on the topic: "Higher nervous activity"

1. The concept of higher nervous activity 3
2. Characteristics of conditioned reflexes in comparison with unconditioned 5
3. The procedure for developing a conditioned reflex 6
4. The value of conditioned reflexes 8
5. The value of conditioned reflexes in the development of diseases in humans 8
6. Inhibition of conditioned reflexes and the significance of inhibition 9
7. Types of higher nervous activity (HNA) 10
8. Temperament 11
9. The meaning and knowledge of temperament in working with patients 12

1. The concept of higher nervous activity

Higher nervous activity is the processes occurring in the higher parts of the central nervous system of animals and humans. These processes include a set of conditioned and unconditioned reflexes, as well as "higher" mental functions that provide adequate behavior of animals and humans in changing environmental and social conditions. Higher nervous activity should be distinguished from the work of the central nervous system in synchronizing the work of various parts of the body with each other. Higher nervous activity is associated with neurophysiological processes taking place in the cerebral cortex and the subcortex closest to it.

Sections of the brain

The continuous improvement of the mental processes of higher nervous activity takes place in two ways—empirical and theoretical. Theoretical is carried out in the process of learning (learning someone else's experience). Empirical is carried out in the process of life - when receiving direct experience and verification, formed as a result of theoretical training of stereotypes in personal practice.

Higher nervous activity (HNA) is the activity of the cerebral cortex and the subcortical formations closest to it, which ensures the most perfect adaptation (behavior) of highly organized animals and humans to the environment. The higher nervous activity of the central nervous system should be distinguished from the work of the central nervous system in synchronizing the work of various parts of the body with each other.

The term "higher nervous activity" was first introduced into science by I.P. Pavlov, who considered it equivalent to the concept of mental activity. I.P. Pavlov singled out two main sections in the physiology of higher nervous activity: the physiology of the analyzers and the physiology of the conditioned reflex. In the future, these sections were supplemented by the doctrine of the second human signaling system.

Thanks to the work of I.P. Pavlovian physiology of higher nervous activity becomes the science of the neurophysiological mechanisms of the psyche and behavior, based on the principle of reflex reflection of the external world.

The foundation of GNI are conditioned reflexes. They arise on the basis of a combination of the action of unconditioned reflexes and conditioned stimuli, which include signals that come to a person through vision, hearing, smell, and touch. In humans, the activity of the cerebral cortex has the most developed ability to analyze and synthesize signals coming from the environment and internal environment of the body.

Thinking and consciousness of I.P. Pavlov also attributed to the elements of GNI. Continuous improvement of higher nervous activity occurs in the process of learning (assimilating someone else's experience).

The first experimental studies on animals are associated with the name of the Roman physician Galen (129-201 AD), according to whom mental activity is carried out by the brain and is its function. Galen tested the effect of various medicinal substances on animal organisms, observed their behavior after cutting the nerves going from the sense organs to the brain.

Galen described some of the brain centers that control limb movements, facial expressions, chewing and swallowing. He distinguished between different types of brain activity and for the first time put forward provisions on innate and acquired forms of behavior, on voluntary and involuntary muscle reactions. However, due to the poor development of experimental sciences for many centuries, the study of mental processes took place without any connection with the morphology and physiology of the brain.

2. Characteristics of conditioned reflexes in comparison with unconditioned ones

The term "conditioned reflex" I. P. Pavlov called a reflex reaction that occurs in response to an initially indifferent stimulus if it is combined several times in time with an unconditioned stimulus. The formation of a conditioned reflex is based either on the modification of existing neural connections or the formation of new ones.

The conditioned reflex is characterized by the following features:

Flexibility, the ability to change depending on conditions;

Acquisition and Cancellation;

Signal character (an indifferent stimulus turns into a signal, i.e. becomes a significant conditioned stimulus);

Implementation of a conditioned reflex by the higher parts of the central nervous system.

The biological role of conditioned reflexes is to expand the range of adaptive capabilities of a living organism. Conditioned reflexes complement unconditioned ones and allow you to subtly and flexibly

adapt to a variety of environmental conditions (Table 1).

Table 1

The difference between conditioned reflexes and unconditioned

Unconditioned reflexes	Conditioned reflexes
Congenital, reflect the species characteristics of the organism	Acquired throughout life and reflect the individual characteristics of the body
Relatively constant throughout life	They form, change and can be canceled when they become inadequate to the conditions of life.
Implemented along anatomical pathways determined genetically	Implemented by functionally organized temporary connections
They are characteristic of all levels of the central nervous system and are carried out mainly by its lower sections (spinal cord, stem section, subcortical nuclei)	They are realized with the obligatory participation of the cerebral cortex, and therefore its integrity and safety are required, especially in higher mammals
Each reflex has a specific receptive field and its own specific stimuli.	Reflexes can form from any receptive field to a variety of stimuli
React to the action of a present stimulus that can no longer be avoided	They adapt the body to the action of a stimulus that does not yet exist, it has only to be tested, i.e. they have a warning value

3. The procedure for developing a conditioned reflex

The conditioned reflex connection is not innate, but is formed as a result of learning. A newborn child has only a set of nerve elements for the formation of conditioned reflexes: receptors, ascending and descending nerve pathways, central sections of sensory analyzers that are in the process of formation, and a brain that has unlimited possibilities for combining all these elements.

