title: Reading impairment in schizophrenia: dysconnectivity within the visual system.
abstract: Patients with schizophrenia suffer from perceptual visual deficits. It remains unclear whether those deficits result from an isolated impairment of a localized brain process or from a more diffuse long-range dysconnectivity within the visual system. We aimed to explore, with a reading paradigm, the functioning of both ventral and dorsal visual pathways and their interaction in schizophrenia. Patients with schizophrenia and control subjects were studied using event-related functional MRI (fMRI) while reading words that were progressively degraded through word rotation or letter spacing. Reading intact or minimally degraded single words involves mainly the ventral visual pathway. Conversely, reading in non-optimal conditions involves both the ventral and the dorsal pathway. The reading paradigm thus allowed us to study the functioning of both pathways and their interaction. Behaviourally, patients with schizophrenia were selectively impaired at reading highly degraded words. While fMRI activation level was not different between patients and controls, functional connectivity between the ventral and dorsal visual pathways increased with word degradation in control subjects, but not in patients. Moreover, there was a negative correlation between the patients' behavioural sensitivity to stimulus degradation and dorso-ventral connectivity. This study suggests that perceptual visual deficits in schizophrenia could be related to dysconnectivity between dorsal and ventral visual pathways.
authors.affiliation: Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM), UMRS 975, Equipe "Motivation Brain Behavior", Paris, 75013 France; Inserm, U 975, Paris, 75013 France; CNRS, UMR 7225, Paris, 75013 France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Vinckier
authors.affiliation: Inserm, U 975, Paris, 75013 France; CNRS, UMR 7225, Paris, 75013 France; AP-HP, Groupe hospitalier Pitié-Salpêtrière, Service neurologie, Paris, 75013 France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM), UMRS 975, Equipe "Neuropsychology and Neuroimaging", Paris, 75013 France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Cohen
authors.affiliation: INSERM UMR S894, Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Centre Hospitalier Sainte-Anne, Neuroradiology, Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Oppenheim
authors.affiliation: Centre Hospitalier Sainte-Anne, Department of Psychiatry, Service Hospitalo-Universitaire, Paris, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Salvador
authors.affiliation: Centre Hospitalier Sainte-Anne, Department of Psychiatry, Service Hospitalo-Universitaire, Paris, France; INSERM, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, UMR 894, Paris, France.
authors.forename: Hernan
authors.initials: H
authors.lastname: Picard
authors.affiliation: Centre Hospitalier Sainte-Anne, Department of Psychiatry, Service Hospitalo-Universitaire, Paris, France; INSERM, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, UMR 894, Paris, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Amado
authors.affiliation: INSERM UMR S894, Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Centre Hospitalier Sainte-Anne, Department of Psychiatry, Service Hospitalo-Universitaire, Paris, France; INSERM, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, UMR 894, Paris, France.
authors.forename: Marie-Odile
authors.initials: MO
authors.lastname: Krebs
authors.affiliation: INSERM UMR S894, Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Centre Hospitalier Sainte-Anne, Department of Psychiatry, Service Hospitalo-Universitaire, Paris, France; INSERM, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, UMR 894, Paris, France. Electronic address: raphael.gaillard@normalesup.org.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Gaillard
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D011932:Reading; D012559:Schizophrenia / Q000503:physiopathology*; D013647:Task Performance and Analysis; D014795:Visual Pathways / Q000503:physiopathology; D014796:Visual Perception / Q000502:physiology
keywords: Dorsal stream; Neuropsychology; Reading; Schizophrenia; fMRI