Modulatory effects of language context and language familiarity on flanker task performance in multilinguals

The advantages of bilingualism on executive functioning have received intense attention over the past decade. However, characterizing what makes someone bilingual versus monolingual is complicated. Experiment 1 explores the impact of multilingualism and English-Mandarin language context priming on flanker task performance. Here, multilingualism is measured using the Multilingual Language Diversity (MLD) score. Experiment 2 investigates the influence of a familiar-unfamiliar language context priming (English-Welsh) on the flanker task performance. Experiments 1 and 2 found no significant differences between language contexts. However, the mean RT was similar between the control block and the mixed-language block in Experiment 1, but significantly different in Experiment 2. Only in Experiment 1 did higher MLD scores predict better performance on the flanker task, but only in mixed-language contexts (e.g., English and Mandarin) and not in single-language contexts (e.g., English or Mandarin only) While there were no significant language block differences in Experiment 2, the patterns of results were unexpectedly similar to Experiment 1, where the fastest RT was the control, followed by the mixed and single language blocks. This suggests that the effects of language contexts and the degree of multilingualism are limited to executive function. Additionally, while there were no effects of language familiarity on executive function, the pattern was similar for familiar and unfamiliar language contexts, and this warrants further investigation.