned reflex activity, differentiation, timing, protective). Types of conditioned inhibition, features in children.
Conditioned (internal) inhibition develops in cortical cells under certain conditions under the influence of the same stimuli that previously caused conditioned reflex reactions. In this case, braking does not occur immediately, but after more or less long-term development. Internal inhibition, like a conditioned reflex, occurs after a series of combinations of a conditioned stimulus with the action of a certain inhibitory factor. Such a factor is the abolition of unconditional reinforcement, a change in its nature, etc. Depending on the condition of occurrence, the following types of conditioned inhibition are distinguished: extinction, delayed, differentiation and signaling (“conditioned inhibition”).
Extinction inhibition develops when the conditioned stimulus is not reinforced. It is not associated with fatigue of the cortical cells, since an equally long repetition of a conditioned reflex with reinforcement does not lead to a weakening of the conditioned reaction. Extinctional inhibition develops the easier and faster the less strong the conditioned reflex and the weaker the unconditioned reflex on the basis of which it was developed. Extinction inhibition develops the faster the shorter the interval between conditioned stimuli repeated without reinforcement. Extraneous stimuli cause a temporary weakening and even complete cessation of extinctive inhibition, i.e. temporary restoration of an extinguished reflex (disinhibition). The developed extinction inhibition causes depression of other conditioned reflexes, weak ones and those whose centers are located close to the center of the primary extinction reflexes (this phenomenon is called secondary extinction).
An extinguished conditioned reflex recovers on its own after some time, i.e. extinctive inhibition disappears. This proves that extinction is associated precisely with temporary inhibition, not with a break in the temporary connection. An extinguished conditioned reflex is restored the faster, the stronger it is and the weaker it was inhibited. Repeated extinction of the conditioned reflex occurs faster.
The development of extinction inhibition is of great biological importance, because it helps animals and humans to free themselves from previously acquired conditioned reflexes that have become useless in new, changed conditions.
Delayed braking develops in cortical cells when reinforcement lags in time from the onset of the conditioned stimulus. Externally, this inhibition is expressed in the absence of a conditioned reflex reaction at the beginning of the action of the conditioned stimulus and its appearance after some delay (delay), and the time of this delay corresponds to the duration of the isolated action of the conditioned stimulus. Delayed inhibition develops the faster, the smaller the lag of reinforcement from the onset of the conditioned signal. With continuous action of the conditioned stimulus, it develops faster than with intermittent action.
Extraneous stimuli cause temporary disinhibition of delayed inhibition. Thanks to its development, the conditioned reflex becomes more accurate, timing it to the right moment with a distant conditioned signal. This is its great biological significance.
Differential braking develops in cortical cells under the intermittent action of a constantly reinforced conditioned stimulus and non-reinforced stimuli similar to it.
The newly formed SD usually has a generalized, generalized character, i.e. is caused not only by a specific conditioned stimulus (for example, a 50 Hz tone), but by numerous similar stimuli addressed to the same analyzer (tones of 10-100 Hz). However, if in the future only sounds with a frequency of 50 Hz are reinforced, and others are left without reinforcement, then after some time the reaction to similar stimuli will disappear. In other words, from the mass of similar stimuli, the nervous system will react only to the reinforced one, i.e. biologically significant, and the reaction to other stimuli is inhibited. This inhibition ensures the specialization of the conditioned reflex, vital discrimination, differentiation of stimuli according to their signal value.
The greater the difference between the conditioned stimuli, the easier it is to develop differentiation. Using this inhibition, one can study the ability of animals to distinguish sounds, shapes, colors, etc. Thus, according to Gubergrits, a dog can distinguish a circle from an ellipse with a semi-axial ratio of 8:9.
Extraneous stimuli cause disinhibition of differentiation inhibition. Fasting, pregnancy, neurotic conditions, fatigue, etc. can also lead to disinhibition and distortion of previously developed differentiations.
Signal braking ("conditional brake"). Inhibition of the “conditioned inhibitor” type develops in the cortex when the conditioned stimulus is not reinforced in combination with some additional stimulus, and the conditioned stimulus is reinforced only when it is used in isolation. Under these conditions, a conditioned stimulus in combination with an extraneous one becomes, as a result of the development of differentiation, inhibitory, and the extraneous stimulus itself acquires the property of an inhibitory signal (conditioned brake), it becomes capable of inhibiting any other conditioned reflex if it is attached to a conditioned signal.
A conditioned inhibitor easily develops when a conditioned and an additional stimulus act simultaneously. The dog does not produce it if this interval is more than 10 seconds. Extraneous stimuli cause disinhibition of signal inhibition. Its biological significance lies in the fact that it refines the conditioned reflex.
10. An idea of the limit of performance of cells in the cerebral cortex. Extreme braking.
Extreme braking develops in cortical cells under the influence of a conditioned stimulus, when its intensity begins to exceed a known limit. Transcendental inhibition also develops with the simultaneous action of several individually weak stimuli, when the total effect of the stimuli begins to exceed the performance limit of cortical cells. An increase in the frequency of the conditioned stimulus also leads to the development of inhibition. The development of transcendental inhibition depends not only on the strength and nature of the action of the conditioned stimulus, but also on the state of the cortical cells and their performance. At a low level of efficiency of cortical cells, for example, in animals with a weak nervous system, in old and sick animals, a rapid development of extreme inhibition is observed even with relatively weak stimulation. The same is observed in animals brought to significant nervous exhaustion by prolonged exposure to moderately strong stimuli.
Transcendental inhibition has a protective significance for cortical cells. This is a parabiotic type phenomenon. During its development, similar phases are observed: equalizing, when both strong and moderately strong conditioned stimuli cause a response of the same intensity; paradoxical, when weak stimuli cause a stronger effect than strong stimuli; ultraparadoxical phase, when inhibitory conditioned stimuli cause an effect, but positive ones do not; and, finally, the inhibitory phase, when no stimuli cause a conditioned reaction.
11. Movement of nervous processes in the cerebral cortex: irradiation and concentration of nervous processes. Phenomena of mutual induction.
Movement and interaction of excitation and inhibition processes in the cerebral cortex. Higher nervous activity is determined by the complex relationship between the processes of excitation and inhibition that occur in cortical cells under the influence of various influences from the external and internal environment. This interaction is not limited only to the relevant reflex arcs, but is played out far beyond their borders. The fact is that with any impact on the body, not only corresponding cortical foci of excitation and inhibition arise, but also various changes in various areas of the cortex. These changes are caused, firstly, by the fact that nervous processes can spread (irradiate) from the place of their origin to the surrounding nerve cells, and the irradiation is replaced after some time by the reverse movement of the nervous processes and their concentration at the starting point (concentration). Secondly, changes are caused by the fact that nervous processes, when concentrated in a certain place of the cortex, can cause (induce) the emergence of an opposite nervous process in the surrounding neighboring points of the cortex (spatial induction), and after the cessation of the nervous process, induce the opposite nervous process in the same point (temporary, sequential induction).
The irradiation of nervous processes depends on their strength. At low or high intensity, a tendency to irradiation is clearly expressed. With medium strength - to concentration. According to Kogan, the excitation process radiates through the cortex at a speed of 2-5 m/sec, the inhibitory process is much slower (several millimeters per second).
The intensification or occurrence of the excitation process under the influence of the source of inhibition is called positive induction. The emergence or intensification of the inhibitory process around (or after) excitation is called negativeby induction. Positive induction manifests itself, for example, in the strengthening of a conditioned reflex reaction after the application of a differential stimulus or arousal before bedtime. One of the common manifestations of negative induction is inhibition of the UR under the influence of extraneous stimuli. With weak or excessively strong stimuli, there is no induction.
It can be assumed that induction phenomena are based on processes similar to electrotonic changes.
Irradiation, concentration and induction of nervous processes are closely related to each other, mutually limiting, balancing and strengthening each other, and thus determining the precise adaptation of the body’s activity to environmental conditions.
12. An lysis and synthesis in the cerebral cortex. The concept of a dynamic stereotype, features in childhood. The role of the dynamic stereotype in the work of a doctor.
Analytical and synthetic activity of the cerebral cortex. The ability to form UR and temporary connections shows that the cerebral cortex, firstly, can isolate its individual elements from the environment, distinguish them from each other, i.e. has the ability to analyze. Secondly, it has the ability to combine, merge elements into a single whole, i.e. ability to synthesize. In the process of conditioned reflex activity, constant analysis and synthesis of stimuli from the external and internal environment of the body is carried out.
The ability to analyze and synthesize stimuli is inherent in its simplest form to the peripheral parts of the analyzers - the receptors. Thanks to their specialization, high-quality separation is possible, i.e. environmental analysis. Along with this, the joint action of various stimuli, their complex perception creates the conditions for their fusion, synthesis into a single whole. Analysis and synthesis, determined by the properties and activity of receptors, are called elementary.
