Modality-independent impairments in word processing in a deep dyslexic patient.

An extensive study of the language abilities of one deep dyslexic patient, B.L., was undertaken. Tests of his ability to comprehend and produce words in the auditory, verbal, and graphic modalities revealed striking similarities in performance across modalities, such that the defining symptoms of deep dyslexic reading also held true for this patient’s writing, repetition, and naming. A new dual-deficit model of deep dyslexia is presented which predicts that a variety of “deep dyslexic” syndromes may occur with or without modality-specific impairments.