[Interhemispheric asymmetry of ipsilateral interzonal evoked potentials in the parietal and sensorimotor cortex of...

EPs recorded in response to electrical stimulation of ipsilateral visual or auditory cortex, revealed mostly a positive-negative configuration on the surface of parietal and sensomotor cortex in 66 immobilized cats. The positive phase amplitude of the EPs was higher in the parietal area. The latency of audio-parietal and audio-motor EPs was longer than that of visual-parietal or visual-motor EPs. The distribution of the EPs over the parietal cortex revealed a mirror effect for audio-parietal responses. Interzonal EPs were asymmetrical in parietal cortex of the two hemispheres. The right hemisphere dominated, at that. Some individual interhemispheric asymmetry was also revealed between sensomotor interzonal EPs, their latency dominating in the left hemisphere for both zones. The interhemispheric asymmetry of the parietal EPs was associated to some extent with the sex of the animals.