Systemic organization of memory
From the standpoint of the theory of functional systems, memory is not an isolated process. It is inherent in absolutely all components of the systemic architecture of a behavioral act. For the successful implementation of any action, the organism draws on past experience at the following stages:
- Stage of afferent synthesis (collection and analysis of information about the current situation).
- Decision-making (selection of the optimal response pathway).
- Acceptor of action result (formation of an ideal model of the future result for comparison with reality).
- Efferent synthesis (direct generation of the motor or other command program).
Note: Despite understanding the role of memory in behavior, the exact systemic mechanisms of its operation currently remain practically unexplored in physiology.
Simple forms of memory: Habituation
The simplest forms of learning are found even in animals with the most primitive nervous system, such as mollusks. One of the basic forms of simple learning is habituation (habituation).
Its mechanism consists of the repeated exposure of the organism to a relatively neutral stimulus. The dynamics of the process are as follows:
- Upon the initial exposures to the stimulus, the organism demonstrates a clear response (novelty reaction).
- With the continuous repetition of the same stimulus, the response gradually weakens.
- Ultimately, complete disappearance of the response occurs.
The essence of habituation is that the organism learns to ignore an insignificant stimulus, despite the fact that it continues to act upon it.
Simple forms of memory: Sensitization
The process physiologically opposite to habituation is sensitization (sensitization).
In this case, with continued exposure to the stimulus, the magnitude of the organism's response does not fade, but on the contrary, increases. The main condition for the pronounced manifestation of sensitization is reinforcement: it becomes especially prominent when the initial stimulus is repeatedly associated with events that are subjectively important to the organism. Such events include:
- Appetitive influences (e.g., food reinforcement).
- Aversive influences (e.g., defensive or painful stimuli).
Briefly: answers to topical questions
What components does the stage of afferent synthesis include according to P.K. Anokhin?
The stage of afferent synthesis includes motivation, situational afferentation, and memory; triggering afferentation is also indicated in diagrams.
- Motivation — internal drives, including biological ones; in humans, biological motivations interact with socially determined situational afferentation and memory mechanisms.
- Situational afferentation — environmental influences that continuously enter the CNS via numerous exteroceptors.
- Memory — a component of afferent synthesis; includes genetic and individually acquired memory and influences the organization of behavior.
- Triggering afferentation — designated in sources as TA.
Which brain structures are responsible for memory consolidation?
Sources explicitly state that the hippocampus ensures memory consolidation — the transition of short-term memory to long-term memory.
Also, forgetting functions are closely related to the activity of the hippocampus and the temporal cortex of the cerebral hemispheres: upon damage to these structures, acquired skills are lost very quickly, which is associated with impaired memory consolidation.
- Hippocampus — plays a major role in the consolidation of conscious memory.
- Temporal cortex of the cerebral hemispheres — associated with forgetting functions along with the hippocampus.
What is the acceptor of action result in the theory of functional systems?
The acceptor of action result (AAR) is the apparatus for predicting and evaluating the future result.
At the stage of intention formation, an ideal mental model (image) of the future result is created within this apparatus. In the process of goal-directed activity, via feedback afferentation, continuous comparison occurs between:
- What was originally planned (the model in the AAR).
- What was actually obtained during behavior.
If the achieved result matches the model, the activity concludes; if not, the system is reorganized.
To avoid confusing simple forms of memory, use this association: Habituation is a "minus" (the response decreases and disappears to a boring stimulus), while Sensitization is a "plus" (the response increases when the stimulus promises food or danger).
Class and exam questions
What is memory from the perspective of normal physiology?
This is the basic ability of living organisms to remember, store, and retrieve information about previously experienced events, which is inextricably linked with learning processes.
At which stages of a behavioral act does memory function?
Within the framework of the theory of functional systems, it is engaged at the stages of afferent synthesis, decision-making, the operation of the acceptor of action result, and efferent synthesis.
What is the phenomenon of habituation?
Habituation (habituation) is a form of memory in which the repeated action of a relatively neutral stimulus leads to the weakening and complete disappearance of the organism's response.
What condition is necessary for the development of sensitization?
Sensitization (response enhancement) is most pronounced when a stimulus is repeatedly paired with subjectively appetitive (food) or aversive (defensive) stimuli.
What else to study on this topic
- Theory of functional systems and the role of memory at the stage of afferent synthesis
- Formation and functions of the acceptor of action result
- Specifics of the formation of simple forms of memory in organisms with a primitive nervous system (using mollusks as an example)
- Neurophysiological differences between habituation and sensitization
- The connection of memory processes with brain functions in higher animals
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