Theory of functional systems by P.K. Anokhin. Fundamentals of the Anokhin functional system theory

The most advanced model of the structure of behavior is set out in the concept of functional systems by Pyotr Kuzmich Anokhin (1898-1974).

Defining a functional system as a dynamic, self-regulating organization that selectively combines structures and processes based on nervous and humoral regulatory mechanisms to achieve adaptive results beneficial to the system and the body as a whole, P.K. Anokhin extended the content of this concept to the structure of any purposeful behavior. From these positions, the structure of an individual motor act can also be considered.

The functional system has a branched morphophysiological apparatus, which, due to its inherent laws, provides both the effect of homeostasis and self-regulation. There are two types of functional systems. 1. Functional systems of the first type ensure the constancy of certain constants of the internal environment due to the self-regulation system, the links of which do not extend beyond the boundaries of the organism itself. An example is a functional system for maintaining constant blood pressure, body temperature, etc. Such a system, using various mechanisms, automatically compensates for emerging shifts in the internal environment. 2. Functional systems of the second type use an external link of self-regulation. They provide an adaptive effect by going beyond the body through communication with the outside world, through changes in behavior. It is the functional systems of the second type that underlie various behavioral acts, various types of behavior.

Central architectonics of functional systems, which determine purposeful behavioral acts of varying degrees of complexity, consists of the following stages successively replacing each other: -> afferent synthesis, -> decision making, -> acceptor of action results, -> efferent synthesis, -> action formation, and, finally, -> assessment of the achieved result/

AFFERENT (from Latin afferens - bringing), carrying to or into an organ (for example, afferent artery); transmitting impulses from working organs (glands, muscles) to the nerve center (afferent, or centripetal, nerve fibers). EFFERENT (from Latin efferens - efferent), carrying out, ejecting, transmitting impulses from nerve centers to working organs, for example. efferent, or centrifugal, nerve fibers. ACCEPTOR (from Latin acceptor - accepting).

A behavioral act of any degree of complexity begins from the stage of afferent synthesis. Excitation caused by an external stimulus does not act in isolation. It certainly interacts with other afferent excitations that have a different functional meaning. The brain continuously processes all signals coming through numerous sensory channels. And only as a result of the synthesis of these afferent excitations are conditions created for the implementation of certain goal-directed behavior. The content of afferent synthesis is determined by the influence of several factors: motivational arousal, memory, environmental and trigger afferentation.

Motivational arousal appears in the central nervous system as a result of one or another vital, social or ideal need. The specificity of motivational arousal is determined by the characteristics and type of need that caused it. It is a necessary component of any behavior. The importance of motivational arousal for afferent synthesis already follows from the fact that the conditioned signal loses the ability to cause previously developed food-procuring behavior (for example, a dog running to the feeder to get food) if the animal is already well fed and, therefore, it lacks motivational food arousal.

The role of motivational arousal in the formation of afferent synthesis is determined by the fact that any incoming information is correlated with the currently dominant motivational excitation, which acts as a filter that selects what is most necessary for a given motivational setting. Dominant motivation as the primary system-forming factor determines all subsequent stages of brain activity in the formation of behavioral programs. The specificity of motivation determines the nature and “chemical status” of intracentral integration and the set of brain apparatuses involved. The useful result of a certain behavioral act is the satisfaction of a need, i.e. decreased level of motivation.

The neurophysiological basis of motivational arousal is selective activation of various neural structures, created primarily by the limbic and reticular systems of the brain. At the cortical level, motivational arousal is represented by a specific pattern of arousal.

Conditioned and unconditioned stimuli, key stimuli (a species of hawk - a predator for birds that causes flight behavior, etc.) serve as an impetus for the deployment of a certain behavior or a separate behavioral act. These stimuli have a triggering function. The pattern of arousal created by biologically significant stimuli in sensory systems is trigger afferentation. However, the ability of trigger stimuli to initiate behavior is not absolute. It depends on the environment and conditions in which they operate.

