Susceptibility to motion sickness induced by optokinetic rotation and self-rotation by walking around a vertical pole

31 subjects viewed an optokinetic rotating drum for 12 min, in one session and self-rotated by walking quickly around a vertical pole with eyes closed while alternately flexing and extending the neck in another session, The s elf-rotation session contained 6 trials (3 clockwise and 3 counterclockwise rotations), Each trial contained 20 cycles of self-rotations, Self-reporte d ratings of nausea and symptoms of motion sickness were obtained for each session. The subjects developed symptoms of nausea, sweating, dizziness, he adache, drowsiness, and changes in salivation in both drum rotation and sel f-rotation sessions. However, the subjects reported higher ratings of nause a in the session of optokinetic rotation than in the session of self-rotati on around a vertical pole. These results indicated that both optokinetic ro tation and self-rotation with eyes closed while alternately flexing and ext ending the neck are effective means of inducing nausea and motion sickness.