Cortical Evoked Potentials Due to Photic Stimulation during Sleep in Man

Abstract

The evoked potentials recorded from the surface of the head by photic stimulation were shown to change according to the stage of sleep. During sleep the culmination times of the evoked potentials were prolonged. Having been induced to sleep the 3rd positive wave increased in amplitude, but decreased again in deep sleep. The 4th negative wave, at first, decreased in amplitude, but in the proceeding stages it developed to the dominant component covering the 6th negative wave and became larger than in arousal. In most cases, the stage of sleep determined by the pattern of the evoked potentials coincided with the stage determined by the pattern of the spontaneous activity. During sleep the evoked potentials were localized on the occiput, but the secondary response as arousal reaction was widely distributed from forehead to occiput and showed the maximum amplitude on the parietal area.