Pavlov's conditioned reflex theory. Reflex theory

A reflexive understanding of mental activity is a necessary link between the recognition of mental activity as an activity of the brain, inseparable from it, and understanding it as a reflection of the world. By reflexive understanding of brain activity, these two fundamental principles are combined into one inseparable whole. The mental activity of the brain is at the same time a reflection of the world because the activity of the brain itself is reflexive in nature and is determined by the influences of the external world.

The reflexive understanding of the mental activity of the brain assumes that it is determined by the objective world and is reflective in relation to it. At the same time, a person’s knowledge of the world can be carried out only due to the fact that the functioning of the brain does not consist in the simple reception of influences falling on it, but in activity - in the analysis and synthesis, differentiation and generalization of these influences. The internal logic of the theory of reflection necessarily leads to a reflexive understanding of mental activity.

Just as the internal logic of the theory of reflection of dialectical materialism naturally leads to a reflexive understanding of brain activity, so the reflex theory of brain activity naturally leads to an understanding of mental activity as reflective.

Reflex theory of brain activity is, first of all, a statement about its determination. Recognition of mental activity as reflex activity of the brain does not mean reducing mental activity to nervous, physiological, but extending the reflex concept to mental activity. The reflex theory is, at the same time, ultimately nothing more than an extension of the principle of determinism to the activity of the brain.

The approval of the reflex theory of mental activity in this work actually means nothing more than the extension of the principle of determinism in its dialectical-materialistic understanding to the reflective activity of the brain, to mental phenomena. A certain understanding of determinism corresponds to a corresponding understanding of reflex theory. The reflex theory of Descartes and his immediate successors was nothing more than an extension of mechanistic determinism, the theory of cause as an external push, to the activity of the brain. Significantly different is the reflex theory, which corresponds to the dialectical-materialistic understanding of the determination of phenomena, their universal interconnection, and their interaction. THEM. Sechenov and I.P. Pavlov laid the foundation for the construction of such a reflex theory.

Here we preface the analysis of the reflex understanding of mental activity and the determination of mental phenomena with a historical essay devoted to the teachings of I.M. Sechenov and I.P. Pavlova.

Neither I.M. Sechenov, nor I.P. Pavlov, whose worldview was formed under the influence of Russian revolutionary democrats, did not base their scientific work on Marxist philosophy. However, a philosophical analysis of the reflex theory they created shows that, according to its objective internal logic, it follows the path of a specific natural science implementation in the doctrine of the brain and its activity of the basic methodological principles of dialectical materialism, and approaches it.

The principle of reflex, as we know, was first formulated by Descartes (although he did not yet have the term “reflex”). Descartes' idea of the reflex bore a clear imprint of his mechanistic worldview. Later, in the 18th century, apparently for the first time in Asperuch Montpellier, the very term “reflex” appears. Despite the fact that the concept of “reflex” in physiology has a long history, there is every reason to talk about the reflex theory, the main provisions of which were formulated by I.M. Sechenov and received further development and specific scientific implementation in the teachings of I.P. Pavlova as a fundamentally new concept. THEM. Sechenov and I.P. Pavlov created a new concept of reflex and, most importantly, extended the principles of reflex theory to mental activity.

When characterizing reflex activity in general, and therefore mental activity, they usually note what was rightly emphasized by I.M. Sechenov’s position that its source lies outside, that through it the body’s relations with the outside world are realized. However, the Sechenov-Pavlov reflex theory, in its methodological meaning, is not a mechanistic theory of an external push. The theory of cause as an external push in explaining phenomena organic life suffers a clear collapse: the same external influence causes a different response depending on the internal state of the organism on which these external influences fall. External causes act through internal conditions. This dialectical-materialist position is the decisive methodological basis for the construction of any scientific theory.

Without revealing the internal laws of reflex activity, one would have to confine oneself to purely descriptive statements of the fact that such and such an external influence was followed in such and such a case by such and such a reaction, correlating them directly according to the scheme: stimulus - reaction. This is the path of behaviorism, corresponding to the pragmatic, positivistic methodology from which its representatives now proceed.

Reflex theory of brain activity, based on methodological basis dialectical materialism, is a concrete expression of the general position that every action is an interaction, that the influence of any cause depends not only on it, but also on what it affects, that the action of any external cause, any external conditions is carried out through internal conditions. Hence the determinism of the reflex theory in its true understanding. The activity of the brain, including its mental activity, has its cause, ultimately, in external influences. However, there is no direct mechanical relationship between the external stimulus and the response. The dependence of the response on external influence is mediated by internal conditions. (These internal conditions themselves are formed as a result of external influences. Thus, determinism in its dialectical understanding appears at the same time as historicism: it means that the effect of each momentary influence depends on what influences the organism was exposed to before, on the entire history of the individual and species to which it belongs.) Therefore, to construct a reflex theory of brain activity

it is necessary to reveal the internal patterns of reflex activity of the brain. Such internal laws are the open I.P. Pavlov's laws of irradiation and concentration of excitation and inhibition and their mutual induction.

All of them express the internal relationships of nervous processes that mediate the brain’s relationships between the organism and the conditions of its life - their impact on it and its response activity in its dependence on external conditions.

The mediation of the effect of external influences by internal conditions lies not only in the characteristics and role of the laws of neurodynamics, but also in the entire doctrine of the conditioned reflex activity of the cortex, since, according to this doctrine, the influence of each conditioned stimulus, entering the cortex, enters the whole system of resulting past experience of connections. As a result, the reflex response of the body caused by the acting this moment stimulus is determined not only by it, but also by the entire system of connections that it finds in a given individual. Stimuli receive a variable meaning, varying depending on what they signal for a given individual due to previous experience deposited in the cortex in the form of a system of conditioned neural connections. The determinism of Pavlov's reflex theory, regardless of its individual formulations, which sound mechanistic, is a particular expression in relation to understanding the activity of the brain of the general philosophical principle of determinism in its dialectical-materialistic interpretation.

The core of the reflex understanding of mental activity is the position that mental phenomena arise in the process of interaction of the individual with the world carried out through the brain; Therefore, mental processes, inseparable from the dynamics of nervous processes, cannot be isolated either from the influence of the external world on a person, or from his actions, deeds, practical activities, the regulation of which they serve.

Mental activity is not only a reflection of reality, but also a determinant of the meaning of the reflected phenomena for the individual, their relationship to his needs: therefore, it serves to regulate behavior and practical activity. The assessment of phenomena and the attitude towards them are connected with the psyche from its very origin, as well as their reflection. This assessment, which in animals is reduced to biological significance, acquires social content in humans.

The first initial natural science premise of the reflex theory is the position of the unity of the organism and the environment, the active interaction of the organism with the outside world.

Already Sechenov clearly states the position not only about interconnection, about unity, but also about the active interaction of the individual with the outside world in its special biological expression - in relation to the organism and the environment, to the organism and the conditions of its life. This position constituted the first, general biological, prerequisite for Sechenov’s discovery of brain reflexes

Therefore, mental phenomena contain the initial prerequisites for the development in man not only of cognition as a socio-historical process of the development of scientific knowledge, but also for socially developed ethical standards behavior.

THEM. Sechenov formulates this position (1861) as follows: “An organism without external environment, supporting its existence is impossible; therefore in scientific definition the organism must also include the environment influencing it" (Sechenov I.M. Two final lectures on the significance of so-called plant acts in animal life // Selected works. M.: Publishing House of the USSR Academy of Sciences, 1952. T. 1. S 533). Later (1878) Sechenov writes about the influence on organisms of the “environment in which they live, or, more precisely, the conditions of their existence” (Sechenov I.M. Elements of Thought // Selected philosophical and psychological works. M.: Gospolitizdat , 1947. P. 412). Thus, the environment, the conditions of existence, are introduced into the very definition of the organism: at the same time, the conditions of existence are distinguished from the environment, determined by the requirements that the organism places on the environment.

brain Conditioned by external influences, the reflex activity of the brain is the “mechanism” through which an organism that has a nervous system communicates with the outside world.

