Recovery of cognitive performance and fatigue after one night of sleep deprivation.
OBJECTIVE
The aim of this study was to investigate how subjective sleepiness, mood states, simple and high-order cognitive performance change after one night of sleep deprivation (SD) and recover to after 7 h normal recovery sleep opportunity during three recovery days.


METHODS
Ten healthy subjects participated in this study. We measured their subjective sleepiness, mood states and their performances of 2 simple tasks and 4 high-order cognitive tasks twice a day for 5 days, on the baseline day, post-vigil day and 3 recovery days after SD. This study was conducted considering each participant's motivation for task, learning effect and diurnal variation of performance.


RESULTS
The performances of simple tasks such as addition or short-term memory were not reduced after SD and were the poorest on the baseline day, and improved gradually; however the high-order cognitive performances were at their lowest on the post-vigil day and needed 2 recovery sleep opportunities to return to the baseline level. Fatigue and confusion in mood states and subjective sleepiness were also at their lowest after SD. Subjective sleepiness nearly recovered to the baseline level on the 1st recovery day, but fatigue and confusion reached the baseline levels on the 2nd recovery day.


CONCLUSIONS
These results suggest that cognitive deterioration and the recovery process may differ between simple task performance and high-order cognitive task performance, which needed 2 ordinary sleep opportunities to recover to the baseline level, and the change of subjective mood states were also different for each mood.
Ikegami
Kazunori
K
Department of Mental Health, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan. kikegami@med.uoeh-u.ac.jp
Ogyu
Seizo
S
Arakomo
Yuko
Y
Suzuki
Kiyomi
K
Mafune
Kosuke
K
Hiro
Hisanori
H
Nagata
Shoji
S
D000328:Adult; D000339:Affect; D003071:Cognition; D005221:Fatigue / Q000523:psychology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D012892:Sleep Deprivation / Q000523:psychology*; D011795:Surveys and Questionnaires; D013647:Task Performance and Analysis; D055815:Young Adult