Stressful urban walks: an experimental design for measuring physiological and psychological stress in virtual urban environments

Introduction: Stress is a growing public health concern, with urban environments strongly influencing stress levels. Experimental approaches simulating human motion (i.e., walking) in virtual urban environments may constitute a promising avenue to assess environmental effects on stress. This study aims to systematically examine the ability to induce and measure psychological and physiological stress responses during walking in immersive virtual urban environments. It includes two sub-experiments: one comparing average stress levels between an urban park and a street, and one assessing momentary stress responses to a siren stimulus. Methods: Fifty adults residing in Luxembourg experienced virtual walks through a park and a street, in a randomized crossover design, as well as a walk through the street with a siren stimulus. Physiological responses (electrodermal activity (EDA), heart rate (HR), and pupil diameter) were recorded continuously, while self-reported stress and emotional perceptions were assessed after each session via in-VR questionnaires. Results: Participants reported significantly lower self-reported stress and more positive emotional engagement in the park compared to the street. The standard deviation of HR was higher in the street, possibly indicating higher stress levels, while average pupil diameter was larger in the park, reflecting heightened emotional arousal. Other biomarkers showed no significant differences. Pupil diameter and EDA effectively detected momentary stress after the siren stimulus. Conclusions: Combining virtual environments with a walking simulator and biosensors provides a novel, effective method to study environmental impacts on stress. Findings contribute to identifying stress-inducing urban environments and developing stress reduction interventions.