Analysis and synthesis carried out by the cortex are called higher analysis and synthesis. The main difference is that the cortex analyzes not so much the quality and quantity of information as its signal value.
One of the striking manifestations of the complex analytical and synthetic activity of the cerebral cortex is the formation of the so-called. dynamic stereotype. A dynamic stereotype is a fixed system of conditioned and unconditioned reflexes, combined into a single functional complex, which is formed under the influence of stereotypically repeated changes or influences of the external or internal environment of the body, and in which each previous act is a signal of what follows.
The formation of a dynamic stereotype is of great importance in conditioned reflex activity. It facilitates the activity of cortical cells when performing a stereotypically repeating system of reflexes, making it more economical, and at the same time automatic and clear. In the natural life of animals and humans, stereotypy of reflexes is developed very often. We can say that the basis of the individual form of behavior characteristic of each animal and person is a dynamic stereotype. Dynamic stereotypy underlies the development of various habits in a person, automatic actions in the work process, a certain system of behavior in connection with the established daily routine, etc.
A dynamic stereotype (DS) is developed with difficulty, but once formed, it acquires a certain inertia and, given the unchanged external conditions, becomes more and more stronger. However, when the external stereotype of stimuli changes, the previously fixed system of reflexes begins to change: the old one is destroyed and a new one is formed. Thanks to this ability, the stereotype is called dynamic. However, the alteration of a durable DS is very difficult for the nervous system. It's notoriously difficult to change a habit. Remaking a very strong stereotype can even cause a breakdown of higher nervous activity (neurosis).
Complex analytical and synthetic processes underlie such a form of integral brain activity as conditioned reflex switching when the same conditioned stimulus changes its signal value with a change in the situation. In other words, the animal reacts differently to the same stimulus: for example, in the morning the bell is a signal to write, and in the evening - pain. Conditioned reflex switching manifests itself everywhere in human natural life in various reactions and different forms ah behavior on the same occasion in different environments (at home, at work, etc.) and has great adaptive significance.
13. Teachings of I.P. Pavlova on the types of higher nervous activity. Classification of types and the principles underlying it (strength of nervous processes, balance and mobility).
The higher nervous activity of humans and animals sometimes reveals quite pronounced individual differences. Individual characteristics VND manifest themselves in different rates of formation and strengthening of conditioned reflexes, in different rates of development of internal inhibition, in different difficulties in altering the signal meaning of conditioned stimuli, in different performance of cortical cells, etc. Each individual is characterized by a certain combination of basic properties of cortical activity. It was called the VND type.
The features of the IRR are determined by the nature of the interaction, the ratio of the main cortical processes - excitation and inhibition. Therefore, the classification of types of VND is based on differences in the basic properties of these nervous processes. These properties are:
1.Strength nervous processes. Depending on the performance of cortical cells, nervous processes can be strong And weak.
2. Equilibrium nervous processes. Depending on the ratio of excitation and inhibition, they can be balanced or unbalanced.
3. Mobility nervous processes, i.e. the speed of their occurrence and cessation, the ease of transition from one process to another. Depending on this, nervous processes can be mobile or inert.
Theoretically, 36 combinations of these three properties of nervous processes are conceivable, i.e. a wide variety of types of VND. I.P. Pavlov, however, identified only 4, the most striking types of VND in dogs:
1 - strong unbalanced(with a sharp predominance of excitement);
2 - strong unbalanced mobile;
3 - strong balanced inert;
4 - weak type.
Pavlov considered the identified types to be common to both humans and animals. He showed that the four established types coincide with Hippocrates' description of the four human temperaments - choleric, sanguine, phlegmatic and melancholic.
In the formation of the type of GNI, along with genetic factors (genotype), the external environment and upbringing (phenotype) also take an active part. In the course of further individual development of a person, based on the innate typological characteristics of the nervous system, under the influence of the external environment, a certain set of properties of GNI is formed, manifested in a stable direction of behavior, i.e. what we call character. The type of GNI contributes to the formation of certain character traits.
1. Animals with strong, unbalanced These types are, as a rule, bold and aggressive, extremely excitable, difficult to train, and cannot tolerate restrictions in their activities.
People of this type (cholerics) characterized by lack of restraint and mild excitability. These are energetic, enthusiastic people, bold in their judgments, prone to decisive action, unaware of limits in their work, and often reckless in their actions. Children of this type are often academically capable, but hot-tempered and unbalanced.
2. Dogs strong, balanced, mobile type, in most cases they are sociable, agile, quickly react to every new stimulus, but at the same time they easily restrain themselves. They quickly and easily adapt to changes in the environment.
People of this type ( sanguine people) are distinguished by restraint of character, great self-control, and at the same time ebullient energy and exceptional performance. Sanguine people are lively, inquisitive people, interested in everything and quite versatile in their activities and interests. On the contrary, one-sided, monotonous activity is not in their nature. They are persistent in overcoming difficulties and easily adapt to any changes in life, quickly rebuilding their habits. Children of this type are distinguished by liveliness, mobility, curiosity, and discipline.
3. For dogs strong, balanced, inert type characteristic feature is slowness, calmness. They are unsociable and do not show excessive aggression, reacting weakly to new stimuli. They are characterized by stability of habits and developed stereotypes in behavior.
People of this type (phlegmatic) are distinguished by their slowness, exceptional balance, calmness and evenness in behavior. Despite their slowness, phlegmatic people are very energetic and persistent. They are distinguished by the constancy of their habits (sometimes to the point of pedantry and stubbornness), and the constancy of their attachments. Children of this type are distinguished by good behavior and hard work. They are characterized by a certain slowness of movements and slow, calm speech.
4. In dog behavior weak type as characteristic feature cowardice and a tendency to passive-defensive reactions are noted.
A distinctive feature in the behavior of people of this type ( melancholic people) is timidity, isolation, weak will. Melancholic people often tend to exaggerate the difficulties they encounter in life. They have increased sensitivity. Their feelings are often colored in gloomy tones. Children of the melancholic type outwardly look quiet and timid.
It should be noted that there are few representatives of such pure types, no more than 10% of the human population. Other people have numerous transitional types, combining in their character features of neighboring types.
The type of IRR largely determines the nature of the course of the disease, so it must be taken into account in the clinic. The type should be taken into account at school, when raising an athlete, a warrior, when determining professional suitability, etc. To determine the type of IRR in a person, special methods have been developed, including studies of conditioned reflex activity, processes of excitation and conditioned inhibition.
After Pavlov, his students conducted numerous studies of the types of VNI in humans. It turned out that Pavlov's classification requires significant additions and changes. Thus, research has shown that in humans there are numerous variations within each Pavlovian type due to the gradation of three basic properties of nervous processes. The weak type has especially many variations. Some new combinations of basic properties of the nervous system have also been established, which do not fit the characteristics of any Pavlovian type. These include - a strong unbalanced type with a predominance of inhibition, an unbalanced type with a predominance of excitation, but unlike strong type with a very weak inhibitory process, unbalanced in mobility (with labile excitation, but inert inhibition), etc. Therefore, work is currently ongoing to clarify and supplement the classification of types of internal income.
In addition to the general types of GNI, there are also particular types in humans, characterized by different relationships between the first and second signaling systems. On this basis, three types of GNI are distinguished:
1. Art, in which the activity of the first signaling system is especially pronounced;
2. Thinking type, in which the second signaling system noticeably predominates.
3. Medium type, in which signal systems 1 and 2 are balanced.
The vast majority of people belong to the average type. This type is characterized by a harmonious combination of figurative-emotional and abstract-verbal thinking. The artistic type supplies artists, writers, musicians. Thinking - mathematicians, philosophers, scientists, etc.
14. Features of human higher nervous activity. First and second signaling systems (I.P. Pavlov).
General patterns of conditioned reflex activity established in animals are also characteristic of human GNI. However, the GNI of humans in comparison with animals is characterized to the greatest extent development of analytical and synthetic processes. This is due not only to the further development and improvement in the course of evolution of those mechanisms of cortical activity that are inherent in all animals, but also to the emergence of new mechanisms of this activity.
This specific feature of human GNI is the presence in him, unlike animals, of two systems of signal stimuli: one system, first, consists, like in animals, of direct impacts of external and internal environmental factors body; the other consists in words, indicating the impact of these factors. I.P. Pavlov called her second alarm system since the word is " signal signal"Thanks to the second human signaling system, analysis and synthesis of the surrounding world, its adequate reflection in the cortex, can be carried out not only by operating with direct sensations and impressions, but also by operating only with words. Opportunities are created for abstraction from reality, for abstract thinking.
This significantly expands the possibilities of human adaptation to the environment. He can get a more or less correct idea of the phenomena and objects of the external world without direct contact with reality itself, but from the words of other people or from books. Abstract thinking makes it possible to develop appropriate adaptive reactions also without contact with those specific life conditions in which these adaptive reactions are appropriate. In other words, a person determines in advance and develops a line of behavior in a new environment that he has never seen before. Thus, when going on a trip to new unfamiliar places, a person nevertheless prepares accordingly for unusual climatic conditions, to specific conditions of communication with people, etc.
