Conditioned reflexes are formed in the process. Reflex - example

Pull your hand away from a hot kettle, close your eyes at a flash of light... We perform such actions automatically, without having time to think about what exactly we are doing and why. These are the unconditioned human reflexes - innate reactions that are characteristic of all people without exception.

History of discovery, types, differences

Before considering unconditioned reflexes in detail, we will have to make a short digression into biology and talk about reflex processes in general.

So what is a reflex? In psychology, this is called the body's response to a change in the external or internal environment, which is carried out with the help of the central nervous system. Thanks to this ability, the body quickly adapts to changes in the surrounding world or in its internal state. For its implementation, a reflex arc is necessary, that is, the path along which the signal of irritation passes from the receptor to the corresponding organ.

For the first time, reflex reactions were described by Rene Descartes in the 17th century. But the French scientist considered that this is not a psychological phenomenon. He considered reflexes as part of objective natural science knowledge, while psychology at that time was considered, as it were, not a science, because it dealt only with subjective reality, was not subject to objective experiment.

The very concept of "reflex" in the second half of the 19th century was introduced by the Russian physiologist I. M. Sechenov. He proved that reflex activity is a single principle of operation of the entire central nervous system. The scientist demonstrated that the initial cause of a mental phenomenon or human action is given by the influence of the external environment or irritation of the nervous system inside the body.

And if the sense organs do not experience irritation, and sensitivity is lost, mental life freezes. Recall the well-known expression: "tired until you lose your senses." Indeed, when we are very tired, we, as a rule, do not see dreams and become almost insensitive to external stimuli: noise, light, even pain.

Sechenov's research was continued by IP Pavlov. He came to the conclusion that there are innate reflexes, for the occurrence of which no special conditions are needed, and acquired, arising during the adaptation of the organism to the external environment.

Surely many will now remember the famous Pavlov's dog. And not in vain: while studying digestion in animals, the scientist noticed that in experimental dogs, salivation did not begin when food was served, but already at the sight of the assistant researcher, who usually brought food.

If the release of saliva when serving food is a typical unconditioned reflex, and it is characteristic of all dogs, then saliva already at the sight of an assistant is a typical conditioned reflex developed in individual animals. Hence the main difference between the two types: genetic congestion or occurrence under the influence of the environment. In addition, unconditioned and conditioned reflexes differ in a number of other indicators.

• Unconditioned are present in all individuals of the species, regardless of their living conditions; conditional, on the contrary, arise under the influence of the individual conditions of the organism's life (this difference is clear from the name of each species).
• Unconditioned responses are the foundation upon which conditioned responses can be built, but they need constant reinforcement.
• reflex arcs unconditioned reflexes are closed in the lower parts of the brain, as well as in the spinal cord. Conditional arcs are formed in the cerebral cortex.
• Unconditioned reflex processes are unchanged throughout a person's life, although they can be somewhat transformed in the event of a serious illness. Conditional - appear and disappear. In other words, in one case the reflex arcs are permanent, in the other they are temporary.

From these differences, it is easy to add up general characteristics unconditioned reflexes: they are hereditary, unchanging, inherent in all representatives of the species and support the life of the organism in constant environmental conditions.

Where do

As already mentioned, both conditioned and unconditioned reflexes are possible due to the work of the central nervous system. Its most important components are the brain and spinal cord. As an example of an unconditioned reflex, for which the spinal cord is responsible, we can cite the well-known knee reflex.

The doctor gently hits the hammer in a certain place, which causes involuntary extension of the lower leg. Normally, this reflex should be of medium severity, but if it is too weak or too strong, this is most likely evidence of pathology.

Unconditioned reflexes of the brain are numerous. In the lower parts of this organ there are various reflex centers. So, if you move up from the spinal cord, the first will be the medulla oblongata. Sneezing, coughing, swallowing, salivation - these reflex processes are possible precisely due to the work of the medulla oblongata.

Under the control of the midbrain - reactions that occur in response to visual or auditory impulses. This includes constriction or expansion of the pupil, depending on the amount of light falling on it, a reflex turn towards the source of sound or light. The action of such reflexes extends only to unfamiliar stimuli.

That is, for example, with numerous sharp sounds, a person will each time turn to a new place of the noise, and not continue to listen, trying to understand where the first sound came from. Through the intermediate section of the brain, the so-called unconditioned reflex of posture straightening closes. These are the muscle contractions with which our body responds to a change in posture; they allow the body to be held in a new position.

Classification

Classification of unconditioned reflexes is carried out according to different criteria. For example, there is a division that is understandable even to a non-specialist into simple, complex and complex.