The influence of situational afferentation on the conditioned reflex was most clearly evident in the study of the phenomenon of dynamic stereotype. In these experiments, the animal was trained to perform a series of different conditioned reflexes in a specific order. After long training, it turned out that any random conditioned stimulus can reproduce all the specific effects characteristic of each stimulus in the motor stereotype system. To do this, it is only necessary that it follows in a memorized time sequence. Thus, when inducing conditioned reflexes in a dynamic stereotype system, the order in which they are executed becomes decisive. Consequently, environmental afferentation includes not only excitation from a stationary environment, but also the sequence of afferent excitations that is associated with this environment. Situational afferentation creates latent arousal that can be detected as soon as the trigger stimulus acts. The physiological meaning of triggering afferentation is that, revealing the hidden excitation created by situational afferentation, it timed it to certain moments in time, the most appropriate from the point of view of behavior itself.

The decisive influence of situational afferentation on the conditioned reflex response was shown in experiments by I.I. Laptev – employee P.K. Anokhina. In his experiments, a call in the morning was reinforced with food, and the same call in the evening was accompanied by an electric shock. As a result, two different conditioned reflexes were developed: in the morning - a salivary reaction, in the evening - a defensive reflex. The animal learned to differentiate two sets of stimuli that differed only in their temporal component.

Afferent synthesis includes also the use of the memory apparatus. It is obvious that the functional role of triggering and environmental stimuli is to a certain extent already determined by the past experience of the animal. This is both specific memory and individual memory acquired as a result of training. At the stage of afferent synthesis, exactly those fragments of past experience that are useful and necessary for future behavior are extracted and used from memory.

Thus, based on the interaction of motivational, environmental arousal and memory mechanisms, the so-called integration or readiness to engage in a particular behavior. But in order for it to be transformed into goal-directed behavior, it requires exposure to trigger stimuli. Trigger afferentation is the last component of afferent synthesis.

The processes of afferent synthesis, covering motivational arousal, triggering and environmental afferentation, and the memory apparatus, are realized using a special modulation mechanism that provides the necessary tone of the cerebral cortex and other brain structures. This mechanism regulates and distributes activating and inactivating influences emanating from the limbic and reticular systems of the brain. The behavioral expression of the increase in the level of activation in the central nervous system created by this mechanism is the appearance of orienting exploratory reactions and search activity of the animal.

Completion of the afferent synthesis stage is accompanied by a transition to the decision-making stage, which determines the type and direction of behavior. The decision-making stage is realized through a special and very important stage of the behavioral act - the formation of an acceptor apparatus for the results of the action. This is a device that programs the results of future events. It updates the innate and individual memory of animals and humans in relation to the properties of external objects that can satisfy the emerging need, as well as methods of action aimed at achieving or avoiding the target object. Often this device is programmed with the entire search path for corresponding stimuli in the external environment.

It is assumed that the acceptor of action results is represented by a network of interneurons covered by a ring interaction. Excitation, once in this network, continues to circulate in it for a long time. Thanks to this mechanism, long-term retention of the goal as the main regulator of behavior is achieved.

Before goal-directed behavior begins to be carried out, another stage of the behavioral act develops - stage of program of action or efferent synthesis . At this stage, the integration of somatic and vegetative arousals into a holistic behavioral act occurs. This stage is characterized by the fact that the action has already been formed, but outwardly it is not yet realized.

The next stage is itself implementation of the behavior program . Efferent excitation reaches the actuators, and the action is carried out.

Thanks to the apparatus of the acceptor of action results, in which the goal and methods of behavior are programmed, the body has the opportunity to compare them with incoming afferent information about the results and parameters of the action being performed, i.e. with reverse afferentation. It is the results of the comparison that determine the subsequent construction of behavior, either it is corrected, or it stops, as in the case of achieving the final result.

Consequently, if the signaling of a completed action fully matches the prepared information contained in the action acceptor, then the search behavior ends. The corresponding need is satisfied. And the animal calms down. In the case when the results of an action do not coincide with the acceptor of the action and their mismatch occurs, indicative research activity appears. As a result of this, afferent synthesis is rebuilt, a new decision is made, a new acceptor of the results of action is created, and a new program of action is built. This happens until the results of the behavior correspond to the properties of the new action acceptor. And then the behavioral act ends with the last sanctioning stage - the satisfaction of the need.

Thus, in the concept of a functional system, the most important key stage determining the development of behavior is the identification of the goal of behavior . It is represented by the apparatus of the acceptor of action results, which contains two types of images that regulate behavior - the goals themselves and the ways to achieve them. Target selection is associated with the decision-making operation as the final stage of afferent synthesis.