It goes without saying that the perfection of human adaptive activity with the help of verbal signals will depend on how accurately and completely the surrounding reality is reflected in the cerebral cortex with the help of words. Therefore the only thing the right way testing the correctness of our ideas about reality is practice, i.e. direct interaction with the objective material world.
The second signaling system is socially conditioned. A person is not born with it, he is born only with the ability to form it in the process of communicating with his own kind. Mowgli's children do not have a human second signaling system.
15. The concept of higher mental functions of a person (sensation, perception, thinking).
The basis of the mental world is consciousness, thinking, and intellectual activity of a person, which represent the highest form of adaptive adaptive behavior. Mental activity is a qualitatively new, higher than conditioned reflex behavior, level of higher nervous activity characteristic of humans. In the world of higher animals this level is represented only in rudimentary form.
In the development of the human mental world as an evolving form of reflection, the following 2 stages can be distinguished: 1) the stage of the elementary sensory psyche - reflection of individual properties of objects, phenomena of the surrounding world in the form sensations. Unlike sensations perception - the result of the reflection of the object as a whole and at the same time something still more or less dismembered (this is the beginning of the construction of one’s “I” as a subject of consciousness). A more perfect form of concrete sensory reflection of reality, formed in the process of individual development of the organism, is representation. Performance — figurative reflection an object or phenomenon, manifested in the spatio-temporal connection of its constituent features and properties. The neurophysiological basis of ideas lies in chains of associations, complex temporary connections; 2) formation stage intelligence and consciousness, realized on the basis of the emergence of holistic meaningful images, a holistic perception of the world with an understanding of one’s “I” in this world, one’s own cognitive and creative creative activity. Human mental activity, which most fully realizes this highest level of the psyche, is determined not only by the quantity and quality of impressions, meaningful images and concepts, but also by a significantly higher level of needs, going beyond purely biological needs. A person no longer desires only “bread,” but also “shows,” and builds his behavior accordingly. His actions and behavior become both a consequence of the impressions he receives and the thoughts they generate, and a means of actively obtaining them. The ratio of the volumes of the cortical zones that provide sensory, gnostic and logical functions changes in evolution in favor of the latter.
Human mental activity consists not only in the construction of more complex neural models of the surrounding world (the basis of the cognition process), but also in the production new information, different forms of creativity. Despite the fact that many manifestations of the human mental world turn out to be divorced from direct stimuli, events of the external world and seem to have no real objective causes, there is no doubt that the initial factors that trigger them are completely determined phenomena and objects, reflected in the structures of the brain based on universal neurophysiological mechanism - reflex activity. This idea, expressed by I.M. Sechenov in the form of the thesis “All acts of conscious and unconscious human activity, according to the method of origin, are reflexes,” remains generally accepted.
The subjectivity of mental nervous processes lies in the fact that they are a property of the individual organism, do not exist and cannot exist outside the specific individual brain with its peripheral nerve endings and nerve centers, and are not an absolutely accurate mirror copy of the real world around us.
The simplest, or basic, mental element in the functioning of the brain is sensation. It serves as that elementary act which, on the one hand, connects our psyche directly with external influences, and on the other, is an element in more complex mental processes. Sensation is conscious reception, that is, in the act of sensation there is a certain element of consciousness and self-awareness.
The sensation arises as a result of a certain spatio-temporal distribution of the excitation pattern, but for researchers the transition from knowledge of the spatio-temporal pattern of excited and inhibited neurons to the sensation itself as the neurophysiological basis of the psyche still seems insurmountable. According to L.M. Chailakhyan, the transition from a neurophysiological process amenable to complete physical and chemical analysis to sensation is the main phenomenon of an elementary mental act, the phenomenon of consciousness.
In this regard, the concept of “mental” is presented as a conscious perception of reality, a unique mechanism for the development of the process of natural evolution, a mechanism for transforming neurophysiological mechanisms into the category of the psyche, the consciousness of the subject. Human mental activity is largely determined by the ability to be distracted from real reality and make the transition from direct sensory perceptions to imaginary reality (“virtual” reality). The human ability to imagine the possible consequences of one's actions is highest form abstraction, which is inaccessible to the animal. A striking example The behavior of a monkey in the laboratory of I.P. Pavlov can serve as an example: the animal each time extinguished the fire that was burning on the raft with water, which it brought in a mug from a tank located on the shore, although the raft was in the lake and was surrounded on all sides by water.
The high level of abstraction in the phenomena of the human mental world determines the difficulties in solving the cardinal problem of psychophysiology - finding the neurophysiological correlates of the psyche, the mechanisms for transforming the material neurophysiological process into a subjective image. The main difficulty in explaining specific features mental processes based on the physiological mechanisms of the nervous system activity lies in the inaccessibility of mental processes to direct sensory observation and study. Mental processes are closely related to physiological ones, but cannot be reduced to them.
Thinking is the highest level of human cognition, the process of reflection in the brain of the surrounding real world, based on two fundamentally different psychophysiological mechanisms: the formation and continuous replenishment of the stock of concepts, ideas and the derivation of new judgments and conclusions. Thinking allows you to gain knowledge about such objects, properties and relationships of the surrounding world that cannot be directly perceived using the first signal system. The forms and laws of thinking are the subject of consideration of logic, and psychophysiological mechanisms are the subject of psychology and physiology, respectively.
Human mental activity is inextricably linked with the second signaling system. At the heart of thinking, two processes are distinguished: the transformation of thought into speech (written or oral) and the extraction of thought and content from its specific verbal form of communication. Thought is a form of the most complex generalized abstract reflection of reality, conditioned by certain motives, specific process integration of certain ideas and concepts in specific conditions of social development. Therefore, thought as an element of higher nervous activity is the result of the socio-historical development of the individual with the linguistic form of information processing coming to the fore.
Human creative thinking is associated with the formation of ever new concepts. A word as a signal of signals denotes a dynamic complex of specific stimuli, generalized in a concept expressed by a given word and having a broad context with other words, with other concepts. Throughout life, a person continuously replenishes the content of the concepts he develops by expanding the contextual connections of the words and phrases he uses. Any learning process, as a rule, is associated with expanding the meaning of old and the formation of new concepts.
The verbal basis of mental activity largely determines the nature of development and formation of thinking processes in a child, manifested in the formation and improvement of the nervous mechanism for providing a person’s conceptual apparatus based on the use of logical laws of inference and reasoning (inductive and deductive thinking). The first speech motor temporary connections appear towards the end of the child’s first year of life; at the age of 9-10 months, the word becomes one of the significant elements, components of a complex stimulus, but does not yet act as an independent stimulus. The combination of words into successive complexes, into separate semantic phrases, is observed in the second year of a child’s life.
The depth of mental activity, which determines mental characteristics and forms the basis of human intelligence, is largely due to the development of the generalizing function of the word. In the development of the generalizing function of a word in a person, the following stages, or stages, of the integrative function of the brain are distinguished. At the first stage of integration, the word replaces the sensory perception of a certain object (phenomenon, event) designated by it. At this stage, each word acts as a conventional sign of one specific object; the word does not express its generalizing function, which unites all unambiguous objects of this class. For example, the word “doll” for a child means specifically the doll that he has, but not the doll in a store window, in a nursery, etc. This stage occurs at the end of the 1st - beginning of the 2nd year of life.
At the second stage, the word replaces several sensory images that unite homogeneous objects. The word “doll” for a child becomes a general designation for the various dolls that he sees. This understanding and use of the word occurs by the end of the 2nd year of life. At the third stage, the word replaces a number of sensory images of heterogeneous objects. The child develops an understanding of the general meaning of words: for example, the word “toy” for a child means a doll, a ball, a cube, etc. This level of using words is achieved in the 3rd year of life. Finally, the fourth stage of the integrative function of the word, characterized by verbal generalizations of the second and third order, is formed in the 5th year of the child’s life (he understands that the word “thing” means integrative words of the previous level of generalization, such as “toy”, “food”, “book”, “clothes”, etc.).
The stages of development of the integrative generalizing function of the word as an integral element of mental operations are closely related to the stages and periods of development of cognitive abilities. The first initial period occurs at the stage of development of sensorimotor coordination (child aged 1.5-2 years). The next period of pre-operational thinking (age 2-7 years) is determined by the development of language: the child begins to actively use sensorimotor thinking patterns. The third period is characterized by the development of coherent operations: the child develops the ability to reason logically using specific concepts (age 7-11 years). By the beginning of this period, verbal thinking and activation of the child’s inner speech begin to predominate in the child’s behavior. Finally, the last, final stage of development of cognitive abilities is the period of formation and implementation of logical operations based on the development of elements of abstract thinking, logic of reasoning and inference (11-16 years). At the age of 15-17 years, the formation of neuro- and psychophysiological mechanisms of mental activity is basically completed. Further development mind, intelligence is achieved through quantitative changes; all the basic mechanisms that determine the essence of human intelligence have already been formed.
