Developmental dyslexia in a regular orthography: can the reading profile be reduced to strategic control?

In languages with regular orthographies, the identification of different forms of reading impairment (such as surface or phonological dyslexia) has proved elusive. Alternatively, it has been proposed that different patterns of errors depend upon strategic choices on the part of the reader. The present study aimed to test this strategic interpretation by evaluating the effectiveness of instructions to read quickly (or accurately) in modifying the reading rate and types of errors of dyslexic children. Further, drawing on an error classification based on the contrast between sounding-out behaviour and word substitution, we examined the types of reading error that best characterize the deficit in a language with regular orthography (Italian). Thirty children with dyslexia and 30 chronologically age-matched controls read aloud passages and word lists with instructions to emphasize either rate or accuracy. When asked to read quickly, children with dyslexia increased their reading rate (although less than skilled children). However, the type of instructions had little influence on reading errors. Therefore, the results did not support the view that strategic control has an important role in modulating the types of reading errors made by children with dyslexia. For word lists, sounding-out behaviour, errors in stress assignment, and form-related nonwords were useful to correctly identifying children with dyslexia. For text passages, sounding-out behaviour and form-related errors were the best predictors of group membership. Thus, specific types of errors are a fundamental component of the reading deficit in children who speak a language with regular orthography over and above their reading slowness.