Fig. 2

a Arterial pressure (AP) and mean AP (MAP) responses to 60º head-up tilt (HUT) with (lower panel) and without (upper panel) galvanic vestibular stimulation (GVS). The magnitude of vestibulo-cardiovascular reflex can be estimated by the AP response difference between that without and that with GVS. b Sum of differences in Δ AP between the initial response (within the first 20 s) to HUT without and with GVS [(without GVS) − (with GVS)], at Pre (2–4 months before launch), Post-1 (1–4 days after return), Post-2 (11–15 days after return), and Post-3 (2 months ± 12 days after return). Data are shown as mean ± standard error of the mean for six participants. *P < 0.05 vs. Pre. Revised Figs. 1 and 3 in reference 23.