title: Trait-like vulnerability to total and partial sleep loss.
abstract: OBJECTIVE
  To determine the extent to which individual differences in vulnerability to total sleep deprivation also reflect individual differences in vulnerability to multiple nights of sleep restriction.
  
  
  METHODS
  Two sleep loss conditions (order counterbalanced) separated by 2 to 4 weeks: (a) total sleep deprivation (TSD) of 2 nights (63 h continuous wakefulness); (b) sleep restriction (SR) of 7 nights of 3 h nightly time in bed (TIB). Both conditions were preceded by 7 in-laboratory nights with 10 h nightly TIB; and followed by 3 recovery nights with 8 h nightly TIB. Measures of cognitive performance (psychomotor vigilance, working memory [1-Back], and mathematical processing), objective alertness, subjective sleepiness, and mood were obtained at regular intervals under both conditions. Intra-class correlation coefficients (ICC) were computed using outcome metrics averaged over the last day (08:00-20:00) of TSD and SR.
  
  
  METHODS
  Residential sleep/performance testing facility.
  
  
  METHODS
  Nineteen healthy adults (ages 18-39; 11 males, 8 females).
  
  
  METHODS
  2 nights of TSD and 7 nights SR (3 h nightly TIB).
  
  
  RESULTS
  volunteers who displayed greater vulnerability to TSD displayed greater vulnerability to SR on cognitive performance tasks (ICC: PVT lapses = 0.89; PVT speed = 0.86; 1-Back = 0.88; mathematical processing = 0.68, Ps < 0.05). In addition, trait-like responsivity to TSD/SR was found for mood variables vigor (ICC = 0.91), fatigue (ICC = 0.73), and happiness (ICC = 0.85) (all Ps < 0.05).
  
  
  CONCLUSIONS
  Resilience to sleep loss is a trait-like characteristic that reflects an individual's ability to maintain performance during both types of sleep loss (SR and TSD). Whether the findings extend to sleep schedules other than those investigated here (63 h of TSD and 7 nights of 3 h nightly TIB) will be the focus of future studies.
authors.affiliation: Behavioral Biology Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Rupp
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Wesensten
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Balkin
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect / Q000502:physiology; D001288:Attention / Q000502:physiology*; D005221:Fatigue / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D017286:Polysomnography; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D012892:Sleep Deprivation / Q000503:physiopathology*; D007319:Sleep Initiation and Maintenance Disorders; D012894:Sleep Stages / Q000502:physiology; D013647:Task Performance and Analysis; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult