What conditions are needed to develop a conditional reflex. Development of domestic scientists of the teachings about the highest nervous activity

1. To generate a conditional reflex, you need two stimuli. One of them is an unconditional stimulus, which causes an unconditional reflex reaction (food, pain stimulus, etc.), this irritant is a reinforcement of a reflex reaction. The second stimulus - conditional (signal) will signal the unconditional irritation (light, sound, form of food, etc.). 2. A repeated combination of conditional and unconditional stimulus is necessary (although the formation of conditional reflex is possible with a single combination of conditional and unconditional stimulus). 3. The conditional stimulus must precede the action of unconditional. The time during which the conditional stimulus acts independently, the name of the time of isolated conditional stimulus is called. The time when conditional and unconditional stimuli act together, received the name of the joint action of the conditional and unconditional stimulus. Depending on the duration of the time of the isolated action of the conditional stimulus, the coincident conditional reflex (the time of the isolated action of the conditional stimulus is 1-2 s); If the time of the insulated action of the conditional stimulus is greater than 2 s, then such a reflex is called retrancable, it can be: shortly retired (time of isolated action to 10c); Average set (time of isolated action up to 20 ° C); long set down (time of isolated action 20-30 s); If the unconditional stimulus is valid after 30 s and more after the start of the conditional stimulus, this conditional reflex is called delayed; The traceal reflex - the unconditional stimulus begins to act after the cessation of the conditional stimulus, such reflexes have no time for the joint action of conditional and unconditional stimuli. 4. Any irritant of an external or internal environment can be used as a conditional stimulus, but it must have the following properties: should be indifferent if possible, do not cause a defensive reaction itself; should not be excessive force; Must attract the attention of the animal; Must be an environmentally friendly animal (for example, in fish you can develop a conditional reflex on the call, but for this you need a large number of Combined conventional and unconditional stimuli, and on a combination of water spruce with feed feed, the conditional reflex is produced through 2-3 combinations). In this regard, conditional reflexes are divided into natural and artificial. Natural conventional reflexes are produced on agents, which in vivo act with an irritant causing unconditional reflex (for example, a type of food, its smell, etc.). All other conditional reflexes are artificial, i.e. are produced on agents, in norm not related to the action of an unconditional stimulus, for example, a food saludative reflex on a call. 5. Under the action of conditional and unconditional stimuli, the excitation from the unconditional stimulus should be stronger than from conditional. 6. The unconditional reinforcement must comply with its qualities, for example, food must be edible. 7. When developing conditional reflexes, it is necessary to eliminate foreign stimuli, since they can cause the braking of the conditional reflex. 8. Animal that has a conditional reflex produced, should be healthy and maintained normal behavior. 9. In an animal, when developing a conditional reflex, motivational excitation should be pronounced, for example, when developing food salivary reflex, an animal must be hungry, this reflex is not produced by this reflex. The physiological basis for the occurrence of conditional reflexes is the formation of temporary ties in the most reactive formations of the central nervous system - in the highest departments. Temporary connection is a combination of neurophysiological, biochemical and ultrastructural changes in the brain arising in the process of joint action of conditional and unconditional stimuli. I. P. Pavlov suggested that when developing conditional reflex occurs, the formation of a temporary nervous connection between two groups of cortex cells - with cortical representation of conditional and unconditional reflexes. There are several possibilities for closing such a temporary connection. First, the excitement from the center of the conditional reflex can be transmitted to the center of unconditional reflex from the cell to the cell, from the neuron to neuron is an internecronal path. Secondly, the excitation can be transmitted according to associative fibers of the crust. Consequently, the first way to form a temporary connection between the cortical representations of conditional and unconditional reflexes is an intricant-cortic cortex (the center of the conditional - the center of unconditional reflexes). 1. With the destruction of the cortical representation of the conditional reflex, the developed conditional reflex is maintained. Apparently, the formation of a temporary connection goes between subcortex centers of the conditional reflex and the cortical center of the unconditional reflex (for the type of cortex-bark). 2. With the destruction of the cortical representation of the unconditional reflex, the conditional reflex is also preserved. Consequently, the working out of a temporary connection can go between the cortical center of the conventional reflex and the subcortex center of the unconditional reflex (according to the type of cortex). 3. The separation of cortical centers of conditional and unconditional reflexes by intersection of the cortex of the brain does not prevent the formation of the conditional reflex. This suggests that a temporary connection may be formed between the cortical center of the conditional reflex with a subcortex center of the unconditional reflex and the cortical center of unconditional reflex (but the type of cortex bark-cortex). 4. Further studies have shown that conditional reflexes are preserved by removing the cortex in animals, i.e., temporary connection is maintained at the level of subcortical centers of conditional and unconditional reflexes (by the type of subcortkin). What is the temporary communication mechanism? A number of researchers have shown that the formation of a temporary communication occurs on the principle of dominant. The focus of excitement from the unconditional stimulus is always stronger than from conditional, since the unconditional stimulus is always biologically more significant for the animal. This excitation focus is dominant. A stronger focus of excitement from unconditional irritation attracts the excitement from the focus of conditional irritation. The degree of excitement will increase. The dominant hearth has a property of a long, sustainable existence. Consequently, conditional and unconditional arousal for a long time Will interact with each other. If the excitation passed on any nervous centers, then the next time it will be much easier for these paths. This is based on the first, the phenomenon of the amount of excitations, and secondly, the phenomenon of "paths", accompanied by: long-term increase in the excitability of synaptic formations; By changing protein chains, the accumulation of RNA, a change in the amount of the mediator in synapses, activating the formation of new synapses. Consequently, structural prerequisites are created to the excitation movement by certain paths. Now the excitement from the zone of the cortical representation of the conventional reflex will go on the pavement path and will cause the manifestation of a conditionally reflex reaction. There is another idea of \u200b\u200ba temporary communication mechanism. At the heart of this presentation lies the ability of neurons to respond to irritation of different modalities, i.e. the phenomenon of polybitensor convergence. The existence of neurons on which the excitation from different analyzers conveps, makes it possible to think that the process of establishing time links does not occur due to the combination of various sections of the cortex, and by integrating excitations at the level of one neuron - the neurons of the cortex can integrate the conditional and unconditional excitation. Conditional and unconditional excitation, reaching neurons, is fixed in them in the form of durable chemical compounds, the formation of which is a mechanism for closing a conditionally reflex communication. Such the theory of the closing mechanism of the temporary connection received the name of the convergent theory.

