Executive functioning during verbal fluency tasks in bilinguals: A systematic review

Background: Bilingualism is widespread and being bilingual is more com- mon than being monolingual. The lifelong practice bilinguals receive from managing two languages seems to lead to a cognitive benefit. Conversely, bilin- gualism seems to affect language ability negatively due to less use of each known language. Aims: This systematic review aims to summarize the results of the studies on the effect of bilingualism on executive functioning assessed by verbal fluency tasks. The verbal fluency task is a neuropsychological measure of lexical retrieval efficiency and executive functioning. Methods: The review was conducted according to the PRISMA statement through searches in the scientific databases PsycINFO, PsycARTICLES, MED- LINE, PubMed, Web of Science and SCOPUS. Studies included in this review had at least one bilingual and monolingual group, participants over 18 years and one verbal fluency task. Studies that considered bimodal bilingual, second lan- guage learners, trilingual or multilingual people, and clinical populations were excluded. A total of 38 studies were included in the systematic review. Main Contribution: Quantitative analysis of performance did not show signif- icant differences between monolinguals and bilinguals. Qualitative results are mixed, and no definitive conclusions can be drawn about a bilingual advantage or disadvantage in the verbal fluency tasks. Conclusions: Normative data based on the monolingual population are not appropriate to test a bilingual population. It is necessary to take precautions in using this task, especially in clinical practice.