Selective writing impairment: Beyond the allographic code

A single subject (MP) with a selective writing impairment persisting after recovery from transcortical sensory aphasia due to left parieto-occipital haemorrhage, was evaluated with reference to current models of writing. His writing deficit was localized to the post-graphemic stages and more specifically, to the stage in which the allographic code is transferred to the graphic motor pattern store. A detailed error analysis, with attention to graphic motor complexity and letter frequency, enabled us to specify the factors influencing this transfer process and provides new insight into the neuropsychological mechanisms involved in writing.