The formation of conditioned reflexes requires certain conditions:

1) the presence of two stimuli - an unconditioned (food, pain stimulus, etc.), "triggering" an unconditioned reflex reaction, and a conditioned (signal) preceding the unconditioned;

2) repeated exposure to a conditioned stimulus preceding the unconditioned one;

3) the indifferent nature of the conditioned stimulus (should not be excessive, cause a defensive or any other unconditioned reaction);

4) the unconditioned stimulus must be sufficiently significant and strong, the excitation from it must be more pronounced than from the conditioned stimulus;

5) the formation of a conditioned reflex is hindered by extraneous (distracting) stimuli;

6) the tone of the cerebral cortex must be sufficient for the formation of a temporary connection - a state of fatigue or ill health prevents the formation of a conditioned reflex.

The process of forming a classical conditioned reflex consists of three stages:

The first stage is the pregeneralization stage. It is characterized by a pronounced concentration of excitation, primarily in the projection zones of the conditioned and unconditioned stimuli. This stage of concentration of excitation is short-term, and it is followed by the second stage - the stage of generalization of the conditioned reflex. The stage of generalization is based on the process of diffuse spread of excitation (irradiation). During this period, conditioned reactions arise both to signal and other stimuli (the phenomenon of afferent generalization). Reactions also occur in the intervals between presentations of the conditioned stimulus - these are intersignal reactions. In the third stage, as only the conditioned stimulus is reinforced, the intersignal responses fade away, and the conditioned response arises only to the conditioned stimulus. This stage is called the stage of specialization, during which the bioelectrical activity of the brain becomes more limited and is associated mainly with the action of a conditioned stimulus. This process provides differentiation (fine discrimination) of stimuli and automation of the conditioned reflex.

4. The meaning of conditioned reflexes

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

The conditioned stimulus must somewhat precede the unconditioned stimulus, i.e., signal about it. During the formation of a conditioned reflex, a temporary connection arises between the centers of the analyzer of the conditioned stimulus and the center of the unconditioned reflex. Pavlov called the conditioned reflex a temporary connection, because this reflex appears only while the conditions under which it was formed are in effect. Conditioned reflexes are the basis of skills, habits, training, education, development of speech and thinking in a child, labor, social and creative activities.

Conditioned reflexes may arise, or they may disappear if the signal is incorrect. However, if the need for a reflex does not disappear, it can exist throughout life.

1. The value of conditioned reflexes in the development of diseases in humans

Such well-known scientists as C. Sherrington and R. Magnus proved that reflexes can be quite complex, involving entire organ systems in their implementation. Examples of such reflexes are walking, setting the head, eyes and torso in space.

It has been shown that the reflex principle underlies all

processes in the body associated with the maintenance of life (respiration, circulation, digestion, etc.), motor

activity, perceptual processes, etc.

Individual features of the manifestation of higher nervous activity depend on the character, temperament, intelligence, attention, memory, and other properties of the body and psyche. A disorder of the higher nervous activity of a person (neurosis) is caused by unfavorable environmental conditions (biological and social), physical and mental overstrain and is accompanied by dysfunctions of various organs and systems.

6. Inhibition of conditioned reflexes and the significance of inhibition

Inhibition is the activation of inhibitory neurons, which leads to a decrease in excitation in the centers of an already developed conditioned reflex. Inhibition of conditioned reflex activity manifests itself in the form of external, or unconditioned, inhibition and in the form of internal, or conditioned, inhibition.

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

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

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

The biological significance of external inhibition is that the body delays its reaction to secondary events and focuses its activity on the most important at the moment.

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

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

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

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

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

7. Types of higher nervous activity (HNA)

The balance of nervous processes is the balance of the processes of excitation and inhibition, which creates the basis for a more balanced behavior.

Additional properties of nervous processes have been 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 occurrence and termination of nervous processes. This property allows you to make movements with great frequency, quickly and clearly starting and ending the movement.

Activation - characterizes the individual level of activation of nervous processes and underlies the processes of memorization and reproduction.

Based on various combinations of the three main properties of nervous processes, various types of GNI are formed. In the classification of I.P. Pavlov, four main types of GNI are distinguished, differing in adaptability to external conditions:

1) a strong, unbalanced ("unrestrained") type is characterized by a high strength of excitation processes that prevail over inhibition. This is a person with a high level of activity, quick-tempered, energetic, irritable, carried away, with strong, quickly emerging emotions that are clearly reflected in speech, gestures and facial expressions;

2) a strong, balanced, mobile (labile or "live") type is characterized by strong balanced processes of excitation and inhibition with the ability to easily change one process to another. These people are energetic, with great self-control, decisive, able to quickly navigate in a new environment, mobile, impressionable, vividly expressing their emotions;

3) a strong, balanced, inert (calm) type is distinguished 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 hard-working, able to restrain themselves, calm people, but slow, with a weak manifestation of feelings, it is difficult to switch from one type of activity to another, committed to their habits;

4) the weak type is characterized by weak excitatory processes and easily occurring inhibitory reactions. These are weak-willed, dull, dreary people, with high emotional vulnerability, suspicious, prone to gloomy thoughts, to an oppressed mood, they are shy, often amenable to other people's influence.

8.Temperament

These types of GNA correspond to the classical description of temperaments created by Hippocrates, an ancient Greek physician who lived almost 2.5 millennia before IP Pavlov (Table 2).

table 2

Correlation of types of higher nervous activity and temperaments according to Hippocrates

Temperaments according to Hippocrates		Equilibrium	Mobility
		Unbalanced, with a predominance of the excitation process
sanguine		Balanced	Mobile
Phlegmatic person		Balanced	Inert
melancholic

However, usually the combination of properties of the nervous system is more diverse, and therefore one rarely sees such "pure" types of HNA in life. Even IP Pavlov noted that between the main types there are "intermediate, transitional types, and you need to know them in order to navigate in human behavior."