The second, physiological, prerequisite for the reflex theory was Sechenov’s discovery of central inhibition.

The fundamental significance of the discovery of central inhibition for the construction of a reflex theory lies primarily in the fact that it was the first step towards the discovery of internal patterns of brain activity, and the discovery of these latter was a necessary prerequisite for overcoming the mechanistic understanding of reflex activity according to the “stimulus-response” scheme, according to the mechanistic theory of cause as an external push, supposedly uniquely determining

reaction effect.

The position on the unity of the organism and the conditions of its existence and the discovery of central inhibition are the main steps on the path to “Reflexes of the brain.” They directly follow each other in time: in 1861, Sechenov’s article on the significance of plant acts of an animal organism was published, in which he formulated the position about the unity of the organism and the environment; in 1862, the scientist carried out his experiments, which led to the discovery of the central braking. Having completed his first major work on central inhibition, Sechenov immediately realized his plans in the field of psychology: already in 1863 he published “Reflexes of the Brain.”

We can safely say that Sechenov made two great discoveries in his scientific activity: central inhibition - in the field of physiology and the reflex nature of the psyche - in the field of psychology. It is the latter that belongs to the number of those that, while relating directly to the subject of one science, at the same time go far beyond its boundaries, acquiring a general ideological significance.

These two discoveries, as well as Sechenov’s scientific activity in general in the fields of psychology and physiology of the nervous system, were closely related. Sechenov himself noted the role that his studies in psychology and interest in the problem of will played in his discovery of central inhibition.

On the other hand, without the discovery of the latter, Sechenov could not have understood mental processes, devoid of a visible effector, motor end, as reflex processes

The extension of the reflex principle to the brain could not be limited to a simple transfer of the same concept to new area- this transfer necessarily required significant changes in the very concept of reflex. What are the main, specific features of brain reflexes? The brain reflex is, according to Sechenov, a learned reflex, i.e. not innate, but acquired during individual development and depending on conditions, in

Another point 3 of the “Theses” that were attached to IM’s dissertation. Sechenov “Materials for the future physiology of intoxication”, stated: “The most general character of normal brain activity (since it is expressed by movement) is the discrepancy between excitation and the action it causes - movement” (Sechenov IM. Izbr. proiz. 1956. T. II. P. 864). This means that the prehistory of Sechenov’s reflex theory already, in essence, contained a denial of the “stimulus-response” scheme and the mechanistic idea of the ability of an external cause (an external push) to directly determine the result of brain activity.

The first explanation for this discrepancy between the response movement and the excitation caused by external influence was inhibition; it is an internal condition that determines one or another effect of external influence.

» See: Sechenov IM. Autobiographical notes. M.: Publishing House of the USSR Academy of Sciences, 1952. P. 183-186. Hence the famous position of “Reflexes of the Brain”: “Thought is the first two-thirds of a mental reflex” (Sechenov I.M. Selected philosophical and psychological works. P. 155). From “the ability to delay one’s movements,” according to Sechenov, “follows that enormous series of phenomena where mental activity remains, as they say, without external expression, in the form of thoughts, intentions, desires, etc.” (Ibid. p. 154).

which it is formed. (Expressing the same idea in terms of his doctrine of higher nervous activity, Pavlov will say that this is a conditioned reflex, that this is a temporary connection.)

The brain reflex is the connection between the body and its living conditions. This feature of the brain reflex will appear with complete certainty and fundamental acuteness in Pavlov’s doctrine of conditioned reflexes. Pavlov figuratively characterizes a conditioned reflex, a temporary connection as a temporary closure of conductive circuits between phenomena of the external world and the reactions of the animal organism to them. Reflex activity is the activity through which an organism that has a nervous system realizes its connection with living conditions and all its variable relationships with the outside world. Conditioned reflex activity as a signal activity is aimed, according to Pavlov, at finding in a constantly changing environment “the basic conditions of existence necessary for an animal, serving as unconditional stimuli...”. In Pavlov’s concept of reflex activity as a whole, the central place in this regard belongs to the concept of reinforcement: that reflex activity that is “reinforced” is carried out.

The third is necessarily connected with the first two features of the brain reflex. Being “learned,” temporary, changing with changing conditions, the brain reflex cannot be determined morphologically by once and for all fixed paths.

This tendency was completed and fully realized only by Pavlov. Pavlov's reflex theory overcame the idea that the reflex is supposedly entirely determined by the morphologically fixed paths in the structure of the nervous system on which the stimulus falls. She showed that the reflex activity of the brain (always including both unconditioned and conditioned reflexes) is a product of the dynamics of nervous processes confined to the brain structures, “expressing the variable relationship of the individual with the outside world.”

Finally, and most importantly, the brain reflex is a reflex with a “mental complication.” The advancement of the reflex principle on the brain led to the inclusion of mental activity in the reflex activity of the brain. This is a fundamentally important feature of Sechenov’s concept of brain reflexes.

If we adhere to I.M.’s own formulations. Sechenov, the reflex understanding of mental activity can be expressed in two positions.

1. The general scheme of the mental process is the same as that of any reflex act: like any reflex act, the mental process originates in an external influence, continues with central nervous activity and ends with the individual’s response activity (movement, action, speech).

See Pavlov I.P. Poly. collection Op. 2nd ed. T. III. Book 1M.; L. 1951. P. 116. "See Ibid. Book 2. P. 108.

Describing the essence of his concept in the preface to the book “Physiology of Nerve Centers”, I.M. Sechenov wrote that he wanted “first of all to present to the experts an attempt to introduce a physiological system into the description of central nervous phenomena in place of the anatomical one that still dominates today, i.e. to put in the foreground not form, but activity, not topographical isolation of organs, but the combination of central processes into natural groups” (Sechenov I.M. Physiology of nerve centers. M.: Publishing House of the USSR Academy of Sciences, 1952. P. 21).

A similar opposition of the functional dynamic concept to the anatomical and morphological concept of preformed nerve pathways clearly appears in Sechenov and in “Elements of Thought” (Sechenov I.M. Elements of Thought // Selected philosophical and psychological works. P. 443-444).

“It was this feature of Pavlov’s reflex theory that K.M. noted as decisive. Bykov in his report on the 18th International Congress physiologists in Copenhagen on August 15-18, 1950 (See: Bykov KM. The doctrine of conditioned reflexes and reflex theory // Vesti. Leningrad University. 1950. No. 9. P. 8-16.

Mental phenomena arise as a result of an individual’s “meeting” with the outside world.

2. Mental activity cannot be separated from the single reflex activity of the brain. It is the “integral part” of the latter.

Thus, mental phenomena cannot be isolated either from objective reality or from the reflex activity of the brain.

If we analyze the general meaning of these provisions, it turns out that Sechenov’s reflex understanding of mental activity means that 1) mental phenomena arise in the process of interaction of an individual with the outside world, 2) they are inseparable from the material nervous activity of the brain, thanks to which this interaction is carried out.

In these two provisions, the reflex theory of the psyche directly connects with the provisions of dialectical materialism.

Understanding mental activity as a “meeting” of a subject with objective reality, THEM. Sechenov overcomes the “isolation” of the mental not only from the material, physiological substrate, but also from the object: the reflexive understanding of mental activity by this side is opposed to introspectionism, the closure of mental phenomena in the inner world of consciousness, isolated from the external material world.

