ADAPTATION TO OPTOKINETIC ROTATION-INDUCED MOTION SICKNESS WITHOUT EXPERIENCING NAUSEA

17 subjects highly susceptible to motion sickness were divided into Na usea and No-nausea groups depending upon whether the subjects experien ced nausea during adaptation to nauseagenic rotation. Eight subjects i n the Nausea group viewed an optokinetic rotation drum for repeated se ssions of 16 min., with an interval of two days between every two sess ions. During each session the subjects continuously viewed the rotatin g drum 16 min. even if they experienced nausea. Nine subjects in the N o-nausea group likewise viewed an optokinetic rotation drum for at mos t 16 min. but immediately stopped viewing the rotating drum whenever t hey experienced nausea during the session. The criteria for full adapt ation were that the subject reported no feelings of stomach discomfort and nausea during a 16-min. session. The mean number of sessions to r each full adaptation was 3.9 (SD=0.6) with a range 3 to 5 sessions for the subjects in the Nausea group and 3.2 (SD=0.8) with a range 2 to 4 for the subjects in the No-nausea group. It was concluded that subjec ts can adapt to a nauseagenic optokinetic rotation by repeated exposur e without experiencing nausea and vomiting during adaptation.