title: Modulation of fronto-parietal connections during the rubber hand illusion.
abstract: Accumulating evidence suggests that parieto-frontal connections play a role in adjusting body ownership during the Rubber Hand Illusion (RHI). Using a motor version of the rubber hand illusion paradigm, we applied single-site and dual-site transcranial magnetic stimulation (TMS) to investigate cortico-spinal and parietal-frontal connectivity during perceived rubber hand ownership. Healthy volunteers received a conditioning TMS pulse over left anterior intraparietal sulcus (aIPS) and a test TMS pulse over left primary motor cortex (M1). Motor Evoked Potentials (MEPs) were recorded at rest and during three RHI conditions: (i) agency and ownership, (ii) agency but no ownership and (iii) neither agency nor ownership. Parietal-motor communication differed among experimental conditions. The induction of action ownership was associated with an inhibitory parietal-to-motor connectivity, which was comparable to the aIPS-to-M1 inhibition present at rest. This aIPS-to-M1 inhibition disappeared during movement conditions not inducing ownership. Cortico-spinal excitability was not significantly modulated during the motor RHI as indicated by the task-constant MEP amplitude elicited by the M1 test pulse alone. Our results indicate that the perceived ownership over the rubber hand is associated with normal parietal-motor communication. This communication is disturbed if the sensorimotor conflict between one's own hand and the rubber hand is not resolved.
authors.affiliation: Danish Research Center for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Kettegård Allé 30, DK-2650, Hvidovre, Denmark.|Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Anke Ninija
authors.initials: AN
authors.lastname: Karabanov
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.|Helene Elsass Institute, Charlottenlund, Denmark.
authors.forename: Anina
authors.initials: A
authors.lastname: Ritterband-Rosenbaum
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.|Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.|Cognitive Neuroscience Research Unit, Aarhus University, Aarhus, Denmark.
authors.forename: Mark Schram
authors.initials: MS
authors.lastname: Christensen
authors.affiliation: Danish Research Center for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Kettegård Allé 30, DK-2650, Hvidovre, Denmark.|Department of Neurology, Copenhagen University Hospital Bispebjerg, København, NV, Denmark.
authors.forename: Hartwig Roman
authors.initials: HR
authors.lastname: Siebner
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.|Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jens Bo
authors.initials: JB
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D019054:Evoked Potentials, Motor; D006225:Hand / Q000294:innervation / Q000502:physiology*; D006801:Humans; D007088:Illusions / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement; D009433:Neural Inhibition; D010296:Parietal Lobe / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology; D050781:Transcranial Magnetic Stimulation
keywords: anterior intraparietal sulcus; body ownership; paired-pulse TMS; primary motor cortex; sensory-motor mismatch