Evaluating the Effect of Multi-Sensory Stimulation on Startle Response Using the Virtual Reality Locomotion Interface MS.TPAWT

Abstract

The purpose of the study was to understand how various aspects of virtual reality and extended reality, specifically, environmental displays (e.g., wind, heat, smell, and moisture), audio, and graphics, can be exploited to cause a good startle, or to prevent them. The TreadPort Active Wind Tunnel (TPAWT) was modified to include several haptic environmental displays: heat, wind, olfactory, and mist, resulting in the Multi-Sensory TreadPort Active Wind Tunnel (MS.TPAWT). In total, 120 participants played a VR game that contained three startling situations. Audio and environmental effects were varied in a two-way analysis of variance (ANOVA) study. Muscle activity levels of their orbicularis oculi, sternocleidomastoid, and trapezius were measured using electromyography (EMG). Participants then answered surveys on their perceived levels of startle for each situation. We show that adjusting audio and environmental levels can alter participants physiological and psychological response to the virtual world. Notably, audio is key for eliciting stronger responses and perceptions of the startling experiences, but environmental displays can be used to either amplify those responses or to diminish them. The results also highlight that traditional eye muscle response measurements of startles may not be valid for measuring startle responses to strong environmental displays, suggesting that alternate muscle groups should be used. The study’s implications, in practice, will allow designers to control the participants response by adjusting these settings.