Central Adaptation to Repeated Galvanic Vestibular Stimulation: Implications for Pre-Flight Astronaut Training
Figure 2
Computerized dynamic posturography data from all 10 subjects (mean and 95%CI) without (blue trace) and with (red trace) 5 mA GVS.
(A) The composite equilibrium score was significantly lower when first exposed to GVS, but recovered to baseline after 7 weeks (70 min total) exposure, and this recovery was retained for up to 6 months post adaptation. (B) The somatosensory index, and (C) the visual index, were unaffected by GVS exposure. (D) In contrast, the vestibular index (SOT5/SOT1 ratio), was significantly affected by GVS exposure, illustrating the almost exclusive impact of GVS on the vestibular component of postural control. The vestibular index recovered to baseline by week 8, following 70 min of cumulative GVS exposure, and this recovery was maintained 6 months post-adaptation.