Emotional influences on cognitive control: a missing factor in research on 'bilingual advantages'?

Over half of the world’s population is multilingual with globalisation and migration ensuring a steady growth. This fact has inspired several flourishing research fields within the areas of emotion, cognition and linguistics. Yet, existing research on cognitive consequences of bilingualism has not taken into account the effect of emotion on this relationship. This dissertation addresses this gap. Based on the hypothesis that bilingualism leads to adaptations in the mechanisms underlying both emotion and cognitive control, we propose a framework that integrates theoretical and empirical perspectives from emotion, cognition, and linguistics research. To validate our approach, we devise three novel studies in order to test cognition–emotion interactions across different groups of monolinguals and bilinguals. In Study 1, 24 English monolingual and 24 German–English bilingual adults completed a flanker-go/no-go (FNG) task. The participants viewed sets of three faces side-by-side in the centre of a computer screen and were instructed to press a button if the gender of the central neutral target face corresponded to the ‘go’ gender, which occurred in 66% of trials. The task-irrelevant ‘flanker’ faces expressed either positive, negative, or neutral emotion and were furthermore either gender-congruent or -incongruent to the target. In Study 2, 28 diverse bi- and multilingual adults completed the FNG task alongside 28 monolinguals. In addition, 29 monolinguals and 29 bilinguals completed a forced-choice flanker-only (FO) variant of the task. Study 3 repeated Study 2 with 10–11 year-old monolingual and English–French/German bilingual children. 36 bilinguals and 20 monolinguals completed the FNG task, while 35 bilinguals and 23 monolinguals completed the FO task. Differences between the monolingual and bilingual groups were observed across all studies in the FNG task, but not in the FO task. Notably, the bilingual children also made significantly fewer errors in no-go trials across all conditions than their monolingual counterparts, providing novel evidence for a bilingual advantage in response inhibition. In Study 2, the multilinguals evidenced different response strategies than the other groups, suggesting that adaptations in cognitive control can vary based on the type of multilingual experience. We interpret these findings based on an integrative theoretical framework of cognitive control, emotion, and bilingualism, and discuss their implications for research across all three fields.