Electrophysiological correlates of habituation and conditioning.

Abstract

1. During habituation of the animal to the experimental situation there is a gradual decrease in the mean coefficient of correlation between the EEG of different cortical points, accompanied by a decrease in the degree of representation of frequencies of the theta-band in spectral and coherent functions. This process is observed during the first four days of habituation, after which the electrographic manifestations show no regular changes. 2. For the first few days of conditioning the mean coefficient of correlation between the EEG of different cortical points rises gradually; this is usually followed by a temporary phase of a decrease in the coefficient, accompanied by a simultaneous decrease in the number of correct conditioned responses, after which the level of spatial synchronization of cortical potentials rises again. The increase in the mean coefficient of correlation is usually accompanied by an increase in the degree of representation of theta-frequencies in the spectral and coherent functions and, conversely, during the phase of weakening of conditioned-reflex activity the degree of representation of the theta-frequencies falls.