Effects of normobaric hypoxic confinement on visual and motor performance.
BACKGROUND
The use of reduced oxygen levels has been suggested for fire prevention in closed spaces, such as submarines. However, if humans are to work and live in environments with reduced oxygen levels, the effect of hypoxia on human performance must be further assessed.


METHODS
In 3, 11- to 14-d confinements a total of 22 subjects were exposed to different levels of normobaric hypoxia (13, 14, and 15 kPa O2), for up to 10 d, with intervening periods of normoxia. In each experiment eight subjects were divided into two teams, working in 6-h shifts around the clock. Subjects performed tests of spatial orientation, visual reaction time, parallel processing and motor skills. Performance tests and questionnaires were administered once or twice in every 24-h period.


RESULTS
All of the subjects appeared to tolerate the acute reduction in oxygen partial pressure well. In many of the tests performance improved with time as a result of learning, despite reductions in the oxygen level. No reduction in performance or decrease in rate of learning was observed at any of the oxygen levels tested.


CONCLUSIONS
Oxygen levels down to 14 kPa appear not to impair visual and motor performance during rest.
Gustafsson
C
C
Department of Naval Medicine, National Defence Research Establishment, Harsfjärden, Sweden.
Gennser
M
M
Ornhagen
H
H
Derefeldt
G
G
D000328:Adult; D018504:Ecological Systems, Closed; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008606:Mental Processes; D009483:Neuropsychological Tests; D009949:Orientation; D011597:Psychomotor Performance; D013037:Spatial Behavior; D011795:Surveys and Questionnaires; D014940:Work Schedule Tolerance