Any work with people is inextricably linked with the process and problems of communication, it permeates the professional activities of health workers at any level. The individual characteristics of the patient's psyche in terms of therapeutic relationships and interactions come into contact with the psychological properties of the medical worker. The purpose of this contact is to help the patient.

Conflicts of interest are the source of conflicts, but the factors that provoke conflict are extremely diverse. These can include the character and logical features of a person: reduced self-criticism, prejudice and envy, selfishness, selfishness, the desire to subjugate others to oneself; his mood, well-being, intellect, knowledge and ignorance of human psychology, psychology of communication, etc.

As a result, everything that makes up the interpersonal situation of communication can act as a conflict factor, a barrier in communication, and create a difficult psychological situation.

The likelihood of conflict increases when:

Incompatibility of characters and psychological types;

The presence of a choleric temperament;

The absence of three qualities: the ability to be critical of oneself, tolerance for others and trust in others.

Calmness and understanding, restraint and tolerance, responsiveness and culture of behavior of a medical worker will positively affect the established relationship with the patient, and form his confidence in doctors and medicine.

List of used literature:

1. Batuev A. S. Higher nervous activity: Proc. for universities on special "Biology", "Psychology". - M .: Higher. school., 1991.—256 p.

2. Human anatomy: a textbook for students of institutions providing education in the specialty "Nursing" / E.S. Okolokulak, K.M. Kovalevich, Yu.M. Kiselevsky. Edited by E.S. Around the fist. - Grodno: GrGMU, 2008. - 424 p.

3. Smirnov V.M., Budylina S.M. Physiology of sensory systems and higher nervous activity. / Moscow, Academa, 2003.

4. Physiology of higher nervous activity / H.H. Danilova, A.L. Krylov. - Rostov n / a: "Phoenix", 2005. - 478, p.

5. Physiology of higher nervous activity: a textbook for students. institutions of higher prof. education / VV Shulgovskiy. - 3rd ed., revised. - M .: Publishing Center "Academy", 2014. - 384 p.

The formation and significance of conditioned reflexes is quite an interesting issue to consider.

Values ​​of conditioned reflexes

Once the scientist Pavlov divided all reflex reactions into 2 groups - conditioned and unconditioned reflexes.

The formation of conditioned reflexes occurs in the process of combining a conditioned stimulus with an unconditioned reflex. For this to happen, two conditions must be met:

1. The action of the conditioned stimulus must be somewhat preceded by the action of the unconditioned stimulus.
2. The conditioned stimulus is repeatedly reinforced by the action of the unconditioned stimulus.

The environment is in constantly changing conditions, therefore, in order to preserve the vital activity of the organism and adaptive behavior, conditioned reflexes are needed, the impact of which is possible due to the participation of the large hemispheres of the brain.

It is worth noting that conditioned reflexes are not innate, they are formed throughout life on the basis of unconditioned reflexes under the influence of certain environmental factors. Such reflexes are individual, that is, in individuals of the same species, the same reflex may be absent in some, while others may be present.

The mechanism of formation of conditioned reflexes consists in the process of establishing a temporary connection between 2 sources of excitation in the foci of the brain. In higher animals, they are produced constantly, especially in humans. This can be explained by the dynamism of the environment, the constant change of living conditions, to which the nervous system must quickly adapt.

The biological significance of the conditioned reflex huge in the life of animals and humans - they provide adaptive behavior. Thanks to them, it is possible to accurately navigate in time and space, find food, avoid dangers and eliminate harmful effects on the body. The number of conditioned reflexes increases with age. In addition, the experience of behavior is acquired, which helps adult organisms to better adapt to life.

Conditioned reflexes and their meaning.

The environmental conditions in which people and animals are located are constantly changing. Since the unconditioned reflexes are quite conservative, they cannot ensure that the reactions of the body are adapted in every way to these changes. In the process of evolution, animals developed the ability to form reflexes that manifest themselves only under certain conditions, called I. P. Pavlov conditioned reflexes.

conditioned reflexes, unlike unconditional, they are temporary and can fade with changing environmental conditions. Coinciding in their action with unconditioned stimuli, conditioned stimuli acquire a signal, warning value. They provide humans and animals with the opportunity to respond in advance to negative or positive stimuli.

Conditioned reflexes are formed on the basis of unconditioned ones. In the process of development of the organism, they subjugate the function of the unconditioned, adapting them according to the new requirements of the environment. When forming conditioned reflexes, certain rules and conditions should be followed. The first and main condition is coincidence in time a one-time or multiple action of a conditioned stimulus (indifferent) with an unconditioned stimulus or actions immediately after it. For example, for the formation of a conditioned salivary reflex in dogs to the sound of a bell, this sound must precede feeding several times. After such a combination in time of the conditioned and unconditioned stimuli, saliva is released when only the bell is turned on without being accompanied by food. Consequently, the bell became a conditioned salivary stimulus. In the same way, conditioned reflexes are formed in humans. For example, eating lemon causes salivation. This is an unconditional reflex reaction. Combining drinking lemon several times with turning on the light, only turning on the light will cause salivation. This is a conditioned response.

