Revisiting the pit room : the effect of the plausibility illusion in stressful virtual reality experiences

Abstract

The feeling of presence is an important factor to consider when developing virtual experiences. Understanding the aspects that contribute to presence can give us better ideas on how to design and implement virtual reality (VR) applications. Previous studies have shown that presence involves a person’s sense of being in a virtual environment (VE), and how genuine the events taking place there feel, often referred to as place illusion (PI) and plausibility illusion (PSI) respectively. According to previous studies, we need both PI and PSI to elicit realistic responses.

This thesis is a pilot study that explores the impact of PSI on people’s realistic responses in a stressful VE by introducing an unrealistic event that breaks PSI while still maintaining PI.

To achieve this, a pit-room experiment was implemented and the users’ physiological changes, specifically heart rate, were analyzed while performing an interaction task under two conditions: one with the unrealistic event (non-scary) and one without (scary). In both conditions, the participants were tasked to drop bottles down the pit, however, in the non-scary condition, the bottles would float in the air rather than drop to the bottom.

A within-subjects study was conducted on 20 participants with 2 sessions each. Participants’ responses were recorded using electrocardiogram (ECG) devices and questionnaires. Although the findings didn’t produce significant differences between the two conditions, the physiological data presented a trend according to which the unrealistic event in the non-scary condition appeared to calm participants slightly. These results give further insights into the effects of PSI in a VE and provide a basis for conducting further confirmatory studies on this topic.