Method of stress reaction induction in disaster scenarios based on virtual reality

As natural disasters have major impacts on urban security, research on the behavior of individuals in disaster scenarios is crucial to support emergency decision-making. However, disaster occurrence is highly uncertain, making it difficult to collect data in disaster scenarios.

This paper proposes a stress induction method for disaster scenarios that can be conducted in a laboratory, that is, to induce the stress reaction of individuals who are facing disasters by using virtual reality (VR) videos with disaster scenarios. This study also tested the effectiveness of the method through two experiments. The first experiment comprised the baseline, stress, and recovery periods, representing before, during, and after watching the VR videos. Questionnaires and physiological data, such as photoplethysmography (PPG) and electrodermal activity (EDA), of 180 participants were collected. The second experiment was a simulated driving experiment with 75 participants. This experiment was conducted in two sessions, which were separated by at least one week to avoid memory interference. In the first session, we collected car-following data on a highway. In the second session, participants drove in the same traffic scenario as in the first session after watching the VR video.

The results of the first experiment indicated significant differences in the physical and psychological indicators among the baseline, stress, and recovery periods. The positive affect and negative affect scale (PANAS) data demonstrated that the VR video stimulated evident scared, nervous, and jittery emotions, which were consistent with negative compound emotions in disaster scenarios. Meanwhile, interested and attentive emotions did not change significantly, indicating that the participants were in good condition during the experiment. In addition, more than 80% of the participants reported that the VR video induced a high excitation level. Nearly 90% of them did not feel dizzy while watching the video. Furthermore, pulse rate variability indicators, such as standard deviation of NN intervals (SDNN), low frequency (LF), and EDA, were significantly higher in the stress period than in the baseline period. Changes in physiological indicators indicated that the participants were sympathetically excited and got stressed after watching the VR video. However, some physiological indicators had a high standard deviation due to individual variability. Therefore, VR videos used as stressors should be standardized. In general, the second driving simulation experiment showed a significant increase in acceleration and a significant decrease in headway after watching the VR video compared to when the video was not watched. This demonstrated that their driving style might become more aggressive after watching the VR video. This result is consistent with the findings of previous studies on driving characteristics in normal and emergency situations. In fact, the changing pattern of driving behavior in two sessions showed individual variability, which required further study.

Results of the two experiments indicate that VR videos can induce stress reactions in disaster scenarios, which is demonstrated in physical, psychological, and behavioral aspects. This paper provides a research method for investigating human behavior characteristics in disaster scenarios.