Non-hierarchical Influence of Visual Form, Touch, and Position Cues on Embodiment, Agency, and Presence in Virtual Reality.

Stephen C Pritchard,Vince Polito,Regine Zopf,Mark A Williams,David M Kaplan

doi:10.3389/fpsyg.2016.01649

Abstract

The concept of self-representation is commonly decomposed into three component constructs (sense of embodiment, sense of agency, and sense of presence), and each is typically investigated separately across different experimental contexts. For example, embodiment has been explored in bodily illusions; agency has been investigated in hypnosis research; and presence has been primarily studied in the context of Virtual Reality (VR) technology. Given that each component involves the integration of multiple cues within and across sensory modalities, they may rely on similar underlying mechanisms. However, the degree to which this may be true remains unclear when they are independently studied. As a first step toward addressing this issue, we manipulated a range of cues relevant to these components of self-representation within a single experimental context. Using consumer-grade Oculus Rift VR technology, and a new implementation of the Virtual Hand Illusion, we systematically manipulated visual form plausibility, visual–tactile synchrony, and visual–proprioceptive spatial offset to explore their influence on self-representation. Our results show that these cues differentially influence embodiment, agency, and presence. We provide evidence that each type of cue can independently and non-hierarchically influence self-representation yet none of these cues strictly constrains or gates the influence of the others. We discuss theoretical implications for understanding self-representation as well as practical implications for VR experiment design, including the suitability of consumer-based VR technology in research settings.

Highlights

Researchers have long puzzled over how best to describe and study the way we experience and represent ourselves
ANOVA for each rating scale separately showed that viewing a hand resulted in significantly higher mean values compared to viewing a sphere for embodiment– ownership, embodiment–agency, embodiment–location, presence and effortlessness, but not involuntariness
We found a significant effect of touch synchrony for embodiment–location and presence, such that synchronous touch led to higher self-representation ratings [embodiment–location: F(1, 48) = 8.03, p < 0.001, ηp2 = 0.269; presence: F(1, 48) = 8.88, p = 0.005, ηp2 = 0.156]

Summary

Introduction

Researchers have long puzzled over how best to describe and study the way we experience and represent ourselves. To gain traction on this problem, a common strategy is to decompose the concept of self-representation into several distinct components These include: sense of embodiment—the experience of owning a body and knowing its location (Longo et al, 2008b); sense of agency—the experience of causing actions and events in the world (Wegner, 2004); Cues for Self-Representation in Virtual Reality and sense of presence—the experience of “being there,” of being situated in an environment (Sanchez-Vives and Slater, 2005). These components of self-representation have typically been studied independently in a variety of different experimental contexts.

Methods

Results

Discussion

Conclusion