Phonological agraphia

Abstract

Two writing routes (phonological and lexical) have been postulated. We studied four patients who had disruption of the phonological route (ie, inability to write pronounceable nonwords) but with a preserved lexical route. Results showed that the phonological route has two components: segmentation and phoneme-grapheme conversion. Disruption of either function may induce phonological agraphia. The preserved lexical route uses a whole-word mechanism and is strongly affected by semantic factors, such as imageability, emotionality, and grammatic class. Results of CT suggest that a portion of the supramarginal gyrus is the most likely anatomic substrate of phonological agraphia.