Understanding Fear in a Multimodal and Multidimensional Way: Evidence from Driving Simulator Studies

Kurzfassung

Fear is a common emotion that can influence drivers’ risk perception and, in the context of autonomous driving, may decrease occupants’ trust in autonomous cars. Therefore, assessing fear is a relevant capability for future in-vehicle occupant monitoring systems. However, this capability has not been widely employed, possibly because the dynamic change of indicators for fear is not fully understood and theoretically described. The appraisal theory and the appraisal-based Component Process Model (CPM) describes emotions as an appraisal-driven and multi-component process, offering a comprehensive framework for emotion assessment. The dissertation aimed to explore the emotional theory framework and validate the multidimensional as well as multimodal assessment of emotions in vehicles using occupants’ fear as an example. For this, driving simulator studies were conducted, where participants’ fear was elicited by driving-context events in the simulated environment. In Study 1, facial temperature was used to validate that the power appraisal of fear, derived from the appraisal theory, could be used to distinguish fear from other emotions. The study also demonstrated the ability of virtual reality to induce fear. Through facial expressions, Study 2 investigated the power and novelty appraisal in fear. This study validated the temporal differences between novelty and power, which is consistent with the assumption of emotional dynamics in CPM. Study 3 validated the appraisal-driven emotion hypothesis by revealing the association of novelty with facial expressions and physiological responses, which were collected in Study 1. In summary, this dissertation provided empirical support for assumptions of appraisal-driven and multi-component emotion processes and the CPM in assessment of occupants’ fear. A multimodal and multidimensional approach was proposed to cover a wider range of components and appraisals of fear in practical applications.