Reading has been thought to consist of three main processing components: the orthographic, phonological, and semantic lexicons. In traditional psycholinguistic models, these components have been treated independently such that the selective dysfunction of one does not necessarily imply the breakdown of another. Recently, it has been proposed that a word's semantic representation is essential to...

Primary progressive aphasia (PPA) is a group of disorders with progressive language impairment. Abnormal behaviour may develop in PPA as the disease evolves, but the clinical features and brain basis of behavioural change in PPA have not been fully defined. 33 PPA patients (9 semantic dementia, SD, 14 progressive nonfluent aphasia, PNFA, 7 logopenic/phonological aphasia, LPA and 3 patients with...