Regions of Dysfunctional Neural Tissue Associated with Impairment of the Graphemic Buffer in Spelling

摘要

The graphemic buffer is a working memory component of the spelling system that temporarily stores the sequence of graphemes while each grapheme is written or spelled aloud. We evaluated 331 patients with left hemisphere stroke on oral and written spelling to dictation, and written picture naming tasks and MRI including within 48 hours of stroke onset. Spelling performance was examined to identify presence or absence of graphemic buffer deficit. A voxel-wise chi-square map revealed that graphemic buffer deficits were associated with ischemia in pre- and post-central gyri, posterior inferior frontal and lateral occipital cortex.