title: Confinement and sleep deprivation effects on propensity to take risks.
abstract: BACKGROUND
  The impact of confinement and sleep deprivation on risk-taking propensity is a key issue in crew management. We investigated both confinement and gender effects on risk propensity and performance during up to 36 h of extended wakefulness.
  
  
  METHODS
  We studied 4 groups of 3 men and 3 women [N = 24, mean age (+/- SD) = 32.9 +/- 5.8 yr] for 10 consecutive days: a 7-d confined period (CONF) or a 7-d baseline (BASE) condition preceding one control night of normal sleep, one night of sleep deprivation, and one recovery night in the laboratory. Risk propensity (EVAR scale) and simple reaction time task (SRTT) performances were monitored every 2.25 h (0930-1945) during CONF and every 2.11 h (0930-0745) during the sleep deprivation condition.
  
  
  RESULTS
  Overall risk propensity during extended wakefulness showed a variation in both conditions with two diurnal peaks separated by a nocturnal minima. After the confinement period, no second peak was found. Number of lapses (reaction time > 500 ms) on the SRTT varied daily in both conditions. In the normal sleep schedule, subjects increased their level of impulsiveness between the first day and the end of confinement (P < 0.05).
  
  
  CONCLUSIONS
  During the night of sleep deprivation, risk-taking propensity decreases and remains stable the following day in the confinement condition while it increases after the baseline period. In a confined environment under a normal sleep-wake schedule, impulsiveness increases in men and women.
authors.affiliation: Department of Psychology, University of Bordeaux, Bordeaux, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Chaumet
authors.forename: Jacques
authors.initials: J
authors.lastname: Taillard
authors.forename: Patricia
authors.initials: P
authors.lastname: Sagaspe
authors.forename: Massimo
authors.initials: M
authors.lastname: Pagani
authors.forename: David F
authors.initials: DF
authors.lastname: Dinges
authors.forename: Anne
authors.initials: A
authors.lastname: Pavy-Le-Traon
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Bareille
authors.forename: Olivier
authors.initials: O
authors.lastname: Rascol
authors.forename: Pierre
authors.initials: P
authors.lastname: Philip
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D020378:Confined Spaces; D018592:Cross-Over Studies; D003657:Decision Making; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011930:Reaction Time; D012309:Risk-Taking; D012892:Sleep Deprivation / Q000453:epidemiology / Q000523:psychology*; D013997:Time Factors