Conditioned reflexes dominate over unconditioned congenital ones. What are conditioned reflexes? What is a conditioned reflex

Reflex- this is the body's response to irritation of receptors, carried out by the nervous system. The path along which the nerve impulse passes during the implementation of the reflex is called the reflex arc.

The concept of "reflex" introduced Sechenov, he believed that "reflexes form the basis of the nervous activity of man and animals." Pavlov divided reflexes into conditioned and unconditioned.

Comparison of conditioned and unconditioned reflexes

unconditional	conditional
present from birth	acquired over a lifetime
do not change or disappear during life	may change or disappear over the course of a lifetime
the same in all organisms of the same species	each organism has its own individual
adapt the body to constant conditions	adapt the body to changing conditions
reflex arc passes through the spinal cord or brainstem	temporary connection is formed in the cerebral cortex
Examples
salivation when lemon is in the mouth	salivation at the sight of a lemon
sucking reflex of the newborn	reaction of a 6 month old baby to a bottle of milk
sneezing, coughing, withdrawing hand from a hot kettle	reaction of a cat / dog to a nickname

Development of a conditioned reflex

Conditional (indifferent) stimulus must precede unconditional(causing an unconditioned reflex). For example: a lamp is lit, after 10 seconds the dog is given meat.

Conditional (non-reinforcement): the lamp is lit, but no meat is given to the dog. Gradually, salivation to the switched on lamp stops (there is a fading of the conditioned reflex).

Unconditional: during the action of a conditioned stimulus, a powerful unconditioned stimulus arises. For example, when the lamp is turned on, the bell rings loudly. Saliva is not secreted.

MORE INFO: Reflex, reflex arc, conditioned and unconditioned reflexes, Production and inhibition of conditioned reflexes
PART 2 ASSIGNMENTS: Reflexes

Tests and assignments

Choose one, the most correct option. The centers of conditioned reflexes, unlike unconditioned ones, are located in humans in
1) cerebral cortex
2) medulla oblongata
3) cerebellum
4) midbrain

Choose one, the most correct option. Salivation in a person at the sight of a lemon - a reflex
1) conditional
2) unconditional
3) protective
4) indicative

Choose three options. The peculiarity of unconditioned reflexes is that they



5) are congenital
6) are not inherited

Choose three correct answers from six and write down the numbers under which they are indicated. Unconditioned reflexes that ensure the vital activity of the human body,
1) are developed in the process of individual development
2) formed in the process of historical development
3) are present in all individuals of the species
4) strictly individual
5) formed under relatively constant environmental conditions
6) are not congenital

Choose three correct answers from six and write down the numbers under which they are indicated. The peculiarity of unconditioned reflexes is that they
1) arise as a result of repeated repetition
2) are a feature characteristic of a single individual of the species
3) are genetically programmed
4) characteristic of all individuals of the species
5) are congenital
6) form skills

Choose one, the most correct option. What are the features of spinal reflexes in humans and mammals
1) are acquired during life
2) are inherited
3) different in different individuals
4) allow the organism to survive in changing environmental conditions

Choose one, the most correct option. The extinction of a conditioned reflex when it is not reinforced by an unconditioned stimulus is
1) unconditional braking
2) conditional inhibition
3) rational action
4) a conscious act

Choose one, the most correct option. Conditioned reflexes in humans and animals provide
1) adaptation of the body to constant environmental conditions
2) adaptation of the body to a changing external world
3) development of organisms of new motor skills
4) differentiation of the trainer's commands by animals

Choose one, the most correct option. A baby's reaction to a bottle of milk is a reflex that
1) is inherited
2) is formed without the participation of the cerebral cortex
3) are acquired during life
4) persists throughout life

Choose one, the most correct option. When developing a conditioned reflex, the conditioned stimulus must
1) act 2 hours after the unconditional
2) follow immediately after the unconditional
3) precede unconditional
4) gradually loosen

1. Establish a correspondence between the value of the reflex and its type: 1) unconditional, 2) conditional. Write the numbers 1 and 2 in the correct order.
A) provides instinctive behavior
B) provides adaptation of the organism to environmental conditions in which many generations of this species lived
C) allows you to gain new experience
D) determines the behavior of the organism in changing conditions

2. Establish a correspondence between the types of reflexes and their characteristics: 1) conditional, 2) unconditional. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) are congenital
B) adaptations to new emerging factors
C) reflex arcs are formed in the process of life
D) the same for all representatives of the same species
D) underlie learning
E) are constant, practically do not fade during life

3. Establish a correspondence between the characteristics and types of reflexes: 1) conditional, 2) unconditional. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) acquired in the course of life
B) characteristic of all representatives of this species
B) unstable, able to fade
D) provide adaptation to changing environmental conditions
D) permanent, persist throughout life
E) are passed on to offspring in generations

Choose one, the most correct option. Conditional (internal) braking
1) depends on the type of higher nervous activity
2) appears when a stronger stimulus occurs
3) causes the formation of unconditioned reflexes
4) occurs when the conditioned reflex fades

Choose one, the most correct option. The basis of the nervous activity of humans and animals is
1) thinking
2) instinct
3) arousal
4) reflex

