Cross-referenced body and action for the unified self: empirical, developmental, and clinical perspectives

Abstract

This chapter discusses how the self emerges in the brain through the body and bodily actions. In terms of minimal selfhood, self-representation has two aspects: sense of body ownership and sense of agency over action. In the rubber hand illusion paradigm, multisensory and sensorimotor signals induce illusory ownership over a fake hand. Studies in healthy adults suggest a cross-referenced relationship between body and action as a mechanism of the self-representation. Specifically, one’s own hand can spontaneously move towards the fake hand due to illusory ownership, suggesting a body-to-action relationship. In contrast, an object which is moving synchronously with one’s hand can entail a sense of body ownership as well as a sense of agency, suggesting an action-to-body relationship. The chapter also discusses developmental and clinical perspectives. Immature self-recognition and body part localization in children suggest a prerequisite of representations of the self and body. Although such representations can deteriorate due to damage to the body and brain, amputees can incorporate phantom limb and prosthesis into their body representation through visuo-motor rehabilitation, regaining senses of ownership and agency over these limbs once again. The chapter proposes generation-loss-regeneration dynamism in self-representation originating from the cross-referenced body and action.