Ivan Petrovich Pavlov. Conditioned reflex There is no need to prove that I.P. Pavlov was an outstanding scientist. During his long life (1849–1936) he achieved enormous success thanks to great diligence, purposeful work, keen insight, theoretical clarity,

Conditional abbreviations aa-t-RNA - aminoacyl (complex) with transport RNAATP - adenosine triphosphoric acidDNA - deoxyribonucleic acid-RNA (i-RNA) - matrix (information) RNANAD - nicotinamide adenine dinucleotide NADP -

Conventional abbreviations AG - Golgi apparatus ACTH - adrenocorticotropic hormone AMP - adenosine monophosphate ATP - adenosine triphosphate VND - higher nervous activity GABA - β-aminobutyric acid GMP - guanosine monophosphate GTP - guanine triphosphoric acid DVP -

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

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

The orienting reflex occupies a special place among the unconditioned reflexes in ensuring safety. It appears in response to a new stimulus: a person becomes alert, listens, turns his head, squints his eyes, and thinks. The orienting reflex ensures the perception of an unfamiliar stimulus.

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

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

Conditioned reflexes formed during the learning process allow the body to adapt more flexibly to specific environmental conditions and form the basis for the development of a person’s habits and entire lifestyle.

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

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

Words, like other environmental factors (physical, chemical and biological), can be indifferent to human health, can have a beneficial effect, or can cause harm - even death (suicide).

1. 1. Introduction3
2. 2. Physiology of unconditioned reflexes3
3. 3. Classification of unconditioned reflexes5
4. 4. The importance of unconditioned reflexes for the body7
5. 5. Conclusion7

References8

Introduction

Unconditioned reflexes are hereditarily transmitted (innate), inherent to the entire species. They perform a protective function, as well as the function of maintaining homeostasis.

Unconditioned reflexes are an inherited, unchangeable reaction of the body to external and internal signals, regardless of the conditions for the occurrence and course of reactions. Unconditioned reflexes ensure the body's adaptation to constant environmental conditions. They are a species behavioral characteristic. The main types of unconditioned reflexes: food, protective, orienting.

An example of a defensive reflex is the reflexive withdrawal of the hand from a hot object. Homeostasis is maintained, for example, by a reflex increase in breathing when there is an excess of carbon dioxide in the blood. Almost every part of the body and every organ is involved in reflex reactions.

Physiology of unconditioned reflexes

An unconditioned reflex is an innate response of the body to irritation with the obligatory participation of the central nervous system (CNS). In this case, the cerebral cortex does not directly participate, but exercises its highest control over these reflexes, which allowed I.P. Pavlov to assert the presence of a “cortical representation” of each unconditioned reflex. Unconditioned reflexes are the physiological basis:

1. Human species memory, i.e. congenital, inherited, constant, common to the entire human species;

2. Lower nervous activity (LNA). NND from the point of view of unconditioned reflexes is an unconditioned reflex activity that provides the body with the unification of its parts into a single functional whole. Another definition of NND. NND is a set of neurophysiological processes that ensure the implementation of unconditioned reflexes and instincts.

The simplest neural networks, or arcs (according to Sherrington), involved in unconditioned reflexes, are closed in the segmental apparatus of the spinal cord, but can also be closed higher (for example, in the subcortical ganglia or in the cortex). Other parts of the nervous system are also involved in reflexes: the brain stem, cerebellum, and cerebral cortex.

The arcs of unconditioned reflexes are formed at the time of birth and remain throughout life. However, they can change under the influence of illness. Many unconditioned reflexes appear only at a certain age; Thus, the grasping reflex characteristic of newborns fades away at the age of 3-4 months.

There are monosynaptic (involving the transmission of impulses to the command neuron through one synaptic transmission) and polysynaptic (involving the transmission of impulses through chains of neurons) reflexes.

Approximate unconditioned reflexes, occurring with the direct participation of the cerebral cortex, are physiological mechanisms of human cognitive activity and involuntary attention. In addition, the extinction of orientation reflexes constitutes the physiological basis of addiction and boredom. Habituation is the extinction of an orienting reflex: if a stimulus is repeated many times and has no particular meaning for the body, the body stops responding to it, and addiction develops. So, a person living on a noisy street gradually gets used to the noise and no longer pays attention to it.

Instincts are a form of innate behavior. Their physiological mechanism is a chain of innate unconditioned reflexes, into which, under the influence of individual life conditions, links of acquired conditioned reflexes can be “woven together.”

Rice. 1. Scheme of organization of instinctive behavior: S - stimulus, P - reception, P - behavioral act; the dotted line is the modulating influence, the solid line is the activity of the modulating system as an evaluative authority.

Reflection as the essence of the psyche occurs at different levels. There are three levels of brain activity: specific, individual and socio-historical. Reflection at the species level is carried out by unconditioned reflexes.

