What are the first conditioned reflexes connected with. Conditioned reflexes

12.10.2019

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 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.

Inhibition of conditioned reflexes

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.

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

Answer

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

Answer

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

5) are congenital
6) are not inherited

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. Unconditioned reflexes that ensure vital activity 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

Answer

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

Answer

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

Answer

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

Answer

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

Answer

Choose one, the most correct option. The 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

Answer

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

Answer

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

Answer

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

Answer

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

Answer

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

Answer

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

Answer

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

Answer

The main activity of the nervous system is reflex. All reflexes are usually divided into unconditional and conditional.

Unconditioned reflexes	Conditioned reflexes
1. congenital, genetically programmed reactions of the body, characteristic of all animals and humans. 2. The reflex arcs of these reflexes are formed in the process prenatal development, and sometimes postnatal period. Ex: congenital sexual reflexes are finally formed in a person only by the time of puberty in adolescence. They have little-changing reflex arcs passing through the subcortical sections of the central nervous system. The participation of the cortex in the course of many unconditioned reflexes is not necessary. 3. Are species-specific, i.e. formed in the process of evolution and are characteristic of all representatives of this species. 4. Relatively constant and persist throughout the life of the organism. 5. Arise on specific(adequate) stimulus for each reflex. 6. Reflex centers are at the level spinal cord and in brain stem	1. Acquired reactions of higher animals and humans developed as a result of learning (experience). 2. Reflex arcs are formed in the process postnatal development. They are characterized by high mobility, the ability to change under the influence of environmental factors. Reflex arcs of conditioned reflexes pass through the highest part of the brain - the cerebral cortex. 3. Are individual, i.e. arise from life experience. 4. fickle and depending on certain conditions, they can be developed, consolidated or fade away. 5. May form on any irritant perceived by the body 6. Reflex centers are located in cerebral cortex
Example: food, sexual, defensive, indicative.	Example: salivation for the smell of food, precise movements when writing, playing musical instruments.
Meaning: help survival, it is "the application of the experience of ancestors in practice"	Meaning: help to adapt to changing environmental conditions.

Classification of unconditioned reflexes.

The question of classifying unconditioned reflexes is still open, although the main types of these reactions are well known.

1. Food reflexes. For example, salivation when food enters the oral cavity or the sucking reflex in a newborn baby.

2. Defensive Reflexes. Protect the body from various adverse effects. For example, the reflex of pulling the hand with painful irritation of the finger.

3. Orienting reflexes, or reflexes "What is it?", as IP Pavlov called them. A new and unexpected stimulus draws attention, such as turning the head towards an unexpected sound. A similar reaction to novelty, which has an important adaptive value, is also observed in various animals. It is expressed in alertness and listening, sniffing and examining new objects.

4.Game reflexes. For example, children's games in the family, hospital, etc., during which children create models of possible life situations and carry out a kind of "preparation" for various life surprises. unconditioned reflex play activity the child quickly acquires a rich "spectrum" of conditioned reflexes, and therefore the game is the most important mechanism for the formation of the child's psyche.

5.Sexual reflexes.

6. Parental reflexes are associated with the birth and feeding of offspring.

7. Reflexes that provide movement and balance of the body in space.

8. Reflexes that support constancy of the internal environment of the body.

Complex unconditioned reflexes I.P. Pavlov called instincts, the biological nature of which is still unclear in its details. In a simplified form, instincts can be represented as a complex interconnected series of simple innate reflexes.

Physiological mechanisms of formation of conditioned reflexes

To understand the nervous mechanisms of conditioned reflexes, consider such a simple conditioned reflex reaction as an increase in salivation in a person at the sight of a lemon. This natural conditioned reflex. In a person who has never tried a lemon, this object does not cause any reactions, except for curiosity (orienting reflex). What physiological connection exists between such functionally distant organs as the eyes and salivary glands? I.P. dealt with this issue. Pavlov.

The connection between the nerve centers that regulate the processes of salivation and analyze visual stimuli arises as follows:

The excitation that occurs in the visual receptors at the sight of a lemon, through the centripetal fibers, enters the visual cortex of the cerebral hemispheres (occipital region) and causes excitation cortical neurons- arises focus of excitation.

2. If after this a person gets the opportunity to taste a lemon, then a focus of excitation arises in the subcortical nerve center salivation and in its cortical representation located in the frontal lobes of the cerebral hemispheres (cortical food center).

3. Due to the fact that the unconditioned stimulus (the taste of lemon) is stronger than the conditioned stimulus (external signs of lemon), the food focus of excitation has a dominant (main) value and “attracts” excitation from the visual center.