5.Theory of functional systems P.K. Anokhina.

In the theory of functional systems, the determinant of behavior is not considered an event past in relation to behavior - a stimulus, and the future is the result .

Functional system there is a dynamically developing wide distributed system of heterogeneous physiological formations, all parts of which contribute to obtaining a certain useful result. It is the leading significance of the result and the model of the future created by the brain that allows us to speak not about a reaction to stimuli from the external environment, but about full-fledged goal setting.

rice. 2. General architecture of the functional system (OA - situational afferentation, PA - triggering afferentation) The diagram shows the sequence of actions when implementing one functional system. First it happens afferent synthesis, which accumulates signals from the external environment, memory and motivation of the subject. Based on afferent synthesis a decision is made, on the basis of which it is formed action program And action result acceptor – forecast of the effectiveness of the action taken. After which directly action is taken and the physical parameters of the result are taken. One of the most important parts of this architecture is feedback afferentation - feedback that allows you to judge the success of a particular action. This directly allows the subject to learn, since by comparing the physical parameters of the obtained result and the predicted result, it is possible to evaluate the effectiveness of goal-directed behavior. Moreover, it should be noted that the choice of one action or another is influenced by many factors, the totality of which is processed in the process of afferent synthesis.

The interaction of humans and animals with the environment is carried out through purposeful activity or behavior.

Functional systems- dynamic, self-organizing, self-regulating structures, all of whose components are cooperatively combined to achieve adaptive results that are beneficial for the system itself and the organism as a whole.

There are two types of functional systems.

1. Functional systems of the first type ensure the constancy of certain constants of the internal environment due to the self-regulation system, the links of which do not extend beyond the boundaries of the body itself. An example would be a functional maintenance system constancy of blood pressure, body temperature, etc.. Such a system, using various mechanisms, automatically compensates for emerging shifts in the internal environment.

2. Functional systems of the second type use an external link of self-regulation . They provide an adaptive effect by going beyond the body through communication with the outside world, through changes in behavior. It is the functional systems of the second type that underlie various behavioral acts, various types of behavior.

The central functional system, which determines purposeful behavioral acts of varying degrees of complexity, consists of the following successive stages: -> afferent synthesis, -> decision making, -> acceptor of action results, -> efferent synthesis, -> action formation, and, finally, -> assessment of the achieved result

AFFERENT(from Latin afferens - bringing), carrying to or into an organ (for example, afferent artery); transmitting impulses from working organs (glands, muscles) to the nerve center (afferent, or centripetal, nerve fibers). EFFERENT(from lat. efferens - carrying out), carrying out, removing, transmitting impulses from nerve centers to working organs, for example. efferent, or centrifugal, nerve fibers. ACCEPTOR(from Lat. acceptor - receiving).

(1. A behavioral act of any degree of complexity begins with the stage of afferent synthesis. Excitation caused by an external stimulus does not act in isolation. It certainly interacts with other afferent excitations that have a different functional meaning. The brain continuously processes all signals arriving through numerous sensory channels. And only as a result of the synthesis of these afferent excitations, conditions are created for the implementation of certain goal-directed behavior.

Motivational arousal appears in the central nervous system as a result of one or another vital, social or ideal need. The specificity of motivational arousal is determined by the characteristics and type of need that caused it. The importance of motivational excitation for afferent synthesis follows from the fact that the conditioned signal loses the ability to cause previously developed food-procuring behavior (for example, a dog running to the feeder to get food)

