Habituation to Complex Vestibular Stimulation in Man: Transfer and Retention of Effects from Twelve Days of Rotation at 10 Rpm

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.