PRELIMINARY STUDY ON KANASHIBARI PHENOMENON : A POLYGRAPHIC APPROACH

抄録

In Japan, there is a set of experiences called kanashibari, which is symptomatically identical to sleep paralysis with or without hypnagogic hallucinations. In a former study (Fukuda et al., 1987a), the author and co-workers have investigated this phenomenon by a questionnaire method and have found that among the normal population the phenomenon is apparently more common than has been usually appreciated. The author conducted this study to confirm the coincidence between kanashibari and sleep paralysis polygraphically, and then to investigate the characteristics of sleep onset REM periods (SOREMPs) with the kanashibari phenomenon. The two subjects with frequent experiences of kanashibari and the other two subjects without the experience slept under an altered sleep schedule. The schedule, which consisted of reversal of usual sleep-wakefulness cycle and sleep interruption. One of the subjects reported that she had been about to have a kanashibari attack during the experiment. During the REM sleep, when the subject was probably about to experience kanashibari, abundant alpha EEG and an elevated heart rate were observed. The author suggests the relations between a higher consciousness level in kanashibari and the abundant alpha EEG, and between emotional components of the phenomenon and the increased heart rate.