Slow-wave sleep in daytime and nocturnal sleep: an estimate of the time course of "Process S".
Daan et al. (1984) have proposed that sleep and wakefulness are regulated, in part, by a "Process S" that increases during wakefulness and declines during sleep. Data derived from several studies were taken to determine the time course of Process S during both wakefulness and sleep. As required by the model, slow-wave-sleep (SWS; an index of Process S) was found to increase exponentially as a function of prior wake time (equation 1) and to decline exponentially as a function of time asleep (equation 2). The equations accounted for 91% and 96% of the variance, respectively. In addition, equation 1 accurately predicted the amount the amount of SWS in the first hour of nocturnal sleep.
Knowles
J B
JB
Department of Psychology, Queen's University, Kingston, Ontario, Canada.
MacLean
A W
AW
Salem
L
L
Vetere
C
C
Coulter
M
M
D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology