DYNAMICS OF HIGH-FREQUENCY COMPONENTS OF ELECTRICAL-ACTIVITY OF DOG BRAIN IN THE PROCESS OF COGNITIVE ACTIVITY

Dynamics of parameters of low-voltage high-frequency components (HFC; 40 Hz and higher) of electrical activity (EA) of the brain in a broad frequency range (1-256 Hz) was studied in dogs in the process of condi tioning using correlation and spectral analysis. Motor skill of pressi ng the pedal of the food-dispencer in response to presentation of soun d stimuli was elaborated. Spectra of power, coherence and phase of EA were studied in interstimulus intervals (2-3 minutes) and intervals (1 sec) of EEG reaction to conditioned stimuli preceding the motor respo nse. It follows from the distinctions between the parameters of EA at these states that underlying them mechanisms are different. It is assu med that the dynamics of HFC (40-170 Hz) in interstimulus intervals (i ntensification of HFC and dominance of small phase shifts) is an expre ssion of cognitive activity (forming of the internal integral image of forthcoming activity). Characteristics of EEG re-actions to the condi tioned stimuli (increase of phase shifts between potentials) are regar ded as a <<motor program>> which ensure direct realization of multicom ponent motor reaction.