0005 A circadian-informed lighting intervention markedly improves vigilance in a simulated night shift setting

Abstract Introduction Due to misalignment between circadian timing and the work/rest schedule, cognitive performance during night shift-work is often poor. This study tested a circadian-informed lighting strategy designed improve on-shift through alerting effects, faster adjustment schedule promoting more sleep off-shift, compared standard lighting. Methods A randomised controlled, within-subjects, counter-balanced cross-over was performed examine versus on simulated 8-day schedule. Nineteen healthy sleepers (12 males/7 females, mean±SD aged 28.7±10.4 years) underwent two separate experimental conditions in laboratory. The condition mimicked current submarines (largely dim, blue-depleted light), while administered bright, blue-enriched at times estimated facilitate rapid delay. After an adaptation opportunity from 22:00 – 07:00 (day 1), participants remained awake for 27 hours transition sleeping day (10:00 - 19:00) undertaking (00:00 08:00) days 3-7. primary outcome number of lapses (>500ms responses) psychomotor vigilance task (PVT), six across each work shift. Median reaction time other PVT outcomes were also conditions. Results There significant day-by-condition interactions lapses, p< 0.05. intervention resulted ~50% fewer by final (mean±SD 7.4±5.0 vs. 15.6±6.1 lapses). Similar effects observed outcomes. Conclusion Circadian-informed markedly better than under These findings indicate considerable potential automated interventions safety shift-workers. Support (if any) research supported Commonwealth Australia as represented Defence Science Technology Group Department Research Network Undersea Decision Superiority (research agreement number: 9334), with additional financial support Flinders University provision REDARC.