title: Multiple Causal Links Between Magnocellular-Dorsal Pathway Deficit and Developmental Dyslexia.
abstract: Although impaired auditory-phonological processing is the most popular explanation of developmental dyslexia (DD), the literature shows that the combination of several causes rather than a single factor contributes to DD. Functioning of the visual magnocellular-dorsal (MD) pathway, which plays a key role in motion perception, is a much debated, but heavily suspected factor contributing to DD. Here, we employ a comprehensive approach that incorporates all the accepted methods required to test the relationship between the MD pathway dysfunction and DD. The results of 4 experiments show that (1) Motion perception is impaired in children with dyslexia in comparison both with age-match and with reading-level controls; (2) pre-reading visual motion perception-independently from auditory-phonological skill-predicts future reading development, and (3) targeted MD trainings-not involving any auditory-phonological stimulation-leads to improved reading skill in children and adults with DD. Our findings demonstrate, for the first time, a causal relationship between MD deficits and DD, virtually closing a 30-year long debate. Since MD dysfunction can be diagnosed much earlier than reading and language disorders, our findings pave the way for low resource-intensive, early prevention programs that could drastically reduce the incidence of DD.
authors.affiliation: Department of Human and Social Sciences, University of Bergamo, Bergamo 24129, Italy Child Psychopathology Unit, Scientific Institute "E. Medea", Bosisio Parini, Lecco 23842, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Gori
authors.affiliation: Department of Psychology, University of California - Riverside, Riverside, CA, USA.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Seitz
authors.affiliation: Child Psychopathology Unit, Scientific Institute "E. Medea", Bosisio Parini, Lecco 23842, Italy Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova 35131, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Ronconi
authors.affiliation: Child Psychopathology Unit, Scientific Institute "E. Medea", Bosisio Parini, Lecco 23842, Italy Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova 35131, Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Franceschini
authors.affiliation: Child Psychopathology Unit, Scientific Institute "E. Medea", Bosisio Parini, Lecco 23842, Italy Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova 35131, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Facoetti
keywords: action video games; motion perception; perceptual learning; reading disorders; visual pathways