The Phonological deficit: Cause or consequence of reading disorders?

Castles, A.

Department of Cognitive Science, Macquarie University - Australia

The phonological core deficit hypothesis of dyslexia has dominated research in the field for several decades. In its strongest form, this hypothesis can be seen as reflecting three associated claims: a) that there is only one basic kind of dyslexia, b) that all (or at least the vast majority of) dyslexic children have phonological impairments, and c) that these phonological impairments cause their dyslexia. In this talk, I examine each of these claims in turn and consider evidence both for and against them. I conclude that, although it is clear that many dyslexics perform poorly on tasks designed to tap phonological skills, there is much still to be learned about why this is the case and what the nature of the relationship is between phonological abilities and reading. Evidence from precise and targeted studies is required to untangle the complex pattern of relationships observed.