title: Self-awakening, sleep inertia, and P3 amplitude in elderly people.
abstract: It is well known that sleepiness is sometimes experienced in the afternoon. A short afternoon nap is thought to be effective in reducing sleepiness. However, sleep inertia occurs even after a short nap, and this could be a major risk factor for injuries from falling by the elderly. In the present study, the effect of self-awakening on sleep inertia after a 20-min. nap was examined. Nine participants (M=74.1 yr., SD=5.0 yr.) took part in the three experimental conditions: the self-awakened nap, the forced-awakened nap, and the control (no-nap) conditon. Analysis showed sleepiness and performance after the nap significantly improved compared with the control condition. P3 amplitude tended to be larger after self-awakening than after forced-awakening. The present study indicates a 20-min. nap reduces afternoon sleepiness, and the application of self-awakening may contribute to higher arousal after a nap taken by this elderly group.
authors.affiliation: The Japan Society for Promotion of Science. kaidak@niih.go.jp
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kaida
authors.forename: Keiko
authors.initials: K
authors.lastname: Ogawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nittono
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Hayashi
authors.forename: Masaya
authors.initials: M
authors.lastname: Takahashi
authors.forename: Tadao
authors.initials: T
authors.lastname: Hori
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000503:physiopathology; D002940:Circadian Rhythm / Q000502:physiology*; D006970:Disorders of Excessive Somnolence / Q000503:physiopathology*; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010897:Pitch Discrimination / Q000502:physiology; D017286:Polysomnography; D011930:Reaction Time / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*