Modality specific word comprehension deficits in deep dyslexia.

A deep dyslexic patient was tested on a series of experiments designed to assess her comprehension of abstract words. On tests where a precise semantic representation of words was required, performance was much poorer with visual than with auditory presentation. However, on some but not all categorisation tests performance with both modalities was good. It is argued that deep dyslexia can result from a modality-specific deficit in attaining the meaning of words together with a disorder of the phonological reading route.