The example given at the beginning of the text about pulling the hand away from the teapot is a simple unconditioned reflex. Difficult ones include, for example, sweating. And if we are dealing with a whole chain of simple actions, then we are already talking about a group of the most complex ones: for example, self-preservation reflexes, care for offspring. Such a set of behavioral programs is usually called instinct.

The classification is quite simple in relation to the organism to the stimulus. Based on it, unconditioned reflex reactions are divided into positive (search for food by smell) and negative (desire to escape from the source of noise).

By biological significance the following types of unconditioned reflexes are distinguished:

• Food (swallowing, sucking, salivation).
• Sexual (sexual arousal).
• Defensive or protective (the same withdrawal of hands or the desire to cover the head with hands, if it seems to a person that a blow will follow now).
• Approximate (the desire to identify unfamiliar stimuli: turn your head to a sharp sound or touch). They have already been discussed when we talked about the reflex centers of the midbrain.
• Locomotive, that is, employees for movement (support the body in a certain position in space).

Very often in scientific literature there is a classification proposed by the Russian scientist P. V. Simonov. He divided all unconditioned reflexes into three groups: vital, role and self-development reflexes.

Vital (from the Latin vitalis - "life") are directly related to the preservation of the life of the individual. This is a food, defensive, effort-saving reflex (if the result of actions is the same, one chooses what takes away less strength), regulation of sleep and wakefulness.

If the corresponding need is not satisfied, the physical existence of the organism ceases, another representative of the species is not needed to realize the reflex - these are the signs that unite all the reactions of this group.

Role-playing can be done, on the contrary, only in contact with another individual. These primarily include parental and sexual reflexes. The last group includes such reflexes as play, research, imitation reflex of another individual.

Of course, there are other variants of classification, as well as other views on the methods of division given here. And this is not surprising: unanimity is rarely found among scientists.

Features and meaning

As we have already said, the reflex arcs of unconditioned reflexes are constant, but they themselves can be active at different periods of a person's life. So, for example, sexual reflexes appear when the body reaches a certain age. Other reflex processes, on the contrary, fade away after a certain period of time. Suffice it to recall the infant's unconscious grabbing of an adult's finger when pressing on his palm, which disappears with age.

The value of unconditioned reflexes is enormous. It is they who help to survive not only an individual organism, but the whole species. They are most significant in early stages life of a person, when knowledge about the world has not yet been accumulated and the activities of the child are guided precisely by reflex processes.

Unconditioned reflexes begin to work from the very moment of birth. Thanks to them, the body does not die during an abrupt transition to new conditions of existence: adaptation to a new type of breathing and nutrition occurs instantly, and the mechanism of thermoregulation is gradually being established.

Moreover, according to recent research, certain unconditioned reflexes are carried out even in the womb (for example, sucking). With age, more and more conditioned reflexes are added to the unconditioned, which allow a person to better adapt to a changing environment. Author: Evgenia Bessonova

The body on the action of the stimulus, which is carried out with the participation of the nervous system and is controlled by it. According to Pavlov's ideas, the main principle of the nervous system is the reflex principle, and the material basis is the reflex arc. Reflexes are conditional and unconditional.

Reflexes are conditional and unconditional. are reflexes that are inherited, passed down from generation to generation. In humans, by the time of birth, the almost reflex arc of unconditioned reflexes is fully formed, with the exception of sexual reflexes. Unconditioned reflexes are species-specific, that is, they are characteristic of individuals of a given species.

Conditioned reflexes(UR) is an individually acquired reaction of the body to a previously indifferent stimulus ( stimulus- any material agent, external or internal, conscious or unconscious, acting as a condition for subsequent states of the organism. Signal stimulus (aka indifferent) - an irritant that did not previously cause an appropriate reaction, but under certain conditions of formation, which begins to cause it), reproducing an unconditioned reflex. SD are formed during life, associated with the accumulation of life. They are individual for each person or animal. Able to fade if not reinforced. Quenched conditioned reflexes do not disappear completely, that is, they are capable of recovery.

The physiological basis of the conditioned reflex is the formation of new or modification of existing nerve connections that occur under the influence of changes in the external and internal environment. These are temporary connections belt connection- this is a set of neurophysiological, biochemical and ultrastructural changes in the brain that occur in the process of combining conditioned and unconditioned stimuli and form certain relationships between various brain formations), which are inhibited when the situation is canceled or changed.

