Drift and ownership toward a distant virtual body

Abstract

In body ownership illusions participants feel that a mannequin or virtual body (VB) is their own. Earlier results suggest that body ownership over a body seen from behind in extra personal space is possible when the surrogate body is visually stroked and tapped on its back, while spatially and temporal synchronous tactile stimulation is applied to the participant's back. This result has been disputed with the claim that the results can be explained by self-recognition rather than somatic body ownership. We carried out an experiment with 30 participants in a between-groups design. They all saw the back of a VB 1.2 m in front, that moved in real-time determined by upper body motion capture. All felt tactile stimulation on their back, and for 15 of them this was spatially and temporally synchronous with stimulation that they saw on the back of the VB, but asynchronous for the other 15. After 3 min a revolving fan above the VB descended and stopped at the position of the VB neck. A questionnaire assessed referral of touch to the VB, body ownership, the illusion of drifting forwards toward the VB, and the VB drifting backwards. Heart rate deceleration (HRD) and the amount of head movement during the threat period were used to assess the response to the threat from the fan. Results showed that although referral of touch was significantly greater in the synchronous condition than the asynchronous, there were no other differences between the conditions. However, a further multivariate analysis revealed that in the visuotactile synchronous condition HRD and head movement increased with the illusion of forward drift and decreased with backwards drift. Body ownership contributed positively to these drift sensations. Our conclusion is that the setup results in a contradiction—somatic feelings associated with a distant body—that the brain attempts to resolve by generating drift illusions that would make the two bodies coincide.

The Embodiment of Objects: Review, Analysis, and Future Directions

“…A similar result found that "visual capture by a fake hand (without any synchronous or asynchronous tactile stimulation) affects body ownership in a group of hemiplegic patients with or without disturbed sensation of limb ownership" (Martinaud et al, 2017, p. 174). On the other hand, others do not observe significant differences between first and third person perspectives for embodiment (Pomés and Slater, 2013).…”

Enhancing Our Lives with Immersive Virtual Reality

“…There has been a lot of work on building virtual embodiment technology (Spanlang et al, 2013(Spanlang et al, , 2014, studying the conditions that can lead to such body ownership illusions (Slater et al, , 2010bSanchez-Vives et al, 2010;Borland et al, 2013;González-Franco et al, 2013;Llobera et al, 2013;Slater, 2013, 2014;Pomes and Slater, 2013;Blom et al, 2014;Kokkinara and Slater, 2014) and exploring the effects of distortions away from the normal form of a person's actual body (Slater et al, 2010b;Normand et al, 2011;Kilteni et al, 2012;Steptoe et al, 2013). There have also been studies on how illusions of body ownership might result in various changes to the real body.…”

FIJI: A Framework for the Immersion-Journalism Intersection

“…However, researchers have demonstrated that immersive VR systems can be used to create body ownership illusions, in which "healthy subjects experience an artificial body as if it were their own physical body" (Maselli and Slater, 2013). In other words, users may unconsciously accept an avatar representation of themselves as their own body and respond to events involving their avatar, such as possible harm (González-Franco et al, 2014), uncontrolled movements (Pomes and Slater, 2013), expected social behaviors (Kilteni et al, 2013), and even time travel (Friedman et al, 2014). If immersive technologies can be used to induce such body ownership illusions, particularly time travel, they can clearly be used to place the audience within a news story.…”