Dyslexia (specific reading disability).
Converging evidence from a number of lines of investigation indicates that dyslexia represents a disorder within the language system and more specifically within a particular subcomponent of that system, phonological processing. Recent advances in imaging technology, particularly the development of functional magnetic resonance imaging, provide evidence of a neurobiological signature for dyslexia, specifically a disruption of two left hemisphere posterior brain systems, one parieto-temporal, the other occipito-temporal, with compensatory engagement of anterior systems around the inferior frontal gyrus and a posterior (right occipito-temporal) system. Furthermore, good evidence indicates a computational role for the left occipito-temporal system: the development of fluent (automatic) reading. The brain systems for reading are malleable and their disruption in dyslexic children may be remediated by provision of an evidence-based, effective reading intervention. In addition, functional magnetic resonance imaging studies of young adults with reading difficulties followed prospectively and longitudinally from age 5 through their mid twenties suggests that there may be two types of reading difficulties, one primarily on a genetic basis, the other, and far more common, reflecting environmental influences. These studies offer the promise for more precise identification and effective management of dyslexia in children, adolescents and adults.
Shaywitz
Sally E
SE
National Institute of Child Health and Human Development-Yale Center for the Study of Learning and Attention, New Haven, Connecticut, USA. sally.shaywitz@yale.edu
Shaywitz
Bennett A
BA
D000367:Age Factors; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology; D004410:Dyslexia / Q000453:epidemiology / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology*; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D011932:Reading