The concept of “drive and drive reflex” by the Polish physiologist and psychologist J. Konorski played a significant role in the development of the theoretical foundations of the organization of behavior. According to the theory of Yu. Konorsky, brain activity is divided into executive and preparatory, and all reflex processes fall into two categories: preparatory (incentive, drive, motivational) and executive (consummatory, consummatory, reinforcing).

Executive functioning involves many specific responses to many specific stimuli, so this activity is provided by the cognitive or gnostic system, which includes the stimulus recognition system. Preparatory activity is associated with less specific reactions and is more controlled by the internal needs of the body. It is anatomically and functionally different from the system responsible for perception and cognitive activity, learning, and is called by Yu. Konorsky the emotive, or motivational system.

The cognitive and emotive systems are served by different brain structures.

Most unconditioned reflexes are complex reactions that include several components. So, for example, with an unconditioned defensive reflex caused in a dog by strong electrodermal irritation of the limb, along with defensive movements, breathing also increases and increases, cardiac activity accelerates, vocal reactions appear (squealing, barking), the blood system changes (leukocytosis, thrombocytosis and etc.). The food reflex is also distinguished by its motor (grabbing food, chewing, swallowing), secretory, respiratory, cardiovascular and other components.

So, the most complex unconditioned reflexes are an innate holistic behavioral act, a systemic morphophysiological formation that includes stimulating and reinforcing components (preparatory and executive reflexes). Instinctive behavior is realized by external and internal determinants by “evaluating” the relationships between significant components of the environment and the internal state of the organism, determined by the actualized need.

Classification of unconditioned reflexes

The entire set of unconditioned and conditioned reflexes formed on their basis is usually divided into a number of groups according to their functional significance. The main ones are nutritional, defensive, sexual, statokinetic and locomotor, orientation, maintaining homeostasis and some others. Food reflexes include reflex acts of swallowing, chewing, sucking, salivation, secretion of gastric and pancreatic juice, etc. Defensive reflexes are reactions to eliminate damaging and painful stimuli. The group of sexual reflexes includes all reflexes associated with sexual intercourse; This group also includes the so-called parental reflexes associated with feeding and nursing the offspring. Statokinetic and locomotor reflexes are reflex reactions of maintaining a certain position and movement of the body in space. Reflexes that support the preservation of homeostasis include thermoregulatory, respiratory, cardiac and those vascular reflexes that help maintain a constant blood pressure, and some others. The orienting reflex occupies a special place among unconditioned reflexes. This is a reflex to novelty.

It occurs in response to any fairly quickly occurring fluctuation in the environment and is expressed externally in alertness, listening to a new sound, sniffing, turning the eyes and head, and sometimes the whole body towards the emerging light stimulus, etc. The implementation of this reflex provides better perception of the acting agent and has important adaptive significance. This reaction is innate and does not disappear with complete removal of the cerebral cortex in animals; it is also observed in children with underdeveloped cerebral hemispheres - anencephals. The difference between the orienting reflex and other unconditioned reflex reactions is that it fades away relatively quickly with repeated applications of the same stimulus. This feature of the orientation reflex depends on the influence of the cerebral cortex on it.

Rice. 1. Comparison of the most complex unconditioned reflexes (instincts) of higher animals with human needs: double arrows - phylogenetic connections of the most complex reflexes of animals with human needs, dotted - the interaction of human needs, solid - the influence of needs on the sphere of consciousness

The importance of unconditioned reflexes for the body

The meaning of unconditioned reflexes:

♦ maintaining a constant internal environment (homeostasis);

♦ maintaining the integrity of the body (protection from damaging environmental factors);

♦ reproduction and preservation of the species as a whole.

Conclusion

Unconditioned reflexes, the formation of which is completed in postnatal ontogenesis, are genetically predetermined and strictly adjusted to certain environmental conditions corresponding to a given species.

Congenital reflexes are characterized by a stereotypical species-specific sequence of implementation of a behavioral act. They arise at their first need, with the appearance of a “specific” stimulus for each of them, thereby ensuring the steady performance of the most vital functions of the body, regardless of random, transient environmental conditions. A characteristic feature of unconditioned reflexes is that their implementation is determined by both internal determinants and an external stimulus program.

As noted by P.V. Simonov, the definition of an unconditioned reflex as hereditary, unchangeable, the implementation of which is machine-like and independent of the achievements of its adaptive goal, is usually exaggerated. Its implementation depends on the existing functional state of the animal and correlates with the currently dominant need. It may fade or intensify.

Satisfying a variety of needs would have been impossible if, in the process of evolution, a specific overcoming reaction, the freedom reflex, had not arisen. Pavlov considered the fact that an animal resists coercion and attempts to limit its motor activity much deeper than just a type of defensive reaction. The freedom reflex is an independent active form of behavior for which an obstacle serves as no less an adequate stimulus than food for food search, pain for a defensive reaction, and a new and unexpected stimulus for an orienting reflex.

