Touching with the eyes: oculomotor self-touch induces illusory body ownership

Self-touch plays a central role in the construction of the bodily self. Yet, the underlying mechanisms are still unclear. Previous accounts emphasise the convergence of proprioceptive and tactile signals from the touching and the touched body parts. Here, we hypothesise that proprioceptive information from the moving effector is not strictly necessary for self-touch modulation of body-ownership. Since eye movements do not rely on proprioceptive signals as limb movements do, we developed a novel oculomotor self-touch paradigm where voluntary eye movements generated corresponding tactile sensations. We then compared the effectiveness of eye versus hand self-touch movements in generating an illusion of owning a rubber hand. Voluntary oculomotor self-touch was as effective as hand-driven self-touch, suggesting that proprioception does not mediate the contribution of self-touch to body ownership. Self-touch may contribute to a unified sense of bodily self by binding voluntary actions toward our own body with their tactile consequences.