Anormalidades cerebrales en sujetos disléxicos

Resum

Since decades ago, significant research had been directed to pinpoint the biological foundations of dyslexia. Throughout history, several functional and morphological differences in dyslexics� brains have been reported. In this paper, the evidence about brain abnormalities in different structures associated with dyslexia is examined: planum temporale, parietal lobe, corpus callosum, cerebellum, insula and right hemisphere. Potential genetic factors involved in dyslexia are analyzed. It is emphasized that a defect in the phonological language processing may represent the core defect in dyslexia. It is concluded that dyslexia probably is not a discrete entity; most likely, it presents a continued gradation. Diversity in symptomatology and associated defects could be related with the involvement of different variables. Furthermore, the specific characteristics of the different writing systems could affect the apparent dyslexia frequency and its specific manifestations, as well as the likelihood to find brain abnormalities.