Individual differences in compensatory rebound of REM sleep, with particular reference to their relationship to personality and behavioral characteristics.

In subjecting 14 healthy university students to partial differential rapid eye movement (REM) sleep deprivation (PDRD), the compensatory rebound of REM sleep during the next night was determined, and showed fairly substantial individual differences in the increased percentage of REM sleep time. This rate was approximately the same for the same individual for two sleep recordings. These individual differences had no positive correlation with the decreased rate of REM time in the PDRD nights or with the percentage of REM time in the baseline night. Therefore, the individual differences in the increased percentage of REM time can be presumed to reflect individual differences in need for deprived REM sleep. Next, we looked into the relationship between the individual subject's personality and behavior characteristics, and his increased percentage of REM time. This revealed that the individuals who were extrovertive, active, optimistic, showy, and who had many friends had significantly higher increases in the percentage of REM time than the individuals who were introvertive, neurotic, inactive, nervous, modest, and who had few friends. Also discussed was the neurophysiological and biochemical basis of the central nervous system as the background for the relationship between the personality and behavioral characteristics and the increased percentage of REM sleep time.