Citation

Williamson A, Friswell R. Accid. Anal. Prev. 2011; 43(3): 690-697.

Affiliation

Department of Aviation, University of New South Wales (UNSW), Sydney, NSW 2052, Australia.

Copyright

(Copyright © 2011, Elsevier Publishing)

DOI

10.1016/j.aap.2010.10.013

PMID

21376856

Abstract

Time of day and the time since last sleep are acknowledged causes of fatigue, but comparatively little is known about how they interact. This study examines the relative effects of time of day and sleep deprivation on fatigue and performance. Two independent groups were exposed to 28h of sleep deprivation beginning at 06:00h for one group (n=39) and at 00:00h for the other (n=22). By varying the start time for the two groups, but keeping constant the duration of sleep deprivation, the effects of variations in the time of day of testing could be examined. For the 06:00h start group the longest period without sleep occurred close to the low point of the circadian rhythm. For the 00:00h start group the circadian low point coincided with only two to six hours of sleep deprivation. Performance was evaluated two-hourly using eight computer-based tests and subjective fatigue ratings. The results showed a clear interaction effect. Both time of day and sleep deprivation affected performance but only in combination; neither had independent effects. These findings have implications for fatigue management.

Language: en