THEM. Sechenov emphasizes the real life significance of the psyche. Sechenov characterizes the first part of the reflex act, beginning with perception, with sensory arousal, as signaling. At the same time, sensory signals from the higher sense organs “notify” what is happening in environment. In accordance with the signals entering the central nervous system, the second part of the nerve regulator carries out movement. Sechenov emphasizes the role of “feeling” in the regulation of movement. Sensory images - the appearance of a wolf for a sheep or a sheep for a wolf, using Sechenov’s examples, entail a restructuring of all the vital functions of the wolf and the sheep and cause motor reactions of the opposite meaning in each animal. In this active role of feeling, Sechenov sees its “vital significance”, its “meaning”. In the ability to serve to “discriminate the conditions of action” and thus open up the possibility of actions “corresponding to these conditions,” Sechenov finds “two general meanings", which characterize feeling.

In Sechenov's concept of the signal value of feeling and its “predictive” role lie the origins of Pavlov’s understanding of sensations as signals of reality.

Revealing the meaning of the reflex understanding of the mental, Sechenov rejected any attempts to derive the content of the mental from the nature of the brain. Defending the reflex theory in his polemics with Kavelin, Sechenov rejected, as based on misunderstanding, Kavelin’s assertion that he, Sechenov, was trying to derive the essence of the psyche, its content, from the “structure of nerve centers.” This does not mean some kind of limitation of the reflex theory, but precisely its inexorable consistent implementation. To try to derive the content of the psyche from the structure of the brain would mean, in modern terms, to take the position of psycho-morphologism and inevitably slide into physiological idealism.

Recognition that the content of mental activity as a reflex activity cannot be deduced from the “nature of nerve centers”, that it is determined

“Feeling plays essentially the same signaling role everywhere” (Sechenov I.M. Physiology

nerve centers. M.: Publishing House of the USSR Academy of Sciences, 1952. P. 27). » Sechena I.M. First lecture at Moscow University // Izbr. prod. T. 1. P. 582. Sechenov I.M. Elements of thought. P. 416. See: Sechenov I.M. Comments on Mr. Kavelin’s book “Problems of Psychology” // Izbr. Philosopher and psychol.

prod. P. 192.

objective being and is its image - this is the cardinal position of Sechenov’s reflexive understanding of the psyche. The affirmation of the reflexive nature of the psyche is naturally connected with the recognition of the psyche as a reflection of being.”

Thus, no matter in what direction we trace the conclusions of the reflex theory of the mind, we invariably come to conclusions leading to the theory of reflection of dialectical materialism. This is the case with the philosophical meaning of the reflexive understanding of the psyche.

Sechenov reveals the psychological content of the reflex theory primarily in relation to the process of cognition. This psychological content consists, in short, in the fact that mental activity is mainly the activity of analysis, synthesis and generalization. Promoting and defending the reflex understanding of mental activity, Sechenov is far from reducing mental activity to physiological activity. For him, we are talking about something else - about extending the principles of reflex theory to the study of mental activity.

The actual physiological patterns of central cortical activity in general I.M. Sechenov was not yet known. He believed that their discovery was a matter of the distant future. These laws were discovered by I.P. Pavlov, thereby raising the reflex theory to a qualitatively new higher level. The reflex concept of brain activity, developed and enriched by Pavlov, first turned into a strictly scientific physiological doctrine. In this regard, the physiological aspect of the reflex theory necessarily and naturally comes to the fore in Pavlov’s works. At the same time, Pavlov declares with complete certainty and utmost clarity that the central concept of his entire doctrine of higher nervous activity - the “conditioned reflex” - is both a physiological and mental phenomenon. He himself concentrated his attention on the physiological analysis of reflex activity and - although very significant, but still only incidentally - touched upon the psychological aspect of the reflex concept in his published works.

Probably in connection with this, some representatives of the doctrine of higher nervous activity, especially in last years, sought to completely exclude any psychological content from Pavlov’s reflex concept, despite the fact that Pavlov directly characterized the main object of his study - the conditioned reflex - as not only a physiological, but also a mental phenomenon.

In its critical part, Sechenov’s polemic with Kavelin, who defended the idea of studying consciousness based on the products of spiritual activity, was a struggle against the line of “objective idealism”, against the path that German psychology took from Wundt to Dilthey and Spranger. The study of the products of spiritual activity in isolation from the process led to a confusion of individual and social consciousness and meant a separation of the psychological from its material substrate, from physiological, nervous activity.

To characterize the philosophical meaning of Sechenov’s reflex concept, it is very instructive, in particular, the fact that the logic of his reflex concept led him to criticize the mechanistic understanding of cause as an external push and to the assertion that every action is an interaction. In the article “Objective Thought and Reality” Sechenov notes that “in nature there is no action without reaction”, shows with a number of examples that the effect of external influence depends not only on the body that affects another, but also on this latter, and comes to the conclusion about the interaction of phenomena, a conclusion that brings him closer to the dialectical-materialistic understanding of the interdependence of phenomena.

(See: Sechenov I.M. Objective thought and reality // Selected works. T. 1. P. 48284).

Thus, in recent years, one has heard statements that completely fence off the “strictly objective Pavlovian method” from any contact with subjective mental phenomena, such as sensations. (See: Ivanov-Smolensky A.G. Some issues in the study joint activities first and second signaling systems // Journal. higher nervous activities. 1952. T. II. Vol. 6. pp. 862-867). In the work “Interoreceptors and the doctrine of higher nervous activity.” M.: Publishing House of the USSR Academy of Sciences, 1952) E.Sh. Airapetyants, in essence, proposes to exclude the concept of sensitivity from the doctrine of higher

This interpretation completely separates Pavlov’s doctrine of higher nervous activity from the line outlined by Sechenov; it essentially contrasts Pavlov's concept of reflex activity of the brain with Sechenov's. In fact, there are no grounds for such a opposition. Pavlov declared the impossibility of separating “in unconditional complex reflexes (instincts) the physiological, somatic from the mental, i.e. from experiencing powerful emotions of hunger, sexual desire, anger, etc.” He directly called sensations, perceptions and ideas “the first signals of reality”, divided human types into artistic and mental, etc.

In his research I.P. Pavlov actually took into account the mental aspect of higher nervous activity.

In order to be convinced of this, it is necessary to compare, for example, Pavlov’s interpretation of the trial and error method with the behavioristic, Thorndikeian one. According to Thorndike, when an animal placed in a cage solves the problem of getting food that is behind bars, it all comes down to the fact that the animal makes various chaotic movements until, by accidentally opening the cage, it takes possession of the food. The entire process of an animal solving a problem thus consists of movements and does not contain anything other than motor reactions.

Pavlov analyzes this process quite differently. When a monkey, in the process of previous trials, having differentiated a stick as an object of a certain shape, so that this shape has become a signal sign for getting food or a fruit, tries to reach a far away fruit with an insufficiently long stick, what happens in this case is not reduced, according to Pavlov, only to movement, not reaching a certain point, but also involves differentiation of the distance of the fruit from the animal and the size of the stick: new characteristics are differentiated, i.e. appear in sensation (or perception) and acquire signaling significance. That's the point. That is why Pavlov talks about the elementary or concrete thinking of animals. In the process of action, they “know” reality, reflecting it in sensations and perceptions. The process of sensory reflection of reality is included in all animal behavior. Without this, the behavior of animals, their adaptation to living conditions, and even more so the behavior of humans and their activities are impossible. To turn off the role of the sensory reflection of reality, as some interpreters of Pavlov are trying to do, too zealous guardians of the virgin purity of his teaching, trying to protect him from sinful contact with anything mental, means, grossly distorting Pavlov, reducing his position to the position of Thorndike.

