The use of transdermal scopolamine to solve methodological issues raised by gender differences in susceptibility to simulator sickness

- Motion-based simulator fails to reduce gender difference to simulator sickness.
- The higher the exposure to the simulator, the greater the gender difference widens.
- Scopolamine cancels gender differences in susceptibility to simulator sickness.
- The use of scopolamine paves the way toward better-controlled driving studies.
- The origins of gender differences are more likely physiological than sociological.

While car driving simulators are an essential research tool for assessing drivers' behavior under safe and controlled conditions, gender differences in susceptibility to simulator sickness is a major drawback for the interpretation of the outcomes. The present study assessed the efficacy of a technological (Experiment 1; the use of motion-based driving simulator) and a pharmacological (Experiment 2; the use of transdermal scopolamine) solution to solve the methodological issues raised by gender differences in susceptibility to simulator sickness. In experiment 1, twenty-four women and twenty-four men performed two driving sessions lasting 16 min within a high-fidelity motion-based driving simulator. In experiment 2, eight women and eight men were tested in the same simulator but received, in a counterbalanced between subjects design, either a placebo or a scopolamine patch 12 h before the experimentation. In both experiments, simulator sickness questionnaire scores were computed before the first driving session and after the first and the second driving sessions. The results showed that only the pharmacological solution was efficient for solving these methodological issues. Indeed, whereas women experienced greater simulator sickness than men under placebo influence (p < 0.01) there was no gender difference in susceptibility to simulator sickness following the transdermal scopolamine administration (p > 0.05). As a whole, this demonstration paves the way toward better-controlled experiments. Moreover, beyond their implications in many research fields, the results from car driving simulator studies are of use to road safety policy makers. Thus, this approach allowing cancellation of gender differences in susceptibility to simulator sickness is of critical importance at a society level.