To determine the level of human intelligence as a general property of the mind and talents, IQ 1 is widely used - IQ, calculated based on the results of psychological testing.
The search for unambiguous, sufficiently substantiated correlations between the level of human mental abilities, the depth of mental processes and the corresponding brain structures still remains unsuccessful.
16. FatnkciAnd speech, localization of their sensory and motor zones in the human cerebral cortex. Development of speech function in children.
The function of speech includes the ability not only to encode, but also to decode a given message using appropriate conventional signs, while maintaining its meaningful semantic meaning. In the absence of such information modeling isomorphism, it becomes impossible to use this form of communication in interpersonal communication. Thus, people cease to understand each other if they use different code elements ( different languages, inaccessible to all persons participating in the communication). The same mutual misunderstanding occurs when different semantic contents are embedded in the same speech signals.
The symbol system used by a person reflects the most important perceptual and symbolic structures in the communication system. It should be noted that mastering a language significantly complements his ability to perceive the world around him on the basis of the first signal system, thereby constituting that “extraordinary increase” that I. P. Pavlov spoke about, noting a fundamentally important difference in the content of higher nervous activity of a person compared to animals.
Words as a form of transmission of thought form the only really observable basis of speech activity. While the words that make up the structure of a particular language can be seen and heard, their meaning and content remain beyond the means of direct sensory perception. The meaning of words is determined by the structure and volume of memory, the information thesaurus of the individual. The semantic (semantic) structure of the language is contained in the subject's information thesaurus in the form of a specific semantic code that converts the corresponding physical parameters of the verbal signal into its semantic code equivalent. At the same time, oral speech serves as a means of immediate direct communication, written language allows one to accumulate knowledge, information and acts as a means of communication mediated in time and space.
Neurophysiological studies of speech activity have shown that during the perception of words, syllables and their combinations, specific patterns with a certain spatial and temporal characteristic are formed in the impulse activity of neural populations of the human brain. Usage different words and parts of words (syllables) in special experiments makes it possible to differentiate in the electrical reactions (impulse flows) of central neurons both physical (acoustic) and semantic (semantic) components of brain codes of mental activity (N. P. Bekhtereva).
The presence of an individual’s information thesaurus and its active influence on the processes of perception and processing of sensory information are a significant factor explaining the ambiguous interpretation of input information at different points in time and in different functional states of a person. To express any semantic structure, there are many different forms of representations, for example sentences. The well-known phrase: “He met her in a clearing with flowers” allows for three different semantic concepts (flowers in his hands, in her hands, flowers in the clearing). The same words and phrases can also mean different phenomena and objects (bur, weasel, scythe, etc.).
The linguistic form of communication as the leading form of information exchange between people, the daily use of language, where only a few words have an exact, unambiguous meaning, largely contributes to the development of human intuitive ability think and operate with imprecise, vague concepts (which are words and phrases - linguistic variables). The human brain, in the process of developing its second signaling system, the elements of which allow ambiguous relationships between a phenomenon, an object and its designation (a sign - a word), has acquired a remarkable property that allows a person to act intelligently and quite rationally in conditions of a probabilistic, “fuzzy” environment, significant information uncertainty. This property is based on the ability to manipulate, operate with imprecise quantitative data, “fuzzy” logic, as opposed to formal logic and classical mathematics, which deal only with precise, uniquely defined cause-and-effect relationships. Thus, the development of the higher parts of the brain leads not only to the emergence and development of a fundamentally new form of perception, transmission and processing of information in the form of a second signaling system, but the functioning of the latter, in turn, results in the emergence and development of a fundamentally new form of mental activity, the construction of conclusions based on using multi-valued (probabilistic, “fuzzy”) logic, the Human brain operates with “fuzzy”, imprecise terms, concepts, and qualitative assessments more easily than with quantitative categories and numbers. Apparently, the constant practice of using language with its probabilistic relationship between a sign and its denotation (the phenomenon or thing it denotes) has served as excellent training for the human mind in the manipulation of fuzzy concepts. It is the “fuzzy” logic of human mental activity, based on the function of the second signaling system, that provides him with the opportunity heuristic solution many complex problems that cannot be solved by conventional algorithmic methods.
The speech function is carried out by certain structures of the cerebral cortex. The motor speech center responsible for oral speech, known as Broca's area, is located at the base of the inferior frontal gyrus (Fig. 15.8). When this area of the brain is damaged, disorders of the motor reactions that provide oral speech are observed.
The acoustic speech center (Wernicke's center) is located in the posterior third of the superior temporal gyrus and in the adjacent part - the supramarginal gyrus (gyrus supramarginalis). Damage to these areas results in loss of the ability to understand the meaning of words heard. The optical center of speech is located in the angular gyrus (gyrus angularis), damage to this part of the brain makes it impossible to recognize what is written.
The left hemisphere is responsible for the development of abstract logical thinking associated with the primary processing of information at the level of the second signaling system. Right hemisphere ensures the perception and processing of information, mainly at the level of the first signaling system.
Despite the indicated certain left hemisphere localization of speech centers in the structures of the cerebral cortex (and as a result - corresponding violations of oral and written speech when they are damaged), it should be noted that dysfunction of the second signaling system is usually observed with damage to many other structures of the cortex and subcortical formations. The functioning of the second signaling system is determined by the functioning of the entire brain.
Among the most common dysfunctions of the second signaling system are: agnosia - loss of the ability to recognize words (visual agnosia occurs with damage to the occipital zone, auditory agnosia - with damage to the temporal zones of the cerebral cortex), aphasia - speech impairment, agraphia - violation of writing, amnesia - forgetting words.
The word, as the main element of the second signaling system, turns into a signal signal as a result of the process of learning and communication between the child and adults. The word as a signal of signals, with the help of which generalization and abstraction are carried out, characterizing human thinking, has become that exclusive feature of higher nervous activity, which provides the necessary conditions for the progressive development of the human individual. The ability to pronounce and understand words develops in a child as a result of the association of certain sounds - words oral speech. Using language, the child changes the way of cognition: sensory (sensory and motor) experience is replaced by the use of symbols and signs. Learning no longer necessarily requires one's own sensory experience; it can occur indirectly through language; feelings and actions give way to words.
As a complex signal stimulus, the word begins to form in the second half of the child’s first year of life. As the child grows and develops and replenishes his life experience the content of the words he uses expands and deepens. The main tendency in the development of the word is that it generalizes a large number of primary signals and, abstracting from their concrete diversity, makes the concept contained in it more and more abstract.
Higher forms of abstraction in the signaling systems of the brain are usually associated with the act of artistic, creative human activity, in the world of art, where the product of creativity acts as one of the types of encoding and decoding of information. Even Aristotle emphasized the ambiguous probabilistic nature of the information contained in a work of art. Like any other sign signaling system, art has its own specific code (determined by historical and national factors), a system of conventions.. In terms of communication, the information function of art allows people to exchange thoughts and experiences, allows a person to join the historical and national experience of others, far people distant (both temporally and spatially) from him. The sign or figurative thinking underlying creativity is carried out through associations, intuitive anticipations, through a “gap” in information (P. V. Simonov). Apparently connected with this is the fact that many authors of works of art, artists and writers usually begin to create a work of art in the absence of preliminary clear plans, when the final form of a creative product that is perceived by other people is far from unambiguous seems unclear to them (especially if it is a work of abstract art). The source of the versatility and ambiguity of such a work of art is the understatement, the lack of information, especially for the reader, viewer in terms of understanding and interpretation of the work of art. Hemingway spoke about this when he compared work of art with an iceberg: only a small part of it is visible on the surface (and can be perceived more or less unambiguously by everyone), a large and significant part is hidden under water, which provides the viewer and reader with a wide field for imagination.
17. Biological role of emotions, behavioral and autonomic components. Negative emotions (sthenic and asthenic).
Emotion is a specific state of the mental sphere, one of the forms of a holistic behavioral reaction, involving many physiological systems and determined both by certain motives, the needs of the body, and the level of their possible satisfaction. The subjectivity of the emotion category is manifested in a person’s experience of his relationship to surrounding reality. Emotions are reflex reactions of the body to external and internal stimuli, characterized by a pronounced subjective coloring and including almost all types of sensitivity.
Emotions have no biological and physiological value if the body has sufficient information to satisfy its desires and basic needs. The breadth of needs, and therefore the variety of situations in which an individual develops and manifests an emotional reaction, varies significantly. A person with limited needs is less likely to have emotional reactions compared to people with high and varied needs, such as needs related to social status him in society.
