All electroencephalographers are familiar with the apparently spontaneous and unpredictable occurrence of epileptiform activity during recording of the routine electroencephalogram (EEG). In addition, all are well acquainted with certain maneuvers which increase the likelihood that such activity will appear: e.g., eye closure, hyperventilation, darkness, quiet, light sleep. Means for arresting subconvulsive spike or spike-wave (S-W) discharges are also readily demonstrable in many patients: e.g., eye opening, loud sounds, tactile stimuli, and concentrated attention, to name but a few. In a much smaller number of subjects, specific stimuli more or less regularly elicit abnormal discharge, among them: flickered light,10,24 music,7 clicks and tones,3,20 reading,4 tactile stimuli,1,9 and emotional and psychological stimuli.12,21 In the course of our attempts to condition epileptiform discharges of patients with light-sensitive epilepsy to follow a neutral stimulus,22 the relationship of a variety of peripheral stimuli to the occurrence of paroxysmal