4. Between two previously unconnected nerve centers arises nervous temporal connection, i.e. a kind of temporary "pontoon bridge" connecting the two "shores".

5. Now the excitation that occurs in the visual center quickly "passes" along the "bridge" of the temporary connection to the food center, and from there along the efferent nerve fibers to the salivary glands, causing salivation.

Thus, for the formation of a conditioned reflex, the following are necessary conditions:

1. The presence of a conditioned stimulus and unconditioned reinforcement.

2. The conditioned stimulus must always somewhat precede the unconditioned reinforcement.

3. The conditioned stimulus must be weaker than the unconditioned stimulus (reinforcement) in terms of its impact.

4. Repetition.

5. A normal (active) functional state of the nervous system is necessary, first of all, its leading department - the brain, i.e. the cerebral cortex should be in a state of normal excitability and performance.

Conditioned reflexes formed when a conditioned signal is combined with an unconditioned reinforcement are called reflexes of the first order. If the reflex is developed, then it can also become the basis of a new conditioned reflex. It is called reflex of the second order. Reflexes developed on them - third order reflexes etc. In humans, they are formed on verbal signals, supported by the results of the joint activities of people.

A conditioned stimulus can be any change in the environment and internal environment of the organism; a bell, electric light, tactile skin irritations, etc. Food reinforcement and pain stimulation are used as unconditioned stimuli (reinforcers).

The development of conditioned reflexes with such unconditional reinforcement is the fastest. In other words, powerful factors contributing to the formation of conditioned reflex activity are rewards and punishments.

Classifications of conditioned reflexes

Due to their large number, it is difficult.

According to the location of the receptor:

1. exteroceptive- conditioned reflexes formed during stimulation of exteroceptors;

2. interoceptive - reflexes that form when stimulating receptors located in internal organs;

3. proprioceptive, arising from stimulation of muscle receptors.

According to the nature of the receptor:

1. natural- conditioned reflexes, formed under the action of natural unconditioned stimuli on receptors;

2. artificial- under the action of indifferent stimuli. For example, the secretion of saliva in a child at the sight of favorite sweets is a natural conditioned reflex (the secretion of saliva when the mouth is irritated by some food is an unconditioned reflex), and the secretion of saliva that occurs in a hungry child at the sight of dinner utensils is an artificial reflex.

By action sign:

1. If the manifestation of a conditioned reflex is associated with motor or secretory reactions, then such reflexes are called positive.

2. Conditioned reflexes without external motor and secretory effects are called negative or brake.

By the nature of the response:

1. motor;

2. vegetative formed with internal organs– heart, lungs, etc. Impulses from them, penetrating into the cerebral cortex, immediately slow down, not reaching our consciousness, because of this, we do not feel their location in a state of health. And in case of illness, we know exactly where the diseased organ is located.

Reflexes occupy a special place for a while, the formation of which is associated with regularly repeated stimuli at the same time, for example, with food intake. That is why, by the time of eating, the functional activity of the digestive organs increases, which has a biological meaning. Reflexes for a while belong to the group of so-called trace conditioned reflexes. These reflexes are developed if the unconditioned reinforcement is given 10 to 20 seconds after the final action of the conditioned stimulus. In some cases, it is possible to develop trace reflexes even after a 1-2 minute pause.

Reflexes are important imitation, which, according to L.A. Orbeli are also a kind of conditioned reflexes. To develop them, it is enough to be a “spectator” of the experiment. For example, if you develop some kind of conditioned reflex in one person in front of another, then the “spectator” also forms the corresponding temporary connections. In children, imitative reflexes play an important role in the formation of motor skills, speech and social behavior, in adults in the acquisition of labor skills.

There are also extrapolation reflexes - the ability of humans and animals to anticipate favorable or unfavorable situations for life.

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 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

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. The basis of the nervous activity of humans and animals is
1) thinking
2) instinct
3) arousal
4) reflex

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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 normal development 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 body, 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, initially indifferent signals outside 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 disturbed 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
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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 innate behavior 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 pupil constriction, the action electric current makes the dog 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 somatomotion.

V 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 higher nervous and mental activity of an animal person 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.

Progress:

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. In the event that 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.

Control 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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Reflex- the response of the body is not an external or internal irritation, carried out and controlled by the central nervous system. The development of ideas about human behavior, which has always been a mystery, was achieved in the works of Russian scientists I. P. Pavlov and I. M. Sechenov.

Reflexes unconditioned and conditional.

