Artificial grammar learning in vascular and progressive non-fluent aphasias

Publication date: Available online 24 August 2017 Source:Neuropsychologia Author(s): Thomas E. Cope, Benjamin Wilson, Holly Robson, Rebecca Drinkall, Lauren Dean, Manon Grube, P. Simon Jones, Karalyn Patterson, Timothy D. Griffiths, James B. Rowe, Christopher I. Petkov Patients with non-fluent aphasias display impairments of expressive and receptive grammar. This has been attributed to deficits in processing configurational and hierarchical sequencing relationships. This hypothesis had not been formally tested. It was also controversial whether impairments are specific to language, or reflect domain general deficits in processing structured auditory sequences. Here we used an artificial grammar learning paradigm to compare the abilities of controls to participants with agrammatic aphasia of two different aetiologies: stroke and frontotemporal dementia. Ten patients with non-fluent variant primary progressive aphasia (nfvPPA), 12 with non-fluent aphasia due to stroke, and 11 controls implicitly learned a novel mixed-complexity artificial grammar designed to assess processing of increasingly complex sequencing relationships. We compared response profiles for otherwise identical sequences of speech tokens (nonsense words) and tone sweeps. In all three groups the ability to detect grammatical violations varied with sequence complexity, with performance improving over time and better for adjacent than non-adjacent phonological relationships. Patients performed less we...
Source: Neuropsychologia - Category: Neurology Source Type: research