1. Establish a correspondence between examples and types of reflexes: 1) unconditional, 2) conditional. Write the numbers 1 and 2 in the correct order.
A) withdrawing the hand from the fire of a burning match
B) crying of a child at the sight of a man in a white coat
C) stretching the hand of a five-year-old child to the sweets he saw
D) swallowing pieces of cake after chewing them
E) salivation at the sight of a beautifully set table
E) downhill skiing

2. Establish a correspondence between the examples and the types of reflexes they illustrate: 1) unconditional, 2) conditional. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) sucking movements of the child in response to touching his lips
B) constriction of the pupil, illuminated by the bright sun
C) performing hygiene procedures before going to bed
D) sneezing when dust enters the nasal cavity
D) salivation to the sound of dishes when setting the table
E) rollerblading

© D.V. Pozdnyakov, 2009-2018

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Unconditioned reflexes are congenital, hereditarily transmitted reactions of the body. Conditioned reflexes- these are reactions acquired by the body in the process of individual development on the basis of "life experience".

Unconditioned reflexes are specific, i.e.

Unconditioned and conditioned reflexes

common to all members of this species. Conditioned reflexes are individual: some representatives of the same species may have them, while others may not.

Unconditioned reflexes are relatively constant; conditioned reflexes are unstable and, depending on certain conditions, they can be developed, consolidated or disappear; this is their property and is reflected in their very name.

Unconditioned reflexes are carried out in response to adequate stimuli applied to one specific receptive field.

Conditioned reflexes can be formed in response to a wide variety of stimuli applied to various receptive fields.

In animals with a developed cerebral cortex, conditioned reflexes are a function of the cerebral cortex. After the removal of the cerebral cortex, the developed conditioned reflexes disappear and only unconditioned reflexes remain. This indicates that in the implementation of unconditioned reflexes, in contrast to conditioned reflexes, the leading role belongs to the lower parts of the central nervous system - the subcortical nuclei, the brain stem and the spinal cord. It should be noted, however, that in humans and monkeys, which have a high degree of corticalization of functions, many complex unconditioned reflexes are carried out with the obligatory participation of the cerebral cortex. This is proved by the fact that its lesions in primates lead to pathological disturbances of unconditioned reflexes and the disappearance of some of them.

It should also be emphasized that not all unconditioned reflexes appear immediately at the time of birth. Many unconditioned reflexes, for example, those associated with locomotion, sexual intercourse, occur in humans and animals a long time after birth, but they necessarily appear under the condition of normal development of the nervous system. Unconditioned reflexes are part of the fund of reflex reactions that has become stronger in the process of phylogenesis and is hereditarily transmitted.

Conditioned reflexes are developed on the basis of unconditioned reflexes. For the formation of a conditioned reflex, it is necessary to combine in time some kind of litto change in the external environment or the internal state of the organism, perceived by the cerebral cortex, with the implementation of one or another unconditioned reflex. Only under this condition does a change in the external environment or the internal state of the organism become an irritant of the conditioned reflex - a conditioned stimulus, or signal. The stimulus that causes the unconditioned reflex, the unconditioned stimulus, must, during the formation of the conditioned reflex, accompany the conditioned stimulus, reinforce it.

In order for the ringing of knives and forks in the dining room or the knock of a cup from which a dog is fed to cause salivation in the first case in a person, in the second case in a dog, these sounds need to coincide again with food - reinforcement of stimuli that are initially indifferent in relation to salivary secretion by feeding , i.e., unconditioned irritation of the salivary glands. Likewise, the flashing of an electric light before the dog's eyes or the sound of a bell will only cause a conditioned reflex flexion of the paw if they are repeatedly accompanied by electrical stimulation of the skin of the leg, causing an unconditioned flexion reflex with each application.

Similarly, the crying of a child and his pulling his hands away from a burning candle will be observed only if the sight of the candle coincided at least once with the sensation of a burn. In all the examples cited, external agents that are relatively indifferent at the beginning - the ringing of dishes, the sight of a burning candle, the flashing of an electric light bulb, the sound of a bell - become conditioned stimuli if they are reinforced by unconditioned stimuli. Only under this condition, the initially indifferent signals of the external world become irritants of a certain type of activity.

For the formation of conditioned reflexes, it is necessary to create a temporary connection, a circuit between the cortical cells that perceive the conditioned stimulation, and the cortical neurons that make up the arc of the unconditioned reflex.

With the coincidence and combination of conditioned and unconditioned stimuli, a connection is established between various neurons in the cortex of the cerebral hemispheres, and a closure process occurs between them.

Main article: Higher nervous activity

Reflex is the body's response to external and internal stimuli through the nervous system. The reflex is the main and specific function of the central nervous system. All activity of the human body is carried out through reflexes. For example, the sensation of pain, limb movements, breathing, blinking, and other actions are essentially reflexes.

reflex arc

Each reflex has its own reflex arc, which consists of the following five parts:

• a receptor located in tissues and organs and perceiving irritations of the external and internal environment;
• a sensitive nerve fiber that transmits impulses generated by excitation of the receptor to the nerve center;
• the nerve center, which consists of sensory, intercalary, motor nerve cells located in the brain;
• motor nerve fiber, which transmits the excitation of the nerve center to the working organ;
• working organ - muscles, glands, blood vessels, internal organs and others.

Types of reflexes

Depending on which part of the central nervous system is involved in the manifestation of the body's response to stimuli, two types of reflexes are distinguished: unconditioned and conditioned.

