[Relation between changes in arousal level with shift of sleeping time and subsequent sleep stage pattern].
The relationship between decrease in cerebral arousal level and sleep stage pattern was examined when a cycle of 22 h-wake and 8 h-sleep was repeated four times. The subjects of the experiment were six healthy male university students. The results of the experiment showed that the period between the time when the average score of Stanford Sleepiness Scale (SSS) reached point four (a little foggy) and the rising time was gradually decreased by repetition of the 22 h-wake and 8 h-sleep cycle. It was also found that the average score for the 6th experimental day after the third cycle was significantly increased, compared with that for the 1st 22 h waking period. These results show that the cerebral arousal level, which was indicated on the scores of SSS, was gradually decreased under the present experimental wake-sleep condition. The day-to-day variation of critical fusion frequency showed a tendency similar to that of SSS, demonstrating a gradual decrease in arousal level. On the other hand, stage 4 sleep (S4) was significantly increased during sleep after the 1st 22 h waking period, compared with baseline sleep after 16 h waking time. However, a significant increase in S4 was not seen during the sleeping periods in the second to the fourth cycles of 22 h-wake and 8 h-sleep, compared with that during the sleep after the 1st 22 h waking period.(ABSTRACT TRUNCATED AT 250 WORDS)
Saito
Y
Y
Department of Psychology, Chuo University.
Matsumoto
K
K
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001921:Brain / Q000502:physiology; D006801:Humans; D008297:Male; D012892:Sleep Deprivation / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness