Isolating the effects of vection and optokinetic nystagmus on optokinetic rotation-induced motion sickness.

Objective: This study investigates isolated effects of vection and optokinetic nystagmus (OKN) on visually induced motion sickness (VIMS) provoked by rotating optokinetic drum patterns.

Background: VIMS was the subject of recent standardization activities, but the effects of OKN have not been studied in the absence ofvection.

Method: Experiment 1 suppressed OKN by eye fixation and examined VIMS severity (both ordinal and ratio scale) and time spent in saturated vection at four pattern rotating velocities of 0, 2, 14, and 34 degrees per second (dps).