Unconditioned reflexes

see Normal reflexes

The formation of unconditioned reflexes involves the lower parts of the central nervous system - the nerve centers of the spinal, oblong, middle, diencephalon. Unconditioned reflexes are innate, since their nerve pathways already exist in a newborn child. These reflexes serve to ensure important life processes in the human body. For example, chewing write (sucking the breast by a child), swallowing, digestion, excretion of feces and urine, breathing, blood circulation and others. Unconditioned reflexes are constant, that is, they do not change (do not disappear) during a person's life. Their number and appearance are almost the same in all people. These reflexes are inherited.

Conditioned reflexes

The centers of conditioned reflexes are located in the cerebral cortex of the cerebral hemispheres. At the birth of a child, these reflexes are absent, they are formed during a person's life. The neural pathways of conditioned reflexes are also absent at birth, they are subsequently formed as a result of upbringing, training and life experience.

The formation of conditioned reflexes

Conditioned reflexes are formed on the basis of unconditional ones. For the formation of a conditioned reflex, it is necessary that the unconditioned stimulus act first, followed by the conditioned stimulus. So, for example, to develop a salivary conditioned reflex in a dog, first turn on an electric light bulb or a bell as a conditioned one, then give it food as an unconditioned stimulus. When this experience is repeated several times, a temporary connection is formed between the centers of nutrition and vision or hearing in the brain. As a result, just turning on an electric light bulb or a bell will cause the dog to salivate (even in the absence of food), that is, a salivary conditioned reflex will appear in response to a flash of light or a bell (Fig. 70). In this case, the flash of an electric light bulb excites the visual center in the ordinal part of the brain. This excitation, through a temporary connection, causes excitation of the subcortical food center. It, in turn, causes excitation of the food center located in the medulla oblongata, and as a result of increased activity of the salivary glands through nerve fibers, salivation begins. The figure shows, first, under the action of light, the excitation of the subcortical visual center, its distribution through a temporary connection to the subcortical food center, and from it to the subcortical center in the medulla oblongata, and finally, its entry into the salivary glands, causing salivation. Material from the site http://wiki-med.com

Inhibition of conditioned reflexes

It is known that during the implementation of the resulting conditioned reflex, if some strong external stimulus suddenly affects a dog (or a person), then a strong excitation occurs in the nerve center of the brain. This excitation by induction inhibits the center of the conditioned reflex and the reflex temporarily stops. Thus, in the figure one can see how, under the influence of the light of an electric lamp, a conditioned reflex of salivation appears in a dog; as a result of an additional strong stimulus - a call, the auditory center is excited, the centers of conditioned reflexes are inhibited, and salivation stops.

Pathological reflexes

§one. Conditioned and unconditioned reflexes

Pathological reflexes

Study of reflexes

see Study of reflexes

In clinical practice, normal segmental as well as pathological reflexes are examined. The course of segmental processes is influenced by suprasegmental structures, therefore segmental reflexes are often violated even with certain suprasegmental lesions, and suprasegmental disorders are of decisive importance in the implementation of a number of pathological reflexes.

On this page, material on the topics:

• what is reflex reasoning

• essay on reflexes

• stem

• reflex+report

• short message unconditioned and conditioned reflexes

Questions for this article:

• What is the difference between unconditioned and conditioned reflexes?

• How is the conditioned reflex inhibited?

Material from the site http://Wiki-Med.com

Classification of reflexes. What are the reflexes.

The functioning of the nervous system is based on the inseparable unity of congenital and acquired forms of adaptation, i.e. unconditioned and conditioned reflexes.

Unconditioned reflexes are congenital, relatively constant species reactions of the body, carried out through the nervous system in response to the action of certain stimuli. They ensure the coordinated activity of various functional systems of the body, aimed at maintaining its homeostasis and interaction with the environment. Examples of simple unconditioned reflexes can be knee, blinking, swallowing and others.

There is a large group of complex unconditioned reflexes: self-preservation, food, sexual, parental (caring for offspring), migratory, aggressive, locomotor (walking, running, flying, swimming), etc. Such reflexes are called instincts. They underlie the innate behavior of animals and represent complexes of stereotyped species-specific motor acts and complex forms of behavior.

A conditioned reflex is a reaction of the body acquired during an individual life, carried out due to the formation in the higher parts of the central nervous system of temporary variable reflex pathways in response to the action of any signal stimulus, for the perception of which there is a responsible receptor apparatus. An example is the classical conditioned reflex of I. P. Pavlov - salivation by a dog to the sound of a bell, which had previously been combined several times with feeding animals. A conditioned reflex is formed as a result of a combination of the action of two stimuli - conditioned and unconditioned.

Unconditioned is the stimulus that causes the implementation of the unconditioned reflex. For example, turning on a bright light causes a constriction of the pupil, the action of an electric current causes the dog to withdraw its paw.

A conditioned stimulus is any neutral stimulus that, after repeated combination with an unconditioned stimulus, acquires a signal value. Yes, the sound of a call that is repeated leaves the animal indifferent to it. However, the sound of the bell is combined with feeding the animal (unconditioned stimulus), then after several repetitions of both stimuli, the bell becomes a conditioned stimulus, warns the animal about the presentation of food and causes it to salivate.

Conditioned reflexes can be classified according to receptor characteristics, according to the nature of the conditioned stimulus, according to the time of action of the conditioned and unconditioned stimuli, and according to the effector sign.