Emotional arousal as a result of a certain motivational activity is closely related to the satisfaction of three basic human needs: food, protective and sexual. Emotion, as an active state of specialized brain structures, determines changes in the behavior of the body in the direction of either minimizing or maximizing this state. Motivational arousal, associated with various emotional states (thirst, hunger, fear), mobilizes the body to quickly and optimally satisfy the need. A satisfied need is realized in a positive emotion, which acts as a reinforcing factor. Emotions arise in evolution in the form of subjective sensations that allow animals and humans to quickly assess both the needs of the body and the actions on it. various factors external and internal environment. A satisfied need causes an emotional experience of a positive nature and determines the direction of behavioral activity. Positive emotions, being fixed in memory, play an important role in the mechanisms of formation of purposeful activity of the body.
Emotions, realized by a special nervous apparatus, manifest themselves in the absence of accurate information and ways to achieve life's needs. This idea of the nature of emotion allows us to formulate its informational nature in the following form (P. V. Simonov): E=P (N—S), Where E — emotion (a certain quantitative characteristic of the emotional state of the body, usually expressed by important functional parameters of the physiological systems of the body, for example, heart rate, blood pressure, adrenaline level in the body, etc.); P- a vital need of the body (food, defensive, sexual reflexes), aimed at the survival of the individual and procreation, in humans it is additionally determined social motives; N — information necessary to achieve a goal, satisfy a given need; WITH- information that the body possesses and which can be used to organize targeted actions.
This concept was further developed in the works of G.I. Kositsky, who proposed estimating the amount of emotional stress using the formula:
CH = C (I n ∙V n ∙E n - I s ∙V s ∙E s),
Where CH - state of tension, C- target, In,Vn,En - necessary information, time and energy, I s, D s, E s — information, time and energy existing in the body.
The first stage of tension (CHI) is a state of attention, mobilization of activity, increased performance. This stage has training significance, increasing the functionality of the body.
The second stage of tension (CHII) is characterized by a maximum increase in the body's energy resources, an increase in blood pressure, an increase in the frequency of heartbeats and respiration. A sthenic negative emotional reaction occurs, which has external expression in the form of rage and anger.
The third stage (SNH) is an asthenic negative reaction, characterized by depletion of the body’s resources and finding its psychological expression in a state of horror, fear, and melancholy.
The fourth stage (CHIV) is the stage of neurosis.
Emotions should be considered as an additional mechanism of active adaptation, adaptation of the body to the environment in the absence of accurate information about ways to achieve its goals. The adaptability of emotional reactions is confirmed by the fact that they involve in enhanced activity only those organs and systems that ensure better interaction between the body and the environment. The same circumstance is indicated by the sharp activation during emotional reactions of the sympathetic department of the autonomic nervous system, which ensures the adaptive-trophic functions of the body. In an emotional state, there is a significant increase in the intensity of oxidative and energy processes in the body.
An emotional reaction is the total result of both the magnitude of a certain need and the possibility of satisfying this need in at the moment. Ignorance of the means and ways to achieve the goal seems to be a source of strong emotional reactions, while the feeling of anxiety grows, obsessive thoughts become irresistible. This is true of all emotions. Thus, the emotional feeling of fear is characteristic of a person if he does not have the means of possible protection from danger. A feeling of rage arises in a person when he wants to crush an enemy, this or that obstacle, but does not have the corresponding strength (rage as a manifestation of powerlessness). A person experiences grief (an appropriate emotional reaction) when he is unable to make up for a loss.
The sign of an emotional reaction can be determined using the formula of P. V. Simonov. A negative emotion occurs when H>C and, conversely, a positive emotion is expected when H < S. So, a person experiences joy when he has an excess of information necessary to achieve a goal, when the goal turns out to be closer than we thought (the source of the emotion is an unexpected pleasant message, unexpected joy).
In the theory of the functional system of P.K. Anokhin, the neurophysiological nature of emotions is associated with ideas about functional organization adaptive actions of animals and humans based on the concept of “action acceptor”. The signal for the organization and functioning of the nervous apparatus of negative emotions is the fact of mismatch of the “action acceptor” - the afferent model of expected results with the afferentation about the real results of the adaptive act.
Emotions have a significant impact on a person’s subjective state: in a state of emotional upsurge, the intellectual sphere of the body works more actively, a person is inspired, and creative activity increases. Emotions, especially positive ones, play a big role as powerful life incentives for maintaining high performance and human health. All this gives reason to believe that emotion is a state of the highest rise in a person’s spiritual and physical powers.
18. Memory. Short-term and long-term memory. The importance of consolidation (stabilization) of memory traces.
19. Types of memory. Memory processes.
20. Neural structures of memory. Molecular theory of memory.
(combined for convenience)
In the formation and implementation of higher functions of the brain, the general biological property of fixing, storing and reproducing information, united by the concept of memory, is very important. Memory as the basis of learning and thinking processes includes four closely related processes: memorization, storage, recognition, reproduction. Throughout a person's life, his memory becomes a receptacle huge amount information: over the course of 60 years of active creative activity, a person is able to perceive 10 13 - 10 bits of information, of which no more than 5-10% are actually used. This indicates significant memory redundancy and the importance of not only memory processes, but also the process of forgetting. Not everything that is perceived, experienced or done by a person is stored in memory; a significant part of the perceived information is forgotten over time. Forgetting manifests itself in the inability to recognize or remember something or in the form of erroneous recognition or recollection. The reason for forgetting can be various factors related to both the material itself, its perception, and negative influences other stimuli acting directly after memorization (the phenomenon of retroactive inhibition, memory depression). The process of forgetting largely depends on the biological meaning of the perceived information, the type and nature of memory. Forgetting in some cases can be positive character, for example, memory for negative signals, unpleasant events. This is the truth of the wise eastern saying: “Happiness is the joy of memory, grief of oblivion is a friend.”
As a result of the learning process, physical, chemical and morphological changes occur in the nervous structures, which persist for some time and have a significant impact on the reflex reactions carried out by the body. The set of such structural and functional changes in nerve formations, known as "engram" (trace) of acting stimuli becomes an important factor determining the entire variety of adaptive adaptive behavior of the organism.
Types of memory are classified according to the form of manifestation (figurative, emotional, logical, or verbal-logical), according to the temporal characteristics or duration (instant, short-term, long-term).
Figurative memory is manifested by the formation, storage and reproduction of a previously perceived image of a real signal, its neural model. Under emotional memory understand the reproduction of some previously experienced emotional state upon repeated presentation of the signal that caused the primary occurrence of such an emotional state. Emotional memory is characterized by high speed and strength. In this, obviously main reason easier and more stable memorization by a person of emotionally charged signals and stimuli. On the contrary, gray, boring information is much more difficult to remember and is quickly erased from memory. Logical (verbal-logical, semantic) memory - memory for verbal signals denoting both external objects and events and the sensations and ideas caused by them.
Instantaneous (iconic) memory consists in the formation of an instant imprint, a trace of the current stimulus in the receptor structure. This imprint, or the corresponding physico-chemical engram of an external stimulus, is distinguished by its high information content, completeness of signs, properties (hence the name “iconic memory”, i.e. a reflection clearly worked out in detail) of the active signal, but also by a high rate of extinction (it is not stored more than 100-150 ms, unless reinforced or reinforced by a repeated or ongoing stimulus).
The neurophysiological mechanism of iconic memory obviously lies in the processes of reception of the current stimulus and the immediate aftereffect (when the real stimulus is no longer effective), expressed in trace potentials formed on the basis of the receptor electrical potential. The duration and severity of these trace potentials is determined both by the strength of the current stimulus and by the functional state, sensitivity and lability of the perceiving membranes of the receptor structures. Erasing a memory trace occurs in 100-150 ms.
The biological significance of iconic memory is to provide the analyzing structures of the brain with the ability to isolate individual signs and properties of a sensory signal and image recognition. Iconic memory stores not only the information necessary for a clear understanding of sensory signals arriving within a fraction of a second, but also contains an incomparably larger amount of information than can be used and is actually used at the subsequent stages of perception, fixation and reproduction of signals.
With sufficient strength of the current stimulus, iconic memory moves into the category of short-term (short-term) memory. Short-term memory - RAM, which ensures the execution of current behavioral and mental operations. The basis of short-term memory is repeated multiple circulation of pulse discharges along circular closed chains of nerve cells (Fig. 15.3) (Lorente de No, I. S. Beritov). Ring structures can also be formed within the same neuron by return signals formed by the terminal (or lateral, lateral) branches of the axonal process on the dendrites of the same neuron (I. S. Beritov). As a result of repeated passage of impulses through these ring structures, persistent changes are gradually formed in the latter, laying the foundation for the subsequent formation of long-term memory. Not only excitatory, but also inhibitory neurons can participate in these ring structures. The duration of short-term memory is seconds, minutes after the direct action of the corresponding message, phenomenon, object. The reverberation hypothesis of the nature of short-term memory allows for the presence of closed circles of circulation of impulse excitation both within the cerebral cortex and between the cortex and subcortical formations (in particular, thalamocortical nerve circles), containing both sensory and gnostic (learning, recognizing) nerve cells. Intracortical and thalamocortical reverberation circles, as the structural basis of the neurophysiological mechanism of short-term memory, are formed by cortical pyramidal cells of layers V-VI of predominantly the frontal and parietal regions of the cerebral cortex.
