Fig. 2: Experimental design and results for the space experiment and the ground-based control experiments.

a Participants judged the walking direction of an upright or inverted point-light walker (rendered in blue for illustration only) embedded in a dynamic mask. The mask consisted of scrambled walkers with balanced left and right walking direction cues. Blue and white arrows represent the walking directions indicated by the target walker and the noise mask, respectively. Demos of sample BM stimuli are provided as supplementary information. b The normalized BM inversion effect (BMIE) and the task performance for the upright (BMUpr) and inverted (BMInv) conditions obtained before (PreFL), during (InFL), and following (PostFL) the spaceflight. Diamonds show individual data (n = 5). *p = 0.048 (two-tailed paired t-test, Bonferroni corrected). c Results obtained from the isolation control experiment where participants performed the BM perception task before (the first session), during (the second to the fourth session), and after (the fifth session) 30-day isolation. Blue dots represent individual data (n = 2). Error bars indicate ±1 SEM. d Results obtained from the regular control experiment where participants performed the BM perception task repeatedly in five test sessions over more than one month (35 days on average). Blue dots represent individual data (n = 22). Error bars indicate ±1 SEM. Source data are provided as a Source Data file.