Emotion detection using wearable physiological sensors in traffic safety research
Dejan Žagar, Franc Dimc, Marko Golnar, University of Ljubljana, Faculty of Maritime Studies and Transport, Portorož, Slovenia
Matija Svetina, University of Ljubljana, Faculty of Arts, Ljubljana, Slovenia

The study examines whether non-invasive psychophysiological sensors are sensitive enough to detect emotional responses to standardized visual stimuli relevant to road safety. Instead of using a driving simulator, participants viewed calibrated images with established arousal and valence values from recognized image libraries. The experimental design applies principles from traffic psychology, focusing on the role of acute emotional reactions in high-risk driving situations. A sample of nine participants (N = 9) was simultaneously exposed to road-related visual stimuli in a controlled classroom environment. Experimental stimuli consisted of photographs with negative valence and high arousal, whereas neutral stimuli had neutral valence and arousal. Physiological responses were measured using a wearable ring-type sensor that recorded electrodermal activity (EDA) and blood volume pulse (BVP), along with facial expression analysis via a standard web camera. A word association task captured subjective emotional responses. The primary objective was to determine whether the sensors can reliably detect momentary emotional activation. Results indicate that BVP provides rapid response dynamics, while EDA reflects slower, sustained activation patterns. Despite participant variability, preliminary findings suggest the system can detect physiologically relevant responses to emotionally charged stimuli. The study establishes methodological groundwork for future traffic safety research by validating an accessible and scalable approach for detecting emotional precursors to risky driving behavior.