The participation of the structures of the hippocampus and limbic system of the brain in short-term memory is associated with the implementation by these nervous formations of the function of distinguishing the novelty of signals and reading incoming afferent information at the input of the waking brain (O. S. Vinogradova). The implementation of the phenomenon of short-term memory practically does not require and is not really associated with significant chemical and structural changes in neurons and synapses, since the corresponding changes in the synthesis of messenger (messenger) RNA require more time.
Despite the differences in hypotheses and theories about the nature of short-term memory, their initial premise is the occurrence of short-term reversible changes in the physicochemical properties of the membrane, as well as the dynamics of mediators in synapses. Ionic currents across the membrane, combined with short-term metabolic shifts during synaptic activation, can result in changes in synaptic transmission efficiency lasting several seconds.
Converting short-term memory into long-term memory (memory consolidation) general view is caused by the onset of persistent changes in synaptic conductivity as a result of repeated excitation of nerve cells (learning populations, Hebbian ensembles of neurons). The transition of short-term memory to long-term memory (memory consolidation) is caused by chemical and structural changes in the corresponding nerve formations. According to modern neurophysiology and neurochemistry, long-term (long-term) memory is based on complex chemical processes synthesis of protein molecules in brain cells. Memory consolidation is based on many factors that lead to easier transmission of impulses through synaptic structures (increased functioning of certain synapses, increased conductivity for adequate impulse flows). One of these factors may be the well-known phenomenon of post-tetanic potentiation (see Chapter 4), supported by reverberating impulse flows: irritation of afferent nerve structures leads to a fairly long-term (tens of minutes) increase in the conductivity of spinal cord motor neurons. This means that the physicochemical changes in postsynaptic membranes that occur during a persistent shift in membrane potential probably serve as the basis for the formation of memory traces, reflected in changes in the protein substrate of the nerve cell.
Of certain importance in the mechanisms of long-term memory are the changes observed in the mediator mechanisms that ensure the process of chemical transfer of excitation from one nerve cell to another. Plastic chemical changes in synaptic structures are based on the interaction of mediators, for example acetylcholine, with receptor proteins of the postsynaptic membrane and ions (Na +, K +, Ca 2+). The dynamics of transmembrane currents of these ions makes the membrane more sensitive to the action of mediators. It has been established that the learning process is accompanied by an increase in the activity of the enzyme cholinesterase, which destroys acetylcholine, and substances that suppress the action of cholinesterase cause significant memory impairment.
One of the widespread chemical theories of memory is Hiden's hypothesis about the protein nature of memory. According to the author, the information underlying long-term memory is encoded and recorded in the structure of the polynucleotide chain of the molecule. The different structure of impulse potentials, in which certain sensory information is encoded in afferent nerve conductors, leads to different rearrangements of the RNA molecule, to movements of nucleotides in their chain that are specific for each signal. In this way, each signal is fixed in the form of a specific imprint in the structure of the RNA molecule. Based on Hiden's hypothesis, it can be assumed that glial cells, which take part in the trophic provision of neuron functions, are included in the metabolic cycle of encoding incoming signals by changing the nucleotide composition of synthesizing RNAs. The entire set of possible permutations and combinations of nucleotide elements makes it possible to record a huge amount of information in the structure of an RNA molecule: the theoretically calculated volume of this information is 10 -10 20 bits, which significantly exceeds the actual volume of human memory. The process of recording information in nerve cell is reflected in the synthesis of a protein, into the molecule of which the corresponding trace imprint of changes in the RNA molecule is introduced. In this case, the protein molecule becomes sensitive to a specific pattern of the impulse flow, thereby it seems to recognize the afferent signal that is encoded in this impulse pattern. As a result, the mediator is released at the corresponding synapse, leading to the transfer of information from one nerve cell to another in the system of neurons responsible for fixation, storage and reproduction of information.
Possible substrates for long-term memory are some hormonal peptides, simple protein substances, and the specific protein S-100. Such peptides, which stimulate, for example, the conditioned reflex learning mechanism, include some hormones (ACTH, somatotropic hormone, vasopressin, etc.).
An interesting hypothesis about the immunochemical mechanism of memory formation was proposed by I. P. Ashmarin. The hypothesis is based on the recognition of the important role of the active immune response in the consolidation and formation of long-term memory. The essence of this idea is as follows: as a result of metabolic processes on synaptic membranes during the reverberation of excitation at the stage of formation of short-term memory, substances are formed that play the role of an antigen for antibodies produced in glial cells. The binding of an antibody to an antigen occurs with the participation of stimulators of the formation of mediators or an inhibitor of enzymes that destroy and break down these stimulating substances (Fig. 15.4).
A significant place in ensuring the neurophysiological mechanisms of long-term memory is given to glial cells (Galambus, A.I. Roitbak), the number of which in the central nervous formations is an order of magnitude greater than the number of nerve cells. The following mechanism of participation of glial cells in the implementation of the conditioned reflex learning mechanism is assumed. At the stage of formation and strengthening of the conditioned reflex, in the glial cells adjacent to the nerve cell, the synthesis of myelin increases, which envelops the terminal thin branches of the axonal process and thereby facilitates the conduction of nerve impulses along them, resulting in an increase in the efficiency of synaptic transmission of excitation. In turn, stimulation of myelin formation occurs as a result of depolarization of the oligodendrocyte (glial cell) membrane under the influence of an incoming nerve impulse. Thus, long-term memory may be based on conjugate changes in the neuroglial complex of the central nervous formations.
The ability to selectively disable short-term memory without impairing long-term memory and selectively affecting long-term memory in the absence of any impairment of short-term memory is usually considered evidence of the different nature of the underlying neurophysiological mechanisms. Indirect evidence of the presence of certain differences in the mechanisms of short-term and long-term memory is the characteristics of memory disorders when brain structures are damaged. Thus, with some focal lesions of the brain (damages to the temporal zones of the cortex, structures of the hippocampus), when it is concussed, memory disorders occur, expressed in the loss of the ability to remember current events or events of the recent past (occurring shortly before the impact that caused this pathology) while maintaining memory of the previous ones, events that happened long ago. However, a number of other influences have the same type of effect on both short-term and long-term memory. Apparently, despite some noticeable differences in the physiological and biochemical mechanisms responsible for the formation and manifestation of short-term and long-term memory, their nature is much more similar than different; they can be considered as successive stages of a single mechanism for fixing and strengthening trace processes occurring in nervous structures under the influence of repeating or constantly acting signals.
21. Concept of functional systems (P.K. Anokhin). Systematic approach to cognition.
The idea of self-regulation of physiological functions is most fully reflected in the theory of functional systems developed by academician P.K. Anokhin. According to this theory, the balancing of the organism with its environment is carried out by self-organizing functional systems.
Functional systems (FS) are a dynamically developing self-regulating complex of central and peripheral formations, ensuring the achievement of useful adaptive results.
The result of the action of any PS is a vital adaptive indicator necessary for the normal functioning of the body in biological and social terms. This implies the system-forming role of the result of the action. It is to achieve a certain adaptive result that FSs are formed, the complexity of the organization of which is determined by the nature of this result.
The variety of adaptive results useful for the body can be reduced to several groups: 1) metabolic results, which are a consequence of metabolic processes at the molecular (biochemical) level, creating substrates or end products necessary for life; 2) homeopathic results, which are leading indicators of body fluids: blood, lymph, interstitial fluid (osmotic pressure, pH, content of nutrients, oxygen, hormones, etc.), providing various aspects of normal metabolism; 3) the results of behavioral activity of animals and humans, satisfying basic metabolic and biological needs: food, drinking, sexual, etc.; 4) the results of human social activity that satisfy social (creation of a social product of labor, environmental protection, protection of the fatherland, improvement of everyday life) and spiritual (acquisition of knowledge, creativity) needs.
Each FS includes various organs and tissues. The combination of the latter into a FS is carried out by the result for the sake of which the FS is created. This principle of FS organization is called the principle of selective mobilization of the activity of organs and tissues into an integral system. For example, to ensure that the blood gas composition is optimal for metabolism, selective mobilization of the activity of the lungs, heart, blood vessels, kidneys, hematopoietic organs, and blood occurs in the respiratory system.
The inclusion of individual organs and tissues in the FS is carried out according to the principle of interaction, which provides for the active participation of each element of the system in achieving a useful adaptive result.
In the given example, each element actively contributes to maintaining the gas composition of the blood: the lungs provide gas exchange, the blood binds and transports O 2 and CO 2, the heart and blood vessels provide the necessary speed and volume of blood movement.
