Reorganization of activity of neurons of orbital cortex during formation of classical second-order conditioned reflexes.

The reorganizations of the activity of neurons in the orbital cortex during the formation and realization of classical first- and second- order conditioned reflexes were studied in chronic experiments with eight dogs. An analysis of the histograms of the distribution of between-impulse intervals, poststimulus histograms, and the changes in the average discharge frequency showed that the responses of neurons to the presentation of a first-order or second-order conditioned signal (for a second-order reflex) undergo dynamic changes with the development and strengthening of conditioned connections. The pattern of impulse activity during the action of a conditioned signal approximates in form the pattern of discharges during the action of reinforcement. The data are discussed in light of E. A. Asratvan's concepts of the mechanism of formation of complex forms of conditioned reflexes.