The role of conditioned and unconditioned reflexes. Values ​​of conditioned reflexes. Differences between conditioned and unconditioned reflexes

The student learns about conditioned and unconditioned reflexes even at the first lessons of zoology, when a vivid example of the “Pavlov’s dog” is given, which begins to salivate after a certain signal is given. Then the student gets the first idea about the role of reflexes in human life and about the existence of the so-called "first signal system". However, outside the school curriculum there is such a thing as a “second signaling system”, which is no less important.

The role of the system of conditioned and unconditioned reflexes in human life

What are the types of reflexes, what is the difference between conditioned reflexes and unconditioned ones, and what is their significance?

For example, you burned your finger with a match and pull your hand away, and immediately, without hesitation. Painful irritation of the skin was transmitted by nerve fibers to a group of cells in the central nervous system that are in charge of the motor functions of the muscles of the hands. The excitement that arose in them was immediately transmitted along other nerve fibers to the muscles. They contracted sharply - the hand twitched, the fire no longer burns the finger. This type of human reflex is called unconditioned, there are many such reflexes and they are all congenital.

And conditional reflexes need to be created, worked out. Research in this area is associated with the name of our famous physiologist IP Pavlov. It was this scientist who substantiated the importance of reflexes in human life and proved that if the system of unconditioned reflexes is repeatedly accompanied by a certain stimulus, then after a while the stimulus will begin to cause this reflex.

Here is an example. You are pricked with a needle and at the same time the bell is rung. After a certain number of repetitions, the sound of the bell becomes a signal to withdraw the hand. The needle did not prick, and the hand twitched involuntarily. The conditioned reflex has been created.

Conditioned and unconditioned human reflexes play an important role in life. The child, having been burned by fire, further withdraws his hand before the fire again scorches his skin. A forest animal, having become intimately acquainted with some kind of danger, behaves more cautiously at another time. IP Pavlov called such a perception of the surrounding reality by the human and animal brain the first signaling system.

In addition, a person has a second signaling system. In this case, the conditioned stimulus is words-images and concepts. If, say, a person has experienced the strongest fright associated with a fire, then with him it is enough to shout “Fire!” To cause the same fright.

Both signal systems of conditioned reflexes in our body are closely interconnected. They represent the work of our central nervous system. And the latter regulates all the activities of the body. It is known that various emotional experiences (fear, grief, joy, etc.) can cause changes in the work of the heart (acceleration and slowing of the heartbeat, constriction or expansion of blood vessels, redness or blanching of the skin), can lead to gray hair and so on. This means that in one way or another we can influence the work of many internal organs, including the word. It can significantly affect the psyche, and therefore, the work of the whole organism.

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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 ensure 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

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. At 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

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 cerebral hemispheres.

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 in 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.

In the course of evolutionary and social development, a person has developed a natural system of protection from adverse environmental factors, i.e. from dangers. It is based on the nervous system. Thanks to it, the connection of the organism with the external environment (light, sound, smell, mechanical influences) and various information about the processes inside and outside the body is carried out. The body's response to irritation, carried out and controlled by the central nervous system, is called a reflex, and all the activity of the nervous system is called a reflex. In a variety of reflex activities, there are innate unconditioned reflexes that are inherited and persist throughout the life of the organism.

Unconditioned human reflexes are diverse. For example, pulling back a hand in response to a skin burn, closing the eyes when there is a danger of damaging them, profuse release of tears under the influence of substances that irritate the eyes, etc. These and many other reflexes are called defensive.

A special place among the unconditioned reflexes in ensuring security is occupied by the orienting reflex. It appears in response to a new stimulus: a person is alert, listens, turns his head, squints his eyes, thinks. The orienting reflex provides the perception of an unfamiliar stimulus.

Unconditioned reflexes are a hereditary "program" of behavior. They provide normal interaction only with a stable environment. However, man lives in an exceptionally changeable, mobile, diverse environment. Unconditioned reflexes as permanent connections are not enough to ensure flexible response in a changing environment. It is necessary to supplement them with temporary flexible connections. Such connections are called conditioned reflexes.

Conditioned reflexes are formed on the basis of individual experience. Since the acquisition of individual experience is learning, the formation of conditioned reflexes is one of the types of learning.

The conditioned reflexes formed in the learning process allow the body to adapt more flexibly to specific environmental conditions and underlie the development of habits in a person, the whole way of life.

The adaptive value of conditioned reflexes is enormous. Thanks to them, a person can take the necessary actions in advance to protect himself, focusing on the signs of a possible danger, without seeing the danger itself. Conditioned stimuli are signaling in nature. They warn of danger.

All direct sensations, perceptions and corresponding human reactions are carried out on the basis of unconditioned and conditioned reflexes. However, in the specific conditions of the social environment, a person is guided and reacts not only to direct stimuli. For a person, the signal of any stimulus is the word denoting it, and its semantic content. Words spoken, audible and visible are signals, symbols of specific objects and environmental phenomena. The word man denotes everything that he perceives with the help of the senses.

