Neurofunctional correlates of body-ownership and sense of agency: A meta-analytical account of self-consciousness.

Abstract

Self-consciousness consists of several dissociable experiences, including the sense of ownership of one's body and the sense of agency over one's action consequences. The relationship between body-ownership and the sense of agency has been described by different neurocognitive models, each providing specific neurofunctional predictions. According to an "additive" model, the sense of agency entails body-ownership, while an alternative "independence" hypothesis suggests that they represent two qualitatively different processes, underpinned by distinct brain systems. We propose a third "interactive" model, arguing the interdependence between body-ownership and the sense of agency: these constructs might represent different experiences with specific and exclusive brain correlates, but they also could partly overlap at the neurofunctional level. Here we test these three neurocognitive models by reviewing the available neurofunctional literature of body-ownership and the sense of agency, with a quantitative meta-analytical approach that allowed us to compare their neural correlates statistically. We identified (i) a body-ownership-specific network including the left inferior parietal lobule and the left extra-striate body area, (ii) a sense-of-agency-specific network including the left SMA, the left posterior insula, the right postcentral gyrus, and the right superior temporal lobe and (iii) a shared network in the left middle insula. These results provide support for the interactive neurocognitive model of body-ownership and the sense of agency. Body-ownership involves a sensory network in which multisensory inputs are integrated to be self-attributed. On the other hand, the sense of agency is specifically associated with premotor and sensory-motor areas, typically involved in generating motor predictions and in action monitoring. Finally, body-ownership and the sense of agency interact at the level of the left middle insula, a high-level multisensory hub engaged in body and action awareness in general.