Cognitive performance during respirator wear in the absence of other stressors.

Reaction time, decision-making speed, and response accuracy were measured in 12 male and 5 female subjects performing computer-controlled tasks under nonexercise conditions during two 3.5-hour days, one with and one without (control) wearing a respirator, to assess the effects of respirator wear alone on cognitive performance. Tasks included measures of simple and choice reaction time (CRT), serial pattern matching, lexical discrimination (LD), visual selective attention, rapid visual scanning, and form discrimination (FD). Anxiety levels were assessed along with reaction time measures obtained at the start of each test day and after 1, 2, and 3 hours of testing. Reaction time and response accuracy did not differ significantly between respirator and control trials and were not changed over time. However, mean decision-making times were significantly faster during respirator wear compared to control for the LD (0.17 +/- 0.04 versus 0.19 +/- 0.05 sec) and FD (0.32 +/- 0.10 versus 0.36 +/- 0.12 sec) CRT tasks. Females exhibited significantly faster reaction times than males, but no differences within sex groups were observed between control and respirator trials. Response accuracy and decision-making speed did not differ within and between male and female groups for any reaction time tasks during respirator wear. The improvements in decision-making time observed during respirator wear probably reflect the effect of the respirator to increase arousal and improve focusing of attention by excluding peripheral visual stimuli. Furthermore, the results suggest that respirator wear over a relatively short period in the absence of other stressors should not inhibit cognitive function.