Evaluation of physiological responses due to car sickness with a zero-inflated regression approach

Motion sickness as a reaction to passive movement is a serious issue in various forms of transportation like cars. The goal of the study is to identify physiological changes that can be measured as a response to motion sickness in a real driving environment. The observed features were heart rate, pulse, respiration, skin temperature and electrodermal activity. Forty volunteers were passengers in a car while watching a movie. Meanwhile the car moved in a half-automated stop-&go-scenario, which represented the motion sickness stimulus. A remarkable part of the recorded data had to be neglected due to a high level of signal noise caused by the car environment. The minutely recorded subjective sickness feedback had a zero-inflated poisson distribution. Therefore a zero-inflated regression model was used to identify the relevance of each of the aforementioned features. The model shows that electrodermal activity and pulse were the most relevant features indicating an increase in motion sickness. The observation of physiological parameters in the car environment is a promising method to objectively determine motion sickness.