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Background: Patients with the semantic variant of Primary Progressive Aphasia (svPPA) offer a unique opportunity to study the relationship between lexical retrieval and semantics, as they are characterised by progressive degradation of central semantic representations. However, there are few studies of how lexical retrieval across languages is affected in multilingual speakers. Aims: We examine the impact of conceptual degradation in a trilingual patient (TC) with svPPA, to investigate whether the semantic memory breakdown affects her three languages similarly (English-Catalan-Spanish) in different linguistic tasks. Methods & Procedures: We followed up her performance over one year in several tasks including: (a) naming with or without semantic interference contexts, (b) word translation, (c) word- and sentence-picture matching, (d) associative semantic priming and (e) language switching. Outcomes & Results: There was significant response consistency between languages in the items that were relatively well-known and more semantically degraded, at least in a standard picture naming task. The patient’s sentence-to-picture matching did not show progressive deterioration in any language. However, some aspects of lexical retrieval showed language-dependency, as indexed by different patterns of performance in semantically-blocked cyclical naming task across languages. Conclusions: These data suggest that while degradation of central semantic representations affects all languages, this deficit can be amplified or ameliorated by the strength of conceptual to lexical mappings, which varies across languages.
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... Furthermore, language switching tasks have been useful in assessing the integrity of BLC mechanisms. Calabria et al. [23] found that, in semantic dementia, switching abilities measured via language switching tasks may be spared despite a marked degradation of semantic memory and anomic deficits. Finally, a series of studies in patients with neurodegeneration in the basal ganglia have highlighted an increased impact on BLC deficits compared to other control mechanisms; results indicated that language switching abilities can be more affected than non-linguistic control abilities in bilingual patients with Parkinson's disease (PD) [20] and that language switching is clearly dissociated from other language control abilities [21]. ...
... Interestingly, although Pt 3 committed a large number of omission errors across trials (see Table 5), she did so without any clear deficit in language task engagement or disengagement, as she was able to manage cross-language interference and perform switches during the dual-language condition. These results clearly suggest that word production deficits in bilinguals are to some extent dissociated from the deficits in controlling the two languages [23], as the neural models of bilingualism would also suggest. Although these two systems overlap in a number of brain areas [2,5,66], some are specific to language control and the absence of language control deficits in BWAs could indicate that said areas are spared from brain damage. ...
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