Effects of feedforward and feedback consistency on reading and spelling in dyslexia.

We investigated the effects of rime consistency on reading and spelling among dyslexic children and a group of matched reading age skilled readers by manipulating consistency of orthography-tophonology (OP) mappings and consistency of mappings from phonology-to-orthography (PO). For both dyslexic and control children we found feedforward consistency effects on reading (O->P) and spelling (P->O) and feedback (O->P) consistency effects on spelling. Dyslexic children demonstrated feedback (PO) consistency effects in reading but control children did not. Our results challenge accounts of reading and spelling in dyslexia that assume feedforward consistency effects alone. We consider the implications of these results in relation to theories in which children may assess candidate responses for goodness of fit to prior expectations. We discuss the wider implications of our results for the assessment and remediation of dyslexia.