0231 The Impact of At-Home Actigraphy on Performance and Sleepiness in the Lab over 62 Hours of Total Sleep Deprivation

Abstract Introduction It is well-established that sleep loss results in reduced cognitive performance and increased sleepiness, and that these effects are reduced by prior sleep extension. The purpose of the present study was to determine the extent to which individual differences in habitual sleep duration likewise mediate subsequent performance and sleepiness during total sleep deprivation (TSD). Methods Sixteen healthy adults participated in this protocol. The study consisted of two phases: 1) An at-home phase consisting of 12 nights of actigraphy monitoring of normal habitual sleep, and 2) An in-lab phase consisting of a baseline night (8 hours time-in-bed) and 62 hour TSD. Subjects were outfitted with a wrist-worn actigraph to wear for both phases of the study. During Phase 2 of the study, subjects performed a 5-minute Psychomotor Vigilance Test (PVT) and also completed the Karolinska Sleepiness Scale (KSS) every three hours. Utilizing the 2B-Alert performance prediction algorithm from the Biotechnology High Performance Computing Software Applications Institute (BHSAI), it was projected that the worst daily performance on the PVT would occur at 0700 after one and two nights of TSD. Therefore, we investigated the relationship between average at-home total sleep time (TST) and in-lab metrics (PVT speed and KSS) collected at these two time points. Results While there was no significant relationship between at-home TST and PVT speed after one night of TSD, a significant positive relationship was evident after two nights of TSD (r=0.56, p=0.03). The same pattern was evident for the KSS (2 nights of TSD: r=0.53, p=0.04). Conclusion Sleep patterns of healthy adults measured via at-home actigraphy mediate performance and sleepiness during subsequent sleep deprivation in the laboratory. These findings (a) suggest that individual differences in habitual sleep times do not accurately reflect individual differences in actual sleep need; and (b) underscore the utility of collecting actigraphically-determined sleep data in subjects at home prior to their participation in laboratory studies involving sleep loss. Support (If Any) Department of Defense Military Operational Medicine Research Program (MOMRP)