title: Sleep patterns during an antarctic field expedition.
abstract: Extreme conditions in Antarctica pose a significant challenge to members of field parties, stationed military personnel, and civilian support personnel. One of the key issues noted in anecdotal evidence during expeditions is the presence of sleep disturbances, that can lead to a marked loss in the ability to cognitively respond to unusual or dangerous situations.
  
  
  METHODS
  A study was conducted using 14 volunteers who traveled to Antarctica and spent several days in a field camp in Windless Bight (Ross Sea Region). Each participant recorded subjective sleep measures daily and wore an accelerometer on their dominant wrist while in bed for the night before, and while on deployment. Stroop and digit recall tests were given four times, at approximately 3-day intervals.
  
  
  RESULTS
  Overall subjective sleep quality was fair to good in both environments, and neither sleep disturbance nor total hours of sleep showed reliable differences. There were no reliable associations between 3-day sleep disturbance and test performance for either cognitive measure.
  
  
  CONCLUSIONS
  The results show no sign of effects of 24-hour daylight on sleep and cognitive performance. The impact of these findings on the theoretical connection of light to sleep and performance are discussed, as well as the practical implications for management of sleep while in the field.
authors.affiliation: Uniformed Services University of Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
authors.forename: Wells
authors.initials: W
authors.lastname: Weymouth
authors.forename: Gary Daniel
authors.initials: GD
authors.lastname: Steel
mesh_terms: D000293:Adolescent; D000328:Adult; D000864:Antarctic Regions; D003071:Cognition / Q000502:physiology; D020920:Dyssomnias / Q000453:epidemiology* / Q000503:physiopathology; D005101:Expeditions; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012890:Sleep / Q000502:physiology*; D014481:United States / Q000453:epidemiology; D055815:Young Adult