Thus, based on the interaction of motivational, environmental arousal and memory mechanisms, so-called integration or readiness for a certain behavior is formed. But in order for it to be transformed into goal-directed behavior, it requires exposure to trigger stimuli. Trigger afferentation- the last component of afferent synthesis. Completion of the stage of afferent synthesis is accompanied by a transition to the stage decision making, which determines the type and direction of behavior. The decision-making stage is realized through a special and very important stage of the behavioral act - formation of an apparatus for accepting the results of action. This is a device that programs the results of future events. It updates the innate and individual memory of animals and humans in relation to the properties of external objects that can satisfy the emerging need, as well as methods of action aimed at achieving or avoiding the target object. Often this device is programmed with the entire search path for corresponding stimuli in the external environment.. The next stage is the actual implementation of the behavior program. Efferent excitation reaches the actuators, and the action is carried out. Thanks to the apparatus of the acceptor of action results, in which the goal and methods of behavior are programmed, the body has the opportunity to compare them with incoming afferent information about the results and parameters of the action being performed, i.e. With reverse afferentation. It is the results of the comparison that determine the subsequent construction of behavior, either it is corrected, or it stops, as in the case of achieving the final result. Consequently, if the signaling of a completed action fully matches the prepared information contained in the action acceptor, then the search behavior ends. The corresponding need is satisfied. And the animal calms down. In the case when the results of an action do not coincide with the acceptor of the action and their mismatch occurs, indicative research activity appears. As a result of this, afferent synthesis is rebuilt, a new decision is made, a new acceptor of the results of action is created, and a new program of action is built. This happens until the results of the behavior correspond to the properties of the new action acceptor. And then the behavioral act ends with the last sanctioning stage - the satisfaction of the need. Thus, in the concept of a functional system, the most important key stage determining the development of behavior is the identification of the goal of behavior. It is represented by the apparatus of the action result acceptor, which contains two types of images regulating behavior - the goals themselves and ways to achieve them. Target selection is associated with the decision-making operation as the final stage of afferent synthesis. Goal-directed behavior– the search for a target object that satisfies a need is stimulated not only by negative emotional experiences. Ideas about those positive emotions that, as a result of individual past experience, are associated in the memory of an animal and a person with the receipt of future positive reinforcement or reward that satisfies this specific need also have motivating power. Positive emotions are recorded in memory and subsequently arise every time as a kind of idea of a future result when a corresponding need arises. Thus, in the structure of a behavioral act, the formation of an acceptor of the results of an action is mediated by the content of emotional experiences. Leading emotions highlight the goal of behavior and thereby initiate behavior, determining its vector. Situational emotions arising as a result of assessments of individual stages or behavior as a whole encourage the subject to act either in the same direction or to change behavior, its tactics, and methods of achieving the goal. According to the functional system theory, although behavior is based on the reflex principle, it cannot be defined as a sequence or chain of reflexes. Behavior differs from a set of reflexes in the presence a special structure that includes programming as a mandatory element, which performs the function of a proactive reflection of reality. Constant comparison of behavioral results with these programming mechanisms, updating the content of programming itself and determine the purposefulness of behavior. Thus, in the considered structure of a behavioral act, the main characteristics of behavior are clearly presented: its purposefulness and the active role of the subject in the process of constructing behavior.

The theory of functional systems describes the organization of life processes in a complete organism interacting with the environment.

This theory was developed while studying the mechanisms of compensation for impaired body functions. As was shown by P.K. Anokhin, compensation mobilizes a significant number of different physiological components - central and peripheral formations, functionally combined with each other to obtain a useful, adaptive effect necessary for a living organism at a given specific point in time. Such a broad functional unification of variously localized structures and processes to obtain the final adaptive result was called a “functional system.”

A functional system (FS) is a unit of integrative activity of a whole organism, including elements of various anatomical affiliations that actively interact with each other and with the external environment in the direction of achieving a useful, adaptive result.

An adaptive result is a certain relationship between the organism and the external environment, which stops the action aimed at achieving it and makes it possible to implement the next behavioral act. To achieve a result means to change the relationship between the body and the environment in a direction that is beneficial for the body.

Achieving an adaptive result in the FS is carried out using specific mechanisms, of which the most important are:

Afferent synthesis of all information entering the nervous system;

Making a decision with the simultaneous formation of an apparatus for predicting the result in the form of an afferent model of the results of the action;
- the actual action;
- comparison, based on feedback from the afferent model of the acceptor, of the results of the action and the parameters of the action performed;
correction of behavior in case of discrepancy between real and ideal (modeled by the nervous system) action parameters.

The composition of the functional system is not determined by the spatial proximity of the structures or their anatomical affiliation. The FS can include both nearby and distantly located structures of the body. It can involve individual parts of any anatomically integral systems and even parts of individual entire organs. In this case, a separate nerve cell, a muscle, a part of an organ, or an entire organ can participate through its activity in achieving a useful adaptive result only if it is included in the corresponding functional system. The factor determining the selectivity of these compounds is the biological and physiological architecture of the PS itself, and the criterion for the effectiveness of these associations is the final adaptive result.

