Electrophysiological Study of Auditory Eye Opening Response

The auditory response in which the eyes were opened slowly when the sound stimuli were presented to the subjects soon after they are going to fall into sleep was called as the auditory eye opening responses at falling into asleep (AEOR: Suzuki & Notoya, 1980). AEOR was analyzed by electrophysiological techniques. Subjects were two women with normal hearing. AEOR was evoked by warble tone (1kHz, 3kHz 55dB (A)). The results obtained were as follows: 1) AEOR was evoked in the later part of stage wakefulness and the earlier part of sleep stage 1. 2) The latency of AEOR recorded by EMG of eyelid is about 600ms. 3) The latency of AEOR recorded by EEG is about 400ms. 4) The change of EEG were α-blocking and presenting α waves. These results suggest that AEOR is a kind of arousal or searching responses which were controlled by higher levels, and distinguishable from auditory other reflexes such as startle reflex.