OBJECTIVETo explore the effects of high altitude on cognitive flexibility.

METHODSSimulated hypoxia at an altitude of 3 600 m was performed in a hypobaric chamber. Twenty-three volunteers without hypoxic experience were selected and the mean age was about 25.1 years. The physiological parameters (heart rate, blood pressure and oxygen saturation) were measured. Task switch paradigm was used to explore the cognitive flexibility in each phase, and the changing anxiety state was evaluated simultaneously.

RESULTSReaction time (RT) switch cost in hypoxia phase showed a significant increase compared with the baseline; anxiety level in hypoxia phase was higher than the adaptation phase; a remarkable negative correlation between anxiety level and RT switch cost was found in adaptation phase, whereas a positive correlation was found in landing phase.

CONCLUSIONHigh altitude (3 600 m) affects cognitive flexibility and anxiety state. Anxiety before the hypoxia exposure improves the cognitive flexibility performance, while anxiety after the hypoxia exposure hampers the performance because of the post-hypoxia effect.