title: The DCDC2 intron 2 deletion impairs illusory motion perception unveiling the selective role of magnocellular-dorsal stream in reading (dis)ability.
abstract: Developmental dyslexia (DD) is a heritable neurodevelopmental reading disorder that could arise from auditory, visual, and cross-modal integration deficits. A deletion in intron 2 of the DCDC2 gene (hereafter DCDC2d) increases the risk for DD and related phenotypes. In this study, first we report that illusory visual motion perception-specifically processed by the magnocellular-dorsal (M-D) stream-is impaired in children with DD compared with age-matched and reading-level controls. Second, we test for the specificity of the DCDC2d effects on the M-D stream. Children with DD and DCDC2d need significantly more contrast to process illusory motion relative to their counterpart without DCDC2d and to age-matched and reading-level controls. Irrespective of the genetic variant, children with DD perform normally in the parvocellular-ventral task. Finally, we find that DCDC2d is associated with the illusory motion perception also in adult normal readers, showing that the M-D deficit is a potential neurobiological risk factor of DD rather than a simple effect of reading disorder. Our findings demonstrate, for the first time, that a specific neurocognitive dysfunction tapping the M-D stream is linked with a well-defined genetic susceptibility.
authors.affiliation: Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, 35131 Padua, Italy Child Psychopathology Unit, Scientiﬁc Institute, IRCCS Eugenio Medea, 23842 Bosisio Parini, Lecco, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Gori
authors.affiliation: Child Psychopathology Unit, Scientiﬁc Institute, IRCCS Eugenio Medea, 23842 Bosisio Parini, Lecco, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Mascheretti
authors.affiliation: Faculty of Psychology, "Vita-Salute" San Raffaele University, 20132 Milan, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Giora
authors.affiliation: Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, 35131 Padua, Italy Child Psychopathology Unit, Scientiﬁc Institute, IRCCS Eugenio Medea, 23842 Bosisio Parini, Lecco, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Ronconi
authors.affiliation: Child Psychopathology Unit, Scientiﬁc Institute, IRCCS Eugenio Medea, 23842 Bosisio Parini, Lecco, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Ruffino
authors.affiliation: Department of Psychology, University of Milan-Bicocca, 20126 Milan, Italy.
authors.forename: Ermanno
authors.initials: E
authors.lastname: Quadrelli
authors.affiliation: Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, 35131 Padua, Italy Child Psychopathology Unit, Scientiﬁc Institute, IRCCS Eugenio Medea, 23842 Bosisio Parini, Lecco, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Facoetti
authors.affiliation: Child Psychopathology Unit, Scientiﬁc Institute, IRCCS Eugenio Medea, 23842 Bosisio Parini, Lecco, Italy Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec, Québec, QC, Canada G1J 2G3 Département de Psychiatrie et Neurosciences, Faculté de Médecine, Université Laval, Québec, QC, Canada G1V 0A6.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Marino
mesh_terms: D016022:Case-Control Studies; D002648:Child; D004410:Dyslexia / Q000150:complications / Q000235:genetics / Q000473:pathology; D005260:Female; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007088:Illusions / Q000235:genetics*; D007438:Introns / Q000235:genetics*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000172:deficiency* / Q000235:genetics; D009039:Motion Perception / Q000502:physiology*; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000209:etiology* / Q000235:genetics; D010775:Photic Stimulation
chemical_list: C510451:DCDC2 protein, human; D008869:Microtubule-Associated Proteins
keywords: DCDC2; dorsal pathway; illusory motion perception; reading (dis)abilities