According to the receptor basis, conditioned reflexes are divided into external and interoceptive.

• Exteroceptive reflexes are produced in response to visual, auditory, olfactory, gustatory, skin-mechanical stimuli, etc. They play a major role in the relationship of the organism with the environment, and therefore are formed and specialized relatively easily.
• Interoceptive conditioned reflexes are formed by combining irritation of the receptors of internal organs with any unconditioned reflex. They form much more slowly and are diffuse in nature.

By the nature of the conditioned stimulus, conditioned reflexes are divided into natural and artificial. Natural reflexes are formed under the influence of natural unconditioned stimuli, for example, salivation to the smell or type of food. Conditioned reflexes are called artificial. Artificial reflexes are often used in scientific experiments, since their parameters (strength, duration, etc.) can be arbitrarily adjusted.

According to the time of action of the conditioned and unconditioned stimuli, they distinguish existing and trace conditioned reflexes. The existing conditioned reflexes are formed when reinforcement is given within the duration of the conditioned stimulus. Trace reflexes are conditioned reflexes that are formed in the case of the action of a reinforcing stimulus after the end of the action of the conditioned signal. A special kind of trace conditioned reflexes are time reflexes, which are formed under the condition of regular repetition of the unconditioned stimulus at certain intervals.

According to the effector characteristic, conditional reflexes are divided into vegetative and somatomotive. Vegetative include food, cardiovascular, excretory, sexual and similar conditioned reflexes.

Reflex (biology)

An example of a vegetative conditioned reflex is the classic salivary reflex. Protective, food-producing conditioned reflexes, as well as complex behavioral reactions, belong to somatomotive ones.

In real life, conditioned reflexes are usually formed not for one, but for several stimuli, so they can be divided into simple and complex(complex). Complex conditioned reflexes can be simultaneous or sequential, depending on the combination and sequence of action of the totality of stimuli.

Unconditioned reflexes constitute the lower nervous activity, which ensures the implementation of various motor acts of life support, as well as the regulation of the functions of internal organs.

The elements of the higher nervous and mental activity of the human animal are instincts and conditioned reflexes (learning reactions), which manifest themselves in the form of behavioral reactions.

Topic: "Development of a conditioned blinking reflex"

Objective: To master the technique of developing a conditioned blinking reflex.

Equipment: arched stand, tripod, rubber tube with pear, whistle.

Mechanical irritation of the cornea and sclera causes an unconditioned blinking reflex. On the basis of this unconditioned stimulus, a conditioned blinking reflex can also be developed - a bell is used as a conditioned stimulus, an intermittent air stream is used as an unconditioned stimulus.

Working process:

1. Development of an unconditioned blinking reflex. The subject's chin is placed on an arc-shaped stand mounted on a tripod. The end of the tube conducting air from the balloon is placed at eye level at a distance of 5-10 cm.

Conditioned and unconditioned reflexes

The strength of the air jet is selected, which causes an unconditional protective flashing reflex. If the reflex is not evoked, repeat the experiment by changing the position of the metal tube.

Development of a conditioned blinking reflex. The experimenter with a whistle stands behind the subject - his task is to emit a conditioned stimulus (whistling) with the help of a whistle. The second experimenter continues to squeeze the pear and supply a stream of air (an unconditioned stimulus). When giving a sound signal, you must immediately press the pear. After 1-2 minutes, repeat this combination of stimuli, while maintaining the same interval between them. After 8-9 combinations, give a sound signal without reinforcing it with an unconditioned stimulus (air jet) - a conditioned blinking reflex will appear.

3. Draw conclusions based on the experience. Draw a diagram of the unconditioned and conditioned blinking reflex. An example of a conditioned blinking reflex is this scheme:

Rice. 1. Scheme of the conditioned blinking reflex: 1- receptors of the organ of hearing, 2- afferent pathway (auditory nerve), 3- nerve center, 4- efferent pathway (oculomotor nerve), 5- ciliary muscle of the eye.

Test questions:

1. What is a reflex?

2. What types of reflexes do you know?

3. What are unconditioned reflexes?

4. What are conditioned reflexes?

5. What conditions must be observed when developing conditioned reflexes? In what order should the conditioned and unconditioned stimuli be used?

6. What is the essence of the mechanism for the development of conditioned reflexes?

7. How many links does a reflex arc include? Reflex ring?

8. What types of receptors do you know by location?

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Conditioned reflex, definition, classification of conditioned reflexes.

A conditioned reflex is a complex multicomponent reaction that is developed on the basis of unconditioned reflexes using a previous indifferent stimulus. It has a signal character, and the body meets the impact of the unconditioned stimulus prepared. For example, in an athlete in the pre-start period, there is a redistribution of blood, increased respiration and blood circulation, and when the muscle load begins, the body is already prepared for it.

Classification of conditioned reflexes

Conditioned reflexes, as well as unconditioned ones, can be classified according to biological modality - food, drink, defensive;

Depending on the nature of the relationship between signal, conditioned and unconditioned stimuli, conditioned reflexes are divided into natural and artificial. Natural conditioned reflexes are developed to agents that, under natural conditions, are a property of an unconditioned stimulus, act together with an irritant that causes an unconditioned reflex (for example, the type of food, its smell, etc.). All other conditioned reflexes are artificial, i.e. are produced in response to agents that are not normally associated with the action of an unconditioned stimulus, for example, a food salivary-separating reflex to a bell.

