title: Anxiety and psychomotor performance in divers on the surface and underwater at 40 m.
abstract: BACKGROUND
  Performance impairments attributed to the effects of nitrogen narcosis have been reported to be significantly larger in studies conducted underwater compared to in hyperbaric chambers. One suggestion is that the larger impairment results from higher levels of anxiety in the underwater environment. The current study aimed to investigate the impact of anxiety and narcosis, in isolation and in combination, on a measure of psychomotor performance.
  
  
  METHODS
  The effects of self-reported anxiety (anxious vs. not anxious) and depth (surface vs. underwater) on performance on the digit letter substitution test (DLST) were measured in 125 divers.
  
  
  RESULTS
  Change from baseline scores indicated that divers performed significantly worse on the DLST underwater (mean = 3.35; SD = 4.2) compared to the surface (mean = 0.45-0.73; SD = 4.0-4.2). This decrement was increased when divers reported they were also anxious (mean = 7.11; SD = 6.1). There was no difference on DLST performance at the surface between divers reporting they were anxious and those reporting they were not anxious.
  
  
  CONCLUSIONS
  The greater decrement in performance at depth in divers reporting anxiety compared to those not reporting anxiety and the lack of this effect on the surface suggested that anxiety may magnify performance deficits presumed to be caused by narcosis.
authors.affiliation: University of Winchester, Winchester, Hampshire, UK.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Hobbs
authors.forename: Wendy
authors.initials: W
authors.lastname: Kneller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000523:psychology*; D004242:Diving / Q000502:physiology* / Q000523:psychology*; D005260:Female; D006801:Humans; D007222:Inert Gas Narcosis / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology*; D055815:Young Adult