Can short-wavelength depleted bright light during single simulated night shifts prevent circadian phase shifts?. (May 2017)

• Record Type: Journal Article
• Authors: Regente, J.; de Zeeuw, J.; Bes, F.; Nowozin, C.; Appelhoff, S.; Wahnschaffe, A.; Münch, M.; Kunz, D.
• Is Part Of: Applied ergonomics. Volume 61(2017)
• Page Start: 22
• Page End: 30
• Publication Date: 2017-05
• Subjects: Shift work -- Circadian -- Blue-light depletion; Human engineering -- Periodicals; 620.82
• DOI: 10.1016/j.apergo.2016.12.014
• Languages: English
• ISSNs: 0003-6870

Abstract

Abstract: In single night shifts, extending habitual wake episodes leads to sleep deprivation induced decrements of performance during the shift and re-adaptation effects the next day. We investigated whether short-wavelength depleted (=filtered) bright light (FBL) during a simulated night shift would counteract such effects. Twenty-four participants underwent a simulated night shift in dim light (DL) and in FBL. Reaction times, subjective sleepiness and salivary melatonin concentrations were assessed during both nights. Daytime sleep was recorded after both simulated night shifts. During FBL, we found no melatonin suppression compared to DL, but slightly faster reaction times in the second half of the night. Daytime sleep was not statistically different between both lighting conditions (n = 24) and there was no significant phase shift after FBL (n = 11). To conclude, our results showed positive effects from FBL during simulated single night shifts which need to be further tested with larger groups, in more applied studies and compared to standard lighting. Highlights: We performed a simulated night shift pilot study under filtered bright light (FBL). Salivary melatonin concentrations were not suppressed in FBL conditions. No phase shift after one night under FBL conditions. In FBL vigilance was increased in the second half of the night compared to dim light. There were no detrimental effects on subsequent daytime sleep.