Characteristics of the subject’s sleep during the experimental night measured by one scorer (JBE).

Time in bed (TIB), time from lights off to lights on; Sleep period time (SPT), time from the beginning of the first episode of sleep to the end of the last episode of sleep; Wakefulness during SPT, amount of wakefulness during SPT; Total sleep time (TST), SPT minus Wakefulness during SPT. Mean ± Standard deviation of the experimental values are presented. The range of standard values is given from Hirshkowitz et al. 2004. min: minutes.