Verbal fluency as a measure of lexical access and cognitive control in bilingual persons with aphasia
- 14 May 2020
- journal article
- research article
- Published by Taylor & Francis Ltd in Aphasiology
- Vol. 34 (11), 1341-1362
- https://doi.org/10.1080/02687038.2020.1759774
Abstract
Background: Lexical access in bilinguals can be influenced by the demands that different interactional contexts pose on cognitive control processes. However, how varying cognitive control demands impact lexical access in bilingual persons with aphasia (BPWA) remains unclear. Verbal fluency tasks may provide valuable insights into the interplay between cognitive control and lexical access in BPWA by addressing word generation abilities in language contexts that exert varying degrees of cognitive control effort. Aims: The present study aimed to examine the performance of BPWA on a semantic category generation task that required word retrieval in single and dual-language contexts under varying cognitive control demands and a traditional letter fluency task conducted in single-language contexts. We also examined the associations between verbal fluency performance and (i) bilingual language history, and (ii) performance on standardized language assessments in both BPWA and healthy bilinguals. Methods and Procedures: Thirteen Spanish-English BPWA and twenty-two Spanish-English healthy bilinguals completed a language use questionnaire, verbal fluency testing and standardized language assessments in each language. The semantic category generation task included four conditions: two conditions examined word retrieval in the first-acquired (L1) and second-acquired language (L2) in single language contexts (No Switch-L1 and No Switch-L2) and two conditions elicited word retrieval in dual-language contexts (Self-Switch and Forced-Switch) with low and high cognitive control demands by allowing or restricting switching across languages. The letter fluency task was administered in single language contexts only (F, A, S for English and P, M, R for Spanish). Verbal fluency performance was compared across conditions and groups using multivariate analyses. Further, correlational analyses were used to examine associations between verbal fluency tasks and bilingual language history, language assessments, and cognitive function. Outcomes and Results: Overall, the healthy bilinguals produced a higher proportion of accurate words in both verbal fluency tasks relative to the BPWA. Results indicate that BPWA were more sensitive to the effects of increased cognitive control on lexical access relative to healthy bilinguals. BPWA and healthy bilinguals’ performance on both verbal fluency tasks was associated with metrics of bilingual language history and standardized language assessments. Additionally, for BPWA, L2 letter fluency performance was associated with cognitive function. Conclusion: Our findings suggest that verbal fluency tasks can help characterize the impact of cognitive control on lexical access in BPWA in single and mixed language contexts with important clinical implications.Keywords
Funding Information
- National Institutes of Health (U01DC014922)
This publication has 34 references indexed in Scilit:
- Language control in bilinguals: The adaptive control hypothesisJournal of Cognitive Psychology, 2013
- Is it time to leave behind the Revised Hierarchical Model of bilingual language processing after fifteen years of service?Bilingualism: Language and Cognition, 2010
- Bilingual MindsPsychological Science in the Public Interest, 2009
- Spanish Multicenter Normative Studies (NEURONORMA Project): Norms for Verbal Fluency TestsArchives of Clinical Neuropsychology, 2009
- Bilingual language production: The neurocognition of language representation and controlJournal of Neurolinguistics, 2007
- Language selectivity is the exception, not the rule: Arguments against a fixed locus of language selection in bilingual speechBilingualism: Language and Cognition, 2006
- A Meta-Analytic Review of Verbal Fluency Performance Following Focal Cortical Lesions.Neuropsychology, 2004
- Adult Age Differences in Strategy Use During Verbal Fluency PerformanceJournal of Clinical and Experimental Neuropsychology, 2002
- Commonalities and differences in the working memory components underlying letter and category fluency tasks: A dual-task investigation.Neuropsychology, 2002
- Bilingual Language Mixing: Why Do Bilinguals Code-Switch?Current Directions in Psychological Science, 2001