[Rearrangement of the activity of orbital cortex neurons during second-order classical conditioning]

In chronic experiments on 8 dogs, rearrangements of unit activity were studied in the orbital cortex in the course of classic conditioning of the I and the II order. Histograms of the interspike intervals distribution changes of the mean firing rate revealed that, in the course of conditioning, the neuronal responses to presentation of conditioned stimuli of the I and II order (for the II order reflexes) underwent dynamic changes. The unit activity pattern under the effect of a conditioned stimulus approximates the form of the pattern in reinforcement. The data are discussed in the light of E.A. Asratian's ideas of the mechanism for formation of complex forms of conditioned reflexes.