title: Predictive coding accounts of shared representations in parieto-insular networks.
abstract: The discovery of mirror neurons in the ventral premotor cortex (area F5) and inferior parietal cortex (area PFG) in the macaque monkey brain has provided the physiological evidence for direct matching of the intrinsic motor representations of the self and the visual image of the actions of others. The existence of mirror neurons implies that the brain has mechanisms reflecting shared self and other action representations. This may further imply that the neural basis self-body representations may also incorporate components that are shared with other-body representations. It is likely that such a mechanism is also involved in predicting other's touch sensations and emotions. However, the neural basis of shared body representations has remained unclear. Here, we propose a neural basis of body representation of the self and of others in both human and non-human primates. We review a series of behavioral and physiological findings which together paint a picture that the systems underlying such shared representations require integration of conscious exteroception and interoception subserved by a cortical sensory-motor network involving parieto-inner perisylvian circuits (the ventral intraparietal area [VIP]/inferior parietal area [PFG]-secondary somatosensory cortex [SII]/posterior insular cortex [pIC]/anterior insular cortex [aIC]). Based on these findings, we propose a computational mechanism of the shared body representation in the predictive coding (PC) framework. Our mechanism proposes that processes emerging from generative models embedded in these specific neuronal circuits play a pivotal role in distinguishing a self-specific body representation from a shared one. The model successfully accounts for normal and abnormal shared body phenomena such as mirror-touch synesthesia and somatoparaphrenia. In addition, it generates a set of testable experimental predictions.
authors.affiliation: Istituto Italiano di Tecnologia (IIT), Brain Center for Social and Motor Cognition (BCSMC), Parma, Italy; Frontal Lobe Function Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan. Electronic address: ishida-hr@igakuken.or.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ishida
authors.affiliation: Sackler Center for Consciousness Science, University of Sussex, Brighton, UK; School of Informatics and Engineering, University of Sussex, Brighton, UK.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Neuroscience, Unit of Physiology, Parma University, Parma, Italy.
authors.forename: Laura Clara
authors.initials: LC
authors.lastname: Grandi
mesh_terms: D000818:Animals; D001828:Body Image; D001931:Brain Mapping; D006801:Humans; D059167:Mirror Neurons / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology; D009415:Nerve Net / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D011237:Predictive Value of Tests; D012677:Sensation / Q000502:physiology
keywords: Body representation; Insular cortex; Mirror neurons; Multisensory integration; Parietal cortex; Predictive coding; Secondary somatosensory cortex; Sensory-motor integration; Shared body representation; Social touch