Difference from reflex theory
Classical reflex theory posits that response organization follows the reflex principle and terminates in a reaction to an external stimulus—that is, the reflected action itself. The analysis stops there.
The theory of functional systems goes fundamentally further: it does not stop at the action. For survival and adaptation, what matters to the organism is not motor acts per se, but the achievement of a useful adaptive result. The system carries its analysis right up to the point of satisfying the need.
Need and motivation as the basis of the system
Any behavioral activity is based on biological and social needs. They act as system-forming and system-mobilizing factors that:
- Give an active vector to acts.
- Unite previously chaotic elements into coordinated working ensembles—constellations.
However, as I.M. Sechenov noted, needs and motivations by themselves are not capable of fully forming a functional system. The feeling of hunger may compel an animal to get up and passionately search for food, but the motivation itself contains no ready-made instruction on how exactly to obtain this food. Interaction with the external environment is required.
Result as the leading factor of behavior
The formation of behavioral-level systems relies on two components: the result itself and the action result acceptor (the apparatus of prediction and evaluation).
Features of the behavioral result:
- Requires active interaction with the environment.
- Changes the dynamics of the system: both homeostatic and behavioral processes are restructured depending on the parameters of the achieved goal.
- Divided into biologically significant (thirst, aggression, reproduction) and socially significant (education, profession, ethics).
Fixation mechanism: As soon as the subject achieves the goal, a useful integration of physiological processes is formed and immediately consolidated. Example: A newborn moose calf spends a few minutes in chaotic trials trying to stand up. But as soon as it manages to maintain an upright posture (the result is achieved), the successful muscle integration is fixed. The second attempt to get up takes only a matter of seconds.
Experimental evidence of the role of the result
Behavior is determined not by a set of external stimuli, but by an internal need for an adaptive result.
- Predator–prey model: A hungry cat actively catches a mouse to satisfy its feeding need. If the cat is fed (or lacks hunting skills), it will not react to the same stimuli. Without a need, external stimuli do not trigger behavior.
- Canary experiment (Porter): A bird with clipped wings needs to reach suspended food. First, it makes unsuccessful attempts (a purely reflex stage). Then it reorganizes its behavior: it uses children's blocks lying in the room, builds a pyramid, and climbs up to the food. Hunger, past experience, motor skills, and environmental assessment merged into a single system.
- Social interactions: In a game of chess, what matters is not the physical hand moves, but the intermediate and final results leading to a socially significant goal—victory.
Behavior in a social environment and extreme situations
The significance of the result is clearly traceable in zoo-social and human activity.
Chimpanzee example (Jane Goodall): A low-ranking monkey, running away from the dominant one, accidentally hits an empty barrel, making a terrible clatter that frightens the troop. The animal evaluates the situation and subsequently uses the barrel purposefully for intimidation. Achieving this new result changes the structure of the entire colony: the outcast becomes the leader.
Extreme situations (locked room, hypoxia): The behavioral dynamics of a group of people are always subject to one law:
- Primary (reflex) stage: Chaotic vocal and motor reactions, panic occur. They do not lead to rescue.
- Secondary (goal-directed) stage: A strict functional system is formed. Efforts are concentrated on achieving a useful result (breaking the door down, finding a key).
This same principle explains the evolution of tools: needles or wheels changed shape over the centuries, but survived in history because they invariably provided the required adaptive result.
Briefly: answers to topical questions
What nodal mechanisms make up the central architecture of a behavioral act according to P.K. Anokhin?
The central architecture of a behavioral act consists of several sequential and interconnected nodal stages. It includes:
- Afferent synthesis — the initial stage of information processing, including motivation, memory, and situational afferentation.
- Decision making — the formation of a dominant line of behavior with the elimination of redundant degrees of freedom.
- Action result acceptor — the apparatus for predicting and evaluating the future result.
- Efferent synthesis — the organization of the action itself and the formation of the efferent program.
The architecture also includes triggering afferentation and feedback afferentation, which provides information about the actually obtained result for comparison.
What is the action result acceptor and how is it formed in the CNS?
The action result acceptor is an apparatus that predicts the properties of the required result and the methods leading to its achievement. It is built under the influence of preceding reinforcements (experience of successful need satisfaction).
The basis of this apparatus is formed by interneurons of various parts of the brain. Formation occurs before the action begins: when pyramidal neurons of the cortex form efferent commands for effector organs, copies of these commands propagate along the collaterals of the pyramidal tract to interneurons. Due to cyclic relationships within this group of neurons, a predictive model of the expected result is created, against which incoming feedback afferentation is subsequently compared.
Which brain structures are the pacemakers of biological motivations?
The pacemaker role in the formation of basic biological motivations belongs to the motivaciogenic centers of the hypothalamus.
By analogy with the sinus node of the heart, hypothalamic centers control structures of other brain levels and keep them in morphological and functional dependence. Motivational excitation arising initially in the hypothalamus spreads to the limbic system and reticular formation, and through them to the cerebral cortex. Deactivation of hypothalamic centers leads to the disintegration of the elements united into motivational excitation, while destruction of hypothalamic centers results in the elimination of biological motivations.
Class and exam questions
Does an external stimulus trigger behavior on its own?
No, without a dominant need (e.g., hunger), an external stimulus will not lead to goal-directed behavior. This is proven by the experiment with a well-fed cat, which ignores the mouse.
How does behavior change in an emergency situation?
Useless reflex reactions (fuss, shouting) predominate at first. Then they are replaced by goal-directed actions—a system is formed to achieve the result (e.g., escaping danger).
What else to study on this topic
- Formation and role of the action result acceptor
- Classification of needs and dominant motivation
- Situational afferentation in system organization
- Dynamic restructuring of homeostatic systems during behavior
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