Words, like other environmental factors (physical, chemical and biological), in relation to human health can be indifferent, can have a beneficial effect, or can be harmful - up to death (suicide).

A reflex is the body's response to an internal or external stimulus, carried out and controlled by the central nervous system. Our compatriots I.P. Pavlov and I.M. Sechenov.

What are unconditioned reflexes?

An unconditioned reflex is an innate stereotyped reaction of the body to the influence of the internal or environment, inherited from the offspring from the parents. It remains with a person throughout his life. Reflex arcs pass through the brain and the cerebral cortex does not take part in their formation. The significance of the unconditioned reflex is that it ensures the adaptation of the human body directly to those changes in the environment that often accompanied many generations of his ancestors.

What reflexes are unconditioned?

The unconditioned reflex is the main form of activity of the nervous system, an automatic response to a stimulus. And since a person is influenced by various factors, then the reflexes are different: food, defensive, indicative, sexual ... Salivation, swallowing and sucking are food. Defensive are coughing, blinking, sneezing, withdrawal of limbs from hot objects. Orienting reactions can be called turns of the head, squinting of the eyes. Sexual instincts include reproduction, as well as caring for offspring. The value of the unconditioned reflex lies in the fact that it ensures the preservation of the integrity of the body, maintains the constancy of the internal environment. Thanks to him, reproduction occurs. Even in newborns, an elementary unconditioned reflex can be observed - this is sucking. By the way, it is the most important. The irritant in this case is the touch to the lips of an object (nipples, mother's breasts, toys or fingers). Another important unconditioned reflex is blinking, which occurs when a foreign body approaches the eye or touches the cornea. This reaction refers to the protective or defensive group. It is also observed in children, for example, when exposed to strong light. However, the signs of unconditioned reflexes are most pronounced in various animals.

What are conditioned reflexes?

Reflexes acquired by the body during life are called conditioned reflexes. They are formed on the basis of inherited ones, subject to the influence of an external stimulus (time, knock, light, and so on). A vivid example is the experiments carried out on dogs by Academician I.P. Pavlov. He studied the formation of this type of reflexes in animals and was the developer of a unique technique for obtaining them. So, to develop such reactions, it is necessary to have a regular stimulus - a signal. It starts the mechanism, and repeated repetition of the stimulus effect allows you to develop. In this case, a so-called temporary connection arises between the arcs of the unconditioned reflex and the centers of the analyzers. Now the basic instinct is awakening under the action of fundamentally new signals of an external nature. These stimuli of the surrounding world, to which the body was previously indifferent, begin to acquire exceptional, vital importance. Each living being can develop many different conditioned reflexes during his life, which form the basis of his experience. However, this applies only to this particular individual; this life experience will not be inherited.

An independent category of conditioned reflexes

In an independent category, it is customary to single out conditioned reflexes of a motor nature developed during life, that is, skills or automated actions. Their meaning lies in the development of new skills, as well as the development of new motor forms. For example, over the entire period of his life, a person masters many special motor skills that are associated with his profession. They are the basis of our behavior. Thinking, attention, consciousness are freed when performing operations that have reached automatism and have become a reality of everyday life. The most successful way of mastering the skills is the systematic implementation of the exercise, the timely correction of the noticed mistakes, as well as the knowledge of the ultimate goal of any task. In the event that the conditioned stimulus is not reinforced for some time by the unconditioned stimulus, its inhibition occurs. However, it does not completely disappear. If, after some time, the action is repeated, the reflex will quickly recover. Inhibition can also occur under the condition of the appearance of an irritant of even greater force.

Compare unconditioned and conditioned reflexes

As mentioned above, these reactions differ in the nature of their occurrence and have a different formation mechanism. In order to understand what the difference is, just compare unconditioned and conditioned reflexes. So, the first are present in a living being from birth, during the whole life they do not change and do not disappear. In addition, unconditioned reflexes are the same in all organisms of a particular species. Their meaning is to prepare the living being for constant conditions. The reflex arc of such a reaction passes through the brain stem or spinal cord. As an example, here are some (congenital): active salivation when a lemon enters the mouth; sucking movement of the newborn; coughing, sneezing, pulling hands away from a hot object. Now consider the characteristics of conditioned reactions. They are acquired throughout life, can change or disappear, and, no less important, they are individual (their own) for each organism. Their main function is the adaptation of a living being to changing conditions. Their temporary connection (centers of reflexes) is created in the cerebral cortex. An example of a conditioned reflex is the reaction of an animal to a nickname, or the reaction of a six-month-old child to a bottle of milk.

