Correlations between the Effectiveness of Performance of Cognitive Tests and Blood Flow Reactions in Humans in Normoxia and Hypoxia

Changes in pulse rate and the dynamics of cerebral blood flow were studied on exposure to moderate and severe normobaric hypoxia and during performance of cognitive loading in conditions of normoxia and hypoxia. Changes in values from baseline on performance of cognitive tests in normoxia (CTN) and hypoxia (CTH) and in hypoxia without cognitive loading (H) were compared, as were changes in the rate and accuracy of performance of the cognitive tasks in the CTH situation as compared with the CTN situation. People with high pulse responses in the CTN and H situations were found to show more significant decreases in the rate of cognitive operations in severe hypoxia from 6 to 15 min in the CTH situation with severe hypoxia as compared with the analogous period in the CTN situation than people with relatively low pulse responses. These results are assessed from the point of view of individual stress reactivity, which can be reflected in blood flow reactions to cognitive and hypoxic loads and can affect the effectiveness of cognitive activity. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.