Since for any living organism the number of possible adaptive situations is in principle unlimited, therefore, the same nerve cell, muscle, part of an organ, or the organ itself can be part of several functional systems in which they will perform different functions.

Thus, when studying the interaction of an organism with the environment, the unit of analysis is a holistic, dynamically organized functional system. Types and levels of complexity of FS. Functional systems have different specializations. Some are responsible for breathing, others for movement, others for nutrition, etc. FS can belong to different hierarchical levels and be of varying degrees of complexity: some of them are characteristic of all individuals of a given species (and even other species); others are individual, i.e. are formed throughout life in the process of mastering experience and form the basis of learning.

Hierarchy is the arrangement of parts or elements of a whole in order from highest to lowest, with each higher level endowed with special powers in relation to the lower ones. Heterarchy is the principle of interaction between levels, when none of them has a permanent leading role and a coalition of higher and lower levels into a single system of action is allowed.

Functional systems differ in the degree of plasticity, i.e. by the ability to change their constituent components. For example, the respiratory system consists predominantly of stable (innate) structures and therefore has little plasticity: the act of breathing, as a rule, involves the same central and peripheral components. At the same time, the FS that ensures the movement of the body is plastic and can quite easily rearrange component relationships (you can reach something, run, jump, crawl).

Afferent synthesis. The initial stage of a behavioral act of any degree of complexity, and, consequently, the beginning of the functioning of the PS, is afferent synthesis. Afferent synthesis is the process of selection and synthesis of various signals about the environment and the degree of success of the body’s activity in its conditions, on the basis of which the goal of the activity and its management are formed.

The importance of afferent synthesis lies in the fact that this stage determines all subsequent behavior of the organism. The task of this stage is to collect the necessary information about various parameters of the external environment. Thanks to afferent synthesis, from a variety of external and internal stimuli, the body selects the main ones and creates the goal of behavior. Since the choice of such information is influenced by both the purpose of behavior and previous life experience, afferent synthesis is always individual. At this stage, the interaction of three components occurs: motivational arousal, situational afferentation (i.e. information about the external environment) and traces of past experience extracted from memory.

Motivation is the impulses that cause the activity of the body and determine its direction. Motivational arousal appears in the central nervous system when any need arises in an animal or person. It is a necessary component of any behavior that is always aimed at satisfying a dominant need: vital, social or ideal. The importance of motivational arousal for afferent synthesis is already evident from the fact that a conditioned signal loses the ability to cause previously developed behavior (for example, a dog coming to a certain feeder to get food) if the animal is already well fed and, therefore, it lacks food motivational arousal.

Motivational arousal plays a special role in the formation of afferent synthesis. Any information entering the central nervous system is correlated with the dominant motivational excitation at a given time, which is like a filter that selects what is necessary and discards what is unnecessary for a given motivational setting.

Situational afferentation – information about the external environment. As a result of processing and synthesis of environmental stimuli, a decision is made about “what to do” and a transition occurs to the formation of an action program that ensures the selection and subsequent implementation of one action from many potential ones. The command, represented by a complex of efferent excitations, is sent to the peripheral executive organs and is embodied in the corresponding action. An important feature of FS is its individual and changing requirements for afferentation. It is the quantity and quality of afferent impulses that characterizes the degree of complexity, arbitrariness or automation of the functional system. Completion of the afferent synthesis stage is accompanied by a transition to the decision-making stage, which determines the type and direction of behavior. The decision-making stage is realized through a special, important stage of the behavioral act - the formation of an apparatus for accepting the results of the action.

A necessary part of the FS is the acceptor of action results - the central apparatus for assessing the results and parameters of an action that has not yet taken place. Thus, even before the implementation of any behavioral act, a living organism already has an idea about it, a kind of model or image of the expected result.

A behavioral act is a segment of the behavioral continuum from one result to another result. Behavioral continuum is a sequence of behavioral acts. In the process of real action, efferent signals go from the acceptor to the nervous and motor structures that ensure the achievement of the required goal. The success or failure of a behavioral act is signaled by afferent impulses entering the brain from all receptors that record the successive stages of performing a specific action (reverse afferentation). Reverse afferentation is a process of behavior correction based on external information received by the brain about the results of ongoing activities. Assessing a behavioral act, both in general and in detail, is impossible without such accurate information about the results of each action. This mechanism is absolutely necessary for the successful implementation of every behavioral act.