An important condition for the formation of conditioned reflexes is a certain sequence of stimuli due to the fact that under the influence of an unconditioned stimulus in the cerebral cortex in the nerve center of this stimulus, a strong focus of excitation is formed. The excitability of other parts of the cortex is then reduced, so a weak conditioned stimulus will not cause excitation of the corresponding zone of the cortex. For the formation of conditioned reflexes, it is also necessary that the cerebral cortex be free from other types of activity, and the body be in a normal functional state. The action of constant stimuli, the diseased state of the body significantly complicate the formation of conditioned reflexes. Unlike the brain of animals, the human brain is able to form conditioned reflexes not only in response to specific signals, but also to heard or read words, numbers, drawings, which provides the possibility of abstraction and generalization. The latter form the basis of our thinking and consciousness.

The mechanism of formation of conditioned reflexes. IP Pavlov's research established that the formation of conditioned reflexes is based on the establishment of temporary connections in the cerebral cortex between the nerve centers of unconditioned and conditioned stimuli. Temporary neural connection is formed as a result of the interaction of the processes of excitation and cutting (laying) the path for its implementation, which simultaneously and repeatedly occur in the cortical centers of unconditioned and conditioned stimuli. The formation of temporary connections is characteristic not only of the cerebral cortex, but also of other parts of the central nervous system. This is evidenced by experiments in which simple conditioned reflexes were developed in animals with a removed cortex. Reactions such as conditioned reflexes can be developed in animals that do not have a cortex, and even in invertebrates with a very primitive nervous system, such as annelids.

However, for higher animals and humans, the main role in the formation of temporary connections is played by the cerebral cortex, although subcortical structures are also important for the formation of conditioned reflexes.

Thus, conditioned reflexes are formed as a result of mutually coordinated activity of the cortex and subcortical centers, so the structure of the reflex arc of conditioned reflexes is quite complex. The role of the cortex and subcortical structures in the formation of various reflexes is not the same. For example, in the formation of vegetative conditioned reflexes, the cortex and subcortex play the same role, while in complex behavioral reactions the leading role belongs to the cortex. However, in these cases, the subcortical centers and the reticular formation contribute to the formation of conditioned reflexes.

The activity of various parts of the central nervous system during the formation of complex behavioral conditioned reflexes is manifested in the fact that the processes of their formation are accompanied by the appearance of orienting reflex reactions. Increased excitability of the cerebral cortex contributes to the closure of temporary nerve connections.

So, conditioned reflexes enable a person to adapt his behavior according to changes in the environment. Conditioned reflexes are formed on the basis of unconditioned ones. The basis of the mechanism for the formation of conditioned reflexes is the establishment of temporary nerve connections in the cerebral cortex between the nerve centers of unconditioned and conditioned stimuli.

2. Reflex - a concept, its role and significance in the body

Reflexes (from the Latin slot reflexus - reflected) are the body's responses to irritation of receptors. In the receptors, nerve impulses arise, which, through the sensory (centripetal) neurons, enter the central nervous system. There, the information received is processed by intercalary neurons, after which motor (centrifugal) neurons are excited and nerve impulses actuate the executive organs - muscles or glands. Intercalary neurons are called neurons, the bodies and processes of which do not go beyond the central nervous system. The path along which nerve impulses pass from the receptor to the executive organ is called the reflex arc.

Reflex actions are holistic actions aimed at satisfying a specific need for food, water, security, etc. They contribute to the survival of an individual or species as a whole. They are classified into food, water-producing, defensive, sexual, orienting, nest-building, etc. There are reflexes that establish a certain order (hierarchy) in a herd or flock, and territorial reflexes that determine the territory captured by one or another individual or flock.

There are positive reflexes, when the stimulus causes a certain activity, and negative, inhibitory, in which the activity stops. The latter, for example, include a passive-defensive reflex in animals, when they freeze at the appearance of a predator, an unfamiliar sound.

Reflexes play an exceptional role in maintaining the constancy of the internal environment of the body, its homeostasis. So, for example, with an increase in blood pressure, a reflex slowdown of cardiac activity and an expansion of the lumen of the arteries occur, so the pressure decreases. With its strong fall, opposite reflexes arise, strengthening and speeding up the contractions of the heart and narrowing the lumen of the arteries, as a result, the pressure rises. It continuously fluctuates around a certain constant value, which is called the physiological constant. This value is genetically determined.

The famous Soviet physiologist P. K. Anokhin showed that the actions of animals and humans are determined by their needs. For example, the lack of water in the body is first replenished by internal reserves. There are reflexes that delay the loss of water in the kidneys, the absorption of water from the intestines increases, etc. If this does not lead to the desired result, excitation occurs in the centers of the brain that regulate the flow of water and a feeling of thirst appears. This arousal causes goal-directed behavior, the search for water. Thanks to direct connections, nerve impulses going from the brain to the executive organs, the necessary actions are provided (the animal finds and drinks water), and thanks to feedback, nerve impulses going in the opposite direction - from peripheral organs: the oral cavity and stomach - to brain, informs the latter about the results of the action. So, while drinking, the center of water saturation is excited, and when the thirst is satisfied, the corresponding center is inhibited. This is how the controlling function of the central nervous system is carried out.

A great achievement of physiology was the discovery by IP Pavlov of conditioned reflexes.

Unconditioned reflexes are inborn, inherited by the body reactions to environmental influences. Unconditioned reflexes are characterized by constancy and do not depend on training and special conditions for their occurrence. For example, the body responds to pain irritation with a defensive reaction. There is a wide variety of unconditioned reflexes: defensive, food, orientation, sexual, etc.

