title: Self-awakening improves alertness in the morning and during the day after partial sleep deprivation.
abstract: The ability to awaken at a predetermined time without an alarm is known as self-awakening. Self-awakening improves morning alertness by eliminating sleep inertia; however, the effects of self-awakening on daytime alertness and alertness that has deteriorated as a result of sleep loss are unknown. The aim of this study was to determine the effects of self-awakening on both morning and daytime alertness after partial sleep deprivation. Fifteen healthy males without the habit of self-awakening participated in a cross-over trial including forced awakening and self-awakening conditions. In each condition, participants' sleep was restricted to 5 h per night in their homes for 4 consecutive days. They completed a psychomotor vigilance task and subjective ratings of sleepiness immediately upon awakening each morning. On the fourth day, participants completed subjective ratings of sleepiness, a psychomotor vigilance task and sleep latency tests in the laboratory seven times at 1-h intervals during the day. The response speed on the psychomotor vigilance task, in the morning and during the day, was higher in the self-awakening than the forced awakening condition. Our results showed that self-awakening improved alertness (assessed by response speeds) by reducing sleep inertia and alleviated daytime sleepiness heightened by partial sleep deprivation.
authors.affiliation: Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Health Administration and Psychosocial Factor Research Group, National Institute of Occupational Safety and Health, Kawasaki, Kanagawa, Japan.
authors.forename: Tomohide
authors.initials: T
authors.lastname: Kubo
authors.affiliation: Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kuriyama
authors.affiliation: Health Administration and Psychosocial Factor Research Group, National Institute of Occupational Safety and Health, Kawasaki, Kanagawa, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D032762:Autoexperimentation; D003071:Cognition; D006801:Humans; D008297:Male; D011597:Psychomotor Performance; D011930:Reaction Time / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology* / Q000523:psychology*; D012894:Sleep Stages / Q000502:physiology; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology*
keywords: daytime sleepiness; forced awakening; sleep inertia