Introduction to Developmental Cognitive Neuropsychology
The existence of children like NG enable rejection of the theory broadly held by developmental psychologists that reading disorders always result from phonological disorders and requires an amendment permitting the view that reading disorders often result from phonological disorders. In relation to the multiple route models, surface dyslexia is interpreted as reflecting impaired development of the lexical and semantic reading route with consequent over-reliance upon the phonological reading route. Phonological dyslexia is interpreted as reflecting impaired performance development of the phonological reading route, with over-reliance in lexical and semantic reading routes. Deep dyslexia reflects absence of both the phonological and the direct route and use of an isolated and intrinsically unstable semantic route, or an isolated and damaged semantic route. The evidence for the developmental independence of the phonological and semantic reading routes is therefore strong, incorporating a modular organisation to the reading system within development.