General properties of conditioned reflexes. Despite certain differences, conditioned reflexes are characterized by the following general properties (features):

• All conditioned reflexes are one of the forms of adaptive reactions of the body to changing environmental conditions.
• SD are acquired and canceled in the course of the individual life of each individual.
• All SDs are formed with the participation of .
• SD are formed on the basis of unconditioned reflexes; without reinforcement, conditioned reflexes are weakened and suppressed over time.
• All types of conditioned reflex activity are signal warning character. Those. precede, prevent the subsequent occurrence of BR. Prepare the body for any biologically purposeful activity. SD is a reaction to a future event. SDs are formed due to the plasticity of the NS.

The biological role of SD is to expand the range of adaptive capabilities of the organism. SD complements BR and allows you to subtly and flexibly adapt to a wide variety of conditions environment.

Differences between conditioned reflexes and unconditioned

1. Unconditioned reactions are congenital, hereditary reactions, they are formed on the basis of hereditary factors and most of them begin to function immediately after birth. Conditioned reflexes are acquired reactions in the process of individual life.
2. Unconditioned reflexes are specific, i.e., these reflexes are characteristic of all representatives of a given species. Conditioned reflexes are individual, in some animals some conditioned reflexes can be developed, in others others.
3. Unconditioned reflexes are constant, they persist throughout the life of the organism. Conditioned reflexes are fickle, they can arise, gain a foothold and disappear.
4. Unconditioned reflexes are carried out at the expense of the lower parts of the central nervous system (subcortical nuclei,). Conditioned reflexes are predominantly a function of the higher parts of the central nervous system - the cerebral cortex.
5. Unconditioned reflexes are always carried out in response to adequate stimuli acting on a certain receptive field, that is, they are structurally fixed. Conditioned reflexes can be formed to any stimuli, from any receptive field.
6. Unconditioned reflexes are reactions to direct stimuli (food, being in the oral cavity, causes salivation). Conditioned reflex - a reaction to the properties (signs) of the stimulus (food, type of food cause salivation). Conditional reactions are always signal in nature. They signal the upcoming action of the stimulus and the body meets the impact of the unconditioned stimulus, when all the responses are already turned on, ensuring the body is balanced by the factors that cause this unconditioned reflex. So, for example, food, getting into the oral cavity, meets saliva there, which is released conditioned reflex (by the type of food, by its smell); muscular work begins when the conditioned reflexes developed for it have already caused a redistribution of blood, an increase in respiration and blood circulation, etc. This manifests the highest adaptive nature of conditioned reflexes.
7. Conditioned reflexes are developed on the basis of unconditioned ones.
8. A conditioned reflex is a complex multicomponent reaction.
9. Conditioned reflexes can be developed in life and in laboratory conditions.

Conditioned reflexes are complex adaptive reactions of the body, carried out by the higher parts of the central nervous system by forming a temporary connection between the signal stimulus and the unconditional reflex act that reinforces this stimulus. Based on the analysis of the patterns of formation of conditioned reflexes, the school created the doctrine of higher nervous activity (see). Unlike unconditioned reflexes (see), which ensure the adaptation of the body to the constant influences of the external environment, conditioned reflexes enable the body to adapt to changing environmental conditions. Conditioned reflexes are formed on the basis of unconditioned reflexes, which requires the coincidence in time of some stimulus from the external environment (conditioned stimulus) with the implementation of one or another unconditioned reflex. The conditioned stimulus becomes a signal of a dangerous or favorable situation, enabling the body to respond with an adaptive reaction.

Conditioned reflexes are unstable and are acquired in the process of individual development of the organism. Conditioned reflexes are divided into natural and artificial. The first ones arise in response to natural stimuli in the natural conditions of existence: the puppy, which received meat for the first time, sniffs it for a long time and timidly eats it, and this act of eating is accompanied. In the future, only the sight and smell of meat causes the puppy to lick and excrete. Artificial conditioned reflexes are developed in an experimental setting, when the conditioned stimulus for the animal is an impact that is not related to unconditioned reactions in the natural habitat of animals (for example, flashing light, the sound of a metronome, sound clicks).

Conditioned reflexes are divided into food, defensive, sexual, indicative, depending on the unconditioned reaction that reinforces the conditioned stimulus. Conditioned reflexes can be named depending on the recorded response of the body: motor, secretory, vegetative, excretory, and can also be designated by the type of conditioned stimulus - light, sound, etc.

For the development of conditioned reflexes in an experiment, a number of conditions are necessary: ​​1) the conditioned stimulus must always precede the unconditioned stimulus in time; 2) the conditioned stimulus should not be strong so as not to cause its own reaction of the organism; 3) as a conditional stimulus is taken, usually found in the surrounding conditions of the habitat of a given animal or person; 4) the animal or person must be healthy, vigorous and have sufficient motivation (see).

