Prolonged high-altitude residence impacts verbal working memory: an fMRI study

Area of Science:

• Neuroscience
• Cognitive Science
• Altitude Physiology

Background:

• Oxygen is vital for brain function and development.
• High altitude environments with low oxygen pressure can impair cognitive abilities, including working memory.
• These cognitive effects may persist with prolonged high-altitude residence.

Purpose of the Study:

• To investigate the impact of high-altitude living on verbal working memory.
• To compare the brain activity and behavioral performance of high-altitude residents with sea-level residents using functional magnetic resonance imaging (fMRI).

Main Methods:

• The study involved 28 healthy college students residing at high altitude and 30 at sea level, matched for age, gender, and socioeconomic status.
• Participants underwent a 2-back verbal working memory task while undergoing blood oxygen level dependent (BOLD) fMRI.
• Behavioral data (reaction time, accuracy) and fMRI data (BOLD signal, Granger causality) were analyzed and compared between groups.

Main Results:

• High-altitude residents exhibited slower reaction times and lower response accuracy on the verbal working memory task.
• Both groups showed typical brain activation patterns, but high-altitude residents displayed decreased activation in key brain regions, including the frontal gyrus, occipital gyrus, lingual gyrus, cerebellar vermis, and thalamus.
• Behavioral performance correlated significantly with BOLD signal changes and interregional connectivity in both groups.

Conclusions:

• Prolonged exposure to high-altitude hypoxia is associated with impaired verbal working memory in residents.
• Reduced brain activation in specific cortical and subcortical regions may underlie these cognitive deficits.
• The findings highlight the neurobiological impact of chronic hypoxia on cognitive functions.