The conditionally reflex activity of Pavlov studied on dogs. The animal was placed in special straps, hanging fistula on the saliva gland. The experimenter was sitting separately. Condition is absolute silence. The experiment was carried out on intact animals, that is, they should not be exposed to any extraneous stimuli. The unconditional stimulus performed as conditional. Two stimuli:

1. Unconditional stimulus - food.
2. Conditional stimulus (first an indie stimulus, then became conditional stimuli) - light, sound, pain irritant, tactile stimulus, etc.

The main mechanism for the formation of conditional is to establish a temporary connection between conditional and unconditional. This is a connection between cerebral centers that are responsible for unconditional and centers associated with the conditional stimulus. Conditionally reflex communication is the establishment of the pulsed activity of neurons, which is formed between these centers.

- This is an acquired response organism for irritation with the direct participation of the highest department, i.e. cortex brain.

To form a conditional reflex requires the following conditions:

1. Normal (active) nervous system and above all its leading department - brain; Those it is necessary to the activity of the bark of the GM.
2. The presence of a conditional stimulus and unconditional reinforcement.
3. The conditional stimulus should always be somewhat preceded by unconditional reinforcement (almost at the same time), i.e. serve for a person or animal by a biologically significant signal;
4. The submission of an unconditional stimulus should be carried out at the end of the conditional stimulus, that is, we give light, and in the last seconds of the lighting of the light signal is supplied. If the light is given on the background of food, the animal will not respond to light.
5. The conditional stimulus (the one that was previously an indeference) should be physiologically weaker if it is too strong, it will cause braking, in addition, he should not attract attention. Under the action of conditional and unconditional stimuli, the excitation from the unconditional stimulus should be stronger than from conditional.
6. Multiple combination of conditional and unconditional stimuli.
7. There should be no action of extraneous stimuli. All foreign stimuli distract the animal (person) from performing a reflex.
8. Conditional reflexes are able to fade over time if the effect of the conditional stimulus is not supported unconditional. There is the possibility of spontaneous reproduction of baked conditional reflexes (that is, they can restore themselves).
9. The conditional reflex should always be supported by the action of unconditional stimulus (reinforcement). If this does not happen, then temporary connection is broken, and the conditional reflex - fuses.

