Studying the Role of Self and External Touch in the Appropriation of Dysmorphic Hands

Abstract

Figure 1: We assessed the sense of body ownership towards different dysmorphic hands, induced by two visuotactile stimulation techniques (right part of the figure, from left to right): self-touch (users inducing themselves the tactile stimulation) and externaltouch (experimenter inducing it). The left part of this figure shows all the hand appearances that we studied, from left to right: anthropomorphic, longer-finger and block, hatched lines show matching tactile stimulation areas.

Beyond my Real Body: Characterization, Impacts, Applications and Perspectives of “Dissimilar” Avatars in Virtual Reality

“…Such results were obtained with avatars either presenting dissimilarities in terms of: structural proportions (e.g. a longer fingers [19]), limbs addition (e.g. an additional finger [43] or a robotic arm [32]), or limbs reduction (e.g.…”

“…The incorporation of a volume or structural dissimilarity generates a risk of visuo-haptic mismatch (i.e., a misalignment between the visual information and the tactile sensation), which can hinder interaction performance [56] or virtual body perception [14]. This issue can be addressed using movement retargeting algorithms, consisting in dynamically repositioning the virtual body in order to align real and virtual points of contact [19]. However, to the best of our knowledge, no algorithm have been proposed to satisfy complex interactions involving multiple contact points.…”

“…However, to the best of our knowledge, no algorithm have been proposed to satisfy complex interactions involving multiple contact points. Moreover, previous results indicate that the quality of the tactile interaction engendered by this technique might depend on the type of avatar dissimilarity [19]. As a result, most studies proposing visuo-tactile stimulation towards avatars whose volume varies sharply from the user 's body, require constrained setups (e.g., by asking the user to keep the stimulated limb still [51,80] and/or by generating the contacts externally following a controlled pattern [43,51]).…”

“…The application of such sensory correlation can elicit a sense of body ownership towards avatars showing different types of dissimilarities: superficial aspect (material [16,83,87] or attire [69]), volume [80], or structure (whether it is structural proportion [51], limb addition [43] or limb subtraction [65]). However, several studies also report that the type of dissimilarity remains an important factor impacting the sense of body ownership [5,19,63,126]. Specifically, it was reported that structural dissimilarities have a stronger negative impact on the sense of body ownership than volume dissimilarities [5,19,63,126], and that volume dissimilarities have a stronger negative impact than material dissimilarities [5,63,126].…”

“…However, several studies also report that the type of dissimilarity remains an important factor impacting the sense of body ownership [5,19,63,126]. Specifically, it was reported that structural dissimilarities have a stronger negative impact on the sense of body ownership than volume dissimilarities [5,19,63,126], and that volume dissimilarities have a stronger negative impact than material dissimilarities [5,63,126]. Furthermore, it was found that an increased appearance truthfulness tends to improve the sense of body ownership [28,46].…”