Moderate hypoxia decreases selective attention performance as assessed via a domain‐specific gamified assessment
Authors: Hite M. J. , Keeler Jason M. , Tourula Erica , Kerr Payton M. , Baker Tyler B. , Port Nicholas L. , Schlader Zachary J. 
Published: May 2022

INTRODUCTION

The effect of acute hypoxia on cognition is a function of the magnitude and duration of hypoxia and the assessed cognitive domain. For example, there is little effect of acute exposure to a fraction of inspired oxygen (FiO2) of 11‐14% on simple cognitive tasks. However, performance on more complex tasks, such as those involving aspects of executive function, can be hindered under the same conditions. These possible cognitive changes underlie the use of supplemental oxygen when flying in unpressurized aircraft for >1 h at altitudes >3048 m. People often cannot recognize their own symptoms of hypoxia. Thus, there is a need for tools that can identify detrimental cognitive effects of hypoxia. One potential solution is gamified cognitive assessments, where electronic games can provide targeted metrics of cognitive function, such as working memory and selective attention. However, whether gamified assessments of executive function are sensitive to moderate hypoxia is unknown.

PURPOSE

Test the hypothesis that moderate normobaric hypoxia decreases gamified working memory and selective attention performance.

METHODS

Following three consecutive days of practice, twenty‐one healthy adults (27 ± 5 y, 9 females) completed five 1 min rounds of the tablet‐based games Capacity and Multitracker (Statespace Labs, Inc.) at Baseline and 60 and 90 min after exposure to a chamber with an FiO2 = 14.0 ± 0.2% (hypoxia) and FiO2 = 20.6 ± 0.3% (normoxia). Both conditions were completed on the same day and were administered in a single‐blind, block randomized manner. Capacity (a visuospatial working memory game) and Multitracker (a multiple object tracking and selective attention game) in which participant performance is measured as median time to hit (s), correct trials (#), incorrect trials (#), proportion of correct trials (%), and mean difficulty (#). Arterial oxyhemoglobin saturation was estimated via forehead pulse oximetry (SpO2). Data were analyzed using ANCOVA with a covariate of Baseline and are presented as adjusted means (95% confidence intervals).

RESULTS

Compared to normoxia (98 ± 1%), SpO2was lower (p < 0.001) at 60 (91 ± 3%) and 90 (90 ± 3%) min of hypoxia. For Capacity, there were no condition, time, or interaction effects for the median time to hit (p ≥ 0.268), correct trials (p ≥ 0.310), incorrect trials (p ≥ 0.258), proportion of correction trials (p ≥ 0.272), and mean difficulty (p ≥ 0.761). For Multitracker, a main effect of condition was identified for mean difficulty (p = 0.008), such that, independent of time, the mean difficulty achieved was higher in normoxia [249 (235, 264) vs. 244 (233, 254)]. A main effect of time was identified for correct trials, such that, independent of condition, the number of correct trials increased from 60 [28.5 (27.6, 29.3)] to 90 [28.7 (28.0, 29.4)] min. There were no condition, time, or interaction effects for the median time to hit (p ≥ 0.584), incorrect trials (p ≥ 0.248), and proportion of correction trials (p ≥ 0.162).

CONCLUSION

These preliminary findings indicate that, compared to normoxia, acute moderate hypoxia reduces selective attention, but not working memory, performance determined via domain‐specific cognitive games.