0266 A Brief Nap During a Period of Sleep Deprivation Does Not Mitigate Cognitive Deficits

Abstract

Introduction: Sleep deprivation consistently impairs vigilant attention and placekeeping, which is the ability to maintain place in a sequence of steps without skipping or repeating steps. Placekeeping is a broadly important component of higher-order cognition. Previously, we found that caffeine benefitted vigilant attention but had no effect on placekeeping for most individuals. Here, we investigated the extent to which another intervention, brief naps, mitigated deficits in vigilant attention and placekeeping during a period of sleep deprivation. Methods: In the evening, participants completed assessments of placekeeping and vigilant attention, the UNRAVEL task and Psychomotor Vigilance Task (PVT), respectively. Participants were then randomly assigned to either stay awake in the laboratory overnight (Sleep-deprived) or sleep at home (Rested). Sleep-deprived participants were also randomly given a 0, 30, or 60 minute nap opportunity. During the naps, participants were setup with partial polysomnography. In the morning, Rested participants returned and everyone completed UNRAVEL and PVT again. Results: Sleep deprivation increased placekeeping errors, particularly following interrupted performance, and increased attentional lapses. A brief nap opportunity did not mitigate placekeeping or vigilant attention deficits. Polysomnography data showed that total sleep time was negatively related to placekeeping errors following an interruption; participants who slept more made fewer postinterruption errors. Slow wave sleep (SWS) was negatively related to attentional lapses and placekeeping errors on non-interruption trials; participants who obtained more SWS made fewer lapses and non-interruption errors. Sleep latency was also negatively related to attentional lapses, such that participants who fell asleep quickly, an indication of greater sleepiness, had more attentional lapses. Conclusion: A brief nap during a period of sleep deprivation is not a viable intervention and longer naps may be required before observable performance benefits emerge. However, specific aspects of sleep architecture were related to performance on the two tasks, suggesting domain-specific deficits due to sleep deprivation.