Abstract
It is well established that hypoxia impairs cognitive function (1). Hypoxia has been recognized as one of the most serious single hazards during flight at altitude. Performance of central executive function as assessed by n-back task is known to be reduced with hypoxia and there is a strong correlation between n-back task performance (i.e. working memory capacity) and reductions in cerebral oxygenation (2). But none of these studies has investigated the physiological variables such as cerebral oxygenation and heart rate (HR) as predictors of altitude-induced decrease cognitive performance.Controlled protocols in a laboratory setting need to be performed first with the concomitant measures of cerebral oxygenation state and HR during standard cognitive tasks before the implementation of a protocol in an ecological situation. The present study aimed to test the association between changes in cerebral oxygenation, HR and cognitive performance during acute normobaric hypoxia exposure at an inspired oxygen fraction (FiO2) of 11.3% (5000m). Additionally, we sought to identify cerebral oxygenation and HR threshold values that are predictive of decreased cognitive performance.