Having a body versus moving your body: neural signatures of agency and body-ownership.
The exact relation between the sense that one's body is one's own (body-ownership) and the sense that one controls one's own bodily actions (agency) has been the focus of much speculation, but remains unclear. On an 'additive' model, agency and body-ownership are strongly related; the ability to control actions is a powerful cue to body-ownership. This view implies a component common to the senses of body-ownership and agency, plus possible additional components unique to agency. An alternative 'independence' model holds that agency and body-ownership are qualitatively different experiences, triggered by different inputs, and recruiting distinct brain networks. We tested these two specific models by investigating the sensory and motor aspects of body-representation in the brain using fMRI. Activations in midline cortical structures were associated with a sensory-driven sense of body-ownership, and were absent in agency conditions. Activity in the pre-SMA was linked to the sense of agency, but distinct from the sense of body-ownership. No shared activations that would support the additive model were found. The results support the independence model. Body-ownership involves a psychophysiological baseline, linked to activation of the brain's default mode network. Agency is linked to premotor and parietal areas involved in generating motor intentions and subsequent action monitoring.
Tsakiris
Manos
M
Department of Psychology, Royal Holloway, University of London, Egham, Surrey, UK. manos.tsakiris@rhul.ac.uk
Longo
Matthew R
MR
Haggard
Patrick
P
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001828:Body Image; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D030141:Feedback, Psychological; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007699:Kinesthesis / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008960:Models, Psychological; D009068:Movement / Q000502:physiology*; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010470:Perceptual Masking / Q000502:physiology; D011594:Psychometrics; D011601:Psychophysics; D055815:Young Adult
D010100:Oxygen