Bidirectional Predictors Between Neurobehavioural Measures During Total Sleep Deprivation and Baseline and Recovery Sleep Measures.

For the first time, we examined bidirectional predictors between baseline night (B2) and recovery night 1 (R1) actigraphic sleep measures and neurobehavioural indices during total sleep deprivation (TSD) in a 5-day experiment with 32 healthy adults. During the B2 and R1 nights, wrist actigraphy assessed sleep indices. Neurobehavioural measures were collected during B2 daytime and TSD. Simple linear regression assessed bidirectional predictors between B2 and R1 night sleep measures and TSD neurobehavioural measures. We found greater B2 sleep efficiency predicted lower TSD Karolinska Sleepiness Scale (KSS) scores, and later B2 sleep onset and sleep midpoint predicted lower TSD Profile of Mood States Fatigue (POMS-F) scores. Overall, B2 sleep measures predicted 14.2%-17.2% of the variance in subjective sleepiness and fatigue measures during TSD. Better TSD Digit Symbol Substitution Test performance predicted shorter R1 sleep duration, longer sleep onset latency, and later sleep onset; and better TSD Digit Span Test performance predicted later sleep onset. Furthermore, greater TSD 10-min. Psychomotor Vigilance Test (PVT) lapses predicted longer R1 sleep duration, lower sleep efficiency, greater wake after sleep onset, lower percent sleep, and later sleep offset. Overall, cognitive performance measures during TSD predicted 13.6%-29.9% of the variance in R1 sleep measures. Notably, females showed more significant predictive bidirectional relationships. Our novel findings demonstrate that baseline sleep measures predict subjective sleepiness and fatigue resilience during TSD, whereas cognitive performance resilience during TSD predicts subsequent recovery sleep measures. In summary, our results underscore predictors, mechanisms, and biomarkers between sleep health and individual differences in neurobehavioural performance during TSD.