Each PS has the ability for self-regulation, which is inherent in it as a whole. In the event of a possible defect in the FS, its constituent components are quickly processed so that the required result, even if less efficiently (both in time and energy costs), is still achieved.

Main signs of FS. P.K. Anokhin formulated the following features of a functional system:

1) The FS, as a rule, is a central-peripheral formation, thus becoming a specific apparatus of self-regulation. It maintains its unity based on the circulation of information from the periphery to the centers and from the centers to the periphery.
2) The existence of any PS is necessarily associated with the existence of some clearly defined adaptive effect. It is this final effect that determines this or that distribution of excitation and activity throughout the functional system as a whole.
3) The presence of receptor apparatus allows one to evaluate the results of the action of a functional system. In some cases they can be congenital, and in others they can be developed during life.
4) Each adaptive effect of the FS (i.e., the result of any action performed by the body) forms a flow of reverse afferentations, which represents in sufficient detail all the visual signs (parameters) of the results obtained. In the case when, when selecting the most effective result, this reverse afferentation reinforces the most successful action, it becomes a “sanctioning” (determining) afferentation.
5) Functional systems, on the basis of which the adaptive activity of newborn animals is built to their characteristic environmental factors, have all the above-mentioned features and are architecturally mature at the time of birth. It follows from this that the combination of parts of the FS (the principle of consolidation) should become functionally complete at some stage of fetal development even before the moment of birth.

The significance of the FS theory for psychology. From its first steps, the theory of functional systems received recognition from natural science psychology. In the most concise form, the significance of a new stage in the development of Russian physiology was formulated by A.R. Luria (1978).

He believed that the introduction of the theory of functional systems allows for a new approach to solving many problems in the organization of the physiological foundations of behavior and psyche.

Thanks to the FS theory:

The simplified understanding of the stimulus as the only causative agent of behavior has been replaced by more complex ideas about the factors determining behavior, including models of the required future or an image of the expected result.
- an idea was formulated about the role of “reverse afferentation” and its significance for the further fate of the action being performed, the latter radically changes the picture, showing that all further behavior depends on the action performed.
- the idea of a new functional apparatus was introduced, which compares the initial image of the expected result with the effect of the real action - the “acceptor” of the results of the action. Acceptor of action results is a psychophysiological mechanism for predicting and evaluating the results of activity, functioning in the decision-making process and acting on the basis of correlation with the model of the expected result in memory.

P.K. Anokhin came close to analyzing the physiological mechanisms of decision making. The FS theory represents an example of a rejection of the tendency to reduce the most complex forms of mental activity to isolated elementary physiological processes and an attempt to create a new doctrine about the physiological foundations of active forms of mental activity. However, it should be emphasized that, despite the importance of the FS theory for modern psychology, there are many controversial issues regarding the scope of its application.

Thus, it has been repeatedly noted that the universal theory of functional systems needs to be specified in relation to psychology and requires more meaningful development in the process of studying the psyche and human behavior. Very thorough steps in this direction were taken by V.B. Shvyrkov (1978, 1989), V.D. Shadrikov (1994, 1997). It would be premature to claim that the PS theory has become the main research paradigm in psychophysiology. There are stable psychological constructs and phenomena that do not receive the necessary justification in the context of the theory of functional systems. We are talking about the problem of consciousness, the psychophysiological aspects of which are currently being developed very productively.

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FS is the morpho-physiological basis of the HMF as a set of all processes occurring in various systems that ensure the functioning of the HMF (afferent and efferent components).

Studying the physiological structure of a behavioral act, P.K. Anokhin came to the conclusion that it is necessary to distinguish between private integration mechanisms when these private mechanisms enter into complex coordinated interaction with each other. The main provisions of the theory of a functional system were formulated by P.K. Anokhin back in 1935. The theory of functional systems proposed by P.K. Anokhin postulates a fundamentally new approach to physiological phenomena. It changes traditional “organ” thinking and opens up a picture of the holistic integrative functions of the body. Having emerged on the basis of I.P. Pavlov’s theory of conditioned reflexes, the theory of functional systems was its creative development. At the same time, in the process of developing the theory of functional systems itself, it went beyond the framework of the classical reflex theory and took shape into an independent principle of organization of physiological functions. Functional systems have a cyclic dynamic organization different from the reflex arc, all the activities of the constituent components of which are aimed at providing various adaptive results useful for the body and for its interaction with the environment and its own kind.