The above-mentioned interpreters of Pavlov, of course, do not deny the presence of sensation not only in people, but also in animals. But sensations, perceptions, etc. seem to them to be subjectively experienced phenomena that can only serve as indicators of certain objective physiological processes. In scientific knowledge, the latter are supposedly substituted for the former, which then lose all meaning. This is, apparently, how they understand Pavlov’s “overlay” of the mental on the physiological and their merging. The attitude of these interpreters to Pavlov’s genuine teaching is objectively the same as the attitude of some neo-Darwinists to Darwin, who place their teacher’s theory in the Procrustean bed of dogmatic nervous activity, replacing it with the concept of signaling. It is not without interest that the same author is in the messages. devoted to the same research that he summarizes in the above book, he previously spoke about interoceptive sensations, more or less clearly registered by consciousness. See, for example, his article “Higher nervous activity and interoreception” (Vesti. Leningrad University, 1946. No. 4-5). He saw the main meaning and, so to speak, “pathos” of his research in the fact that they open the way “to understanding the psychology of the subconscious” (see: K. M. Bykov, E. Sh. Airamtyants. A test of the application of the doctrine of interoreception to understanding psychology of the subconscious // Abstracts of reports at a meeting of physiologists in Leningrad, dedicated to the fifth anniversary of the death of I.P. Pavlov (M.; Leningrad: Publishing House of the Academy of Sciences of the USSR, 1941. pp. 3-4). » Pavlov I.P. Colon. collection Op. T. III. Book 2. P. 335.

strictly accepted scheme, erasing from it exactly what is at the junction various areas and contains the greatest opportunities for further growth of science.

This comparison with neo-Darwinism is not only an external analogy. It concerns the very essence of the matter. If we do not recognize the reflection of objective conditions in images, sensations and perceptions, then the adaptability of response actions to conditions will have to be reduced to “natural selection” adequate reactions from among those that arise randomly, selection carried out by inhibiting reactions that are not supported by reality, just as neo-Darwinism, and partly Darwinism in general, reduces the explanation of an organism’s adaptability to the environment to the natural selection of organisms. Neo-Darwinism reduces everything to the selection of organisms, being unable to explain their formation by living conditions. As a result, he is forced to consider this process as being entirely in the power of chance - random changes (mutations). Similarly, in a theory that separates action from the reflection of reality, the process of formation of action adapted to objective conditions is inevitably given over to the undivided power of chance. The proof is Thorndike's theory, according to which an action that meets the conditions is selected from a number of completely random reactions, since there is no “mechanism” capable of, in the process of the formation of the action itself, naturally bringing it into conformity with objective conditions. This theory is an exact analogue of the theory that explains the adaptability of organisms to their living conditions solely by natural selection, without any consideration of metabolic processes between organisms and the conditions of their life that determine their formation.

Pavlov outlined a different path, fundamentally different from Thorndike’s. According to Pavlov, the very process of forming an action that meets objective conditions using the “trial and error” method does not appear as a blind game of chance, but as a natural process. Pavlov achieves this precisely by showing how, in the course of an animal’s actions, analysis and synthesis, differentiation and generalization of stimuli reflected in sensation, in the concrete “thinking” of animals, are carried out.

If, having focused on such a brilliantly solved problem of the physiological analysis of reflex activity, Pavlov did not pay as much attention as Sechenov to its psychological analysis, this does not mean that, in contrast to the latter, he ignored or even rejected the role of figurative reflection of reality in the reflex activity of the cerebral cortex . Fundamental to the Pavlovian concept, the proposition that sensation, perception, and idea are the “first signals of reality” is direct and indisputable proof that they have a single line on this issue; There is not the slightest reason to contrast Pavlov with Sechenov or Sechenov with Pavlov in this matter.

Fundamental installations of I.M. Sechenov and I.P. Pavlova on the issue of place mental reflection in brain activity are the same, they have a common line in this matter.

In this common cause I.P. Pavlov made a contribution that is difficult to overestimate: he discovered the laws of reflex activity of the cortex - he created the doctrine of higher nervous activity.

The doctrine of higher nervous activity is a discipline bordering between

physiology and psychology; being a physiological discipline in its method, at the same time in its tasks it belongs to the field of psychology. Since its ultimate task is to explain mental phenomena (the emergence of sensations as a result of differentiation of stimuli and the determination, through signal connections, of the meaning of objects and phenomena of reality for the life and activity of an individual), the doctrine of higher nervous activity moves into the field of psychology, but does not exhaust it in any way. The relationship of the doctrine of higher nervous activity to psychology can be compared with the relationship of biochemistry

(not chemistry) to biology. Pavlov's doctrine of higher nervous activity belongs to those borderline scientific disciplines that lie at the junction of two sciences and form a transition between them, which play a leading role in the modern system of scientific knowledge. The role of the doctrine of higher nervous activity is especially great, since here we are talking about the transition from material physiological processes to mental ones, between which the dualistic worldview creates a gap, an abyss.

His doctrine of higher nervous activity, developed on animals, I.P. Pavlov significantly expanded this in relation to man with his thought about a second signal system of reality, interacting with the first and acting according to the same physiological laws as it.

The introduction of the second signaling system into the doctrine of higher nervous activity is of significant, one might say, fundamental importance, because it outlines a program for the physiological explanation of human consciousness as a product of social life in its specific characteristics.

For the second signaling system, the decisive thing is that the stimulus in it is the word - a means of communication, a carrier of abstraction and generalization, the reality of thought. At the same time, the second signaling system, like the first, is not a system of external phenomena that serve as stimuli, but a system of reflex connections in their physiological expression; the second signaling system is not language, speech, or thinking, but a principle of cortical activity that forms the physiological basis for their explanation. The second signaling system is not language, not the word as such, as a unit of language, but the system of connections and reactions that are formed to the word as a stimulus. The specific factual content of the concept of the second signaling system lies, first of all, in the experimental proof that the word, both pronounced by a person and influencing him and perceived by him, is firmly “grounded” in all organic human life. A word pronounced by a person has as its “basal component” speech motor kinesthesia, conditionally reflexively associated with all the activities of the cortex. The word, visible and audible, perceived by a person, is a real stimulus for him, capable under certain conditions of becoming stronger than the “primary signal” stimulus. This fact, established by physiological research, has fundamental importance to understand the entire human psychology

T r and interrelated features characterize Pavlovian physiology of the brain.

1. Pavlov was the first to create the physiology of the brain, its highest department. This is of decisive importance for understanding mental activity. Before Pavlov, only sensation was subject to physiological analysis; Pre-Pavlovian physiology was the physiology of sensory organs as peripheral devices - receptors. For Pavlov, the cortex itself is a grandiose sensory organ, consisting of the central cortical ends of the analyzer.

As is known, Pavlov also considers the so-called motor zone of the cortex as a motor analyzer, i.e. also as a sensory organ that analyzes signals coming from a moving organ. On the other hand, the so-called sensitive zones of the cortex inevitably perform motor functions; because the

Thus, the experiments of K.M. Bykov and A.T. Pshonik showed that if, for example, you apply a thermal stimulus—a heated plate—to your hand and say “cold” to the subject, then, with a strengthened system of corresponding conditioned connections, the vascular reactions of the subject will follow the verbal stimulus contrary to the direct stimulus (See: Bykov K M., Pshonik A.T. On the nature of the conditioned reflex // Physiological journal of the USSR, 1949. T. XXXV, No. 5. P. 509-523. See also: Pshonik A.T. Cerebral cortex and receptor function of the body. M.. 1952.

