Modeling Neurocognitive Decline and Recovery During Repeated Cycles of Extended Sleep and Chronic Sleep Deficiency

• Published in: Sleep (New York, N.Y.) Vol. 40; no. 1
• Main Authors: St. Hilaire, Melissa A., Rüger, Melanie, Fratelli, Federico, Hull, Joseph T., Phillips, Andrew J. K., Lockley, Steven W.
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 01.01.2017
• Subjects: Chronic Disease - psychology; Cognition - physiology; Cognition - radiation effects; Historically Controlled Study; Humans; Light; Male; Mathematical models; Original; Sleep - physiology; Sleep - radiation effects; Sleep deprivation; Sleep Deprivation - physiopathology; Sleep Deprivation - psychology; Sleep Initiation and Maintenance Disorders - physiopathology; Sleep Initiation and Maintenance Disorders - psychology; Sleep Stages - physiology; Sleep Stages - radiation effects; Time Factors; Wakefulness - physiology; Wakefulness - radiation effects; Young Adult; neurobehavioral performance; recovery sleep; physiological adaptation; chronic variable sleep deficiency; subjective sleepiness; recovery of function
• ISSN: 0161-8105; 1550-9109
• DOI: 10.1093/sleep/zsw009

Abstract Study Objectives: Intraindividual night-to-night sleep duration is often insufficient and variable. Here we report the effects of such chronic variable sleep deficiency on neurobehavioral performance and the ability of state-of-the-art models to predict these changes. Methods: Eight healthy males (mean age ± SD: 23.9 ± 2.4 years) studied at our inpatient intensive physiologic monitoring unit completed an 11-day protocol with a baseline 10-hour sleep opportunity and three cycles of two 3-hour time-in-bed (TIB) and one 10-hour TIB sleep opportunities. Participants received one of three polychromatic white light interventions (200 lux 4100K, 200 or 400 lux 17000K) for 3.5 hours on the morning following the second 3-hour TIB opportunity each cycle. Neurocognitive performance was assessed using the psychomotor vigilance test (PVT) administered every 1–2 hours. PVT data were compared to predictions of five group-average mathematical models that incorporate chronic sleep loss functions. Results: While PVT performance deteriorated cumulatively following each cycle of two 3-hour sleep opportunities, and improved following each 10-hour sleep opportunity, performance declined cumulatively throughout the protocol at a more accelerated rate than predicted by state-of-the-art group-average mathematical models. Subjective sleepiness did not reflect performance. The light interventions had minimal effect. Conclusions: Despite apparent recovery following each extended sleep opportunity, residual performance impairment remained and deteriorated rapidly when rechallenged with subsequent sleep loss. None of the group-average models were capable of predicting both the build-up in impairment and recovery profile of performance observed at the group or individual level, raising concerns regarding their use in real-world settings to predict performance and improve safety.