Unconditioned reflexes- these are innate reflexes that are inherited by offspring from parents and persist throughout a person's life. Arcs of unconditioned reflexes pass through the spinal cord or brain stem. The cerebral cortex does not participate in their formation. Unconditioned reflexes provide only those changes in the environment that many generations of a given species often encountered.

To include:

Food (salivation, sucking, swallowing);
Defensive (coughing, sneezing, blinking, pulling the hand away from a hot object);
Approximate ( skew eyes, turns);
Sexual (reflexes associated with reproduction and care of offspring).
The significance of unconditioned reflexes lies in the fact that thanks to them the integrity of the body is preserved, the maintenance of constancy and reproduction occurs. Already in a newborn child, the simplest unconditioned reflexes are observed.
The most important of these is the sucking reflex. The irritant of the sucking reflex is the touch of an object on the child's lips (mother's breasts, nipples, toys, fingers). The sucking reflex is an unconditioned food reflex. In addition, the newborn already has some protective unconditioned reflexes: blinking, which occurs if a foreign body approaches the eye or touches the cornea, constriction of the pupil when strong light is applied to the eyes.

Particularly pronounced unconditioned reflexes in various animals. Not only individual reflexes can be innate, but also more complex forms of behavior, which are called instincts.

Conditioned reflexes- these are reflexes that are easily acquired by the body during life and are formed on the basis of an unconditioned reflex under the action of a conditioned stimulus (light, knock, time, etc.). IP Pavlov studied the formation of conditioned reflexes in dogs and developed a method for obtaining them. To develop a conditioned reflex, an irritant is needed - a signal that triggers a conditioned reflex, repeated repetition of the action of the stimulus allows you to develop a conditioned reflex. During the formation of conditioned reflexes, a temporary connection arises between the centers and centers of the unconditioned reflex. Now this unconditioned reflex is not carried out under the influence of completely new external signals. These irritations from the surrounding world, to which we were indifferent, can now acquire a vital importance. During life, many conditioned reflexes are developed, which form the basis of our life experience. But this life experience makes sense only for this individual and is not inherited by its descendants.

into a separate category conditioned reflexes allocate motor conditioned reflexes developed during our life, i.e. skills or automated actions. The meaning of these conditioned reflexes is the development of new motor skills, the development of new forms of movements. During his life, a person masters many special motor skills associated with his profession. Skills are the basis of our behavior. Consciousness, thinking, attention are freed from performing those operations that have become automated and become skills. Everyday life. The most successful way to master skills is through systematic exercises, correcting mistakes noticed in time, knowing the ultimate goal of each exercise.

If the conditioned stimulus is not reinforced for some time by the unconditioned stimulus, then the conditioned stimulus is inhibited. But it doesn't disappear completely. When the experiment is repeated, the reflex is very quickly restored. Inhibition is also observed under the influence of another stimulus of greater force.

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. The entire nervous system. 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 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 body. 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. Inhibition of the reaction of the body contributes to the overflow of the bladder, vomiting, internal inflammatory processes etc. All of them depress 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. Possibility of orientation in various difficult 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. This leads to an important conclusion for philosophy and natural sciences that 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 human brain has a qualitative specificity and a fundamental difference from the work of the animal brain.

What are the first conditioned reflexes connected with. Conditioned reflexes

Comparison of conditioned and unconditioned reflexes

Development of a conditioned reflex

Inhibition of conditioned reflexes

Comparison of conditioned and unconditioned reflexes

Development of a conditioned reflex

Tests and assignments

Unconditioned and conditioned reflexes

reflex arc

Types of reflexes

Unconditioned reflexes

Conditioned reflexes

The formation of conditioned reflexes

Inhibition of conditioned reflexes

Pathological reflexes

§one. Conditioned and unconditioned reflexes

Study of reflexes

what is reflex reasoning

essay on reflexes

stem

reflex+report

short message unconditioned and conditioned reflexes

What is the difference between unconditioned and conditioned reflexes?

How is the conditioned reflex inhibited?

Classification of reflexes. What are the reflexes.

Reflex (biology)

Conditioned and unconditioned reflexes

Conditioned reflex, definition, classification of conditioned reflexes.

CONDITIONAL AND UNCONDITIONAL REFLEXES

Reflexes unconditioned and conditional.

Story

instincts

Classification of instincts

The emergence of conditioned reflexes

Examples

Reaction components

Classification of conditioned reflexes

Natural and artificial reactions of the body

First and highest order

Positive and negative reactions

Mechanism of education

Inhibition of conditioned reactions

External braking

Internal braking

Varieties of internal inhibition

The Importance of Eliminating Reactions

Conclusion