The relative contribution of five key perceptual cues and their interaction to the sense of embodiment.

Abstract

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 1 min in a virtual environment seen through a 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. Twenty-eight 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 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.

Immersive Virtual Reality Avatars for Embodiment Illusions in People with Mild to Borderline Intellectual Disability: User-Centered Development and Feasibility Study. (Preprint)

“…However, the SoE factors cannot be regarded isolated from each other, as interrelations were identified [36], such as appearance influences on agency [37], and control/haptics on ownership [38][39][40]. Here, recent findings showed that primarily visuo-proprioceptive congruence contributes to the sense of agency and ownership, as well as a better task performance [28]. Moreover, Fribourg et al (2020) explored the user preferences for three vital factors (i.e.…”

“…For instance, an egocentric POV has been shown to reliably induce the sense of self-location [23], while a third-person perspective tends to lower it [24,25]. The sense of agency is induced through the experienced control toward the virtual body [15], influenced by the visuomotor congruence between real body and avatar [26][27][28], while incongruences tend to lower it [29,30]. Lastly, the sense of ownership is influenced by the body appearance and has been induced through avatar models with different degrees of anthropomorphism [31].…”

“…Yet, using congruent body feedback could circumvent this issue, considering that haptics (e.g. self-touch) benefits the SoE and manipulation performance [28,57,58]. Lastly, an identified usability barrier are objects that are out-of-reach or placed low.…”

Immersive Virtual Reality Avatars for Embodiment Illusions in People With Mild to Borderline Intellectual Disability: User-Centered Development and Feasibility Study

“…For instance, an egocentric POV has been shown to reliably induce the sense of self-location [27], whereas a third-person perspective tends to lower it [28,29]. The sense of agency is induced through the experienced control of the virtual body [19], influenced by the visuomotor congruence between the real body and avatar [30][31][32], whereas incongruences tend to lower it [33,34]. Finally, the sense of ownership is influenced by body appearance and has been induced through avatar models with different degrees of anthropomorphism [35].…”

“…However, the SoE factors cannot be considered to be isolated from each other, as interrelations have been identified [ 40 ], such as influence of appearance on agency [ 41 ] and control and haptics on ownership [ 42 - 44 ]. Here, recent findings showed that primarily visuoproprioceptive congruence contributes to the sense of agency and ownership and better task performance [ 32 ]. Moreover, Fribourg et al [ 40 ] explored the user preferences for 3 vital factors (ie, POV, control, and appearance), showing the need for an egocentric perspective and high motor control to outweigh the avatar’s appearance.…”