Acquired dyslexia and dysgraphia

Dual-route models of graphemic word processing have become paradigm cases for cognitive science and have been very successful in accounting for word and nonword reading and writing and their impairments. Although they were originally based on English, research has meanwhile been conducted on other languages and orthographies. Data are now available on several other European languages based on alphabetic scripts (French, German, and Italian), consonantal scripts (Hebrew), syllabic scripts (Japanese kana), and ideographic scripts (Chinese and Japanese kanji). Taken together, these studies point to the universality of two routes for reading, a lexical and a sublexical one, applying to nonalphabetic as well as alphabetic languages, and each route can be selectively impaired, thus suggesting their independent neural organization (Butterworth & Yin, 1991; Weekes, 2005). At the same time, neuroimaging studies of subjects in different alphabetic languages with a different degree of transparency between graphemes and phonemes suggest that a greater reliance on one or the other route depends on language-specific features (Paulesu et al., 2001). Given the similarity between languages with respect to the architecture of the model, future research can now focus on the role of specific differences.