Mckeown, D. J.; Angus, D. J.; Moustafa, A. A.; Schinazi, V. R.

This systematic and meta-analytical review examined how a reduction in oxygen availability to tissue (hypoxia) affects cognitive function. Hypoxia had a moderate-to-large detrimental effect on general cognitive ability and across domains, including memory, attention, executive function, processing speed, and psychomotor speed. Increased hypoxic severity was associated with greater declines in general cognitive ability and executive function, while longer duration of exposure was associated with greater declines in executive function and psychomotor speed. Participant age was a moderator for executive function and psychomotor speed, with older adults experiencing greater impairments. For executive function and psychomotor speed, the magnitude of these effects was less pronounced during intermittent and hypobaric exposures, potentially due to adaptive physiological mechanisms. While our models accounted for exposure characteristics and age of participants, substantial unexplained variance remained. These findings highlight hypoxias impact on cognition and emphasize the need to investigate underlying neurophysiological mechanisms that may influence individual vulnerability.