There are also conditioned reflexes of various orders. When a conditioned stimulus is reinforced with an unconditioned stimulus, a first-order conditioned reflex is developed. If some stimulus is reinforced by a conditioned stimulus, to which a conditioned reflex has already been developed, then a second-order conditioned reflex is developed to the first stimulus. Conditioned reflexes of higher orders are developed with difficulty, which depends on the level of organization of a living organism.

In a dog, it is possible to develop conditioned reflexes up to 5-6 orders, in a monkey - up to 10-12 orders, in a person - up to 50-100 orders.

The works of I. P. Pavlov and his students established that the leading role in the mechanism of the occurrence of conditioned reflexes belongs to the formation of a functional connection between the centers of excitation from conditioned and unconditioned stimuli. An important role was assigned to the cerebral cortex, where the conditioned and unconditioned stimuli, creating foci of excitation, began to interact with each other, creating temporary connections. Later, using electrophysiological research methods, it was found that the interaction between conditioned and unconditioned excitations can first occur at the level of the subcortical structures of the brain, and at the level of the cerebral cortex, the formation of an integral conditioned reflex activity is carried out.

However, the cerebral cortex always keeps the activity of subcortical formations under control.

Studies of the activity of single neurons of the central nervous system by the microelectrode method showed that both conditioned and unconditioned excitations (sensory-biological convergence) come to one neuron. It is especially pronounced in the neurons of the cerebral cortex. These data forced us to abandon the idea of ​​the presence of foci of conditioned and unconditioned excitation in the cerebral cortex and create the theory of convergent closure of the conditioned reflex. According to this theory, a temporary connection between conditioned and unconditioned excitation arises in the form of a chain of biochemical reactions in the protoplasm of the nerve cell of the cerebral cortex.

Modern ideas about conditioned reflexes have been significantly expanded and deepened due to the study of the higher nervous activity of animals in the conditions of their free natural behavior. It has been established that the environment, along with the time factor, plays an important role in the behavior of the animal. Any stimulus from the external environment can become conditional, allowing the body to adapt to environmental conditions. As a result of the formation of conditioned reflexes, the body reacts some time before exposure to an unconditioned stimulus. Consequently, conditioned reflexes contribute to the successful finding of food by animals, help to avoid danger in advance and most perfectly navigate in the changing conditions of existence.

Our nervous system is a complex mechanism for the interaction of neurons that send impulses to the brain, and it, in turn, controls all organs and ensures their work. This process of interaction is possible due to the presence in humans of the main inseparable acquired and innate forms of adaptation - conditional and unconditional reactions. A reflex is a conscious response of the body to certain conditions or stimuli. Such well-coordinated work of nerve endings helps us interact with the outside world. A person is born with a set of simple skills - this is called An example of such behavior: the ability of an infant to suck on its mother's breast, swallow food, blink.

and animal

As soon as a living being is born, he needs certain skills that will help ensure his life. The body actively adapts to the surrounding world, that is, it develops a whole range of purposeful motor skills. This mechanism is called species behavior. Each living organism has its own set of reactions and congenital reflexes, which is inherited and does not change throughout life. But the behavior itself is distinguished by the method of its implementation and application in life: congenital and acquired forms.

Unconditioned reflexes

Scientists claim that congenital form behavior is an unconditioned reflex. An example of such manifestations has been observed since the birth of a person: sneezing, coughing, swallowing saliva, blinking. The transfer of such information is carried out by inheritance of the parent program by centers that are responsible for reactions to stimuli. These centers are located in the brain stem or spinal cord. Unconditioned reflexes help a person quickly and accurately respond to changes in the external environment and homeostasis. Such reactions have a clear demarcation depending on biological needs.

• Food.
• Approximate.
• Protective.
• Sexual.

Depending on the species, living beings have different reactions to the world, but all mammals, including humans, have a sucking skill. If you attach an infant or a young animal to the mother's nipple, a reaction will immediately occur in the brain and the feeding process will begin. This is the unconditioned reflex. Examples of eating behavior are inherited in all creatures that receive nutrients from mother's milk.

Defense reactions

These types of reactions to external stimuli are inherited and are called natural instincts. Evolution has laid in us the need to protect ourselves and take care of our safety in order to survive. Therefore, we have learned to instinctively respond to danger, this is an unconditioned reflex. Example: Have you noticed how the head deviates if someone raises a fist over it? When you touch a hot surface, your hand withdraws. This behavior is also called hardly a person in their right mind will try to jump from a height or eat unfamiliar berries in the forest. The brain immediately starts the process of processing information that will make it clear whether it is worth risking your life. And even if it seems to you that you don’t even think about it, the instinct immediately works.

