Functional regional asymmetry in intrahemisphere coherencein the EEG during conditioning in dogs.

The individual characteristics of regional interhemisphere relationships were studied during acquisition of a food-related conditioned reflex in dogs. Electrical activity was recorded from symmetrical anterior (frontal and motor) and posterior (auditory and visual) areas of the brain. Comparison of averaged intrahemisphere EEG coherence values in the left and right hemispheres of the brain revealed individual features of regional interhemisphere relationships. In dogs with the strong type of nervous system, higher levels of EEG coherence in the anterior areas of the cerebral cortex were seen in the left hemisphere, while coherence in the posterior areas was greater in the right hemisphere. The opposite pattern was seen in animals with the weak type of nervous system. Thus, the spatial organization of cortical electrical activity differed in the associative and projection areas.