Cognitive Effects of Repeated Acute Exposure to Very High Altitude Among Altitude-Experienced Workers at 5050 m


Background: We investigated altitude effects on different cognitive domains among perennial shift-workers at the Atacama Large Millimeter/submillimeter Array Observatory (5050 m), Chile.

Materials and Methods: Twenty healthy male workers were recruited and assigned to either a moderate-altitude first (MAF group, Test 1: 2900 m and Test 2: 5050 m) or to a high-altitude first (HAF group, Test 1: 5050 m and Test 2: 2900 m). Test 1 was conducted at the beginning and Test 2 at the end of the shift-work week. Processing speed (RTI, reaction time), attention (AST, attention-switching task, and RVP, rapid visual processing), and executive function (OTS, One Touch Stockings of Cambridge) were assessed.

Results: Of the three cognitive domains assessed, only processing speed showed altitude-at-test group interaction (RTI median five choice reaction time: F1, 17 = 6.980,  = 0.291, p = 0.017). With acclimatization, there was a decrease in AST reaction latency mean (t17 = −2.155, dz = 1.086, p = 0.046), an increase in RVP accuracy (t17 = 2.733, dz = 1.398, p = 0.014), and a decrease in OTS mean latency first choice (t17 = −2.375, dz = 1.211, p = 0.03). Decreased variability in cognitive function was observed in AST reaction latency standard deviation (t17 = −2.524, dz = 1.282, p = 0.022) and in RVP response latency standard deviation (t17 = −2.35, dz = 1.177, p = 0.03) with acclimatization. At 5050 m of elevation, SpO2 was positively correlated with executive function in the MAF group (OTS problems solved on first choice: r(5) = 0.839, p = 0.018) and negatively correlated with executive function latency standard deviations in the HAF group (OTS latency to first choice standard deviation: r(10) = −0.618, p = 0.032).

Conclusions: Our findings highlight the importance of acclimatization and improvement of blood oxygen level, even among high altitude-experienced workers, to optimize performance of cognitively demanding work and reduce high altitude-associated health risks.


ICB Affiliated Authors

Pun, M, Guadagni, V., Drogos, L. L., Pon, C., Hartmann, S. E., Furian, M., Lichtblau, M., Muralt, L., Bader, P. R., Moraga, F. A., Soza, D., Lopez, I., Rawling, J. W., Ulrich, S., Bloch, K.E., Giesbrecht, B., Poulin, M. J.
Peer-Reviewed Article
High Altitude Medicine & Biology