title: Decreased motor cortex excitability mirrors own hand disembodiment during the rubber hand illusion.
abstract: During the rubber hand illusion (RHI), subjects experience an artificial hand as part of their own body, while the real hand is subject to a sort of 'disembodiment'. Can this altered belief about the body also affect physiological mechanisms involved in body-ownership, such as motor control? Here we ask whether the excitability of the motor pathways to the real (disembodied) hand are affected by the illusion. Our results show that the amplitude of the motor-evoked potentials recorded from the real hand is significantly reduced, with respect to baseline, when subjects in the synchronous (but not in the asynchronous) condition experience the fake hand as their own. This finding contributes to the theoretical understanding of the relationship between body-ownership and motor system, and provides the first physiological evidence that a significant drop in motor excitability in M1 hand circuits accompanies the disembodiment of the real hand during the RHI experience.
authors.affiliation: Department of Philosophy, University of Milan, Milan, Italy.|Department of Health Sciences, University of Milan Medical School, Milan, Italy.
authors.forename: Francesco
authors.identifier: 0000-0003-3471-6595
authors.initials: F
authors.lastname: Della Gatta
authors.affiliation: SAMBA Research Group, Department of Psychology, University of Turin, Turin, Italy.
authors.forename: Francesca
authors.identifier: 0000-0003-1210-0175
authors.initials: F
authors.lastname: Garbarini
authors.affiliation: Department of Health Sciences, University of Milan Medical School, Milan, Italy.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Puglisi
authors.affiliation: Department of Health Sciences, University of Milan Medical School, Milan, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Leonetti
authors.affiliation: Neuroscience Institute of Turin, University of Turin, Turin, Italy.
authors.forename: Annamaria
authors.identifier: 0000-0001-9972-5543
authors.initials: A
authors.lastname: Berti
authors.affiliation: Department of Health Sciences, University of Milan Medical School, Milan, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Borroni
mesh_terms: D000200:Action Potentials; D000328:Adult; D000071080:Cortical Excitability; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D007088:Illusions; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D011434:Proprioception; D055698:Touch Perception; D014796:Visual Perception; D055815:Young Adult
keywords: body ownership; human; magnetic transcranical stimulation-; neuroscience; primary motor cortex