FIGURE 8.

SANS vs. No-SANS Group Differences. Left: regions in which HDBR + CO₂ participants who developed signs of Spaceflight-Associated Neuroccular Syndrome (SANS) showed a stronger correlation between pre- to post- change in brain activity during vestibular stimulation and pre- to post- change in balance ratio compared to those who did not develop signs of SANS (no-SANS). Balance ratio was calculated as: (balance—eyes open score/balance—eyes closed score) ^∗ 100. Results overlaid onto MNI standard template; non-parametric p < 0.0005, k = 10. One of the five SANS subjects was excluded from analysis here due to outlier values for their eyes closed balance score; thus n = 4 for the SANS group and n = 6 for the no-SANS group. Right: correlation between brain changes and visual dependence balance ratio change for an example cluster; SANS subjects are shown in pink, no-SANS subjects are shown in purple. Regression lines are shown for each group for reference only and do not represent the results of any statistical tests.