[Interaction of forward and backward conditioned connections as the neurophysiologic basis of the motivation for behavior].

Motivation is defined as a physiological mechanism of activation of traces, kept in memory (engramms) of those external objects which can satisfy the organism's need and those actions which can satisfy it. In the last years E. A. Asratyan advanced and substantiated the concept that the physiological mechanism of motivation is based on the interaction of forward and backward conditioned connections where the backward connection is an activating influence of reinforcing reflex on the structures receiving conditioned signal and achieving the action which was earlier followed by reinforcement. It is experimentally shown that the appearance and extent of the backward conditioned connections generalization depend on the degree of motivational excitation. The backward conditioned connection is a specialized Ukchtomsky's dominant in the functional structure of the consolidated conditioned reflex, which makes the behaviour goaldirected and active. Thus, fundamental phenomena lay in the basis of behaviour: dominant and conditioned reflex--discovered and introduced in the science by A. A. Ukchtomsky and I. P. Pavlov. In the individual adaptive behaviour the dominant and conditioned reflex play the same role as variability and selection in the process of evolutionary adaptation. That is why the suggestion made by K. Popper and J. Eccles (1977) to replace Pavlov's theory of conditioned reflexes by the hypotheses theory is unfounded.