title: Circadian rhythms in humans' delta sleep electroencephalogram.
abstract: Eight healthy young male volunteers entered a 20-40 min ultrashort sleep-wake schedule for 78 h in the time-isolation facility. Rectal temperature was continuously recorded. Sleep electroencephalograms (EEGs) obtained during 20 min nap trials were stored in the computer and later analyzed by fast Fourier transform. A two-way repeated-measures ANOVA (with day and time-of-day as the repeated measures) revealed significant circadian rhythms in the powers of sigma and delta sleep EEGs, and in rectal temperature. These results obtained under conditions in which behavioral confounding factors of retiring and rising were experimentally minimized suggest that the circadian pacemaker contributes to determining the hours of day when one can sleep deeply.
authors.affiliation: Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, 272-0827, Ichikawa, Japan.
authors.forename: Xin
authors.initials: X
authors.lastname: Tan
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Kayo
authors.initials: K
authors.lastname: Shibui
authors.forename: Hirokuni
authors.initials: H
authors.lastname: Tagaya
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kamei
authors.forename: Kyuja
authors.initials: K
authors.lastname: Kim
authors.forename: Sayaka
authors.initials: S
authors.lastname: Aritake
authors.forename: Sayaka
authors.initials: S
authors.lastname: Aritaka
authors.forename: Akiko
authors.initials: A
authors.lastname: Ozaki
authors.forename: Kiyohisa
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D001831:Body Temperature; D002940:Circadian Rhythm; D003700:Delta Rhythm; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D012890:Sleep; D014851:Wakefulness