Abstract
Nine men rotated at 10 rpm for 12 days. Control Ss were tested at comparable intervals. Tests conducted before and after the 12-day run demonstrated that nystagmus and subjective effects produced by head movements during the accustomed direction of rotation (CCW) had diminished markedly, whereas during CW rotation, 1 hr. after the 12-day run, nystagmus and subjective reactions approximately equaled reactions prior to the 12-day run. The unequal reduction was attributed to conditioned compensatory reactions. Two days later, responses to both rotation directions were suppressed as compared with initial levels of response; compensatory reactions had apparently dissipated. Some response decline was still present after 3 wk. rest, but tests after 3 mo. revealed considerable recovery toward initial response levels. Reactions to passive whole-body angular acceleration were not greatly altered by the 12-day run.