The activity of the cortex is reflexive, its final link being motor effect reactions. This position necessarily follows from all the works of Pavlov and his school, showing that the activity of the cortex is of a reflex nature. The idea of the cortex as a sensory organ, as a set of central cortical ends of analyzers, overcomes the isolation of the peripheral receptor as a sensory organ. In this way, it leads to overcoming the idealistic theory of sensation of Müller-Helmholtz and creates the prerequisites for eliminating the gap between sensation, on the one hand, and perception and thinking, on the other. The same situation is overcome not only by the isolation of the peripheral receptor from the central cortical devices, but also by the isolation of the central cortical devices of the cerebral cortex from the effects on peripheral receptors. Thus, all brain activity is placed under the control of the influences of the external world and eliminates the idealistic idea of supposedly purely “spontaneous” brain activity.

The concept of the cortex, coming from the doctrine of analyzers, is a necessary prerequisite for the implementation of the reflex principle in all brain activity. It is therefore easy to understand the fundamental significance of this concept of the cortex.

The difference between the concepts of brain physiology and peripheral physiology of the sense organs is fundamental.

“Physiology of the sense organs,” limiting its competence to elementary forms of sensitivity, left full possibility of an idealistic interpretation of all “higher” mental processes. Physiology of the Brain excludes this possibility.

It is not for nothing that American behaviorists, who openly oppose Pavlov’s teachings (such as Ghazri), or disguise themselves as belonging to the “neo-Pavlovian” school (for example, Hull and his followers), direct their efforts precisely to the fact that the most Pavlovian concepts of excitation and inhibition , irradiation, etc., meaning in I.P. Pavlov's central and cortical processes are presented as peripheral phenomena. They use the same peripheral concept that Müller and Helmholtz carried out in their study of the receptor functions of the sense organs. Substituted in place of Pavlovian teaching, the peripheral, mechanistic understanding of the “conditioning” of reactions, in its obvious inability to explain complex forms of behavior, directly leads to building on top of them more and more frank idealistic concepts of behavior, supposedly based on “insight,” etc. .

2. The physiology of the brain differs from the peripheral physiology of receptors and effectors not only in where, according to one and another theory, the main activity of the nervous device is carried out, but also in what it consists of. And this is the main point. According to the peripheral theory, the role of the brain is reduced to the elementary functions of simple transfer of excitation from receptor to effector; peripheral devices - receptors and effectors - quite obviously cannot perform the functions that, according to Pavlov, are performed by the brain, the cortex.

Research by Pavlov and his school showed that the brain produces complex analysis and synthesis, differentiation and generalization of stimuli. It is in this—analysis and synthesis, differentiation and generalization—that the higher nervous or mental activity of the brain consists. Through analysis, synthesis, etc. and the relationship between the organism and the individual with the surrounding world is carried out. Moreover, the (highest) analysis carried out by the cortex is an analysis of stimuli not only according to their composition, but also according to their significance for the body. That is why Pavlovian physiology is the physiology of behavior-activity, through which the relationship of the individual, the organism with the environment is carried out, and not just the reaction of a separate organ - the effector (as with the American representatives of the doctrine of conditioning).

3. The object of Pavlov’s study was the single integral activity of the cortex - the higher part of the brain, higher nervous activity, both physiological and mental. This single higher nervous activity of I.P. Pavlov consistently subjects him to physiological research. The goal of his research is to give this higher nervous system, i.e. materialistically understood mental activity, physiological explanation. To do this, he turns to the study of the dynamics of those nervous processes through which the reflex activity of the cortex is carried out - analysis, synthesis, differentiation and generalization of stimuli - and builds his “real” (as he himself qualifies it) physiology of the higher part of the brain.

Excitation and inhibition - their irradiation, concentration and mutual induction - these are the physiological processes through which analysis, synthesis, etc. are carried out. The function that these processes perform is reflected in the very physiological characteristics of cortical processes and their dynamics. The change in the basic processes, excitation and inhibition, is subordinated to the task in which they are included - to carry out the relationship of the individual with the conditions of his life. This is most clearly reflected in the fact that physically the same stimulus can turn from an exciter of a certain reaction into an inhibitor of it, if this reaction has not received “reinforcement”. This means that the very property of a stimulus to be a stimulus or inhibitor of certain reactions depends on the behavioral effect of the reaction to it. This quite clearly and pointedly expresses critical position that it is impossible to understand the activity of the brain without the interaction of the individual with the outside world, without taking into account both the impact of the world on the brain and the response of the individual.

At the same time, all Pavlovian laws of nervous processes are internal, i.e. specific physiological laws. The laws of irradiation, concentration and mutual production determine the internal relationships of nervous processes to each other. These internal relationships of nervous processes to each other and the internal laws that express them mediate all the individual’s responses to external influences. It is precisely thanks to the discovery of these internal laws of brain activity, which mediate the effect of all external influences, that the determinism of Pavlov’s reflex theory acquires not a mechanistic, but a dialectical-materialistic character. Without such internal laws that determine the internal relationships of nervous cortical processes to each other, there would be no physiology of the brain as a science.

Analysis of the teachings of I.P. Pavlova about higher nervous activity allows, as does the analysis of the works of I.M. Sechenov, to isolate from their special natural science content the general philosophical framework of the reflex theory. The most general and fundamental content of the reflex theory, isolated from the works of I.M. Sechenov and I.P. Pavlova, can be briefly formulated in the following provisions.

1. Mental phenomena arise in the process of interaction of an individual with the outside world.

2. Mental activity, during which mental phenomena arise, is the reflex activity of the nervous system, the brain. Reflex theory of I.M. Sechenova-I.P. Pavlova concerns not only the physiological foundations of mental activity, but also itself.

Mental activity as a reflexive, reflective activity is an analytical-synthetic activity.

3. Due to the reflexive nature of mental activity, mental phenomena are a reflection of the reality affecting the brain.

“We... having come out of physiology, we always strictly adhere to the physiological point of view and study and systematize the entire subject only physiologically” (Pavlov I.P. Complete collected works. T. IV. P. 22).

4. The reflective activity of the brain is determined by external conditions acting through internal ones.

Thus, from the specific natural science content of the reflex theory, a common theoretical core is isolated, which, in its internal logic, in its objective methodological meaning (regardless of the personal views of I.M. Sechenov and I.P. Pavlov in their historical conditionality) naturally leads to the theory of reflection and determinism in their dialectical-materialistic understanding. It is precisely because of this that the reflex theory, which implements these general principles in the specific natural science content of the doctrine of brain activity, has acquired such fundamental importance for Soviet psychology. It is, however, necessary to distinguish between the special form of manifestation of general philosophical principles, in which they appear in the reflex theory of brain activity as a physiological doctrine of higher nervous activity, and these philosophical principles themselves. Otherwise, the possibility of substitution is created private form manifestations of philosophical positions in place of these latter. Thus, what is the content of the philosophical theory itself is transferred to the reflex theory of brain activity as a natural science theory, and the role of this latter is masked. So it turns out that the principle of determinism now often appears for psychologists as one of the provisions of the reflex theory in the doctrine of higher nervous activity, while in reality the reflex theory itself is a particular expression of the principle of determinism of dialectical materialism.

The danger and harm of such a substitution in place of a general philosophical principle for a special form of its manifestation in one or another particular science, in this case in the doctrine of higher nervous activity, lies in the false position that such a substitution creates for other, related sciences - in this case for psychology. This latter is faced with a false alternative: either not to implement this principle at all, or to accept it in that special form of its manifestation, which is specific to another science; meanwhile, the real task of every science, including psychology, is to find for the initial philosophical principles common to a number of sciences a form of their manifestation specific to a given science. The commonality of principles, which would thus appear in their own way in the doctrine of higher nervous activity and psychology, is the only solid foundation in order for psychology to “overlay” the doctrine of higher nervous activity and merge with it without compromising the specificity of each of these sciences. To sum up, we must be clear about the following.