The reactions underlying unconditioned reflexes in animals have been developed over thousands of years in the course of adaptation of various animal species to the environment, in the process of struggle for existence. Gradually, under conditions of long evolution, the unconditioned reflex reactions necessary to satisfy biological needs and preserve the vital activity of the organism were fixed and inherited, and those of the unconditioned reflex reactions that lost their value for the life of the organism lost their expediency, on the contrary, disappeared, not recovering.

Under the influence of a constant change in the environment, more durable and perfect forms of animal response were required to ensure the adaptation of the organism to the changed conditions of life. In the process of individual development, highly organized animals form a special type of reflexes, which IP Pavlov called conditional.

Conditioned reflexes acquired by an organism during its lifetime ensure the corresponding reaction of a living organism to changes in the environment and, on this basis, balance the organism with the environment. Unlike unconditioned reflexes, which are usually carried out by the lower parts of the central nervous system (spinal cord, medulla oblongata, subcortical nodes), conditioned reflexes in highly organized animals and humans are carried out mainly by the higher part of the central nervous system (cerebral cortex).

The observation of the phenomenon of "mental secretion" in a dog helped IP Pavlov to discover the conditioned reflex. The animal, seeing food at a distance, intensively salivated even before the food was served. This fact has been interpreted in different ways. The essence of "mental secretion" was explained by IP Pavlov. He found that, firstly, in order for a dog to start salivating at the sight of meat, it had to see and eat it at least once before. And, secondly, any stimulus (for example, the type of food, a bell, a flashing light, etc.) can cause salivation, provided that the time of action of this stimulus and the time of feeding coincide. If, for example, feeding was constantly preceded by the knocking of a cup in which the food was located, then there always came a moment when the dog began to salivate just at one knock. Reactions that are caused by stimuli that were previously indifferent. I. P. Pavlov called conditioned reflex. The conditioned reflex, I. P. Pavlov noted, is a physiological phenomenon, since it is associated with the activity of the central nervous system, and at the same time, a psychological one, since it is a reflection in the brain of the specific properties of stimuli from the outside world.

Conditioned reflexes in animals in the experiments of I. P. Pavlov were most often developed on the basis of an unconditioned food reflex, when food served as an unconditioned stimulus, and one of the stimuli (light, sound, etc.) indifferent (indifferent) to food performed the function of a conditioned stimulus. .).

There are natural conditioned stimuli, which serve as one of the signs of unconditioned stimuli (the smell of food, the squeak of a chicken for a chicken, which causes a parental conditioned reflex in it, the squeak of a mouse for a cat, etc.), and artificial conditioned stimuli that are completely unrelated to unconditioned reflex stimuli. (for example, a light bulb, to the light of which a salivary reflex was developed in a dog, the ringing of a gong, on which moose gather for feeding, etc.). However, any conditioned reflex has a signal value, and if the conditioned stimulus loses it, then the conditioned reflex gradually fades away.

