The Relative Contribution of Five Key Perceptual Cues and their Interaction to the Sense of Embodiment

A range of perceptual cues drive the Sense of Embodiment (SoE) with an external object, such as a virtual arm that looks like one’s own or can be controlled like one’s own. Since most experiments test one or two cues at a time, it is difficult to establish their relative contribution and possible interaction. This work aims at investigating the importance of five key perceptual cues (field of view, visuo-proprioceptive synchronicity, tactile feedback, visual human-likeness, and connectedness) and their potential interaction in a single, full factorial experiment. Participants touched a target dot, which changed position after a hit, for one minute in a virtual environment seen through an head-mounted display. Participants’ arm and hand motions were mapped to a virtual arm and hand. All perceptual cues had two levels: SoE supportive and SoE suppressive. 28 participants completed the task in all possible combinations. We recorded Task Performance and self-ratings of Sense of Ownership and Sense of Agency. Results showed that visuo-proprioceptive synchronicity had the largest effect on on all three measures. The relative importance of the remaining four cues differed for the three dependent variables. The cues did not have significant interactive effects. We conclude that when designing an interface for maximum supportive embodiment, visuo-proprioceptive synchronicity is the most important perceptual cue. The extent to which other supportive cues can improve the embodiment experience depends on the considered variables, but generally the more other supportive cues can be added, the better.