Indifferent stimulus - light causes arousal in the visual cortex center. However, the salivary center is dominant (because the dog is hungry) and it attracts the excitement from the visual center. There is a connection between them. After a multiple combination, the excitation of a salivary cue is excited in response to light. If the unconditional stimulus will precede the indifferent ur not formed. If the indifferent stimulus is too strong, he will cause braking in all centers and ur will not be formed.

The physiological basis for the occurrence of conditional reflexes is the formation of temporary ties in the most reactive formations of the central nervous system - in the highest departments. Temporary connection is a combination of neurophysiological, biochemical and ultrastructural changes in the brain arising in the process of joint action of conditional and unconditional stimuli. Initially, Pavlov suggested that when the conditional reflex was the formation of a temporary nervous connection between two groups of cortex cells - with cortical representations of conditional and subcortex unconditional reflexes. Then the idea was expressed that the conditional closure occurs in the cortex between the cortical end of the signal analyzer and the cortical link of a complex unconditional center. The hypothesis of the cortex mechanism of the closure of a temporary connection received further development In the analysis of the mechanisms of convergence of excitation on individual neurons of the cortex of a large brain (PK Anokhin).

Modern ideas about the paths of closure of temporary connections:

1. The first way to form a temporary connection between the cortical representations of conditional and unconditional reflexes is intactical by type bark-bark (Center conditional - the center of unconditional reflexes).
2. With the destruction of the cortical representation of the conditional reflex, the developed conditional reflex is maintained. Apparently, the formation of a temporary connection goes between subcortex centers of conditional reflex and cortical center (by type subcord-bark).
3. In the destruction of the cortical representation of unconditional reflex, the conditional reflex is also preserved. Consequently, the development of a temporary connection can go between the Corner Center of the Conditional Reflex and the subcortex center of the unconditional reflex (by type cora-subcount).
4. Disagreement of the cortical centers of conditional and unconditional reflexes by intersection of the cortex of the brain does not prevent the formation of the conditional reflex. This suggests that a temporary connection may be formed between the Correspondent Corolon Reflex with a subcortex center of unconditional reflex and the Correspondent Unconditional Reflex (but Type cortex ).
5. Further studies have shown that conditional reflexes are preserved by removing the crust in animals, i.e., temporary connection is maintained at the level of subcortical centers of conditional and unconditional reflexes (by type subcortical subcount ).

Conditional reflexes are called so because it requires compliance with some conditions for their work out, namely:

1. The presence of basic reflex . The conditional reflex can only be produced on the basis of the already existing reflex - unconditional or previously developed conditional.

2. Excellent action of conditional stimulus . Future conditional (originally indifferent, indifferent) stimulus should have signal value, i.e. to prevail the action of unconditional ( reinforcing) Irritant.

3. Ligger biological significance of the conditional stimulus . The significance of the reinforcing stimulus should be greater than the future conditional. Exactly reinforcing stimulus must be associated with the satisfaction of the dominant need. .

4. Optimal power of irritants . Both signal, and supporting stimuli must be a certain force, since too weak and too strong irritants do not allow you to develop a stable conditional reflex.

5. Repeated repetition of both stimuli . This condition is important for the development of sustainable conditional reflex, since in the individual memory only the most likely combinations of the conditional stimulus and unconditional reaction are recorded. Accidentally occurred connections will slow down.

6. Lack of extraneous stimuli . It is necessary that at the time of developing conditional reflex to the body did not act other stimuli.

7. The optimal performance of the cerebral cortex . To form a conditional connection is needed enough high level excitability of cortex cells and equilibrium excitation and braking processes.

4.6.2. Conditional reflexes formation mechanisms

The mechanisms for the formation of conditional reflexes are largely unclear. It is not sufficiently studied as a structural basis of temporary communication and its physiological nature. To solve these issues, numerous studies on the system and cellular levelsAt the same time, electrophysiological and biochemical indicators of the functional state of nerve cells and their complexes are studied.

