Cognitive Impact of Social Virtual Reality: Audience and Mere Presence Effect of Virtual Companions

Sharing experiences with others is an important part of everyday life. Immersive virtual reality (IVR) promises to simulate these experiences. However, whether IVR elicits a similar level of social presence as measured in the real world is unclear. It is also uncertain whether AI-driven virtual humans (agents) can elicit a similar level of meaningful social copresence as people-driven virtual-humans (avatars). The current study demonstrates that both virtual human types can elicit a cognitive impact on a social partner. The current experiment tested participants' cognitive performance changes in the presence of virtual social partners by measuring the social facilitation effect (SFE). The SFE-related performance change can occur through either vigilance-based mechanisms related to other people's copresence (known as the mere presence effect (MPE)) or reputation management mechanisms related to other people's monitoring (the audience effect (AE)). In this study, we hypothesised AE and MPE as distinct mechanisms of eliciting SFE. Firstly, we predicted that, if head-mounted IVR can simulate sufficient copresence, any social companion's visual presence would elicit SFE through MPE. The results demonstrated that companion presence decreased participants' performance irrespective of whether AI or human-driven. Secondly, we predicted that monitoring by a human-driven, but not an AI-driven, companion would elicit SFE through AE. The results demonstrated that monitoring by a human-driven companion affected participant performance more than AI-driven, worsening performance marginally in accuracy and significantly in reaction times. We discuss how the current results explain the findings in prior SFE in virtual-world literature and map out future considerations for social-IVR testing, such as participants' virtual self-presence and affordances of physical and IVR testing environments.