Enhancement of slow wave sleep: implications for insomnia.

摘要

Slow wave sleep (SWS) is defined as the sum of stage 3 and stage 4 sleep and is characterized by high-voltage, synchronized electroencephalographic (EEG) waveforms, often measured as slow wave activity (SWA). SWS has been widely hypothesized to be a time of relatively heightened neu-rophysiologic restoration or recuperation. This viewpoint is prompted by a number of observations including: (1) enhanced SWA following sleep deprivation in proportion to the duration of prior wakefulness; (2) reduced SWA during nocturnal sleep following afternoon/evening naps; (3) a gradual decline in SWA across a night of sleep; and (4) increased SWS following nights of fragmented sleep. Within the two-process model of sleep regulation, heightened SWS/SWA has been viewed as reflecting Process S, the homeostatic component. Other authors have proposed that increased SWS/SWA represents ongoing cortical recovery from activities during prior wakefulness.