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Sleep on the Night Shift: 24‐Hour EEG Monitoring of Spontaneous Sleep/Wake Behavior
Author(s) -
Torsvall Lars,
Akerstedt Torbjöurn,
Gillander Katja,
Knutsson Anders
Publication year - 1989
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.1989.tb01934.x
Subject(s) - wakefulness , nap , sleep (system call) , psychology , circadian rhythm , audiology , sleep onset , electroencephalography , slow wave sleep , non rapid eye movement sleep , night work , shift work , medicine , insomnia , psychiatry , neuroscience , computer science , operating system
The present study sought to objectively describe the spontaneous sleep/wakefulness pattern of shift workers during a 24‐hour period. Portable Medilog tape‐recorders were used for ambulatory EEG monitoring of 25 male papermill workders (25–55 years) during days with night and afternoon work. The rusults showed that sleep after night work was two hours shorter than after afternoon worl. The sleep reduction affected mainly Stage 2 and REM sleep while slow wave sleep was unchanged. In connection with night work 28% of the workders took a nap in the afternoon. These naps contained a large proportion of slow wave sleep and were, apparently, caused by the sleep deficit after the short main sleep period. The EEG recordings also revealed that 20% of the participants had sleep episodes during night work. These naps were as long as the afternoon naps, were experienced as “dozing off” ragher than naps. Occurred at the time of the though of the circadian wakefulness rhythm, and were concomitant with extreme subjective sleepiness and low rated work load. It was concluded that not only the sleep of shift workders was disturbed, but also the wakefulness‐ to the extent that sleepiness during night work sometimes reached a level where reasonable wakefulness could not be maintained. The latter observation is probably of special importance in work situations demanding a great responsiility of human lives or for great economic values.