Scheme of the unconditioned reflex

According to the research of academician I.P. Pavlov, the general scheme of unconditioned reflexes is as follows. Certain receptor nervous devices are affected by certain stimuli of the internal or external world of the organism. As a result, the resulting irritation transforms the entire process into the so-called phenomenon of nervous excitation. It is transmitted through nerve fibers (as through wires) to the central nervous system, and from there it goes to a specific working organ, already turning into a specific process at the cellular level of this part of the body. It turns out that these or those irritants are naturally connected with this or that activity in the same way as the cause with the effect.

Features of unconditioned reflexes

The characteristic of unconditioned reflexes presented below, as it were, systematizes the material presented above, it will help to finally understand the phenomenon we are considering. So, what are the features of inherited reactions?

Unconditional instinct and animal reflex

The exceptional constancy of the nervous connection underlying the unconditional instinct is explained by the fact that all animals are born with a nervous system. She is already able to respond properly to specific environmental stimuli. For example, a creature might flinch at a harsh sound; he will secrete digestive juice and saliva when food enters the mouth or stomach; it will blink with visual stimulation, and so on. Innate in animals and humans are not only individual unconditioned reflexes, but also much more complex forms of reactions. They are called instincts.

The unconditioned reflex, in fact, is not a completely monotonous, stereotyped, transfer reaction of an animal to an external stimulus. It is characterized, though elementary, primitive, but still by variability, variability, depending on external conditions (strength, peculiarities of the situation, position of the stimulus). In addition, it is also influenced by the internal states of the animal (reduced or increased activity, posture, and others). So, even I.M. Sechenov, in his experiments with decapitated (spinal) frogs, showed that when the toes of the hind legs of this amphibian are acted upon, the opposite motor reaction occurs. From this we can conclude that the unconditioned reflex still has adaptive variability, but within insignificant limits. As a result, we find that the balancing of the organism and the external environment achieved with the help of these reactions can be relatively perfect only in relation to slightly changing factors of the surrounding world. The unconditioned reflex is not able to ensure the adaptation of the animal to new or dramatically changing conditions.

As for the instincts, sometimes they are expressed in the form of simple actions. For example, a rider, thanks to his sense of smell, looks for the larvae of another insect under the bark. He pierces the bark and lays his egg in the found victim. This is the end of all its action, which ensures the continuation of the genus. There are also complex unconditioned reflexes. Instincts of this kind consist of a chain of actions, the totality of which ensures the continuation of the species. Examples include birds, ants, bees and other animals.

Species specificity

Unconditioned reflexes (species) are present in both humans and animals. It should be understood that such reactions in all representatives of the same species will be the same. An example is a turtle. All species of these amphibians retract their heads and limbs into their shells when threatened. And all the hedgehogs jump up and make a hissing sound. In addition, you should be aware that not all unconditioned reflexes occur at the same time. These reactions change according to age and season. For example, the breeding season or the motor and sucking actions that appear in an 18-week-old fetus. Thus, unconditioned reactions are a kind of development for conditioned reflexes in humans and animals. For example, in young children, as they grow older, there is a transition to the category of synthetic complexes. They increase the adaptability of the body to external environmental conditions.

Unconditional braking

In the process of life, each organism is regularly exposed - both from the outside and from the inside - to various stimuli. Each of them is able to cause a corresponding reaction - a reflex. If all of them could be realized, then the vital activity of such an organism would become chaotic. However, this does not happen. On the contrary, reactionary activity is characterized by consistency and orderliness. This is explained by the fact that inhibition of unconditioned reflexes occurs in the body. This means that the most important reflex at a particular moment of time delays the secondary ones. Usually, external inhibition can occur at the time of the start of another activity. The new exciter, being stronger, leads to the attenuation of the old one. And as a result, the previous activity will automatically stop. For example, a dog is eating and at that moment the doorbell rings. The animal immediately stops eating and runs to meet the visitor. There is an abrupt change in activity, and the dog's salivation stops at that moment. Certain innate reactions are also referred to as unconditional inhibition of reflexes. In them, certain pathogens cause a complete cessation of some actions. For example, the anxious clucking of a chicken causes the chickens to freeze and cling to the ground, and the onset of darkness forces the kenar to stop singing.

In addition, there is also a protective id that arises as a response to a very strong stimulus that requires actions from the body that exceed its capabilities. The level of such exposure is determined by the frequency of impulses of the nervous system. The stronger the neuron is excited, the higher the frequency of the flow of nerve impulses that it generates will be. However, if this flow exceeds certain limits, then a process will occur that will begin to prevent the passage of excitation through the neural circuit. The flow of impulses along the reflex arc of the spinal cord and brain is interrupted, as a result, inhibition occurs, which preserves the executive organs from complete exhaustion. What follows from this? Thanks to the inhibition of unconditioned reflexes, the body selects from all possible options the most adequate one, able to protect against excessive activity. This process also contributes to the manifestation of the so-called biological caution.