microsleep
   A term introduced in or shortly before 1966 by the Russian-American neurophysiologist Wladimir Theodore Liberson (1904-1994) to denote a sleep state lasting for a short lapse of time, typically a few seconds to a minute. The definition and diagnostic criteria of the microsleep tend to differ somewhat across authors, and consensus on how to assess them is lacking. Some authors assess microsleeps on the basis of clinical signs such as a blank stare, drooping eyelids, prolonged eye closure, hypnagogic jerks, unintended paroxysmal vocalizations, snoring, and cataplexy, whereas others rely on the electroencephalogram (EEG) to assess the microsleep. On the EEG, microsleeps are characterized by a lowering of alpha activity (i.e. the activity characteristic of the waking state) and the appearance of theta activity (associated with stage N1 sleep). Microsleeps can occur in any one person, especially in a warm and poorly ventilated environment, during the performance of monotonous tasks, and during times of the day when the brain is 'programmed' to enter the sleep state, such as the pre-dawn and mid-afternoon hours. The incidence of microsleeps tends to be heightened in individuals suffering from conditions such as * sleep deprivation, physical or mental fatigue, the sleep apnea syndrome, and narcolepsy. During microsleeps the affected individual may enter the * dream state or the hypnagogic state virtually without a threshold, and without being aware of a discontinuity in the perceptual and cognitive state. This may entail the experiencing of dream images or * hypnagogic hallucinations, and lead up to life-threatening situations in individuals operating a machine or vehicle, for example. It is not unthinkable that the * daymare (i.e. the daytime equivalent of the classical * nightmare) and the microsleep have certain neurophysiological correlates in common.
   References
   Harrison, Y., Horne, J.A. (1996). Occurrence of 'microsleeps' during daytime sleep onset in normal subjects. Electroencephalography and Clinical Neurophysiology, 98, 411-416.
   Liberson, W.T., Liberson, C.T. (1966). EEG recordings, reaction times, eye movements, respiration and mental content during drowsiness. Proceedings of the Society for Biological Psychiatry, 19, 295-302.

Dictionary of Hallucinations. . 2010.

Look at other dictionaries:

  • Microsleep — A microsleep is an episode of sleep which may last for a fraction of a second or up to thirty seconds.[1] Often, it is the result of sleep deprivation, mental fatigue, depression, sleep apnea, hypoxia, narcolepsy, or hypersomnia. For the sleep… …   Wikipedia

  • microsleep — n. A brief period (usually only a few seconds) in which the brain enters a sleep state regardless of the activity the person is performing at the time. Example Citation: If we ignore sleep needs and get behind the wheel of a car, a catastrophe… …   New words

  • microsleep — /muy kroh sleep /, n. Psychol. a moment of sleep followed by disorientation, experienced esp. by persons suffering from narcolepsy or sleep deprivation. [1940 45; MICRO + SLEEP] * * * …   Universalium

  • microsleep — noun A brief period of sleep, usually of a few seconds, that may result from sleep deprivation or various medical conditions …   Wiktionary

  • microsleep — /ˈmaɪkroʊslip/ (say muykrohsleep) noun an unintended period of sleep lasting from a few seconds to a few minutes, usually resulting from fatigue or boredom, especially one which overcomes the driver of a vehicle …   Australian English dictionary

  • microsleep — /muy kroh sleep /, n. Psychol. a moment of sleep followed by disorientation, experienced esp. by persons suffering from narcolepsy or sleep deprivation. [1940 45; MICRO + SLEEP] …   Useful english dictionary

  • Микросон — это кратковременный сон, длительность которого может составлять от долей секунды до тридцати секунд.[1] Часто это результат депривации сна, умственного утомления, депрессии, апноэ во сне, гипоксии, нарколепсии или гиперсомнии. Микросон может… …   Википедия

  • Sleep — Waking up redirects here. For other uses, see Waking Up (disambiguation). This article is about sleep in general; for specifically non human sleep see Sleep (non human); for other uses, see Sleep (disambiguation). Sleeping child Sleep is a… …   Wikipedia

  • Fatigue (medical) — Exhausted redirects here. For the alternative rock song, see Exhausted (song). Exhaustion redirects here. For other uses, see Exhaust (disambiguation). Lethargy redirects here. For the metal band, see Lethargy (band). Fatigue Occupations that… …   Wikipedia

  • Waterfall rail accident — infobox AU rail accident title = Waterfall rail accident date = 31 January 2003 time = 7:15 am location = Waterfall, New South Wales location dist = 37 location dir = SW location city = Sydney line = Eastern Suburbs Illawarra railway line, Sydney …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”