Cognitive and Perceptual Performance Effects of Controlled Exposure to Acute Hypoxic Stress

摘要

Since FY-2000, DoD has reported four hypoxia-related Class A mishaps costing four pilots' lives and over $300 million in aircraft. In addition, the F/A-18 community has filed 113 hypoxia-related HAZREPS since 2001. A 2010 survey conducted on tactical aviators indicated that 79% of hypoxic episodes go unreported, suggesting that the problem is far more prevalent than official statistics suggest (Deussing et al., 2011). Current emergency procedures for hypoxic events require pilots to self-administer supplemental O2, descend below 10,000 ft, recover, and land as soon as possible. However, the time required for individuals to fully recover cognitive and physiological functions following hypoxic exposure remains undetermined. A recent NAMRU-D experiment provided a more comprehensive understanding of the functional state of pilots and flight crew during and immediately following hypoxia exposure. Hypoxia- associated effects on specific cognitive and perceptual tasks were documented, as well as the time required for full restoration of cognitive and perceptual performance to pre-exposure levels. The results provide a more comprehensive picture of the effects of hypoxia on specific cognitive and perceptual processes, and the duration of hypoxic effects post-exposure. The lingering effects of hypoxia on simple and choice reaction time supports the conclusion by Phillips et al. (2009), that some aspects of performance do not recover immediately after subjects are returned to a sea-level equivalent environment.