Chronic high-altitude exposure is associated with an internally-directed perceptual shift: differential links with attention networks and autonomic regulation.

BACKGROUND: High-altitude environments impose unique physiological and cognitive demands that may reorganize brain-body communication. Our study investigates whether chronic high-altitude exposure is associated with a shift in perceptual priority toward internally-directed processing, rather than merely modifying external processing speed or accuracy. METHODS: We recruited 112 Han immigrants residing at high altitude to complete assessments of visual imagery vividness under eyes-open (externally-oriented) and eyes-closed (internally-oriented) conditions, along with attention network tests. We also collected a comprehensive panel of multimodal physiological indices, including markers of inflammation, erythrocytic parameters, liver function, cardiovascular metrics, and heart rate variability (as a proxy for autonomic regulation). Analyses employed latent profile analysis and regression mixture modeling. RESULTS: We found that prolonged high-altitude exposure showed a trend toward selectively enhancing internally-oriented imagery vividness under eyes-closed conditions, while externally-oriented processing remained stable. Critically, enhanced internally-oriented imagery was differentially associated with improved orienting attention, whereas externally-oriented imagery was linked to alerting attention, suggesting a functional differentiation in attentional reorganization. Physiologically, interleukin-6 levels were associated with externally-oriented vividness, whereas erythrocytic heterogeneity, liver function, and high-frequency heart rate variability (an index of parasympathetic-associated cardiac regulation) selectively correlated with internally-oriented processing. CONCLUSION: These results suggest that chronic high-altitude exposure may be associated with a reweighting of perceptual resource allocation toward an internally-oriented processing bias, with parasympathetic-associated autonomic regulation as a potential brain-body integrative mechanism. This work extends prior findings by proposing a shift in perceptual priority rather than merely processing efficiency, advancing a multi-system framework for understanding human brain-body adaptation in extreme environments.