The most fundamental position of the theory is that systems can be very diverse in the type of problems they solve and in the complexity of these problems, but the architecture of the systems remains the same. This means that various functional systems - from the thermoregulation system to the political control system - have a similar structure. The main components of any functional systems are the following:

Afferent synthesis;

Decision-making;

Action results model (action acceptor) and action program;

Action and its result;

Feedback.

Afferent synthesis is a generalization of information flows coming both from outside and from outside. The subcomponents of afferent synthesis are dominant motivation, situational afferentation, trigger afferentation and memory. The function of dominant motivation is to ensure general motivational activation. The “root cause” of any action is need, motivation. An overfed animal will not frantically search for food; a person devoid of ambition is little concerned with the desire to advance up the career ladder. The function of situational afferentation is to ensure general readiness for action. As soon as something appears in the environment that can satisfy our need, the triggering afferentation mechanism is activated. Trigger afferentation initiates behavior. Thus, based on the interaction of motivational, environmental arousal and memory mechanisms, so-called integration or readiness for a certain behavior is formed. But in order for it to be transformed into goal-directed behavior, it requires exposure to trigger stimuli. Trigger afferentation is the last component of afferent synthesis.

Completion of the afferent synthesis stage is accompanied by a transition to the decision-making stage, which determines the type and direction of behavior. The decision-making stage is realized through a special and very important stage of the behavioral act - the formation of an acceptor apparatus for the results of the action. This is a device that programs the results of future events. It updates the innate and individual memory of animals and humans in relation to the properties of external objects that can satisfy the emerging need, as well as methods of action aimed at achieving or avoiding the target object. Often this device is programmed with the entire search path for corresponding stimuli in the external environment. It is assumed that the acceptor of action results is represented by a network of interneurons covered by a ring interaction. Excitation, once in this network, continues to circulate in it for a long time. Thanks to this mechanism, long-term retention of the goal as the main regulator of behavior is achieved.

The next stage is the actual implementation of the behavior program. Efferent excitation reaches the actuators, and the action is carried out.

Consequently, if the signaling of a completed action fully matches the prepared information contained in the action acceptor, then the search behavior ends. The corresponding need is satisfied.

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Functional system P.K. Anokhin is a schematic model of the main blocks of the brain that ensure goal-directed behavior, i.e. behavior aimed at achieving a specific goal. It reflects a more complex neural mechanism that provides behavior compared to reflex arcs.

Functional system P.K. Anokhina

In order to make it easier to remember this diagram, I slightly modified it in comparison with the diagram that is given in textbooks on physiology.

So, let’s remember the functional system of P.K. Anokhina:

three entrances
three blocks
three floors in each block
three output phenomena
three innovations (ARD, reverse afferentation, outcome parameters).

Internal afferentation

Need, i.e. the lack of something in the body gives rise to internal afferentation.

Internal afferentation is a sensory (afferent) flow of impulses from interoceptors located in internal organs, muscles, and blood vessels. Interoreceptors (or interoceptors) respond to changes in the internal environment of the body.

In the motivation block, led by the amygdala of the brain, only one most biologically significant need is selected from many current needs. On its basis, a flow of motivational excitation is formed.

Let's add P.K. to the diagram. Anokhin's ideas about drive reflexes by Yu. Konorsky. Then it turns out that the flow of motivational excitation is transmitted to the drive reflex system. Drive is a preparatory behavior to increase the likelihood of an executive reflex.
As a result of drive, the body finds itself in a place, or creates a situation, where there is an increased likelihood of finding a trigger stimulus and implementing executive behavior that gives the desired result and satisfies the need.

Action Result Acceptor (ARD) = scheduler, activator, comparator (comparer) and finalizer.

Plans the expected result, or more precisely, its perceived parameters.
Activates program of action to achieve this result.
Compares the obtained parameters with the expected ones.
Completes the activity of the functional system when the obtained result parameters coincide with the expected ones.