A multimodal assessment protocol revealed that Antarctic inland expedition candidates undergoing rapid high-altitude training exhibited altitude-dependent sleep fragmentation, exacerbated anxiety under acute hypoxia, and preserved working memory at 3,700 m mediated by compensatory prefrontal activation.
Key Findings
Results
Antarctic expedition candidates showed significantly elevated agreeableness and conscientiousness compared to Chinese normative data, alongside reduced neuroticism.
Sample consisted of 30 preliminary and backup members of the Antarctic inland expedition team
Agreeableness was significantly elevated compared to normative data (t=3.940, P<0.001)
Conscientiousness was significantly elevated compared to normative data (t=9.736, P<0.001)
Neuroticism was significantly reduced compared to normative data (t=-14.087, P<0.001)
Personality was assessed using the BFI-44 psychometric scale
Results
Acute hypoxia significantly exacerbated anxiety in expedition team members, with greater severity observed in ethnic minority members.
Anxiety increased significantly under acute hypoxia conditions (Z=-4.098, P<0.001)
Anxiety was assessed using the DASS-21 psychometric scale
Ethnic minority members showed greater anxiety severity compared to other participants (H=6.405, P=0.011)
Testing was conducted at altitudes of 0 m, 3,700 m, and 4,300 m a.s.l. over an 8-day cycle
Results
Actigraphy demonstrated altitude-dependent sleep fragmentation, with wake after sleep onset (WASO) significantly increased at 4,300 m compared to baseline.
Sleep fragmentation was measured using wrist actigraphy with 24/8 monitoring including 8-hour nocturnal recordings
WASO at 4,300 m a.s.l. was significantly greater than baseline (P=0.028)
Sleep was also assessed using the PSQI psychometric scale
The finding indicates altitude-dependent worsening of sleep continuity
Results
Working memory accuracy was preserved at 3,700 m a.s.l. and was mediated by compensatory prefrontal cortical activation.
N-back task accuracy at 3,700 m a.s.l. was significantly different from another condition (P=0.027), indicating preserved working memory performance
Compensatory activation was observed in the left anterior prefrontal cortex (L-aPFC) (P=0.043)
Prefrontal activation was measured using functional near-infrared spectroscopy (fNIRS)
The compensatory prefrontal activation mediated the preservation of working memory accuracy under hypoxic conditions
Methods
The study established a multidimensional assessment protocol integrating psychometric, behavioral, neuroimaging, and actigraphy measures across varying altitudes.
Protocol integrated BFI-44, DASS-21, and PSQI psychometric scales; N-back behavioral paradigm; fNIRS; and wrist actigraphy
Assessments were conducted at three altitude conditions: 0 m, 3,700 m, and 4,300 m a.s.l.
The protocol was implemented over an 8-day rapid ascent training cycle
The framework was designed to quantify prefrontal compensatory activation, sleep fragmentation dynamics, and altitude-induced anxiety fluctuations
The authors state the data establish 'evidence-based selection criteria for polar science expeditions in high-altitude settings'
What This Means
This research suggests that people selected for Antarctic inland expeditions already have distinct psychological profiles compared to the general population — specifically, they tend to be more agreeable and conscientious, and less emotionally unstable (neurotic), than average. When these same individuals underwent rapid altitude training (ascending to elevations up to 4,300 meters above sea level over 8 days), they experienced measurable changes in anxiety, sleep quality, and brain function. Anxiety worsened significantly at high altitude, and this effect was more pronounced among participants from ethnic minority groups. Sleep quality also deteriorated with increasing altitude, with participants waking more frequently during the night at the highest elevation tested.
Despite these stressors, the expedition candidates largely maintained their working memory performance at moderate altitude (3,700 m). Brain imaging using near-infrared spectroscopy revealed that the brain compensated for the oxygen-reduced environment by increasing activity in the prefrontal cortex — a region critical for complex thinking and decision-making. This suggests the brain can adapt to mild hypoxia by recruiting additional neural resources to maintain cognitive function.
This research matters because Antarctic inland expeditions involve extreme and prolonged environmental stress, and selecting the right team members is critical for mission success and safety. By identifying how psychological traits, sleep, and cognition change during high-altitude training — a proxy for polar stress — this protocol could help establish science-based criteria for screening and preparing future expedition members. The finding that ethnic minority participants experienced greater anxiety at altitude also highlights the importance of considering individual differences in expedition preparation and support.
Xie J, Jin X, Lian H, Ma Q, Wang Y, Tang Y, et al.. (2026). Psychological and Sleep Changes in Pre-Selected Members of the Polar Inland Expedition Team During Rapid Ascent High-Altitude Training.. Journal of visualized experiments : JoVE. https://doi.org/10.3791/68599