According to the effector basis, conditioned reflexes are divided into secretory, motor, cardiac, vascular, etc.

According to the role in the implementation of goal-directed behavior, conditioned reflexes are divided into preparatory and executive.

5. If you develop a strong conditioned food reflex, for example, to light, then such a reflex is a first-order conditioned reflex. On its basis, a second-order conditioned reflex can be developed; for this, a new, previous signal is additionally used, for example, a sound, reinforcing it with a first-order conditioned stimulus (light).

As a result of several combinations of sound and light, the sound stimulus also begins to cause salivation. Thus, a new, more complex mediated temporal connection arises. It should be emphasized that the reinforcement for the second-order conditioned reflex is precisely the first-order conditioned stimulus, and not the unconditioned stimulus (food), since if both light and sound are reinforced with food, then two separate first-order conditioned reflexes will arise. With a sufficiently strong second-order conditioned reflex, a third-order conditioned reflex can be developed. For this, a new stimulus is used, for example, touching the skin. In this case, the touch is reinforced only by a second-order conditioned stimulus (sound), the sound excites the visual center, and the latter excites the food center. An even more complex temporal connection emerges. Reflexes of a higher order (4, 5, 6, etc.) are produced only in primates and humans.

CONDITIONAL AND UNCONDITIONAL REFLEXES

According to the nature of the attitude of an animal or person to an unconditioned stimulus, on the basis of which a conditioned reflex is developed, conditioned reflexes are divided into positive and negative. Positive conditioned reflexes bring them closer to the unconditioned stimulus. Negative catching reflexes either move away from it or prevent it from approaching.

7. Depending on the duration of the period of isolated action of the conditioned signal (PID), conditioned reflexes are divided into coinciding (PID = from 0.5 to 3.0 sec.), Short-delayed (PID = from 3.0 to 30 sec.), Normally-delayed ( PID = 30 to 60 sec.), retarded (PID = more than 60 sec.). The period of isolated action is the period of time from the beginning of the action of the conditioned signal to the moment of action of the unconditioned stimulus.

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The outstanding Russian physiologist I.M. Sechenov was the first to express the idea of ​​the connection between the consciousness and thinking of a person with the reflex activity of his brain. This idea was developed and convincingly confirmed in numerous experiments by I.P. Pavlova. Therefore, I.P. Pavlov is considered the creator of the doctrine of higher nervous activity.

Higher nervous activity- these are the functions of the cerebral cortex and the nearest subcortical formations, where temporary nerve connections (conditioned reflexes) are developed anew, providing the most subtle and perfect individual adaptation of the body to changing environmental conditions.

UNCONDITIONAL AND CONDITIONAL REFLEXES

Higher nervous activity is reflex in nature. Unconditioned and conditioned reflexes are inherent in higher animals and man. Their specifics are as follows.

unconditioned reflexes, ensuring the maintenance of life in relatively constant environmental conditions, inherent in man from birth. These include food (sucking, swallowing, salivation, etc.), defensive (coughing, blinking, hand withdrawal, etc.), reproduction (feeding and caring for offspring), respiratory, etc.

Conditioned reflexes are produced on the basis of unconditioned when exposed to a conditioned stimulus. They provide a more perfect adaptation of the body to changing environmental conditions. They help to find food by smell, get away from danger, navigate, etc.

Meaning of the word. In humans, conditioned reflexes can be formed not only as in animals, on the basis of the first signal system, when the conditioned stimuli are directly objects of the outside world, but also on the basis of the second (speech) signal system, when the conditioned stimuli are words expressing concepts of objects and phenomena . Conditioned reflexes are the physiological basis of technical processes, the basis of thinking. The word is a kind of stimulus for many conditioned reflexes. For example, just talking about food or describing it can cause a person to salivate.

Features of conditioned and unconditioned reflexes

Unconditioned reflexes	Conditioned reflexes (temporary connections)
Congenital, hereditarily transmitted reflex reactions of this type	Acquired in the process of individual development based on unconditioned reflexes
Reflex centers are located in the subcortical nuclei, brain stem and spinal cord	Reflex centers are located in the cerebral cortex
Racks. They persist throughout life. Their number is limited	Changeable. New reflections arise, and the old ones fade away when the environmental conditions change. Quantity is unlimited
Carry out the relationship of parts of the body, reflex self-regulation and maintaining the constancy of the internal environment	Carry out a reflex reaction of the body to a stimulus (conditioned), signaling the upcoming action of an unconditioned stimulus

The consciousness of people is connected with the activity of the cerebral cortex. This has been convincingly proven by numerous experiments by IP Pavlov, as well as by the study of diseases and disorders of the brain.

The teachings of IP Pavlov on the higher nervous activity of a person convincingly proved the inconsistency and anti-science of religious ideas about the "soul".

Inhibition of conditioned reflexes. When environmental conditions change, previously developed conditioned reflexes fade away, new ones are formed. IP Pavlov distinguished two types of inhibition of conditioned reflexes.

External braking occurs when the body is exposed to an irritant that is stronger than the previous one. At the same time, a new focus of excitation is formed in the cerebral cortex. For example, in a dog, a conditioned salivary reflex developed to light (see "Digestion") is inhibited under experimental conditions by a stronger stimulus - the sound of a bell. The latter causes a strong excitation in the auditory zone of the cerebral cortex. At first, it generates inhibition of neighboring areas, and then spreads to the visual zone. Therefore, excitation through the neurons located in it cannot be carried out and the arc of the former conditioned reflex is interrupted.

