Single unit activity was recorded in the neocortex of awake cats during spontaneous spike wave discharges. Ongoing activity was interrupted during paroxysmal events and was replaced by 1. (1) bursts of action potentials coincident with the EEG spike and cessation of firing during the wave, or 2. (2) cessation of firing for the duration of the paroxysm. Other units which displayed little or no background activity were recruited to fire during the EEG spike. Surface cerebellar stimulation at high frequencies led to decreased neuronal activity while single pulse shocks resulted in short latency activation. These results were compared to studies of spike wave activity elicited by electrical stimulation. © 1977.