Common Cues? Toward the Relationship of Spatial Presence and the Sense of Embodiment

The sense of presence and the sense of embodiment are two fundamental qualia, pivotal to many virtual reality experiences. Empirical research indicates a notable interdependence between these two qualia, where manipulations designed to affect one often exhibit a concurrent influence on the other. Existing theories on the development of qualia in virtual reality make no or only insufficient statements on this deep interdependence. In this work, we present a novel theoretical perspective on this connection. Based on existing theories, we argue that all the fundamental cues influencing one quale have the potential to impact the other one too. We present three studies ($n=42, n=42, n=32$) that generally support this novel perspective. Among other things, they show that traditional spatial presence cues such as head-tracking and passive depth cues (stereoscopy, linear perspective, etc.) can potentially also serve as embodiment cues. Conversely, they show that typical embodiment cues such as the visuotactile and visuoproprioceptive synchrony of a virtual hand are also spatial presence cues. The cues only differ in terms of how strongly they influence the respective quale. This novel perspective not only enhances our understanding of fundamental mechanics of virtual reality but it can also guide the development of more effective measurement instruments.