I. P. Pavlov considered that the conventional binding occurs in the cortex cortex between the cortical center, the excitation in which occurs under the action of the conditional stimulus, and the cortical center of the unconditional reflex. For example, under the action of food (unconditional stimulus), a lumbering center of the oblong brain is excited for taste receptors and a saliva-separation reaction occurs. In case of an impact stimulus (future conditional stimulus), the excitement covers the visual area of \u200b\u200bthe crust. If the action of the future conditional and unconditional stimuli will coincide in time, a functional connection is established between the visual and food center of the cortex. With a developed conditional reflex, the excitation, which emerged in the auditorium spreads to the food center, and from there on the efferent paths - to the center of salivation. As a result, a reaction occurs characteristic of the action of an unconditional stimulus (Fig. 4.2).

Fig. 4.2. The mechanism for the formation of conditional reflex (according to I. P. Pavlov): I. The effect of the edible stimulus leads to the unconditional reflector selection of saliva: 1 - excitation in the center of salivation of the oblong brain; 2 - excitation in the food center of the cortex; II. The effect of an indifferent light irritant causes a weak indicative reaction: 3 - excitation in the visual center of the bark; III. The combination of the action of light and food stimuli: there is a functional connection between the visual and food centers of the cortex; IV. Developed Reflex: The action of the light stimulus leads to the excitation of visual and food centers bark; Conditional inflexive salivation occurs

Pavlov believed that bark plays a leading role in the formation of conditional reflexes . However, he spoke about the need to study roles of cortical-subcortical interactions in providing GNI.

Indeed, in numerous studies with the use of various methods, it was convincingly shown circuit of temporary ties through the cortex of the brain. Along with this there are data on the role of subcortical formationsin this process.

Two stages can be distinguished in the formation of conditional reflex: generalization and specialization.

Stage of generalization .At this stageconditional reflex The action causes not only reinforced conditional stimulus, but also a widekTR SK.one with him stimuli. At this time happens primary sensory generalization , generalization of signs of conditional signals. The degree of generalization depends on the characteristics of both conditional and unconditional stimuli.

The value of the generalization stage great, because it largely determines the plasticity of acquired behavior and allows the body to adapt directly to a wide range of similar signals. So, if, after the sound signal, the 400 Hz dog receives food reinforcement, then at the stage of generalization, the salivation will also cause sounds with a frequency of 200-600 Hz. I. P. Pavlov tied this stage of the formation of conditional reflex with broad irradiation of the excitatory processwithin the center that perceives the signal.

Electrophysiological studies have shown that early stages Reception of conditional reflex is observed wide generalization of excitation processes in the crust and subcortical structures . The excitation of the reticular formation leads to the activation of the overlying structures, including the bark, and the activation of the thalamus and hypothalamus ensures the vegetative component of the conditional reflex (change in the operation of the internal organs).

Then in the subcortical formations and in various sections of the crust occurs synchronization of the pulsed activity of neurons (distant synchronization ) . The rhythm of this synchronous activity corresponds to the frequency of the conditional stimulus, which indicates about association to that non-related functionally neurons into a single system . It is shown that for the occurrence of a temporary connection, a distant synchronization of the center of the conditional stimulus is necessary (for example, the center of the visual analyzer) and the center of the unconditional reaction (for example, the motor cortex).

Stage of specialization . In this stage specialization occurs conditional inflexive Answer: It is observed only after the conditional signal is . All-celest, close in quality stimuli, do not cause a response. The degree of specialization and the rate of its offensive depend on the characteristics of conditional and unconditional stimuli.

The meaning of this stage it is that when launching a reflex from a large "set" of possible irritants only a small number of significant signals can cause reaction development .

I. P. Pavlov believed that this stage is connected with a concentration process excitation in the conventional signal analyzer.

The components of the estimated reaction, observed in the grace of generalization, fade, there is a link between the cortical centers of conditional and unconditional stimuli.

The distant synchronization of neurons in these areas of the cortex during the specialization of the reflex becomes more distinct, in the subcortical formations it is oppressing. If, before developing a conditional motor reflex to light in the motorized area of \u200b\u200bthe cortex, only 2.5% of neurons respond to light irritants, then after production - already 40%.

It can be concluded that the specialization of the conditional reflex is associated with the processes of cortical braking, and the severity of this process will depend on the accuracy and stability of the conditionaloreflex reaction.

1. What conditions are required to develop a conditional reflex? 2. In addition, the conditional reflex is fussing? 3. What is dominant? 4. How important is

dominants in life? 5. Dominant focus of excitement usually slows down the neighboring sections of the bark. Explain with what law open Pavlov, it is connected. 6.Kova Communication Dominants with needs?