1. In the actual construction of his doctrine of higher nervous activity, I.P. Pavlov, having discovered the internal physiological laws of neurodynamics, made of the greatest importance a step that actually leads to the implementation of the dialectical-materialist position, according to which external causes act through internal conditions.

2. This general methodological side of the issue is inextricably linked with the specific, factual one. One cannot think that the “mechanisms” discovered by I.P. Pavlov and his school completely, completely explain the activity of human consciousness, not only in general, but also in its specific features. To think this way means to methodologically take a mechanistic position, to reduce the specific to the general. Often in Lately The attempts we have encountered to explain all phenomena through the same schemes without any development, specification, or change threaten to give the operation of Pavlovian teaching or, more precisely, Pavlovian terms and schemes a touch of verbalism and formalism. When verbalism or formalism thoughtlessly stamps various phenomena with the same formulas, regardless of their specificity, it ceases to be only thoughtlessness or personal helplessness of this or that researcher. When it is associated with a tendency to absolutize what has already been achieved in science and turn its concepts into universal ones

master key, it becomes a symptom of trouble in science and a threat to its further development. No matter how great what has already been achieved, it should not close the way to further research, the discovery of ever new “mechanisms” to explain new phenomena in their specific features, in particular, the specific features of increasingly higher forms of mental activity. Least of all is it a question of underestimation general provisions reflex theory; It was here that we brought the generalization of the principle of reflexivity to its limit - to its coincidence with general principle determinism; in this general form it is universal and applies to all phenomena. This is not about denying or belittling the importance of the principles of Pavlovian reflex theory, but about ensuring that the formal use of the results related to the studied and actually explained phenomena does not close the paths for further research and a genuine, rather than verbal explanation of the specific features of higher forms that have not yet been studied . Fetishization of what has already been achieved and stagnation in science are inseparable,

True science does not stand still; it, like human thought, is in constant motion. She knows only temporary stops. She's always on the go. Everything that has already been done is a stage on this path, only a step for further deepening into the essence of phenomena and climbing to new heights of knowledge.

The famous Russian physiologist I.P. Pavlov (1849–1936, “Conditioned reflexes: a study of the physiological activity of the cerebral cortex,” 1925), one of the creators of the reflex theory, proposed that the concepts of reflex and instinct be considered identical.

I.P. Pavlov suggested and proved that new forms of behavior can arise as a result of establishing a connection between innate forms of behavior (unconditioned reflexes) and a new stimulus (conditioned stimulus). If a conditional (new) and an unconditional (serving as a stimulus for an unconditional reaction) stimulus coincide in time and space, the new stimulus begins to cause an unconditional reaction, and this leads to completely new behavioral features. The conditioned reflex formed in this way can subsequently serve as the basis for the formation of conditioned reflexes of the second and higher orders. Thus, according to Pavlov, all human behavior can be understood, studied and predicted on the basis of knowledge of the chain of conditioned reflexes, the mechanisms of their formation and attenuation. Pavlov conducted his experiments on animals, mainly on dogs. Classical conditioning, studied extensively by Pavlov and co-workers, involved the association of salivation when the dog saw food and any other conditioned stimulus (such as the sound of a bell). According to Pavlov, a conditioned reflex is formed as follows: Step 1. The basis of a conditioned reflex is an unconditioned reflex: an unconditioned stimulus (= stimulus) causes an unconditioned reaction. The type of food certainly causes salivation in a dog - this is an innate, unconditioned form of behavior. Step 2. In some situation, the conditioned reflex coincides in time and space with some other event (conditioned stimulus). Together with the presentation of food to the dog, the bell rings. Step 3. If the conditioned and unconditioned stimulus appear together several times, then a new reflex is formed. The conditioned stimulus gradually replaces the unconditioned stimulus in the response pattern. The rate of association of a conditioned stimulus and an unconditioned response depends on the characteristics of the organism. Step 4. A conditioned reflex arises: a conditioned stimulus that previously did not cause any behavior begins to cause an unconditioned response. Now just the sound of the bell is enough to make your dog salivate. This process is called classical conditioning. The result of conditioning is called a conditioned reflex. If for some time the conditioned reflex does not receive reinforcement, that is, the conditioned stimulus is not accompanied by an unconditioned stimulus for a sufficiently long time, then the conditioned reflex fades away - the conditioned stimulus ceases to cause an unconditioned reaction.

A conditioned reflex is an acquired reflex characteristic of an individual (individual). They arise during the life of the individual and are not fixed genetically (not inherited). They appear under certain conditions and disappear in their absence. They are formed on the basis of unconditioned reflexes with the participation of higher parts of the brain. Conditioned reflex reactions depend on past experience, on the specific conditions in which the conditioned reflex is formed.

The doctrine of conditioned reflexes is the doctrine of higher nervous activity. From the first steps of the study of higher nervous activity, Pavlov emphasized with all his might that he was conducting it in order to understand the functioning of the human brain in order to extend accurate scientific research to phenomena designated as mental. The substantiation of the doctrine of conditioned reflexes was a turning point in the history of all natural science. For the first time, human thought went from being a subject of speculative discussion by philosophers and psychologists to becoming a subject of physiological research carried out experimentally. The formation of conditioned reflexes is the main physiological mechanism, which determines the development of new relationships that develop throughout the life of the organism to the world around it. To develop a conditioned reflex it is necessary:

1) the presence of two stimuli, one of which is unconditioned (food, painful stimulus, etc.), causing an unconditioned reflex reaction, and the other is conditioned (signal), signaling the upcoming unconditional stimulus (light, sound, type of food, etc. .);

2) multiple combinations of conditioned and unconditioned stimuli (although the formation of a conditioned reflex is possible with their single combination);

3) the conditioned stimulus must precede the action of the unconditional;

4) any stimulus from the external or internal environment can be used as a conditioned stimulus, which should be as indifferent as possible, not cause a defensive reaction, not have excessive force and be able to attract attention;

5) the unconditioned stimulus must be strong enough, otherwise a temporary connection will not be formed;

6) arousal from an unconditioned stimulus should be stronger than from a conditioned one;

7) it is necessary to eliminate extraneous stimuli, as they can cause inhibition of the conditioned reflex;

8) the animal in which the conditioned reflex is developed must be healthy;

9) when developing a conditioned reflex, motivation must be expressed, for example, when developing a food salivary reflex, the animal must be hungry, but in a well-fed animal, this reflex is not developed.

Conditioned reflexes are easier to develop in response to environmentally similar influences for a given animal. In this regard, conditioned reflexes are divided into natural and artificial. Natural conditioned reflexes are developed to agents that, under natural conditions, act together with a stimulus 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, the food salivary reflex to a bell.

Reflex arc (nerve arc) is the path traversed by nerve impulses during the implementation of a reflex. The reflex arc consists of:

§ receptor - a nerve link that perceives irritation;

§ afferent link - centripetal nerve fiber - processes of receptor neurons that transmit impulses from sensory nerve endings to the central nervous system;

§ central link - nerve center (optional element, for example for the axon reflex);

§ efferent link - carries out transmission from the nerve center to the effector.

§ effector - an executive organ whose activity changes as a result of a reflex.

There are: - monosynaptic, two-neuron reflex arcs; - polysynaptic reflex arcs (include three or more neurons).

The concept was introduced by M. Hall in 1850. Currently, the concept of a reflex arc does not fully reflect the mechanism of the reflex, and in connection with this, N. A. Bernstein proposed a new term - Reflex ring, which includes the missing link of control carried out by the nervous system. the center for the progress of the work of the executive body - the so-called. reverse afferentation.

