Sex differences in the incidence of motion sickness induced by linear visual oscillation

BACKGROUND: In field studies, motion sickness is more common among women than among men. In laboratory research sex differences have been smaller, or absent. However, laboratory research on sex differences in motion sickness has employed exclusively rotational motion stimuli. We evaluated sex differences when motion sickness was induced using linear visual oscillation. METHOD: Standing subjects were exposed to linear visual oscillation along the line of sight. We separately assessed the incidence of motion sickness and the severity of symptoms that are associated with motion sickness. RESULTS: The incidence of motion sickness was 38% among women, but only 9% among men. Among subjects who stated that they were motion sick, the severity of symptoms did not differ between women and men. CONCLUSIONS: Motion sickness induced using linear visual oscillatory stimuli exhibited sex differences greater than those that have been reported in field studies. Sex differences in motion sickness may vary as a function of the type of motion stimulation (linear versus angular).