Full body illusion is associated with widespread skin temperature reduction

Abstract

A central feature of our consciousness is the experience of the self as a unified entity residing in a physical body, termed bodily self-consciousness. This phenomenon includes aspects such as the sense of owning a body (also known as body ownership) and has been suggested to arise from the integration of sensory signals from the body. Several studies have shown that temporally synchronous tactile stimulation of the real body and visual stimulation of a fake or virtual body can induce changes in bodily self-consciousness, typically resulting in a sense of illusory ownership over the fake body. The present study assessed the effect of anatomical congruency of visuo-tactile stimulation on bodily self-consciousness. A virtual body was presented and temporally synchronous visuo-tactile stroking was applied simultaneously to the participants' body and to the virtual body. We manipulated the anatomical locations of the visuo-tactile stroking (i.e., on the back, on the leg), resulting in congruent stroking (stroking was felt and seen on the back or the leg) or incongruent stroking (i.e., stroking was felt on the leg and seen on the back). We measured self-identification with the virtual body and self-location as well as skin temperature. Illusory self-identification with the avatar as well as changes in self-location were experienced in the congruent stroking conditions. Participants showed a decrease in skin temperature across several body locations during congruent stimulation. These data establish that the full-body illusion (FBI) alters bodily self-consciousness and instigates widespread physiological changes in the participant's body.

Are You Suggesting That’s My Hand? The Relation Between Hypnotic Suggestibility and the Rubber Hand Illusion

“…However, the insula which is implicated in proprioceptive drift (see above) is also associated with the sensation of cooling (Hua et al 2005); this region could be involved in the cooling of the counterpart real hand that can accompany feelings of ownership of a rubber hand (Moseley et al 2008). Further research could also explore whether individual differences in hypnotic suggestibility extend to the perceptual illusion of body swapping (Petkova et al 2011;Salomon et al 2013). An interesting research question is whether hypnotic procedures (Deeley et al 2013a;Walsh et al 2014b) would further modulate performance during the RHI.…”

The bodily self: Insights from clinical and experimental research

“…Self-identification (measured by using questionnaires) was significantly stronger after synchronous than asynchronous visuo-tactile stroking. As for the RHI, self-identification with the avatar decreased skin temperature at the level of the participant's body [97] and reduced the participant's pain perception [95]. In addition, the full-body illusion was characterized by errors in self-localization in space.…”

Uncomfortably numb: new evidence for suppressed emotional reactivity in response to body-threats in those predisposed to sub-clinical dissociative experiences

“…In addition, previous research has argued that drops in body / finger temperature can reflect a psychophysiological anxiety response (Vinkers, et al, 2013), and this has been shown for non-clinical samples in relation to body illusions (full body illusions: Salomon et al, 2013; the RHI: Moseley et al, 2008;Kammers et al, 2011;Thakkar et al, 2011: though see also Hohwy & Paton, 2010;Paton et al, 2012 for failures to replicate). Therefore, finger temperature was measured as an additional objective index of threat-related anxiety, via a separate channel on the same MP36R unit described above.…”

“…Research has argued that the hypothalamus and preoptic area (PO) play crucial roles in effective body temperature regulation, and a wealth of research has explored thermoregulation with respect to behaviour such as psychological reactivity to stress (Hammel, 1968;Nagashima, Nakai, Tanaka, & Kanosue, 2000;Oka, 2015;Oka, Oka & Hori, 2001). Indeed, drops in finger temperature have been associated with fear / anxiety responses (Vinkers et al, 2013), and have been demonstrated under body-illusion conditions (full body illusions: Salomon, Lim, Pfeiffer, Gassert & Blanke, 2013; the Rubber-hand illusion, RHI: Moseley et al, 2008;Kammers, Rose, & Haggard, 2011;Thakkar, Nichols, McIntosh, & Park, 2011: though see also Hohwy & Paton, 2010;Paton, Hohwy, & Enticott, 2012 for failures to replicate). This has led some researchers to suggest that such drops in temperature could also be used as a reliable index of fear processing, and that temperature regulation must therefore involve higher, top-down cognitive processing between physiological regulation of the physical self and the conscious 'self' (Moseley et al, 2008).…”