The neural correlates of semantic feature analysis in chronic aphasia: discordant patterns according to the etiology.

This event-related functional magnetic resonance imaging (fMRI) study reports on the impact of semantic feature analysis (SFA) therapy on the neural substrate sustaining the recovery from severe anomia in two patients: one participant was diagnosed with primary progressive aphasia (PPA) 2 years before this study; the other participant acquired aphasia 8 years before this study. The participant with PPA showed severe progressive nonfluent aphasia (PNFA), the language profile being similar to a Broca's aphasia; the stroke patient presented with Broca's aphasia and a severe apraxia of speech (AOS). To examine the neural substrate allowing for recovery, both patients received brief and intensive therapy with SFA; behavioral and event-related (ER)-fMRI measures during oral picture naming were obtained pre- and post-therapy. Both patients benefitted from SFA to improve their naming performance. Functional MRI performances on trained and correct pretraining items were contrasted. Adaptive brain plasticity appeared to operate differently in each patient, despite the similarity of naming recovery profiles.