Internal braking occurs in the arc of the conditioned reflex when the conditioned stimulus ceases to receive reinforcement from the unconditioned stimulus and the temporary connections formed in the cortex are gradually inhibited. When conditioned reflexes are repeated in the same sequence, dynamic stereotypes are formed that make up habits and skills.

Hygiene of physical and mental labor. The activity of the body depends on the state of the central nervous system. Its overwork leads to a breakdown of the vital functions of the body, reduces perception, attention, memory and performance.

With monotonous physical labor, only one muscle group works and only one section of the central nervous system is excited, which leads to its fatigue.

To avoid overwork, it is useful to carry out industrial gymnastics during breaks, in which other muscles participate. This, in turn, leads to the excitation of new areas of the cerebral cortex, inhibition of previously working areas, their rest and restoration of working capacity.

Mental labor also causes fatigue of the central nervous system. The best rest in this case is gymnastics or other physical activity.

Of great importance in the formation of conditioned reflexes is the regime of the day. If it is observed, a person develops many important conditioned reflexes that stimulate the better functioning of various organ systems and prevent their overwork.

The alternation of physical and mental labor, the rationalization of labor, the observance of the daily routine, and active rest are of paramount importance for protecting the central nervous system from overwork.

Sleep gives the most complete rest to the central nervous system. The alternation of sleep and wakefulness is a necessary condition for human existence. I.P. Pavlov proved experimentally that sleep is an inhibition that covers the cerebral cortex and other parts of the brain. During sleep, metabolism, hearing, smell, and the intensity of activity of a number of organ systems decrease, muscle tone decreases, and thinking is turned off. Sleep is a protective device against overwork of the nervous system. Babies sleep 20-22 hours, schoolchildren - 9-11 hours, adults - 7-8 hours. With lack of sleep, a person loses his ability to work. In order for the body to get the most complete rest during sleep, it is necessary to go to bed at the same time, eliminate bright lights, noise, ventilate the room, etc.

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 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 is the conclusion 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.

Conditioned reflexes are reactions of the whole organism or any part of it to external or internal stimuli. They manifest themselves through the disappearance, weakening or strengthening of certain activities.

Conditioned reflexes are helpers of the body, allowing it to quickly respond to any changes and adapt to them.

Story

For the first time, the idea of ​​a conditioned reflex was put forward by the French philosopher and scientist R. Descartes. Somewhat later, the Russian physiologist I. Sechenov created and experimentally proved a new theory regarding the reactions of the body. For the first time in the history of physiology, it was concluded that conditioned reflexes are a mechanism that is activated not only in its work, the entire nervous system is involved. This allows the body to maintain contact with the environment.

Studied Pavlov. This outstanding Russian scientist was able to explain the mechanism of action of the cerebral cortex and cerebral hemispheres. At the beginning of the 20th century, he created the theory of conditioned reflexes. This scientific work has become a real revolution in physiology. Scientists have proven that conditioned reflexes are reactions of the body that are acquired throughout life, based on unconditioned reflexes.

instincts

Certain reflexes of an unconditioned type are characteristic of each type of living organism. They are called instincts. Some of them are quite complex. Examples of this are bees that make honeycombs, or birds that build nests. Due to the presence of instincts, the body is able to optimally adapt to environmental conditions.

Are congenital. They are inherited. In addition, they are classified as species, since they are characteristic of all representatives of a particular species. Instincts are permanent and persist throughout life. They manifest themselves to adequate stimuli that are attached to a specific single receptive field. Physiologically, unconditioned reflexes are closed in the brainstem and at the level of the spinal cord. They are manifested through anatomically expressed

As for the monkey and man, the implementation of most of the complex unconditioned reflexes is impossible without the participation of the cerebral cortex. When its integrity is violated, pathological changes in unconditioned reflexes occur, and some of them simply disappear.

Classification of instincts

Unconditioned reflexes are very strong. Only under certain conditions, when their manifestation becomes optional, they can disappear. For example, the canary, domesticated about three hundred years ago, does not currently have the instinct to make a nest. There are the following types of unconditioned reflexes:

Which is the body's response to a variety of physical or chemical stimuli. Such reflexes, in turn, may be local (withdrawal of the hand) or complex (flight from danger).
- Food instinct, which is caused by hunger and appetite. This unconditioned reflex includes a whole chain of sequential actions - from searching for prey to attacking it and further eating.
- Parental and sexual instincts associated with the maintenance and reproduction of the species.

Comfort instinct for keeping the body clean (bathing, scratching, shaking, etc.).
- Approximate instinct, when the eyes and head turn towards the stimulus. This reflex is necessary to save life.
- The instinct of freedom, which is especially pronounced in the behavior of animals in captivity. They constantly want to break free and often die, refusing water and food.

The emergence of conditioned reflexes

In the course of life, acquired reactions of the organism are added to the inherited instincts. They are called conditioned reflexes. They are acquired by the body as a result of individual development. The basis for obtaining conditioned reflexes is life experience. Unlike instincts, these reactions are individual. They may be present in some members of the species and absent in others. In addition, a conditioned reflex is a reaction that may not persist throughout life. Under certain conditions, it is produced, fixed, disappears. Conditioned reflexes are reactions that can occur to various stimuli applied to different receptor fields. This is their difference from instincts.

