title: Tracking the evolution of crossmodal plasticity and visual functions before and after sight restoration.
abstract: Visual deprivation leads to massive reorganization in both the structure and function of the occipital cortex, raising crucial challenges for sight restoration. We tracked the behavioral, structural, and neurofunctional changes occurring in an early and severely visually impaired patient before and 1.5 and 7 mo after sight restoration with magnetic resonance imaging. Robust presurgical auditory responses were found in occipital cortex despite residual preoperative vision. In primary visual cortex, crossmodal auditory responses overlapped with visual responses and remained elevated even 7 mo after surgery. However, these crossmodal responses decreased in extrastriate occipital regions after surgery, together with improved behavioral vision and with increases in both gray matter density and neural activation in low-level visual regions. Selective responses in high-level visual regions involved in motion and face processing were observable even before surgery and did not evolve after surgery. Taken together, these findings demonstrate that structural and functional reorganization of occipital regions are present in an individual with a long-standing history of severe visual impairment and that such reorganizations can be partially reversed by visual restoration in adulthood.
authors.affiliation: Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Université de Montréal, Montreal, Quebec, Canada; Institute of Research in Psychology (IPSY), Center for Cognitive and Systems Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium;
authors.forename: Giulia
authors.initials: G
authors.lastname: Dormal
authors.affiliation: Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Université de Montréal, Montreal, Quebec, Canada;
authors.forename: Franco
authors.initials: F
authors.lastname: Lepore
authors.affiliation: Department of Ophthalmology, Centre Hospitalier de l'Université de Montréal (CHUM) Notre Dame, Montreal, Quebec, Canada;
authors.forename: Mona
authors.initials: M
authors.lastname: Harissi-Dagher
authors.affiliation: Centre de recherche de l'Institut Universitaire de Gériatrie de l'Université de Montréal (CRIUGM), Montreal, Quebec, Canada;
authors.forename: Geneviève
authors.initials: G
authors.lastname: Albouy
authors.affiliation: Department of Education and Counselling Psychology, McGill University, Montreal, Quebec, Canada; and.
authors.forename: Armando
authors.initials: A
authors.lastname: Bertone
authors.affiliation: Institute of Research in Psychology (IPSY), Center for Cognitive and Systems Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium;
authors.forename: Bruno
authors.initials: B
authors.lastname: Rossion
authors.affiliation: Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Université de Montréal, Montreal, Quebec, Canada; Centro Interdipartimentale Mente/Cervello (CIMeC), Università di Trento, Mattarello, Italy olivier.collignon@unitn.it.
authors.forename: Olivier
authors.initials: O
authors.lastname: Collignon
mesh_terms: D000328:Adult; D001766:Blindness / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D015354:Vision, Low / Q000175:diagnosis / Q000503:physiopathology*; D014785:Vision, Ocular; D014793:Visual Cortex / Q000502:physiology* / Q000503:physiopathology; D014796:Visual Perception
keywords: blindness; crossmodal plasticity; sight recovery; ventral-dorsal pathways