摘要：Primary Progressive Aphasia (PPA) is a neurodegenerative disease that affects primarily language abilities.Spelling is amongst the first language abilities affected in PPA with prognostic and diagnostic value for the variantof PPA (Sepelyak et ah, 2011). Recent studies have led to the following hypotheses regarding the neural networksthat support two of the main spelling mechanisms: (1) the mechanism of access to the orthographic lexicalrepresentations for the spelling of known words depends in left inferior frontal gyrus and midfusiform gyrus (2) themechanism of phoneme-grapheme conversion (PGC) for the spelling of unfamiliar words depends on left inferiorfrontal gyrus and supramarginal gyrus. Evidence for these neural networks is based in acute stroke studies (Philiposeet al., 2007), case-studies of tumor resections (Tsapkini and Rapp, 2010), and a meta-analysis of chronic strokestudies and fMRI studies of healthy controls (Purcell et al., 2011). In the present study we aimed to evaluate thesehypotheses in PPA in order to subsequently implement targeted neuromodulatory interventions for spelling in PPA.