To achieve results at different levels, multi-level FSs are also formed. FS at any level of organization has a fundamentally similar structure, which includes 5 main components: 1) a useful adaptive result; 2) result acceptors (control devices); 3) reverse afferentation, supplying information from receptors to the central link of the FS; 4) central architectonics - selective unification of nervous elements of various levels into special nodal mechanisms (control devices); 5) executive components (reaction apparatuses) - somatic, autonomic, endocrine, behavioral.
22. Central mechanisms of functional systems that form behavioral acts: motivation, stage of afferent synthesis (situational afferentation, trigger afferentation, memory), stage of decision-making. Formation of an acceptor of action results, reverse afferentation.
The state of the internal environment is constantly monitored by the corresponding receptors. The source of changes in the parameters of the internal environment of the body is the metabolic process (metabolism) continuously flowing in cells, accompanied by the consumption of initial and formation of final products. Any deviation of parameters from parameters that are optimal for metabolism, as well as changes in results at a different level, are perceived by receptors. From the latter, information is transmitted by a feedback link to the corresponding nerve centers. Based on incoming information, structures of various levels of the central nervous system are selectively involved in this PS for mobilization executive bodies and systems (reaction apparatuses). The activity of the latter leads to the restoration of the result necessary for metabolism or social adaptation.
The organization of various PS in the body is fundamentally the same. This is isomorphism principle FS.
At the same time, there are differences in their organization that are determined by the nature of the result. FS that determine various indicators of the internal environment of the body are genetically determined and often include only internal (vegetative, humoral) self-regulation mechanisms. These include PS that determine the optimal level of blood mass, formed elements, environmental reaction (pH), and blood pressure for tissue metabolism. Other PS of the homeostatic level also include an external link of self-regulation, which involves the interaction of the body with the external environment. In the operation of some FS, the external link plays a relatively passive role a source of necessary substrates (for example, oxygen for physical respiration), in others the external link of self-regulation is active and includes purposeful human behavior in the environment, aimed at its transformation. These include PS, which provides the body with optimal levels of nutrients, osmotic pressure, and body temperature.
FS of the behavioral and social level are extremely dynamic in their organization and are formed as the corresponding needs arise. In such FS, the external link of self-regulation plays a leading role. At the same time, human behavior is determined and corrected genetically, individually acquired experience, as well as numerous disturbing influences. An example of such FS is human production activity to achieve a result that is socially significant for society and the individual: the creativity of scientists, artists, writers.
FS control devices. The central architectonics (control apparatus) of the FS, consisting of several stages, is built according to the principle of isomorphism (see Fig. 3.1). The initial stage is the stage of afferent synthesis. It is based on dominant motivation, arising on the basis of the body’s most significant needs at the moment. The excitement created by the dominant motivation mobilizes genetic and individually acquired experience (memory) to satisfy this need. Habitat status information supplied situational afferentation, allows you to assess the possibility in a specific situation and, if necessary, adjust past experience of satisfying the need. The interaction of excitations created by dominant motivation, memory mechanisms and environmental afferentation creates a state of readiness (pre-launch integration) necessary to obtain an adaptive result. Triggering afferentation transfers the system from a state of readiness to a state of activity. At the stage of afferent synthesis, the dominant motivation determines what to do, memory - how to do it, situational and trigger afferentation - when to do it in order to achieve the required result.
The stage of afferent synthesis ends with decision making. At this stage, out of many possible ones, a single path is chosen to satisfy the leading need of the body. There is a restriction in the degrees of freedom of activity of the FS.
Following the decision, an acceptor of the action result and an action program are formed. IN acceptor of action results all the main features of the future result of the action are programmed. This programming occurs on the basis of dominant motivation, which extracts from memory mechanisms the necessary information about the characteristics of the result and the ways to achieve it. Thus, the acceptor of action results is an apparatus for foresight, forecasting, modeling the results of the FS activity, where the parameters of the result are modeled and compared with the afferent model. Information about outcome parameters is provided using reverse afferentation.
The action program (efferent synthesis) is a coordinated interaction of somatic, vegetative and humoral components in order to successfully achieve a useful adaptive result. The action program forms the necessary adaptive act in the form of a certain set of excitations in the central nervous system before its implementation in the form of specific actions begins. This program determines the inclusion of efferent structures necessary to obtain a useful result.
A necessary link in the work of the FS is reverse afferentation. With its help, individual stages and the final result of systems activity are assessed. Information from the receptors arrives through afferent nerves and humoral communication channels to the structures that make up the acceptor of the result of the action. The coincidence of the parameters of the real result and the properties of its model prepared in the acceptor means the satisfaction of the initial need of the organism. The activities of the FS end here. Its components can be used in other file systems. If there is a discrepancy between the parameters of the result and the properties of the model prepared on the basis of afferent synthesis in the acceptor of the results of the action, an indicative-exploratory reaction occurs. It leads to a restructuring of afferent synthesis, the adoption of a new decision, clarification of the characteristics of the model in the acceptor of the results of action and the program for achieving them. The activities of the FS are carried out in a new direction necessary to satisfy the leading need.
Principles of FS interaction. Several functional systems operate simultaneously in the body, which provides for their interaction, which is based on certain principles.
Principle of systemogenesis involves selective maturation and involution of functional systems. Thus, the PS of blood circulation, respiration, nutrition and their individual components in the process of ontogenesis mature and develop earlier than other PS.
Multi-parameter principle (multiple connected) interactions defines the generalized activities of various FS aimed at achieving a multicomponent result. For example, the parameters of homeostasis (osmotic pressure, CBS, etc.) are provided by independent PS, which are combined into a single generalized PS of homeostasis. It determines the unity of the internal environment of the body, as well as its changes due to metabolic processes and the active activity of the body in the external environment. In this case, the deviation of one indicator of the internal environment causes a redistribution in certain ratios of other parameters of the result of the generalized FS of homeostasis.
Hierarchy principle assumes that the body's physical functions are arranged in a certain row in accordance with biological or social significance. For example, in biological terms, the dominant position is occupied by the PS, which ensures the preservation of the integrity of tissues, then by the PS of nutrition, reproduction, etc. The activity of the organism in each time period is determined by the dominant PS in terms of survival or adaptation of the organism to the conditions of existence. After satisfying one leading need, another need, the most important in terms of social or biological significance, takes a dominant position.
The principle of sequential dynamic interaction provides for a clear sequence of changes in the activities of several interconnected FS. The factor determining the beginning of the activity of each subsequent FS is the result of the activity of the previous system. Another principle for organizing the interaction of the FS is the principle of systemic quantization of life activity. For example, in the process of breathing, the following systemic “quanta” with their final results can be distinguished: inhalation and the entry of a certain amount of air into the alveoli; O 2 diffusion from the alveoli to the pulmonary capillaries and the binding of O 2 to hemoglobin; transport of O2 to tissues; diffusion of O 2 from the blood into tissues and CO 2 in the opposite direction; transport of CO 2 to the lungs; diffusion of CO 2 from the blood into the alveolar air; exhalation. The principle of system quantization extends to human behavior.
Thus, managing the vital activity of the organism through the organization of PS at the homeostatic and behavioral levels has a number of properties that allow the organism to adequately adapt to a changing external environment. FS allows you to respond to disturbing influences from the external environment and, based on feedback, restructure the body’s activity when the parameters of the internal environment deviate. In addition, in the central mechanisms of the FS, an apparatus for predicting future results is formed - an acceptor of the result of an action, on the basis of which the organization and initiation of adaptive acts that anticipate actual events occur, which significantly expands the adaptive capabilities of the organism. Comparison of the parameters of the achieved result with the afferent model in the acceptor of action results serves as the basis for correcting the body’s activity in terms of obtaining exactly those results that in the best possible way provide the adaptation process.
23. Physiological nature of sleep. Theories of sleep.
Sleep is a vital, periodically occurring special functional state characterized by specific electrophysiological, somatic and vegetative manifestations.
It is known that the periodic alternation of natural sleep and wakefulness belongs to the so-called circadian rhythms and is largely determined by daily changes in illumination. A person spends about a third of his life sleeping, which has led to a long-standing and keen interest among researchers in this condition.
Theories of sleep mechanisms. According to concepts 3. Freud, sleep is a state in which a person interrupts conscious interaction with the outside world in the name of deepening into the inner world, while external irritations are blocked. According to Z. Freud, the biological purpose of sleep is rest.
Humoral concept explains the main reason for the onset of sleep by the accumulation of metabolic products during the period of wakefulness. According to modern data, specific peptides, such as delta-sleep peptide, play a major role in inducing sleep.
Information deficit theory The main reason for the onset of sleep is the restriction of sensory influx. Indeed, in observations of volunteers during preparation for space flight, it was revealed that sensory deprivation (sharp limitation or cessation of the influx of sensory information) leads to the onset of sleep.
