15 | Using anticipatory cues to mitigate motion sickness

Background: Motion sickness primarily affects passengers rather than drivers, we assume, because drivers can better anticipate the vehicle’s accelerations. Does helping passengers to anticipate accelerations then help to mitigate motion sickness? We investigated this question in three studies using auditory and vibrotactile cues that announced the onset and direction of upcoming displacements. Materials and Methods: We performed the first and second study using a linear sled in the laboratory and the third study using a vehicle on a test track. In the laboratory, the displacements were limited to one-dimensional motion while we used lane changes, accelerations, and decelerations in the test track study. To evaluate the effectiveness of the cues, we compared self-reported motion sickness symptoms rated during a session with anticipatory cues to a session without predictive information on upcoming displacements. Results: In our two laboratory studies, we observed that the anticipatory cues mitigated motion sickness to a small extent, irrespective of their time interval. However, large variability between participants resulted in a lack of statistical power. The effect of anticipatory cues was larger in our test track study, especially for the vibrotactile cue. The auditory cue was less effective and less preferred. The mitigating effect of the vibrotactile cue was substantial: a 40% reduction in motion sickness symptoms. We conclude that anticipatory vibrotactile cues could offer a solution to mitigate motion sickness in automated driving. Our findings demonstrate there is added value of experimentation outside the laboratory.