title: Patterns of neural activity in the human ventral premotor cortex reflect a whole-body multisensory percept.
abstract: Previous research has shown that the integration of multisensory signals from the body in fronto-parietal association areas underlies the perception of a body part as belonging to one's physical self. What are the neural mechanisms that enable the perception of one's entire body as a unified entity? In one behavioral and one fMRI multivoxel pattern analysis experiment, we used a full-body illusion to investigate how congruent visuo-tactile signals from a single body part facilitate the emergence of the sense of ownership of the entire body. To elicit this illusion, participants viewed the body of a mannequin from the first-person perspective via head-mounted displays while synchronous touches were applied to the hand, abdomen, or leg of the bodies of the participant and the mannequin; asynchronous visuo-tactile stimuli served as controls. The psychometric data indicated that the participants perceived ownership of the entire artificial body regardless of the body segment that received the synchronous visuo-tactile stimuli. Based on multivoxel pattern analysis, we found that the neural responses in the left ventral premotor cortex displayed illusion-specific activity patterns that generalized across all tested pairs of body parts. Crucially, a tripartite generalization analysis revealed the whole-body specificity of these premotor activity patterns. Finally, we also identified multivoxel patterns in the premotor, intraparietal, and lateral occipital cortices and in the putamen that reflected multisensory responses specific to individual body parts. Based on these results, we propose that the dynamic formation of a whole-body percept may be mediated by neuronal populations in the ventral premotor cortex that contain visuo-tactile receptive fields encompassing multiple body segments.
authors.affiliation: Brain, Body, and Self Laboratory, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden. Electronic address: gentile.giovanni@gmail.com.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gentile
authors.affiliation: Brain, Body, and Self Laboratory, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; Linköping University, Linköping, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Björnsdotter
authors.affiliation: Brain, Body, and Self Laboratory, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Valeria I
authors.initials: VI
authors.lastname: Petkova
authors.affiliation: Brain, Body, and Self Laboratory, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Zakaryah
authors.initials: Z
authors.lastname: Abdulkarim
authors.affiliation: Brain, Body, and Self Laboratory, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: H Henrik
authors.initials: HH
authors.lastname: Ehrsson
mesh_terms: D000328:Adult; D001828:Body Image; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007088:Illusions; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult