Visuospatial attention at high altitude in two ethnically distinct groups of soldiers

Objectives: For strategic purposes, soldiers of different ethnicities are deployed in high-altitude (HA) areas from time to time. During their operations, hypoxia may influence visuospatial attention. Therefore, assessment of visuospatial attention is of paramount importance during HA tenure. Materials and Methods: Two distinct ethnic groups, composed of Indian and Kyrgyz lowland soldiers, were ascended to 3,200 m to assess visuospatial attention. Visual search experiments were conducted for a target in the presence of distractors while simultaneously recording the eye movements. The target present correct reaction time (RTP), target absent correct reaction time (RTA), slopes and intercept of reaction time X set size, fixation duration and saccade latency were measured at baseline, as well as on days 3, 7, 14 and 21 of the HA stay and day 3 of the return from HA. Results: At HA, most of the parameters were significantly changed. Kyrgyz soldiers had higher RTP (e.g. 2179.99 ± 992.21ms for Indian, and 2641.78 ± 142.28 ms for Kyrgyz, with 12 set size, on day 3 at HA) and RTA values, as well as a higher intercept of the visual search than Indian soldiers. Kyrgyz soldiers had higher fixation duration (e.g. 291.75 ± 7.40 ms for Indians, and 303.78 ± 18.93 ms for Kyrgyz, with 16 set size, on Day 3 at HA) and saccade latency (e.g. 326.21 ± 34.88 ms for Indian, and 356.67 ± 67.48 ms for Kyrgyz, with 12 set size, on day 3 at HA) values than Indian soldiers from day 3 onward. Conclusion: The task performance of Indian soldiers improved after day 3 at HA, whereas Kyrgyz soldiers struggled to adapt throughout their stay. The ethnogenetic diversity, life experience variables and demographic characteristics of Indian and Kyrgyz soldiers could all be contributing causes to differences in their visuospatial attention. The hypobaric and hypoxic environment further interacted with all these variations.