Two auto-detection methods for eye movements during eyes closed

Eye movements during closed eyes closely reflect changes of the arousal lev el during transition from wakefulness to sleep. Because they contain both r apid and slow eye movements (REM and SEM)I it has been difficult to detect them automatically. Hiroshige recently developed the method of linear regre ssion analysis for automatic detection of the two types of eye movements, a nd we have developed a template matching method for autodetection. The aim of the present study was to compare both auto-detection methods and visual scoring for REM and SEM. The results revealed high agreement between the tw o quantitative methods and the visual scoring, indicating that auto-detecti on of eye movements is useful for quantitative evaluation of arousal level.