The simplest reflex arc in humans is formed by two neurons - sensory and motor (motoneuron). An example of a simple reflex is the knee reflex. In other cases, three (or more) neurons are included in the reflex arc - sensory, intercalary and motor. In a simplified form, this is the reflex that occurs when a finger is pricked with a pin. This is a spinal reflex; its arc passes not through the brain, but through the spinal cord. The processes of sensory neurons enter the spinal cord as part of the dorsal root, and the processes of motor neurons exit the spinal cord as part of the anterior root. The bodies of sensory neurons are located in the spinal ganglion of the dorsal root (in the dorsal ganglion), and intercalary and motor neurons are located in the gray matter of the spinal cord. The simple reflex arc described above allows a person to automatically (involuntarily) adapt to changes in the environment, for example, withdrawing a hand from a painful stimulus, changing the size of the pupil depending on lighting conditions. It also helps regulate processes occurring inside the body. All this helps maintain the constancy of the internal environment, that is, maintaining homeostasis. In many cases, a sensory neuron transmits information (usually through several interneurons) to the brain. The brain processes incoming sensory information and stores it for later use. Along with this, the brain can send motor nerve impulses along the descending pathway directly to the spinal motor neurons; spinal motor neurons initiate the effector response.

Conditioned reflex theory

The theory of conditioned reflexes was developed by the great Russian scientist I. P. Pavlov. The basis of his theory is the body's reaction to external stimuli - conditioned and unconditioned reflexes, recognized as the foundation of motivation. Pavlov paid special attention to conditioned reflexes. The stereotype of thinking and behavior serves as the psychophysiological basis of the attitude, which is the central component of the individual’s motivational system.

McGregor's Theories X and Y

Douglas McGregor, a scholar known for his work in the field of leadership, called the assumptions of an authoritarian leader in relation to employees Theory X.

The ideas of a democratic leader about employees differ from the ideas of an authoritarian leader. McGregor called them Theory Y.

These theories create very different guidelines for the implementation of the motivation function. They appeal to different categories of human needs and motives.

As you can see, with different approaches to the issue of motivation, all authors agree on one thing: motive is the reason, the stimulator of human activity. Due to the fact that the motives of each person are individual, determined by the characteristics of his personality, the established system value orientations, social environment, emerging situations, etc., then the ways to satisfy needs are different. The motivational sphere is dynamic and depends on many circumstances. But some motives are relatively stable and, subordinating other motives, become, as it were, the core of the entire sphere.

Differences in the actions of different people in the same conditions when achieving the same goals are explained by the fact that people differ in the degree of energy and perseverance, some respond to various situations with a variety of actions, while others act in the same situations in the same way.

At the heart of any activity is a motive that encourages a person to do it, but the activity cannot always fully satisfy the motive. In this case, a person, having completed one activity, turns to another. If the activity is long-lasting, then the motive may change during its process. So, good pencils and paints encourage the desire to draw with them. However, after a while the drawer may get bored with this activity. Sometimes, on the contrary, while maintaining the motive, the activity performed may change. For example, having first become interested in painting with watercolors, a person then begins to work in oils. “Discrepancies” often arise between the development of a motive and the development of an activity: the development of motives may advance the formation of an activity, or may lag behind it, which affects the result of the activity.

Motivation determines the choice between various possible actions, regulating, directing the action to achieve goal states specific to a given motive and supporting this direction. In short, motivation explains the purposefulness of action.

Motivation is not a single process that permeates behavior evenly from beginning to end. It consists of heterogeneous processes that regulate behavior, primarily before and after an action. So, first there is a process of weighing the possible outcomes of an action and assessing their consequences. Despite the fact that the activity is motivated, i.e. aimed at achieving the goal of the motive, it should not be confused with motivation. Activities consist of components such as skills, abilities, and knowledge. How and in what direction various functional abilities will be used depends on motivation. Motivation explains the choice between different possible actions, different perceptions and possible ways thinking, as well as intensity and persistence in carrying out the chosen action and achieving its results.

Table 1

Analysis of motivation theory

An evolutionary approach to the study of higher nervous activity

Anatomical concept of reflex.

Mechanical concept of reflex.

Development of reflex theory.

This is the teaching of Rene Descartes (1596-1650). He represented nervous processes on the model of the circulatory system, using the principles of optics and mechanics that existed at that time. By reflex, Descartes understood the movement of “animal spirits” from the brain to the muscles according to the type of reflection light beam. Important in his theory is the development of the concept of the stimulus necessary to activate the mechanisms of the human body, i.e. he tried to explain the reflex from a materialistic point of view, but he attributed the ability to think and feel not to the brain, but to the soul (for him they existed separately).

Biological concept of reflex: This is the teaching of the Czech scientist Jiri Prochazka (1749-1820), he introduced the term “reflex” and the description of the reflex arc into science. “External impressions arising in the sensory nerves spread along them, are reflected on the motor nerves and are sent along them to the muscles. The reflex response always manifests itself in size according to the strength of the applied stimulus.” The structure of the reflex and its purpose were considered from a biological point of view. The principle of reflex extended to mental activity.

In the 19th century, the anatomical structure of the nervous system was carefully studied. The English physician Charles Bell (1774-1842) experimentally discovered that when the anterior roots of the spinal nerves are cut, a reflex response is observed: contraction of the back muscles. The French physiologist F. Magendie (1783-1855) came to the same conclusions. These scientists formulated the Bell-Magendie law: the transition of nervous excitation occurs along afferent nerves through the spinal cord to efferent nerves. The English physician Marshall Hall coined the term “reflex arc.” M. Hall and I. Muller believed that the reflex mechanism is characteristic only of the spinal cord.

Charles Darwin in “The Origin of Species by Means of Natural Selection” (1859) formulated the principle of the evolution of living organisms: “the driving force for the development of organisms lies in adaptive relationships with the environment.” Consequently, the main reason for the evolution of behavior is adaptation to environmental conditions. Darwin clearly identified rational activity as one of the main components of complex forms of animal behavior. Darwin's teaching was a prerequisite for the creation of the teaching of I.M. Sechenov.

Sechenov I.M. (1829-1905). His most important work is “Reflexes of the Brain” (1863). He identified two types of reflexes - congenital and acquired. The material processes of brain activity are primary, and the mental processes are secondary. Consciousness is a reflection of reality; the progress of the psyche is associated with the improvement of the brain in the process of evolution in animals. All acts of conscious and unconscious life are reflexes in their origin, but he did not identify mental phenomena with reflexes. Behavioral reactions are carried out through the central nervous system, like reflex reactions. He introduced the evolutionary principle into physiology, but Sechenov's views were only theoretical. Among the main achievements of this scientist was the discovery of the process of inhibition, which exists in the nervous system along with excitation, without which it is impossible to imagine the implementation of integrative functions by the central nervous system. Gained international recognition for the discovery of central braking. He was the first to discover that inhibition is not a passive, but an active process.

In the center of scientific interests of the famous Russian scientist V.M. Bekhterev (1857-1928) there was a human problem. His greatest contributions to science were his works on brain anatomy and neuropathology. He introduced the concept associative, i.e. actually a conditioned reflex as an acquired property of the nervous system, as well as the idea of complex organic reflexes, i.e. instincts, the mechanism of which he also considered purely reflexive. Bekhterev believed that the source of knowledge about the behavior and functioning of the brain of humans and animals is objective observation and experiment, and not a subjective analysis of behavior. In 1926, the book “Fundamentals of Human Reflexology” was published, which reflected the complex theory created by Bekhterev, called “reflexology”.

