Psychological and Sleep Changes in Pre-Selected Members of the Polar Inland Expedition Team During Rapid Ascent High-Altitude Training.

This study established and implemented a multidimensional assessment protocol to systematically investigate neurobehavioral changes among 30 preliminary and backup members of the Antarctic inland expedition team undergoing rapid altitude training. The protocol integrates psychometric scales (BFI-44, DASS-21, PSQI), behavioral paradigms (N-back task), functional near-infrared spectroscopy (fNIRS), and wrist actigraphy to assess neurobehavioral adaptations across varying altitudes (0 m above sea level (a.s.l) / 3,700 m a.s.l / 4,300 m a.s.l) over an 8-day cycle. The core design comprises pre-ascent baseline testing; synchronized cognitive-fNIRS measurements at target altitudes; 24/8 sleep monitoring (including 8 h nocturnal actigraphy). This multimodal framework enables quantitative characterization of prefrontal compensatory activation, sleep fragmentation dynamics, and altitude-induced anxiety fluctuations. Findings reveal that, compared to Chinese normative data, participants exhibited significantly elevated agreeableness (t=3.940, P<0.001) and conscientiousness (t=9.736, P<0.001), alongside reduced neuroticism (t=-14.087, P<0.001). Acute hypoxia exacerbated anxiety (Z=-4.098, P<0.001), with greater severity in ethnic minority members (H=6.405, P=0.011). Actigraphy demonstrated altitude-dependent sleep fragmentation (WASO: 4,300 m a.s.l versus baseline, P=0.028). N-back tasks confirmed preserved working memory at 3,700 m a.s.l. (accuracy P=0.027) mediated by compensatory prefrontal activation (L-aPFC activation P=0.043). These data establish evidence-based selection criteria for polar science expeditions in high-altitude settings and delineate neuroplastic resilience thresholds under hypoxic stress.