This chapter intends firstly to analyze the problem of identifying learning disabilities, from the standpoint of competing diagnostic models. The controversy between different models for identifying learning disabilities was presented, contrasting the characteristics of diagnostic models and models based on response to intervention. Second, an analysis of the main predictive factors of reading and writing was offered, using recent results from research carried out in different languages. The most often studied predictors—phonological awareness, speech perception, the alphabetic principle, rapid automatic naming, and vocabulary—were analyzed for their relationship to reading and writing. Finally, a discussion follows on the effects of certain programs that have been developed in different countries to prevent reading and writing learning disabilities. Most of these programs have been developed in the United States or Spain; they have also been implemented in other countries such as Canada, Australia, Mexico, Chile, and Israel.
Part of the book: Learning Disabilities
The aim of this chapter is to offer a neuropsychological approach to dyslexia. Firstly, the definition of dyslexia is addressed, as a specific learning disability that is neuropsychological in origin. Secondly, the clinical manifestations of dyslexia are discussed: academic, cognitive-linguistic, and socio-emotional. Thirdly, the main clinical explanations are explored, based on genetic theories (familial and twin heritability) and neurological theories, mainly neuroanatomical (brain asymmetry, corpus callosum morphology, cerebellar morphology, and variations in grey/white matter) and neurophysiological hypotheses (magnocellular system, connectivity between brain areas, and functional activity of brain areas). Finally, the main bases of an adequate neuropsychological intervention are detailed, such as training in visual perception, auditory perception, phonological processing, and orthographic processing.
Part of the book: Learning Disabilities