1. What is such a digestion? a) pre-processing of food; b) Mechanical processing of food; c) Mechanical and chemical processing of food. 2.Kone

Does the body have food? a) building function; b) energy function; c) Construction and energy function. 3. Where is bile produced? a) in the liver; b) in the pancreas; c) in the stomach. 4. For infectious diseases of the intestine? a) liver cirrhosis; b) gastritis; c) dysentery. 5. Where does the digestion process begins? a) in the intestine; b) in the oral cavity; c) in the stomach. 6. How is the soft part in the center of the tooth? a) enamel; b) pulp; c) dentin. 7. Where is the center of swallowing? a) in the oblong brain; b) in large hemispheres; c) in the intermediate brain. 8.pysterry system consists of: a) from organs forming a digestive channel; b) from organs forming the digestive channel, and digestive glands; c) from digestive and allocation organs. 9. Scientific, studied the work of the digestive system: a) I.P. Pavlov; b) I.M. Sechens; c) I.I. Swords. 10. The source of the disease with worm diseases may be: a) non-wood fish, poorly roasted; b) poor-quality fish; c) non-freight products. 11. Where is the splitting of some proteins and milk fat? a) in the stomach; b) in the small intestine; c) in a 12-point intestine. 12. Where is the disinfection substance produced - lysozyme? a) in salivary glands; b) in gastric glands; c) in intestinal glands. 13. The function of the enzymes of the salivary glands is: a) the splitting of complex carbohydrates; b) splitting of fats; c) Split cleavage. 14. Where is the splitting of nutrients? a) in the stomach; b) in the small intestine; c) in a thick intestine. 15. What is the function of the enzymes of intestinal glands? a) splitting proteins, fats and carbohydrates; b) crushing of fats on the droplets; c) suction of splitting products. 16. Where is the absorption of water? a) in the stomach; b) in the small intestine; c) in a thick intestine. 17. The function of the nervous tissue in the intestinal walls: a) wave-like cutting of the muscles; b) produces enzymes; c) spends food. 18. What is the cause of salivation? a) reflex; b) chopping of food; c) Establishment. 19. What conditions are needed to split proteins in the stomach? a) an acidic medium, the presence of enzymes, t \u003d 370; b) Alkaline medium, enzymes, t \u003d 370 c) weakly alkaline medium, the presence of enzymes, T \u003d 370. 20. In which alcohol is absorbed in the digestive tract? a) in the small intestine; b) in the thick intestine; c) in the stomach. 21. Why are the rings in the oral cavity quickly heal? a) due to the weakly alkaline environment; b) due to the enzyme lysozyme; c) due to saliva. 22. Due to what is the suction of substances in the small intestine? a) long; b) the small intestine festive; c) a lot of enzymes in the small intestine. 23. Why do physiologists liver called food warehouse? a) produced bile and stored; b) regulates the exchange of proteins, fats, carbohydrates; c) Glucose is converted into glycogen and is stored. 24. What kind of gastric juice enzyme is the main and which substances he splits? a) amyloza, cleaves proteins and carbohydrates; b) pepsin, breaks proteins and milk fat; c) maltose, breaks fats and carbohydrates. 25. Why not digest the walls of the stomach? a) thick muscular layer; b) thick mucous membrane; c) Big abundance of mucus. 26. Branch of the gastric juice by the action of food in the oral cavity is: a) unconditional juice reflex; b) conditional reflex; c) humoral regulation. 27. Where the intestinal chopstick is inhabited, name it is valid. a) in the small intestine, help the cleavage of carbohydrates; b) in the colon, splits fiber; c) in a blind intestine, causes a disease of appendicitis. 28. Why do physiologists figuratively call the liver of the "chemical laboratory"? a) the harmful substances are neutralized; b) the bile is formed; B) enzymes are produced. 29. What is the importance of bile in the process of digestion? a) squabble proteins, fats and carbohydrates; b) neutralizes poisonous substances; c) crushing fats on the droplets. 30. What is the correspondence between the structure of the esophagus of its function? a) walls muscular, soft and mucous membranes; b) walls dense, cartilage; c) walls dense, the presence of connective tissue, inside the mucous.