The mechanism of the conditioned reflex closes at the level. If it is removed, then only instincts remain.

The formation of conditioned reflexes occurs on the basis of unconditioned ones. For the implementation of this process, a certain condition must be met. At the same time, any change in the external environment must be combined in time with the internal state of the organism and perceived by the cerebral cortex with a simultaneous unconditional reaction of the organism. Only in this case does a conditioned stimulus or signal appear that contributes to the emergence of a conditioned reflex.

Examples

For the appearance of such a reaction of the body as salivation when knives and forks ring, as well as when a cup for feeding an animal (in a person and in a dog, respectively), an indispensable condition is the repeated coincidence of these sounds with the process of providing food.

In the same way, the sound of a bell or the switching on of a light bulb will cause the dog's paw to flex if these phenomena are repeatedly accompanied by electrical stimulation of the animal's leg, as a result of which an unconditioned flexion reflex appears.

The conditioned reflex is pulling the child's hands away from the fire and then crying. However, these phenomena will take place only if the type of fire, even once, coincided with the receipt of a burn.

Reaction components

The body's response to irritation is a change in breathing, secretion, movement, etc. As a rule, unconditioned reflexes are rather complex reactions. That is why they include several components at once. For example, a defensive reflex is accompanied not only by defensive movements, but also by an increase in breathing, an acceleration of the activity of the heart muscle, and a change in the composition of the blood. In this case, voice reactions may also appear. As for the food reflex, there are also respiratory, secretory and cardiovascular components.

Conditional reactions usually reproduce the structure of unconditioned ones. This occurs in connection with the excitation of stimuli of the same nerve centers.

Classification of conditioned reflexes

Acquired body responses to various stimuli are divided into types. Some of the existing classifications are of great importance in solving not only theoretical, but also practical problems. One of the areas of application of this knowledge is sports activities.

Natural and artificial reactions of the body

There are conditioned reflexes that arise under the action of signals characteristic of the constant properties of unconditioned stimuli. An example of this is the sight and smell of food. Such conditioned reflexes are natural. They are characterized by the speed of production and great durability. Natural reflexes, even in the absence of subsequent reinforcement, can be maintained throughout life. The value of the conditioned reflex is especially great at the very first stages of the life of the organism, when it adapts to the environment.
However, reactions can also be developed to a variety of indifferent signals, such as smell, sound, temperature changes, light, etc. Under natural conditions, they are not irritants. It is these reactions that are called artificial. They are developed slowly and in the absence of reinforcement quickly disappear. For example, artificial conditioned human reflexes are reactions to the sound of a bell, touching the skin, weakening or strengthening lighting, etc.

First and highest order

There are such types of conditioned reflexes that are formed on the basis of unconditioned ones. These are first order reactions. There are also higher categories. So, reactions that are developed on the basis of already existing conditioned reflexes are referred to as reactions of a higher order. How do they arise? During the development of such conditioned reflexes, the indifferent signal is reinforced with well-learned conditioned stimuli.

For example, irritation in the form of a call is constantly reinforced by food. In this case, a first-order conditioned reflex is developed. On its basis, a reaction to another stimulus, for example, to light, can be fixed. This will become a second-order conditioned reflex.

Positive and negative reactions

Conditioned reflexes can affect the activity of the organism. Such reactions are considered positive. The manifestation of these conditioned reflexes can be secretory or motor functions. If there is no activity of the organism, then the reactions are classified as negative. For the process of adaptation to the constantly changing conditions of the environment of existence, both one and the second type are of great importance.

At the same time, there is a close relationship between them, since when one kind of activity is manifested, another is certainly oppressed. For example, when the command “Attention!” Sounds, the muscles are in a certain position. At the same time, motor reactions (running, walking, etc.) are inhibited.

Mechanism of Education

Conditioned reflexes arise with the simultaneous action of a conditioned stimulus and an unconditioned reflex. In this case, certain conditions must be met:

The unconditioned reflex is biologically stronger;
- the manifestation of the conditioned stimulus is somewhat ahead of the action of the instinct;
- the conditioned stimulus is necessarily reinforced by the influence of the unconditioned;
- the body must be in a waking state and be healthy;
- the condition of the absence of extraneous stimuli producing a distracting effect is observed.

The centers of conditioned reflexes located in the cerebral cortex establish a temporary connection (short circuit) between themselves. In this case, stimulation is perceived by cortical neurons, which are part of the arc of the unconditioned reflex.

Inhibition of conditioned reactions

In order to ensure adequate behavior of the organism and for better adaptation to environmental conditions, the development of conditioned reflexes alone will not be enough. It will take the opposite direction of action. It is the inhibition of conditioned reflexes. This is the process of eliminating those reactions of the body that are not necessary. According to the theory developed by Pavlov, certain types of cortical inhibition are distinguished. The first of these is the unconditional. It appears as a response to the action of some extraneous stimulus. There is also internal inhibition. It's called conditional.

External braking

This reaction received such a name due to the fact that its development is facilitated by the processes taking place in those parts of the cortex that do not take part in the implementation of reflex activity. For example, a foreign smell, sound, or change in lighting before the food reflex begins can reduce it or contribute to its complete disappearance. The new stimulus acts as a brake on the conditioned response.

