Abstract

The spectral characteristics of the EEG were studied in the period immediately preceding slow eye-closures associated with the self-induction of epileptiform activity. Power levels were compared with similar spontaneous eye-closures not associated with paroxysmal activity, with eye closures performed to command, and with EEG preceding eye-blinks. A transient rise in EEG power at low frequencies 1-2 seconds before the slow eye-closure was found to be reliably associated with the subsequent occurrence of paroxysmal activity. This finding suggests that eye-closure may not be initial event in the sequence culminating in paroxysmal activity.