Comparison of a Circadian-based and a Forward Rotating Watch Schedules on Sleep, Mood, and Psychomotor Vigilance Performance

摘要

In the military, any degradation in performance may have serious implications, potentially resulting inloss of life or affecting mission accomplishment. The maritime environment imposes the additional uniquechallenges of waterborne motion on the shipboard crew. Additionally, the U.S. Navy’s 24/7 operationalrequirements mandate rigorous equipment monitoring and shiftwork. This study assesses how crewmembersleep hygiene and psychomotor vigilance performance is affected by a shift from traditional workschedules to an alternative circadian-based schedule. Twenty-eight sailors were assessed while workingtwo watch schedules, a conventional 5-hours on/10-hours off (5/10) rapidly rotating schedule, and analternative 3-hours on/9-hours off (3/9) fixed schedule. Average daily sleep duration was the same for bothwatch schedules. However, compared to their scores on the 5/10, sailors on the 3/9 had significantly lessdaytime sleepiness, improved mood, 30% faster reaction times, and had 40% to 50% fewer errors (i.e.,lapses combined with false starts). The significant improvements in performance, mood, and sleep hygieneobserved in this within-subjects study suggest that circadian watch schedules should be chosen rather thannon-circadian aligned schedules.