Long-term exposure to high altitude attenuates verbal and spatial working memory: Evidence from an event-related potential study

Introduction: This study aimed to determine the neurocognitive basis underlying the effects of long-term high-altitude (HA) exposure on working memory (WM).

Methods: Using event-related potentials (ERPs), we compared the performance of an HA group (individuals who had lived at HA for 3 years but were born and raised at low altitude [LA]) to that of an LA group (individuals who had only lived at LA) on verbal and spatial n-back tasks (i.e., 1- and 2-back memory load).

Results: Response accuracy of the HA group was significantly decreased in comparison to the LA group in both the verbal and spatial 2-back tasks. The P2 amplitude was larger in the HA than in the LA group in the spatial, but not the verbal 2-back task. A smaller late-positive potential (LPP) amplitude was found in the HA group in both the verbal and spatial 2-back tasks.

Conclusions: These results suggest that HA impairs the matching (P2) process in spatial WM tasks and the maintenance (LPP) process in both verbal and spatial WM tasks, indicating that HA had a different effect on verbal and spatial 2-back task performance.