Food reflexes can also be eliminated by painful stimuli. The overflow of the bladder, vomiting, internal inflammatory processes, etc. contribute to the inhibition of the reaction of the body. All of them inhibit food reflexes.

Internal braking

It occurs when the received signal is not reinforced by an unconditioned stimulus. Internal inhibition of conditioned reflexes occurs if, for example, an electric light bulb is periodically turned on in front of the eyes of an animal during the day, without bringing food. It has been experimentally proven that saliva production will decrease each time. As a result, the reaction will die out completely. However, the reflex will not disappear without a trace. He just slows down. This has also been proven experimentally.

Conditioned inhibition of conditioned reflexes can be eliminated the very next day. However, if this is not done, then the reaction of the body to this stimulus will subsequently disappear forever.

Varieties of internal inhibition

Classify several types of elimination of the body's response to stimuli. Thus, at the basis of the disappearance of conditioned reflexes, which are simply not needed under given specific conditions, is extinction inhibition. There is another variation of this phenomenon. This is a distinctive, or differentiated inhibition. So, the animal can distinguish the number of beats of the metronome at which food is brought to it. This happens when the given conditioned reflex has been previously worked out. The animal distinguishes stimuli. This reaction is based on internal inhibition.

The Importance of Eliminating Reactions

Conditioned inhibition plays a significant role in the life of the organism. Thanks to him, the process of adaptation to the environment is much better. The possibility of orientation in a variety of complex situations gives a combination of excitation and inhibition, which are two forms of a single nervous process.

Conclusion

There are an infinite number of conditioned reflexes. They are the factor that determines the behavior of a living organism. With the help of conditioned reflexes, animals and humans adapt to their environment.

There are many indirect signs of body reactions that have a signal value. For example, an animal, knowing in advance about the approach of danger, builds its behavior in a certain way.

The process of developing conditioned reflexes, which belong to the highest order, is a synthesis of temporary connections.

The basic principles and regularities manifested in the formation of not only complex, but also elementary reactions are the same for all living organisms. From this follows an important conclusion for philosophy and the natural sciences that it cannot but obey the general laws of biology. In this regard, it can be studied objectively. However, it should be borne in mind that the activity of the human brain has a qualitative specificity and a fundamental difference from the work of the brain of an animal.

The term "reflex" was introduced by the French scientist R. Descartes in the 17th century. But to explain mental activity, it was used by the founder of Russian materialistic physiology, I. M. Sechenov. Developing the teachings of I. M. Sechenov. IP Pavlov experimentally investigated the features of the functioning of reflexes and used the conditioned reflex as a method for studying higher nervous activity.

All reflexes were divided by him into two groups:

• unconditional;
• conditional.

Unconditioned reflexes

Unconditioned reflexes- innate reactions of the body to vital stimuli (food, danger, etc.).

They do not require any conditions for their production (for example, salivation at the sight of food). Unconditioned reflexes are a natural reserve of ready-made, stereotyped reactions of the body. They arose as a result of a long evolutionary development of this species of animals. Unconditioned reflexes are the same in all individuals of the same species. They are carried out with the help of the spinal and lower parts of the brain. Complex complexes of unconditioned reflexes manifest themselves in the form of instincts.

Rice. Fig. 14. Location of some functional areas in the human cerebral cortex: 1 - area of ​​speech education (Broca's center), 2 - area of ​​the motor analyzer, 3 - area of ​​analysis of oral verbal signals (Wernicke's center), 4 - area of ​​the auditory analyzer, 5 - analysis of written verbal signals, 6 - area of ​​the visual analyzer

Conditioned reflexes

But the behavior of higher animals is characterized not only by innate, i.e., unconditioned reactions, but also by such reactions that are acquired by a given organism in the process of individual life activity, i.e., conditioned reflexes. The biological meaning of the conditioned reflex lies in the fact that numerous external stimuli surrounding the animal in natural conditions and in themselves not of vital importance, preceding food or danger in the experience of the animal, the satisfaction of other biological needs, begin to act as signals, according to which the animal orients its behavior (Fig. 15).

So, the mechanism of hereditary adaptation is an unconditioned reflex, and the mechanism of individual changeable adaptation is conditional. a reflex produced by a combination of vital phenomena with accompanying signals.

Rice. 15. Scheme of the formation of a conditioned reflex

• a - salivation is caused by an unconditioned stimulus - food;
• b - excitation from a food stimulus is associated with the previous indifferent stimulus (the light of a light bulb);
• c - the light of the light bulb became a signal of the possible appearance of food: a conditioned reflex developed on it

A conditioned reflex is developed on the basis of any of the unconditioned reactions. Reflexes to unusual signals that do not occur in a natural setting are called artificial conditioned. In laboratory conditions, you can develop many conditioned reflexes to any artificial stimulus.

With the concept of a conditioned reflex, I. P. Pavlov associated signaling principle of higher nervous activity, the principle of synthesis of external influences and internal states.

The discovery by Pavlov of the main mechanism of higher nervous activity - the conditioned reflex - became one of the revolutionary achievements of natural science, a historical turning point in understanding the connection between the physiological and the mental.

With the knowledge of the dynamics of education and changes in conditioned reflexes, the discovery of complex mechanisms of the activity of the human brain, the identification of patterns of higher nervous activity began.