Purpose: Of the three currently recognized variants of primary progressive aphasia, behavioral differentiation between the nonfluent/agrammatic (nfvPPA) and logopenic (lvPPA) variants is particularly difficult. The challenge includes uncertainty regarding diagnosis of apraxia of speech, which is subsumed within criteria for variant classification.…

Investigated the time course of activation of the mental representations of word meanings in a series of three cross-modal priming experiments. The study interprets the data with respect to both localist and distributed implementations of the cohort model. Results indicate that if early competition among simultaneously activated meanings exists,…

Examines semantic errors produced by normal and aphasic speakers on a picture naming test for their phonological similarity to the targets they replace. A second study examines phonological relationships within sets of semantically related words and shows there is no tendency for these words to share phonological characteristics. (35 references)…