Phonological agraphia

Abstract

Two writing routes (phonological and lexical) were postulated. Four patients were studied who had disruption of the phonological route (i.e. inability to write pronounceable nonwords) but with a preserved lexical route. The phonological route has 2 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 [computed tomography] suggest that a portion of the supramarginal gyrus is the most likely anatomic substrate of phonological agraphia.