The Rubber Hand Illusion Revisited: Visuotactile Integration and Self-Attribution.

Abstract

Watching a rubber hand being stroked, while one's own unseen hand is synchronously stroked, may cause the rubber hand to be attributed to one's own body, to "feel like it's my hand." A behavioral measure of the rubber hand illusion (RHI) is a drift of the perceived position of one's own hand toward the rubber hand. The authors investigated (a) the influence of general body scheme representations on the RHI in Experiments 1 and 2 and (b) the necessary conditions of visuotactile stimulation underlying the RHI in Experiments 3 and 4. Overall, the results suggest that at the level of the process underlying the build up of the RHI, bottom-up processes of visuotactile correlation drive the illusion as a necessary, but not sufficient, condition. Conversely, at the level of the phenomenological content, the illusion is modulated by top-down influences originating from the representation of one's own body.

Shared electrophysiology mechanisms of body ownership and motor imagery

“…In particular, our pilot results indicate that illusory hand ownership and perceived hand position were shifted toward the virtual hand for synchronous as compared to asynchronous visuo-tactile stroking (i.e. significant change in proprioceptive drift; Botvinick and Cohen, 1998;Tsakiris and Haggard, 2005). In contrast to the bilateral induction of the RHI (illusory ownership experiment) and bilateral presentation of visual hands (both illusory ownership and motor imagery experiments), the pilot study involved unilateral induction of the RHI.…”

“…We also note that many of the aforementioned RHI studies (e.g. Botvinick and Cohen, 1998;Ehrsson et al, 2004;Tsakiris and Haggard, 2005) did not collect self-reports for non-body control objects. Concerning illusory hand ownership (item 3), the present self-reports provide evidence that such changes can be induced in a body-specific and synchrony-dependent fashion with our automated setup (see also Slater et al, 2008).…”

“…Hand ownership as studied in the RHI has been shown to be sensitive to various parameters including visuo-tactile stroke duration (Rohde et al, 2011;Tsakiris and Haggard, 2005), distance between proprioceptive and visual hand position (Lloyd, 2007), and visual hand posture (Costantini and Haggard, 2007). In the large majority of these studies, the experimenter applied the visuo-tactile stroking manually (but see also Schütz-Bosbach et al, 2009) and to one hand.…”

“…Ownership for one's hand has been proposed to constitute a crucial aspect of bodily selfconsciousness (De Vignemont, 2011;Gallagher, 2000;Makin et al, 2008;Tsakiris, 2010) and an increasing number of empirical data on the neural underpinnings of body ownership have pointed to the importance of multisensory integration of visual, tactile and proprioceptive signals (Botvinick, 2004;Botvinick and Cohen, 1998;Ehrsson et al, 2005;Tsakiris and Haggard, 2005). A widely used paradigm to study the multisensory perception of upper limbs is the rubber hand illusion (RHI; Botvinick and Cohen, 1998) where participants watch an artificial hand (visual cue) being stroked by a paintbrush in synchrony with stroking on their own corresponding and occluded hand (tactile cue).…”

“…This visuo-tactile manipulation alters bodily experience, inducing the illusion that the artificial hand being touched is one's own hand (measured by questionnaire ratings) and is generally associated with a measurable mislocalization of the participant's hand towards the fake hand. The illusion does not occur when the stroking provided to the real hand and the artificial hand is not synchronous, when the fake hand does not match the posture of the real hand, or when control objects are stroked (Botvinick and Cohen, 1998;Ehrsson et al, 2004;Tsakiris and Haggard, 2005).…”