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Sharp and sleepy: evidence for dissociation between sleep pressure and nocturnal performance
Author(s) -
GALLIAUD ELODIE,
TAILLARD JACQUES,
SAGASPE PATRICIA,
VALTAT CÉDRIC,
BIOULAC BERNARD,
PHILIP PIERRE
Publication year - 2008
Publication title -
journal of sleep research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 117
eISSN - 1365-2869
pISSN - 0962-1105
DOI - 10.1111/j.1365-2869.2008.00629.x
Subject(s) - psychomotor vigilance task , sleep deprivation , vigilance (psychology) , analysis of variance , audiology , psychology , wakefulness , electroencephalography , sleep restriction , medicine , circadian rhythm , psychiatry , neuroscience
Summary While sleep restriction decreases performance, not all individuals are equal with regard to sensitivity to sleep loss. We tested the hypothesis that performance could be independent of sleep pressure as defined by EEG alpha–theta power. Twenty healthy subjects (10 vulnerable and 10 resistant) underwent sleep deprivation for 25 h. Subjects had to rate their sleepiness (Karolinska Sleepiness Scale) and to perform a 10‐min psychomotor vigilance task (PVT) every 2 h (20:00–08:00 hours). Sleep pressure was measured by EEG power spectral analysis (alpha–theta band 6.0–9.0 Hz). Initial performance, EEG spectral power and KSS score were equal in both groups ( anova , NS). The performance of vulnerable subjects significantly increased during the night (r anova , P < 0.01), whereas resistant subjects globally sustained their performance. Homeostatic pressure and subjective sleepiness significantly increased during the night (r anova , P < 0.01) identically in both categories (r anova , NS). Resistant subjects sustained their reaction time independently of the increase in homeostatic pressure. The phenotypic determinants of vulnerability to extended wakefulness remain unknown.