Introduction

Human interaction with reality is carried out through the nervous system.

The human nervous system consists of three sections: the central, peripheral and autonomic nervous systems. The nervous system functions as a single and integral system.

The complex, self-regulating activity of the human nervous system is carried out thanks to reflex nature this activity.

This work will reveal the concept of “reflex”, its role and significance in the body.

Reflex theory and its basic principles

The provisions of the reflex theory developed by I.M. Sechenov. I. P. Pavlov and developed by N. E. Vvedensky. A. A. Ukhtomsky. V. M. Bekhterev, P. K. Anokhin and other physiologists are the scientific and theoretical basis of Soviet physiology and psychology. These provisions find their creative development in the research of Soviet physiologists and psychologists.

The reflex theory, which recognizes the reflex nature of the activity of the nervous system, is based on three main principles:

1) the principle of materialistic determinism;

2) the principle of structure;

3) the principle of analysis and synthesis.

The principle of materialistic determinism means that each nervous process in the brain is determined (caused) by the action of certain stimuli.

The principle of structure is that the differences in the functions of different parts of the nervous system depend on the characteristics of their structure, and changes in the structure of parts of the nervous system during development are determined by changes in functions. Thus, in animals that do not have a brain, the higher nervous activity is much more primitive compared to the higher nervous activity of animals that have a brain. In humans, in the course of historical development, the brain has reached a particularly complex structure and perfection, which is associated with its labor activity and social living conditions that require constant verbal communication.

Principle of analysis and synthesis is expressed as follows. When centripetal impulses enter the central nervous system, excitation occurs in some neurons, and inhibition occurs in others, i.e., physiological analysis occurs. The result is the distinction between specific objects and phenomena of reality and processes occurring inside the body.

At the same time, during the formation of a conditioned reflex, a temporary nervous connection (closure) is established between two foci of excitation, which physiologically expresses synthesis. The conditioned reflex is the unity of analysis and synthesis.

Reflex - concept, its role and significance in the body

Reflexes (from the Latin slot reflexus - reflected) are the body's responses to receptor irritation. Nerve impulses arise in the receptors, which enter the central nervous system via sensory (centripetal) neurons. There, the received information is processed by intercalary neurons, after which motor (centrifugal) neurons are excited and nerve impulses activate the executive organs - muscles or glands. Intercalary neurons are those whose bodies and processes do not extend beyond the central nervous system. The path along which nerve impulses travel from the receptor to the executive organ is called a reflex arc.

Reflex actions are holistic actions aimed at satisfying a specific need for food, water, safety, etc. They contribute to the survival of an individual or species as a whole. They are classified into food, water-producing, defensive, sexual, orientation, nest-building, etc. There are reflexes that establish a certain order (hierarchy) in a herd or flock, and territorial ones, which determine the territory captured by a particular individual or flock.

There are positive reflexes, when a stimulus causes a certain activity, and negative, inhibitory reflexes, when the activity stops. The latter, for example, includes the passive defensive reflex in animals, when they freeze when a predator appears or an unfamiliar sound.

Reflexes play an exceptional role in maintaining the constancy of the body’s internal environment and its homeostasis. For example, when blood pressure increases, a reflex slowdown of cardiac activity occurs and the lumen of the arteries expands, so the pressure decreases. When it drops strongly, opposite reflexes arise, strengthening and speeding up the contractions of the heart and narrowing the lumen of the arteries, as a result of which the pressure increases. It continuously fluctuates around a certain constant value, which is called the physiological constant. This value is determined genetically.

The famous Soviet physiologist P.K. Anokhin showed that the actions of animals and humans are determined by their needs. For example, the lack of water in the body is first replenished from internal reserves. Reflexes arise that delay the loss of water in the kidneys, the absorption of water from the intestines increases, etc. If this does not lead to the desired result, excitement occurs in the centers of the brain that regulate the flow of water and a feeling of thirst appears. This arousal causes goal-directed behavior, the search for water. Thanks to direct connections, nerve impulses going from the brain to the executive organs, the necessary actions are ensured (the animal finds and drinks water), and thanks to feedback connections, nerve impulses going in the opposite direction - from peripheral organs: oral cavity and the stomach - to the brain, informing the latter about the results of the action. Thus, during drinking, the center of water saturation is excited, and when thirst is satisfied, the corresponding center is inhibited. This is how the controlling function of the central nervous system is carried out.

A great achievement in physiology was the discovery of conditioned reflexes by I. P. Pavlov.

Unconditioned reflexes are innate, inherited reactions by the body to environmental influences. Unconditioned reflexes are characterized by constancy and do not depend on training and special conditions for their occurrence. For example, the body responds to painful stimulation with a defensive reaction. There is a wide variety of unconditioned reflexes: defensive, food, orientation, sexual, etc.

The reactions underlying unconditioned reflexes in animals have been developed over thousands of years in the course of adaptation various types animals to the environment, in the process of struggle for existence. Gradually, under the conditions of long-term evolution, the unconditional reflex reactions necessary to satisfy biological needs and preserve the vital functions of the organism were consolidated and passed on by inheritance, and those of the unconditional reflex reactions that lost their value for the life of the organism, lost their expediency, on the contrary, disappeared, without recovering.

Under the influence of constant changes in the environment, stronger and more advanced forms of animal response were required, ensuring the organism’s adaptation to changed living conditions. In the process of individual development, highly organized animals form a special type of reflexes, which I. P. Pavlov called conditioned.

Conditioned reflexes acquired by an organism during life provide an appropriate response of a living organism to changes in the environment and, on this basis, balance the organism with the environment. Unlike unconditioned reflexes, which are usually carried out by the lower parts of the central nervous system (spinal cord, medulla oblongata, subcortical ganglia), conditioned reflexes in highly organized animals and humans are carried out mainly by the higher part of the central nervous system (cerebral cortex).

Observing the phenomenon of “psychic secretion” in a dog helped I.P. Pavlov discover a conditioned reflex. The animal, seeing food from a distance, began to salivate intensively even before the food was served. This fact has been interpreted in different ways. The essence of “psychic secretion” was explained by I. P. Pavlov. He found that, firstly, in order for a dog to start salivating at the sight of meat, it had to have seen and eaten it at least once before. And, secondly, any irritant (for example, the type of food, a bell, the blinking of a light bulb, etc.) can cause salivation, provided that the time of action of this irritant coincides with the time of feeding. If, for example, feeding was constantly preceded by the knocking of a cup containing food, then there always came a moment when the dog began to salivate just by knocking. Reactions that are caused by stimuli that were previously indifferent. I.P. Pavlov called them conditioned reflexes. The conditioned reflex, noted I.P. Pavlov, is a physiological phenomenon, since it is associated with the activity of the central nervous system, and at the same time, psychological, since it is a reflection in the brain of specific properties of stimuli from the outside world.

Conditioned reflexes in animals in the experiments of I. P. Pavlov were most often developed on the basis of food unconditioned reflex, when the unconditioned stimulus was food, and the function of the conditioned stimulus was performed by one of the stimuli that were indifferent (indifferent) to food (light, sound, etc.).

There are natural conditioned stimuli, which serve as one of the signs of unconditioned stimuli (the smell of food, the squeak of a chicken for a hen, causing a parental conditioned reflex in her, the squeak of a mouse for a cat, etc.), and artificial conditioned stimuli, which are completely unrelated to unconditioned reflex stimuli (for example, a light bulb, the light of which caused a dog to develop a salivary reflex, the ringing of a gong, to which moose gather for feeding, etc.). However, any conditioned reflex has a signal value, and if the conditioned stimulus loses it, then the conditioned reflex gradually fades away.

Pavlov's conditioned reflex theory. Reflex theory

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