Impaired visual processing of letter and digit strings in adult dyslexic readers.

The slow word reading of developmental dyslexics may stem from a string processing impairment which in turn reflects visual attentional deficits. We indeed found substantially enhanced recognition time thresholds in the dyslexic adult readers. However, their position profiles were hard to reconcile with any of the discussed visual attentional deficit hypotheses and with the prediction that dyslexic readers suffer from an absent string processing system as they exhibited similar M-shaped position profiles for digit and letter strings as the normal reading controls.