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Since conditioned reflexes are simply special cases of associations in which a stimulus that excites the receiving neurons causes an external reaction, it is obvious that in human life this type of phenomena occurs as often as associations of other types. In this chapter we will briefly consider the conditioned reflexes commonly observed in humans and show that they do not differ in their properties from the conditioned reflexes found in animals.
Conditioned reflexes in people can be divided into two categories: those that are found in every person, because they are an integral part of his life, and those that are formed only in certain circumstances, based on the special experience of one person or group of people. Most defensive conditioned reflexes belong precisely to the second category. It seems to us that dwelling on them is of no interest, since the reader may not have the appropriate reflexes. Let us therefore dwell on the first category of human conditioned reflexes and discuss those of them that seem to us particularly interesting. We will talk about conditioned reflexes associated with eating and sleeping.
Eating. A person usually eats at regular intervals and at certain times of the day. Both the hours of eating and the surroundings in which this takes place, although they vary from nation to nation and social group, are within each group characterized by striking constancy and even austerity. This constancy, which seems natural to us, is directly related to conditioned reflexes. A person who always eats at a certain time of the day and in a certain environment develops a strong conditioned response to hunger, which causes him to eat at the same hours and in the same place on subsequent days. This, in turn, reinforces food conditioned reflexes even more and further strengthens the habit of a certain diet. Moreover, the presence of such habits in the whole group leads to such spatio-temporal events as preparation for food at a certain time, service in certain places, which again establishes clear boundaries for eating, thereby causing further consolidation of the corresponding conditioned reflexes.
It is interesting to analyze the interaction between the two main conditioned reflexes associated with food intake: the conditioned reflex of hunger and the conditioned reflex to food in their manifestations in human life.
The conditioned reflex of hunger is determined mainly by the temporal factor, that is, the period of time that has elapsed since the previous meal. Evidence that this factor acts to a large extent as a conditioned, and not as an unconditioned stimulus, is the fact that the appearance of hunger depends entirely on our daily stereotype and is timed to coincide with it. We feel hungry before our usual moments of eating, regardless of how they are distributed throughout the day and what the intervals are between them. If at the usual time we did not eat, then hunger, as a rule, disappears (discovering its conditioned reflex nature) and appears approximately at the time of the next meal.
These conditioned reflexes of hunger are associated not only with the moment of eating, but also with the quantity and quality of food. Although, as mentioned in Chap. I, and the amount of food consumed during one meal, and its composition (assuming free choice) depends on the intensity of the unconditioned reflex drive of hunger, and selectivity is dictated by the need of the body, nevertheless, the quantity and quality of food eaten largely depend on conditioned reflexes . If we are used to getting a light breakfast at some time, then the intensity of the conditioned hunger reflex will correspond to this and we will be unpleasant if a light snack is replaced by another type of food. On the contrary, having become accustomed to the fact that dinner is usually plentiful, consisting of a number of dishes, we will not be satisfied if we are given a light snack instead. Similarly, if we are accustomed to a breakfast of coffee, toast, eggs, and jam, and are offered soup and meat instead, we will have a negative reaction to this change, since the conditioned hunger drive at that moment is directed to a different type of food. It even seems to us that we were given simply inedible food, although in a few hours we will eat the same dishes with great appetite.
If the conditioned reflexes of hunger are established mainly for a time and to a lesser extent to external stimuli, the conditioned reflex to food, on the contrary, depends exclusively on external stimuli immediately preceding the act of eating, especially on the external environment of the meal. When we get up from our desk, put on our coats, and go to the dining room, we don't salivate, even though we experience a very strong hunger drive. But when we arrive, sit down, unfold a napkin, read the menu - that's when we begin to salivate, a sign of a conditioned reflex to food.
It should be noted that the conditioned reflex to food in the form of salivation can also manifest itself in an environment different from that associated with eating. If, for example, in the company of gourmets, someone skillfully describes various dishes, the listeners begin to salivate profusely. This is because vivid images of food, evoked by the activation of the corresponding gnostic neurons via connections from audioverbal neurons, can replace the direct perception of food; we kind of get food in our imagination.
The relationship between the conditioned reflex to food and the conditioned reflex of hunger in humans is the same as in animals. People who strictly adhere to a stereotype in nutrition (for example, in boarding houses) and usually overeat rarely experience real hunger, and the stimuli that signal for them the moment of eating are of a different nature (for example, social). However, the strong conditioned response to food that begins when they sit down to a well-served table, and especially when they taste the first bites of delicious food, causes a strong hunger drive. To their surprise, they are able to eat all the food with great appetite and pleasure. After all, it’s not for nothing that they say: “Appetite comes with eating.”
And vice versa, if a person experiences strong, even unbearable, hunger, which makes him go to eat, then when he comes and sits down at a well-laid table, powerful conditioned stimuli begin to act on him, signaling the upcoming receipt of food, and the feeling of hunger is weakened.
The satiety state, like the hunger drive, can easily become a conditioned reflex. It is well known that if a person overeats some food in a certain place, then later both this food and the place associated with it cause hostility, since conditioned reflex saturation begins to act, which suppresses appetite.
Dream. Unconditioned reflex sleep, like eating and defensive activity, has a dual nature. It is necessary to clearly distinguish between the sleep drive - the desire to fall asleep, which we call the unconditioned sleepiness reflex, and the actual dream - the unconditioned sleep reflex. The unconditioned drowsiness reflex is stimulated by a more or less prolonged lack of sleep, while the unconditioned sleep reflex develops under the influence of such external stimuli as lying down or semi-lying position, muscle relaxation, monotony of the environment and a comfortable bed.
It is easy to see that, as in the case of food activity, drowsiness and sleep can easily become conditioned reflexes, just like the hunger drive and eating.
The conditioned reflex of drowsiness is developed at the time when, according to the usual daily routine, we go to bed. People who are accustomed to sleeping in the afternoon become drowsy even by this time, and suffer if circumstances prevent them from going to bed. But if this dream is prevented, then drowsiness gradually disappears, which indicates its conditioned reflex character. If after-dinner sleep is prevented from day to day, then drowsiness, not supported by sleep, ceases to appear in accordance with the principles of extinction of conditioned reflexes. Most people begin to feel sleepy in the evening, as they are used to going to bed at this time, but those who work at night, on the contrary, are fresh and alert at this time and become sleepy by morning.
The conditioned sleep reflex, on the contrary, is developed to those stimuli that usually accompany falling asleep: the view of the bedroom, a comfortable bed, night clothes, a certain position in which a person usually falls asleep, reading a book, radio, smoking a cigarette. This is due to the formation of connections between gnostic neurons, in which the corresponding perceptions are represented, and neurons, in which the hypnogenic stimuli listed above are presented. It is well known that if something changes greatly in the usual environment where we are used to sleeping, then it is impossible to fall asleep, unless, of course, you don’t want to sleep very much. Strong unconditioned reflex drowsiness, usually caused by prolonged lack of sleep, makes us fall asleep even in an unusual environment; it helps to establish a new conditioned reflex to a new environment and facilitates the establishment of connections between the corresponding gnostic neurons and hypnogenic neurons.
A legitimate question arises: how can conditioned reflexes of drowsiness and sleep be developed, if both of these states are fundamentally opposite to the “awakening reaction”?
This question can be answered in the following way. As emphasized earlier, the formation of associations does not have to occur against the background of general activation (which generally seems to us to be a physiological artifact obtained under artificial experimental conditions); for this, partial activation is sufficient, affecting only certain structures and not affecting others. Taking this into account, we can assume that drowsiness is a state no less active than any other drive. On the contrary, when drowsy, the animal actively seeks a place to sleep, just as a hungry animal seeks food; it is, of course, more sensitive to all stimuli that are related to the goal. Therefore, drowsiness activates the associations associated with the sleep conditioned reflex just as well as hunger does with respect to the conditioned reflexes to food.
We have given above an ethological analysis of two important conditioned reflexes in order to illustrate the role of preserving classical conditioned reflexes in human life. The main conclusion from this analysis is that both preparatory and executive activity are of an unconditional reflex nature and are regulated primarily by the “needs of the body”, about which it “lets know” to the corresponding nerve centers, mainly through chemoreceptors that are present both on the periphery and and in the central nervous system. However, a finer regulation of one and the other activity is carried out through conditioned reflexes, which, perhaps, are not strong enough to cause significant changes in them, but which distribute them in time and space in such a way as to adapt them to the characteristics of the life of an individual or collective.
Human social behavior turns out to be another area of ​​manifestation of conditioned reflexes; let's call them social conditioned reflexes. The social environment surrounds a person from the moment of his birth until his death, largely determining the conditions of his life; from this environment comes the most external stimuli that affect a person's life. Without intending to enter into all the details of human relationships, we would like, however, to draw attention to only one side of them, which is closely related to the issues under consideration.
Every person, whether an adult or a child, with constant communication with other people, develops highly specific emotional relationships based on conditioned reflexes. The formation of these conditioned reflexes occurs as follows. For a given person, whom we will consider an object (let's call him O), the attitude of other people with whom he is connected can be considered as a kind of unconditional irritations (therefore, let's call them P1, P2, P3-); as a result, various conditioned reflexes arise, both emotional and executive. For example, P1, as a rule, is aggressive towards our O, he insults him or harms him; P2 is always kind and gentle with O; P3 - his partner in sexual life; R4 saves O from danger (real or imagined), thereby weakening the latter's sense of unease; R5 tried to harm O but failed, and O had a sense of victory. Accordingly, behavior P1 causes an unconditioned reflex of fear and rage in O, behavior P2 causes a feeling of attachment, P3 - sexual desire and the corresponding unconditioned executive reflex, P4 - causes a state of relief in O, and P5 - a feeling of satisfaction. Usually, various behavioral acts of a given person cause a number of emotional unconditioned reflexes, either complementary to each other (for example, attachment and sexual desire), and sometimes antagonistic to each other (for example, attachment and fear).
As a result, according to the principles of the formation of conditioned reflexes, a given person, i.e., his face, voice or image, become typical conditioned stimuli and cause the corresponding emotional conditioned reflexes of fear, affection, sexual drive, and relief. The properties of these social conditioned reflexes are surprisingly similar to the properties of classical conditioned reflexes developed in experimental animals. This will be shown again in the next chapter, where we will discuss the reconditioning of conditioned reflexes caused by a change in the reinforcer associated with a given conditioned signal.
Another type of classical conditioned reflexes that play an important role in human life are conditioned reflexes associated with words read or heard. As has been said many times before, there are strong associations between words and the stimulus-objects they denote, and cause their images or hallucinations. If these stimulus-objects, in turn, are associated with unconditioned stimuli from the sphere of emotional or executive reflexes, then the words evoke typical second-order conditioned reflexes.
Here are some examples. If the company talks about tasty food, then very soon this conversation begins to cause in its participants a conditioned reflex of hunger and (or) a conditioned reflex to food. When reading a story that touches on a sexual theme, images that have arisen under the influence of what is read can cause a sexual conditioned reflex. If the story describes some terrible events, then the corresponding images cause a conditioned reflex of fear.