Try to bring your finger to the baby's palm, and he will immediately try to grab it. Such reflexes have been developed over the centuries, however, now such a skill is not really needed by a child. Even among primitive people, the baby clung to the mother, and so she endured him. There are also unconscious innate reactions, which are explained by the connection of several groups of neurons. For example, if you hit the knee with a hammer, it will twitch - an example of a two-neuron reflex. In this case, two neurons come into contact and send a signal to the brain, causing it to respond to an external stimulus.

Delayed reactions

However, not all unconditioned reflexes appear immediately after birth. Some arise as needed. For example, a newborn baby practically does not know how to navigate in space, but after about a couple of weeks he begins to react to external stimuli - this is an unconditioned reflex. Example: the child begins to distinguish the voice of the mother, loud sounds, bright colors. All these factors attract his attention - an indicative skill begins to form. involuntary attention is Starting point in the formation of an assessment of stimuli: the baby begins to understand that when the mother speaks to him and approaches him, most likely, she will take him in her arms or feed him. That is, a person forms a complex form of behavior. His crying will draw attention to him, and he uses this reaction consciously.

sexual reflex

But this reflex belongs to the unconscious and unconditioned, it is aimed at procreation. It occurs during puberty, that is, only when the body is ready for procreation. Scientists say that this reflex is one of the strongest, it determines the complex behavior of a living organism and subsequently triggers the instinct to protect its offspring. Despite the fact that all these reactions are inherently human, they are launched in a certain order.

Conditioned reflexes

In addition to the instinctive responses that we are born with, a person needs many other skills in order to better adapt to the world around him. Acquired behavior is formed both in animals and in humans throughout life, this phenomenon is called "conditioned reflexes". Examples: at the sight of food, salivation occurs, if the diet is observed, there is a feeling of hunger at a certain time of the day. Such a phenomenon is formed by a temporary connection between the center or vision) and the center of the unconditioned reflex. An external stimulus becomes a signal for a certain action. Visual images, sounds, smells are able to form stable connections and give rise to new reflexes. When someone sees a lemon, salivation may begin, and with a sharp smell or contemplation of an unpleasant picture, nausea occurs - these are examples of conditioned reflexes in humans. Note that these reactions can be individual for each living organism, temporary connections are formed in the cerebral cortex and send a signal when an external stimulus occurs.

Throughout life, conditioned responses can come and go. Everything depends on For example, in childhood, a child reacts to the sight of a bottle of milk, realizing that this is food. But when the baby grows up, this object will not form an image of food for him, he will react to a spoon and a plate.

Heredity

As we have already found out, unconditioned reflexes are inherited in every species of living beings. But conditioned reactions affect only the complex behavior of a person, but are not transmitted to descendants. Each organism "adjusts" to a particular situation and the reality surrounding it. Examples of innate reflexes that do not disappear throughout life: eating, swallowing, reaction to the taste of the product. Conditioned stimuli change constantly depending on our preferences and age: in childhood, at the sight of a toy, the baby experiences joyful emotions; in the process of growing up, the reaction is caused, for example, by visual images of a film.

Animal reactions

Animals, like humans, have both unconditioned innate reactions and acquired reflexes throughout their lives. In addition to the instinct of self-preservation and the production of food, living beings also adapt to the environment. They develop a reaction to the nickname (pets), with repeated repetition, an attention reflex appears.

Numerous experiments have shown that it is possible to instill in a pet many reactions to external stimuli. For example, if at each feeding you call the dog with a bell or a certain signal, he will have a strong perception of the situation, and he will immediately react. In the process of training, rewarding a pet for an executed command with a favorite treat forms a conditioned reaction, walking a dog and the type of leash signals an imminent walk where he should relieve himself are examples of reflexes in animals.

Summary

The nervous system constantly sends a lot of signals to our brain, they form the behavior of humans and animals. The constant activity of neurons allows us to perform habitual actions and respond to external stimuli, helping to better adapt to the world around us.

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 its 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 various factors affect a person, 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, was the developer unique methodology receiving 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 organism was previously indifferent, begin to acquire an 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, by inheritance this life experience will not be transmitted.

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 become a reality. 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. Pavlova, general scheme unconditioned reflexes is as follows. Certain receptor nerve devices are affected by certain stimuli of the internal or outside world organism. As a result, the resulting irritation transforms the entire process into the so-called phenomenon nervous excitement. 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 executive bodies from complete exhaustion. What follows from this? Thanks to the inhibition of unconditioned reflexes, the body secretes from all options the most adequate, capable of protecting against unbearable activities. This process also contributes to the manifestation of the so-called biological caution.