Cognitive and emotional processing at high altitude

Exposure to altitude reduces oxygen supply to the central nervous system and may cause a variety of neuropsychological impairments. We investigated the relationship between certain cognitive functions and cardiovascular and respiratory variables during acute hypobaric hypoxia.

There were three groups of seven men who were each exposed to a 2-h altitude profile (AP) involving 30 min at each of the following simulated altitudes (m): AP1, 450-1500-3000; AP2, 450-1500-4500; Control 450-650-650. The neuropsychological tests included word fluency and three word-association tasks tapping processes of cognitive flexibility and emotion regulation. A lateralized tachistoscopic lexical decision task with high and low emotional target words was also administered to assess possible shifts in hemispheric superiorities for positive and negative affect.

No significant differences in word fluency, word association, or lateralized lexical decision performances were found, despite a significant oxygen desaturation and a drop in diastolic BP at 4500 m, indicating the beginning of central hypoxia in terms of a functional impairment of the vasomotor center.

During acute exposure to hypobaric hypoxia, selected cognitive and affective functions mediated by the frontal lobe were preserved. Functional hemispheric asymmetries for emotional processes remained unchanged.