The same principle of verbal conditioned reflexes operates in a related group of phenomena called suggestion. If you confidently tell a person that it is very cold in the room he has just entered, he will actually begin to experience a hallucination of cold and will shiver. Similarly, if you persistently convince someone that there was a worm in the food they just ate, the person may experience nausea and even vomiting. If you suggest to a person that he wants to sleep, his eyelids become heavy and he really falls asleep.
Susceptibility to suggestion varies from person to person and depends, among other things, on the degree of emotionality in general, on the strength of associations between words and emotions, and also on the emotional state in which a person is at the moment and which is determined by his own motives. Thus, it is much easier to convince a person that a bush in a dark forest is a lurking bandit if he is already frightened than if he is in a cheerful, carefree mood. It is much easier for a hungry person to suggest that the smell he smells is the smell of food than for a well-fed person. In the examples given, the summation of the excitation of neurons corresponding to the unconditioned stimulus is clearly detected with the simultaneous action of a weak conditioned signal and a weak unconditioned agent. Naturally, the same mechanism operates here as in the summation of the excitation of gnostic neurons through perception and through associations.

CONCLUSION AND CONCLUSIONS

In accordance with the considerations outlined in this chapter, the development of classical conditioned reflexes is nothing more than the formation of associations between an indifferent and biologically significant stimulus, that is, one that causes an external unconditioned response. In this case, the indifferent stimulus acquires the ability to evoke the same response as the unconditioned stimulus; this allows the association to be studied in an objective and relatively accurate manner. By definition, the classical conditioned reflex includes only those effects elicited by the reinforcing agent, although it is not clear whether all or only part of the effects of the unconditioned stimulus can become conditioned reflexes.
Since the main types of innate activity of the organism consist of preparatory reflexes (drives) and executive reflexes, the same is true for conditioned reflexes. So, food conditioned reflexes can be divided into conditioned reflexes of hunger and conditioned reflexes to food, and defensive ones can be divided into conditioned reflexes of fear and conditioned reflexes of pain, etc.
The basis of the conditioned reflex of hunger is the connection between the receiving neurons of the representation of the conditioned signal and the neurons of the representation of the hunger drive, localized at the highest level of the emotive system. The basis of the conditioned reflex to food is the connection between the neurons of the conditioned signal and certain taste neurons. The main indicator of the conditioned hunger reflex is motor restlessness, which can turn into an instrumental reaction if special training is carried out for this (see Chapter IX). The main indicator of a conditioned reflex to food is the secretion of saliva.
The activating factor that ensures the formation of a conditioned hunger reflex is the unconditioned hunger reflex, and for the conditioned reflex to food - the formed conditioned hunger reflex, which causes simultaneous activation of neurons in the gnostic field of the conditioned signal and in the gnostic gustatory field.

