Citation

Condon R, Colquhoun P, Plett R, De Vol D, Fletcher N. Int. Arch. Occup. Environ. Health 1988; 60(6): 405-411.

Affiliation

MRC Perceptual and Cognitive Performance Unit, University of Sussex, Brighton, UK.

Copyright

(Copyright © 1988, Holtzbrinck Springer Nature Publishing Group)

DOI

unavailable

PMID

3410550

Abstract

Performance scores on both a simple detection task and a complex visual judgment task, together with subjective alertness ratings, were collected 4-hourly from 19 watchkeepers working a "4-on/8-off" routine, and from 20 dayworkers, over consecutive days of voyages on merchant ships. Adaptation of the circadian rhythms in the measures to the shifted hours of work of the three sections of the watchkeeping crews was at best only partial. These rhythms resulted in a depression of the levels of most measures during the night hours, which was exacerbated by the effects of recent awakening from sleep. It is suggested that these unwanted variations in operational effectiveness could be largely removed by replacing the 4-on/8-off watchkeeping system, with its associated "split" sleep pattern, by one which allows a single full length sleep each day. Such a system would encourage better adaptation of the rhythms; effects of recent awakening could be avoided by the provision of an adequate "waking up" period before duty begins.

Language: en