Threatening a rubber hand that you feel is yours elicits a cortical anxiety response

Abstract

The feeling of body ownership is a fundamental aspect of selfconsciousness. The underlying neural mechanisms can be studied by using the illusion where a person is made to feel that a rubber hand is his or her own hand by brushing the person's hidden real hand and synchronously brushing the artificial hand that is in full view. Here we show that threat to the rubber hand can induce a similar level of activity in the brain areas associated with anxiety and interoceptive awareness (insula and anterior cingulate cortex) as when the person's real hand is threatened. We further show that the stronger the feeling of ownership of the artificial hand, the stronger the threat-evoked neuronal responses in the areas reflecting anxiety. Furthermore, across subjects, activity in multisensory areas reflecting ownership predicted the activity in the interoceptive system when the hand was under threat. Finally, we show that there is activity in medial wall motor areas, reflecting an urge to withdraw the artificial hand when it is under threat. These findings suggest that artificial limbs can evoke the same feelings as real limbs and provide objective neurophysiological evidence that the rubber hand is fully incorporated into the body. These findings are of fundamental importance because they suggest that the feeling of body ownership is associated with changes in the interoceptive systems.body image ͉ emotion ͉ fMRI ͉ multisensory ͉ self

Shared electrophysiology mechanisms of body ownership and motor imagery

“…Previous neuroimaging work not only revealed the prominent involvement of premotor and intraparietal cortices in illusory hand ownership, but also implicated other brain regions such as primary somatosensory cortex, insular cortex, anterior cingulate cortex, and the cerebellum (Ehrsson et al, 2004(Ehrsson et al, , 2005(Ehrsson et al, , 2007Lloyd et al, 2006;Tsakiris et al, 2007;Zeller et al, 2011). The present inverse solution data link illusory hand ownership to bilateral premotor and posterior parietal cortices (Ehrsson et al, 2004(Ehrsson et al, , 2005(Ehrsson et al, , 2007 as well as the postcentral gyrus (Ehrsson et al, 2005;Lloyd et al, 2006;Schaefer et al, 2006aSchaefer et al, , 2006bTsakiris et al, 2007; see also Schaefer et al, 2007).…”

“…The present inverse solution data link illusory hand ownership to bilateral premotor and posterior parietal cortices (Ehrsson et al, 2004(Ehrsson et al, , 2005(Ehrsson et al, , 2007 as well as the postcentral gyrus (Ehrsson et al, 2005;Lloyd et al, 2006;Schaefer et al, 2006aSchaefer et al, , 2006bTsakiris et al, 2007; see also Schaefer et al, 2007).…”

“…Using fMRI, illusory ownership as induced by synchronous visuo-tactile stroking on congruent fake hand postures was found to be reflected by BOLD activity in bilateral premotor cortices (Ehrsson et al, 2004), cerebellum (Ehrsson et al, 2005), and intraparietal cortices (Ehrsson et al, 2004(Ehrsson et al, , 2005. If the fake hand is threatened by bringing a needle near to it, other studies found that activity in the supplementary motor area (Ehrsson et al, 2007) and posterior parietal regions (Lloyd et al, 2006) reflects illusory ownership. In addition, activity in bilateral anterior insular and anterior cingulate cortices (Ehrsson et al, 2007) or activity in premotor cortex and cerebellum (Ehrsson et al, 2004) was found to correlate with the strength of ownership illusion (as measured by questionnaire ratings).…”

“…If the fake hand is threatened by bringing a needle near to it, other studies found that activity in the supplementary motor area (Ehrsson et al, 2007) and posterior parietal regions (Lloyd et al, 2006) reflects illusory ownership. In addition, activity in bilateral anterior insular and anterior cingulate cortices (Ehrsson et al, 2007) or activity in premotor cortex and cerebellum (Ehrsson et al, 2004) was found to correlate with the strength of ownership illusion (as measured by questionnaire ratings). In a PET study, Tsakiris et al (2007) reported that activity in the right posterior insula, sensorimotor cortices (precentral and postcentral gyri), as well as primary somatosensory cortex was associated with illusory hand ownership.…”

“…fMRI, PET, lesion mapping) have revealed a wide network of brain regions associated with illusory body ownership during the RHI. These regions include the intraparietal cortex, primary somatosensory cortex (precentral and postcentral gyri), the ventral premotor cortex, the right insular lobe, the anterior cingulate cortex, and the cerebellum (Ehrsson et al, 2004(Ehrsson et al, , 2005(Ehrsson et al, , 2007Lloyd et al, 2006;Tsakiris et al, 2007;Zeller et al, 2011).…”