According to the definition of I. P. Pavlov and many of his followers, natural sleep is a diffuse inhibition of cortical and subcortical structures, cessation of contact with the outside world, extinction of afferent and efferent activity, shutdown of conditioned and unconditioned reflexes during sleep, as well as the development of general and particular relaxation. Modern physiological studies have not confirmed the presence of diffuse inhibition. Thus, microelectrode studies revealed a high degree of neuronal activity during sleep in almost all parts of the cerebral cortex. From the analysis of the pattern of these discharges, it was concluded that the state of natural sleep represents a different organization of brain activity, different from brain activity in the waking state.
24. Sleep phases: “slow” and “fast” (paradoxical) according to EEG indicators. Brain structures involved in the regulation of sleep and wakefulness.
The most interesting results were obtained when conducting polygraphic studies during night sleep. During such studies, throughout the night, the electrical activity of the brain is continuously recorded on a multichannel recorder - an electroencephalogram (EEG) at various points (most often in the frontal, occipital and parietal lobes) synchronously with the registration of rapid (REM) and slow (MSG) eye movements and electromyograms of skeletal muscles, as well as a number of vegetative indicators - activity of the heart, digestive tract, respiration, temperature, etc.
EEG during sleep. Discovery by E. Azerinsky and N. Kleitman of the phenomenon of “rapid” or “paradoxical” sleep, during which rapid movements were discovered eyeballs(REM) with closed eyelids and general complete muscle relaxation, served as the basis for modern research sleep physiology. It turned out that sleep is a combination of two alternating phases: “slow” or “orthodox” sleep and “fast” or “paradoxical” sleep. The name of these sleep phases is due to characteristic features EEG: during “slow” sleep, predominantly slow waves are recorded, and during “rapid” sleep, a fast beta rhythm, characteristic of a person’s wakefulness, is recorded, which gives rise to calling this phase of sleep “paradoxical” sleep. Based on the electroencephalographic picture, the phase of “slow” sleep is, in turn, divided into several stages. The following main stages of sleep are distinguished:
Stage I - drowsiness, the process of falling into sleep. This stage is characterized by a polymorphic EEG and the disappearance of the alpha rhythm. During night sleep, this stage is usually short-lived (1-7 minutes). Sometimes you can observe slow movements of the eyeballs (SMG), while fast movements of the eyeballs (REM) are completely absent;
stage II is characterized by the appearance on the EEG of so-called sleep spindles (12-18 per second) and vertex potentials, biphasic waves with an amplitude of about 200 μV against a general background of electrical activity with an amplitude of 50-75 μV, as well as K-complexes (vertex potential with subsequent “sleepy spindle”). This stage is the longest of all; it can take about 50 % the entire night's sleep time. No eye movements are observed;
Stage III is characterized by the presence of K-complexes and rhythmic activity (5-9 per second) and the appearance of slow or delta waves (0.5-4 per second) with an amplitude above 75 μV. The total duration of delta waves in this stage occupies from 20 to 50% of the entire III stage. There are no eye movements. Quite often this stage of sleep is called delta sleep.
Stage IV - the stage of “rapid” or “paradoxical” sleep is characterized by the presence of desynchronized mixed activity on the EEG: fast low-amplitude rhythms (in these manifestations it resembles stage I and active wakefulness - beta rhythm), which can alternate with low-amplitude slow and short bursts of alpha rhythm, sawtooth discharges, REM with closed eyelids.
Night sleep usually consists of 4-5 cycles, each of which begins with the first stages of “slow” sleep and ends with “rapid” sleep. The duration of the cycle in a healthy adult is relatively stable and amounts to 90-100 minutes. In the first two cycles, “slow” sleep predominates, in the last two cycles, “fast” sleep predominates, and “delta” sleep is sharply reduced and may even be absent.
The duration of “slow” sleep is 75-85%, and “paradoxical” sleep is 15-25. % of the total duration of night sleep.
Muscle tone during sleep. Throughout all stages of “slow” sleep, the tone of skeletal muscles progressively decreases; in “rapid” sleep there is no muscle tone.
Vegetative shifts during sleep. During “slow” sleep, the heart slows down, the breathing rate decreases, Cheyne-Stokes breathing may occur, and as “slow” sleep deepens, there may be partial obstruction of the upper respiratory tract and the appearance of snoring. The secretory and motor functions of the digestive tract decrease as slow-wave sleep deepens. Body temperature decreases before falling asleep, and as slow-wave sleep deepens, this decrease progresses. It is believed that a decrease in body temperature may be one of the reasons for the onset of sleep. Waking up is accompanied by an increase in body temperature.
In REM sleep, the heart rate may exceed the heart rate during wakefulness, which may lead to various forms arrhythmias and significant changes in blood pressure. It is believed that the combination of these factors can lead to sudden death during sleep.
Breathing is irregular, and prolonged apnea often occurs. Thermoregulation is impaired. Secretory and motor activity of the digestive tract is practically absent.
The REM stage of sleep is characterized by the presence of an erection of the penis and clitoris, which is observed from the moment of birth.
It is believed that the absence of an erection in adults indicates organic brain damage, and in children it will lead to disruption of normal sexual behavior in adulthood.
The functional significance of individual stages of sleep is different. Currently, sleep in general is considered as an active state, as a phase of the daily (circadian) biorhythm, performing an adaptive function. In a dream, the volume of short-term memory, emotional balance, and a disturbed system of psychological defenses are restored.
During delta sleep, information received during the waking period is organized, taking into account the degree of its significance. It is believed that during delta sleep, physical and mental performance is restored, which is accompanied by muscle relaxation and pleasant experiences; an important component This compensatory function is the synthesis of protein macromolecules during delta sleep, including in the central nervous system, which are subsequently used during REM sleep.
Initial studies of REM sleep found that significant psychological changes occur with prolonged REM sleep deprivation. Emotional and behavioral disinhibition appears, hallucinations, paranoid ideas and other psychotic phenomena occur. Subsequently, these data were not confirmed, but the effect of REM sleep deprivation on emotional status, resistance to stress and psychological defense mechanisms was proven. Moreover, an analysis of many studies shows that REM sleep deprivation has a beneficial therapeutic effect in the case of endogenous depression. REM sleep plays a big role in reducing unproductive anxious tension.
Sleep and mental activity, dreams. When falling asleep, volitional control over thoughts is lost, contact with reality is disrupted, and so-called regressive thinking is formed. It occurs with a decrease in sensory influx and is characterized by the presence of fantastic ideas, dissociation of thoughts and images, and fragmentary scenes. Hypnagogic hallucinations occur, which are a series of visual frozen images (such as slides), while subjective time passes much faster than in the real world. In delta sleep, talking in your sleep is possible. Tense creative activity dramatically increases the duration of REM sleep.
It was initially discovered that dreams occur in REM sleep. It was later shown that dreams are also characteristic of slow-wave sleep, especially the delta stage of sleep. The causes of occurrence, the nature of the content, and the physiological significance of dreams have long attracted the attention of researchers. Among ancient peoples, dreams were surrounded by mystical ideas about the afterlife and were identified with communication with the dead. The content of dreams was attributed to the functions of interpretation, prediction, or prescription for subsequent actions or events. Many historical monuments indicates significant influence the content of dreams on the everyday and socio-political life of people of almost all ancient cultures.
In the ancient era of human history, dreams were also interpreted in their connection with active wakefulness and emotional needs. Sleep, as Aristotle defined, is a continuation of the mental life that a person lives in the waking state. Long before Freud's psychoanalysis, Aristotle believed that sensory function is reduced in sleep, giving way to the sensitivity of dreams to emotional subjective distortions.
I.M. Sechenov called dreams unprecedented combinations of experienced impressions.
All people see dreams, but many do not remember them. It is believed that in some cases this is due to the peculiarities of memory mechanisms in a particular person, and in other cases it is a kind of psychological defense mechanism. There is a kind of repression of dreams that are unacceptable in content, i.e. we “try to forget.”
Physiological meaning of dreams. It lies in the fact that in dreams a mechanism is used imaginative thinking to solve problems that could not be solved in wakefulness with the help of logical thinking. A striking example is the famous case of D.I. Mendeleev, who “saw” the structure of his famous periodic table of elements in a dream.
Dreams are a mechanism of a kind of psychological defense - reconciliation of unresolved conflicts in wakefulness, relieving tension and anxiety. Suffice it to remember the proverb “the morning is wiser than the evening.” When resolving a conflict during sleep, dreams are memorized, otherwise dreams are repressed or dreams of a frightening nature arise - “only nightmares are dreamed.”
Dreams differ between men and women. As a rule, in dreams men are more aggressive, while in women sexual components occupy a large place in the content of dreams.
Sleep and emotional stress. Research has shown that emotional stress significantly affects night sleep, changing the duration of its stages, that is, disrupting the structure of night sleep, and changes the content of dreams. Most often, with emotional stress, a reduction in the period of REM sleep and an extension of the latent period of falling asleep are noted. Before the exam, the subjects had a reduction in the total duration of sleep and its individual stages. For parachutists, before difficult jumps, the period of falling asleep and the first stage of “slow” sleep increase.