Neural correlates of an illusionary sense of agency caused by virtual reality

Abstract

As a part of self-consciousness, sense of agency (SoA) refers to our sensation that we initiate actions that lead to ensuing perceptual consequences. Previous neuroimaging studies manipulated voluntary actions to create differential levels of SoA, and found that the SoA network largely overlaps with the sensorimotor network. It is thus unclear whether effects observed in these regions are attributable to SoA or some specific aspects of action processes (e.g., intentionality of action) related to voluntary action control, or both. To disentangle the effect of action processes, here we utilized virtual reality (VR) technology to induce an illusive SoA in the absence of voluntary action, and examined it by functional magnetic resonance imaging (fMRI). Participants' experience of controlling an avatar hand elicited a persistent increase in temporal binding, a behavioral marker of SoA, when they merely observed the avatar hand's movement in the scanner. fMRI results showed that the SoA with the non-action was associated with a cluster centered in right angular gyrus, extending to right inferior parietal lobule and the right precuneus. These high-level associative areas have been implicated in SoA with voluntary actions for their role in perceptual-motor mismatch detection and action awareness. Other traditional SoA areas, especially those governing action intentionality and motor planning, were not implicated. Hence, controlling a virtual body can generate a salient SoA whose neural correlates are distinct from those supporting action control but partially overlapping with those governing post voluntary-action SoA processes. These findings also highlight the role of angular gyrus in giving rise to the self-consciousness changes associated with virtual body embodiment in VR and metaverse.