11 topics with brief reviews: definitions, key facts, and class questions.
This section focuses on the physiological mechanisms underlying any goal-directed activity. Here, we analyze how the nervous system forms adequate responses to environmental changes, transitioning from strictly predetermined automatisms to complex forms of adaptation.
The section materials thoroughly examine P.K. Anokhin's theory of functional systems and the systemic principle of behavioral organization. You will study the foundation of higher nervous activity: unconditioned and statokinetic reflexes, the mechanisms of temporary connection formation, and the convergent theory of the conditioned reflex. Special attention is paid to the architecture of the behavioral act, the role of feedback (afferent synthesis), and Pavlov's «reflex of purpose,» which directs the organism toward a useful adaptive result.
In practical classes and exams, instructors most frequently ask you to draw and explain the diagram of the behavioral act architecture. The traditional stumbling blocks are the cellular-level mechanisms of temporary connection closure and understanding how the action result acceptor apparatus and feedback specifically correct our behavior.
Internal self-regulation systems do not always cope with maintaining homeostasis. Behavior allows the organism to actively interact with the environment, consuming or excreting substances to restore balance.
What did I.P. Pavlov call the «what-is-it?» reflex?
This is what I.P. Pavlov called the orienting-investigatory reaction of the organism to any novel or unexpected stimuli. It has adaptive significance and underlies learning.
What happens upon the first presentation of a conditioned signal (e.g., light)?
Initially, the organism elicits an innate orienting-investigatory reaction: it turns the head and torso toward the source of the stimulus. Only after repeated pairings with food does this stimulus become conditioned and begin to elicit a feeding reaction.
Why is the formed connection called «temporary»?
It is called temporary because it lacks a rigid innate basis and rapidly disintegrates (extinguishes) if the conditioned stimulus ceases to be reinforced by the unconditioned one.
What is convergence in Anokhin's theory?
This is the convergence of various types of excitations (e.g., sensory and motivational) onto the exact same neurons of the cerebral cortex.
What is the main difference between the reflex of purpose and a simple conditioned reflex?
A simple reflex is a reaction to an already existing external stimulus. The reflex of purpose is triggered by internal tension, forcing the subject to actively and persistently search for the necessary objects in the external world.
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