Food, in addition to a specific unconditioned response, also causes an anti-drive reflex of hunger, which inhibits the hunger drive. The same applies to the conditioned reflex to food. As a result, the conditioned signal of food and the conditioned signal of hunger are usually represented by different stimulus objects. The conditioned signal of hunger is, as a rule, the entire situation associated with feeding and (or) the time of feeding, while the conditioned signal of food is usually a sporadic signal immediately preceding the food unconditioned stimulus. Both conditioned reflexes - the hunger reflex and the food reflex - are often intertwined, replacing each other in the presence of the same conditioned signal. If an indifferent stimulus is usually reinforced by the presentation of food during a short isolated action of the conditioned signal, then in this case the conditioned reflex to food prevails over the conditioned hunger reflex to such an extent that the animal, due to the lack of hunger, is reluctant to take food. If this stimulus is sometimes not reinforced with food, or another similar conditioned agent is introduced, used without reinforcement, then the hunger drive increases. In general, it can be said that the reliance on the appearance of food or any other attractive unconditioned stimulus in the presence of the conditioned signal tends to dampen the corresponding drive, making the animal relatively indifferent to achieving the goal. At the same time, uncertainty, on the contrary, increases the drive and makes the goal more desirable. In fact, the whole courtship ritual, so common in both animals and humans, whose purpose is to delay the sexual act somewhat, leads to an increase in sexual desire and facilitates the subsequent executive sexual reflex. The problem of the relationship between sexual drive and the availability of a sexual goal is analyzed in detail in the monumental work of M. Proust (48).
The situation is somewhat different with regard to defensive conditioned reflexes, since a reinforcing harmful stimulus evokes both an unconditioned fear reflex and an executive defensive unconditioned reflex. Therefore, both corresponding conditioned reflexes overlap each other to a greater extent than with food conditioned reflexes. However, here, too, a long-acting stimulus, for example, an experimental setting, evokes mainly (or even exclusively) a conditioned fear reflex, while a short stimulus that precedes a harmful unconditioned stimulus also evokes a performance conditioned reflex. The stronger the fear component in a given defensive conditioned reflex, the more stable and stronger the executive reaction, unless, of course, the conditioned fear reflex is so strong as to destroy the corresponding association between the conditioned and unconditioned stimuli.
The usual development of conditioned reflexes leads not only to the formation of associations directed from the experimental setting and the sporadic signal to the unconditioned drive agent and the agent of the executive reflex, respectively, but also to the formation of associations of other types: 1) associations between the experimental setting and the conditioned signal; 2) associations between the unconditional drive agent and the conditioned signal (Fig. 51). Due to these associations, the excitability of neurons that perceive the conditioned signal increases during the experiment. This is why the same conditioned signal, given outside the experimental setting, produces a weaker response or no response at all.

The magnitude of classical conditioned reflexes depends on the intensity of activation in the gnostic fields involved in the formation of the conditioned reflex, on the strength of the reinforcing stimulus, and on the nature of the conditioned signal.
Numerous experiments have shown that the strength of the conditioned response evoked by a given conditioned signal depends on its intensity, lack of monotony, and spatial coincidence with the unconditioned agent. In dogs, auditory cues are more effective than visual cues. All these facts find their explanation in the general properties of the excitability of neurons and the influence of activation on them.

Fig. 51. The main relationships between conditioned signals (CS), experimental environment (Exp. obst.) and unconditional agents of the executive (I) and drive reflex (D).
The best time regime for the formation of a conditioned reflex is some advance of the conditioned signal with its partial coincidence with reinforcement. It is not clear, however, why the simultaneous presentation of a conditioned signal and an unconditioned stimulus does not lead to the formation of a conditioned reflex. If in the same setting two stimuli are given in a random order, then mutual weak associations are formed between them. It is possible that the overlap is a special case of this phenomenon.
Experiments with the removal of certain areas of the cortex, as well as the entire new cortex, showed that although such damage impairs the ability to perceive conditioned signals and unconditioned stimuli, the ability to form conditioned reflexes, as such, remains. We propose a hypothesis according to which the gross perception of stimulus-objects is carried out by the basal ganglia; these ganglia are a primitive multi-analyzer system that establishes connections mainly with the emotive brain. This explains why cortical destruction may be detrimental to certain executive conditioned reflexes, but does not impair conditioned drive reflexes.
Experimental data concerning classical conditioned reflexes in animals shed light on analogous phenomena in humans. The following classical conditioned reflexes play an important role in everyday human life: 1) the conditioned reflex of hunger and the conditioned reflex to food; 2) conditioned drive reflexes and executive reflexes associated with other types of conservation activity (sexual behavior, sleep, defecation, etc.); 3) social conditioned reflexes, when acts of behavior of other people serve as unconditional agents for a person, and people themselves become conditioned signals; 4) conditioned reflexes to printed and oral words, which evoke images of stimulus-objects described by words, causing the corresponding conditioned reflexes. The phenomena of suggestion are also based on this mechanism.