Bibliography

1. 1. Bizyuk. A.P. Fundamentals of neuropsychology. Textbook for universities. Publishing house Rech. - 2005
2. 2. Danilova, A.L. Krylova Physiology of higher nervous activity. - Rostov n/a: “Phoenix”, 2005. - 478
3. 3. Psychophysiology /ed. Alexandrova Yu.I. St. Petersburg, publishing house "Peter" 2006
4. 4. Tonkonogiy I.M., Pointe A. Clinical neuropsychology. 1st edition, Publisher: PETER, PUBLISHING HOUSE, 2006
5. 5. Shcherbatykh Yu.V. Turovsky Ya.A. Anatomy of the central nervous system for psychologists: Textbook. St. Petersburg: Peter, 2006. - 128 p.

1. What reflexes are called conditioned? Give examples of a conditioned reflex.

Conditioned reflexes are acquired by the body in the process of its development, i.e. they are individual. Conditioned reflexes do not have ready-made reflex arcs; they are formed under certain conditions. These reflexes are not constant; they can develop and disappear. The conditioned reflex is formed on the basis of the unconditioned reflex and is carried out due to the activity of the cerebral cortex. For the formation of conditioned reflexes, it is necessary to combine two stimuli in time: an indifferent (conditioned) one for a given type of activity (light, sound, for example, for digestion) and an unconditioned one, causing a certain unconditioned reflex (food, etc.). The conditional signal must precede the unconditional signal. Reinforcement of the conditioned signal by the unconditioned must be repeated in the absence of distracting extraneous stimuli. When a conditioned stimulus (for example, light) acts, a focus of excitation appears in the cortex. The subsequent action of an unconditioned stimulus (for example, food) is accompanied by the appearance of a second focus of excitation in the cortex. A temporary connection arises between them (a Pavlovian closure occurs). After several combinations of conditioned and unconditioned stimuli, the connection becomes stronger. Now only one conditioned stimulus is enough to trigger a reflex. An example of a conditioned reflex: salivation at the sight and smell of food.

Conditioned reflexes are not only developed, but also disappear or weaken when the conditions of existence change as a result of inhibition. I.P. Pavlov distinguished two types of inhibition of conditioned reflexes: unconditioned (external) and conditioned (internal). Unconditioned (external) inhibition occurs as a result of the action of a new stimulus of sufficient strength. In this case, a new focus of excitation appears in the cerebral cortex, which causes inhibition of the existing focus of excitation. In a person, for example, with an acute toothache, a severely wounded finger stops hurting. Conditioned (internal) inhibition develops according to the laws of the conditioned reflex, i.e. if the action of the conditioned stimulus is not reinforced by the action of the unconditioned stimulus. Thanks to inhibition in the cortex, unnecessary temporary connections disappear.

2. What reflexes are called unconditioned? Give examples of an unconditioned reflex.Material from the site

Unconditioned reflexes are innate and inherited. Unconditioned reflexes appear at the first application of the stimulus to the corresponding receptors. These reflexes have permanent inherited ready reflex arcs. They are inherent in all representatives of this species and are carried out in response to adequate stimulation. Unconditioned reflexes are carried out at the level of the spinal cord and brain stem, subcortical nuclei. Examples: salivation, swallowing, breathing, etc.

Unconditioned reflexes- These are innate, 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, that is, characteristic of all representatives of a given 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 not constant 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 stimulation applied to one specific receptive field. Conditioned reflexes can be formed 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 removing the cerebral cortex, the developed conditioned reflexes disappear and only unconditioned ones remain. This indicates that in the implementation of unconditioned reflexes, in contrast to conditioned ones, the leading role belongs to the lower parts of the central nervous system - the subcortical nuclei, brain stem and spinal cord. It should be noted, however, that in humans and monkeys, who 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 proven by the fact that its lesions in primates lead to pathological disorders 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 and sexual intercourse, arise 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 strengthened in the process of phylogenesis and 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 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 internal state of the body become a stimulus to a conditioned reflex - a conditioned stimulus, or signal. The irritation that causes an unconditioned reflex - unconditioned irritation - must, during the formation of a conditioned reflex, accompany the conditioned irritation and reinforce it.

In order for the clinking of knives and forks in the dining room or the knocking 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, it is necessary to re-coincidence of these sounds with food - reinforcement of stimuli that are initially indifferent to salivary secretion by feeding , i.e., unconditional irritation of the salivary glands. Likewise, the flashing of an electric light bulb in front of a dog’s eyes or the sound of a bell will only cause conditioned reflex flexion of the paw if they are repeatedly accompanied by electrical irritation of the skin of the leg, causing an unconditioned flexion reflex whenever it is used.

Similarly, a child’s crying and his hands pulling away from a burning candle will be observed only if the sight of the candle first coincided at least once with the feeling of a burn. In all the above examples, external agents that are initially relatively indifferent - the clinking 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 do the initially indifferent signals of the external world become stimuli for a certain type of activity.

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