Successful transfer of adaptation acquired in a slow rotation room to motion environments in Navy flight training

Two flight students, grounded for the reason they were highly susceptible to motion sickness, completed their training after gradually adapting to 10 rpm, achieved by executing head movements during small stepwise increases in angular velocity. Subject 1 executed a total of about 77 000 head movements with a period of 5 months and Subject 2 executed about 108 000 head movements within a period of 42 days. The transfer of adaptation acquired in the laboratory to most motion environments aloft was good; the notable exception involved weightless maneuvers in the case of Subject 1. Both were on flight status when contacted recently. The opportunity was taken to assess the current motion sickness susceptibility in Subject 1 in the fall of 1975. He reached our (mild) motion sickness endpoint, in the rotating room, at 17 rpm: the average endpoint is 7--8 rpm. Some practical and theoretical implications are discussed.