title: Direction-dependent activation of the insular cortex during vertical and horizontal hand movements.
abstract: The planning of any motor action requires a complex multisensory processing by the brain. Gravity - immutable on Earth - has been shown to be a key input to these mechanisms. Seminal fMRI studies performed during visual perception of falling objects and self-motion demonstrated that humans represent the action of gravity in parts of the cortical vestibular system; in particular, the insular cortex and the cerebellum. However, little is known as to whether a specific neural network is engaged when processing non-visual signals relevant to gravity. We asked participants to perform vertical and horizontal hand movements without visual control, while lying in a 3T-MRI scanner. We highlighted brain regions activated in the processing of vertical movements, for which the effects of gravity changed during execution. Precisely, the left insula was activated in vertical movements and not in horizontal movements. Moreover, the network identified by contrasting vertical and horizontal movements overlapped with neural correlates previously associated to the processing of simulated self-motion and visual perception of the vertical direction. Interestingly, we found that the insular cortex activity is direction-dependent which suggests that this brain region processes the effects of gravity on the moving limbs through non-visual signals.
authors.affiliation: Université de Bourgogne Franche-Comté (UBFC), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, F-21078 Dijon, France; Institut National de Santé et de Recherche Médicale (INSERM U1093), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, BP 27877, F-21078 Dijon, France.
authors.forename: C
authors.initials: C
authors.lastname: Rousseau
authors.affiliation: EA 2931, Centre de Recherches sur le Sport et le Mouvement, Campus Universitaire Paris Ouest Nanterre La Défense, UFR STAPS Bât S., 200 avenue de la République, 92000 Nanterre, France; Université de Paris Ouest Nanterre la Défense, UFR STAPS, 92000 Nanterre, France.
authors.forename: L
authors.initials: L
authors.lastname: Fautrelle
authors.affiliation: Université de Bourgogne Franche-Comté (UBFC), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, F-21078 Dijon, France; Institut National de Santé et de Recherche Médicale (INSERM U1093), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, BP 27877, F-21078 Dijon, France. Electronic address: charalambos.papaxanthis@u-bourgogne.fr.
authors.forename: C
authors.initials: C
authors.lastname: Papaxanthis
authors.affiliation: IIT@UNIFE Center for Translational Neurophysiology, Istituto Italiano di Tecnologia, Italy; Section of Human Physiology, Università di Ferrara, Ferrara 44121, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Fadiga
authors.affiliation: Université de Bourgogne Franche-Comté (UBFC), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, F-21078 Dijon, France; Institut National de Santé et de Recherche Médicale (INSERM U1093), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, BP 27877, F-21078 Dijon, France; Institut Universitaire de France (IUF), Paris, France; IIT@UNIFE Center for Translational Neurophysiology, Istituto Italiano di Tecnologia, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Pozzo
authors.affiliation: Université de Bourgogne Franche-Comté (UBFC), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, F-21078 Dijon, France; Institut National de Santé et de Recherche Médicale (INSERM U1093), Cognition Action et Plasticité Sensorimotrice (CAPS) UMR1093, BP 27877, F-21078 Dijon, France.
authors.forename: O
authors.initials: O
authors.lastname: White
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D006112:Gravitation; D006225:Hand / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009068:Movement; D055815:Young Adult
keywords: fMRI; gravitational force; hand movements; insular cortex; internal model