Cognitive control for language switching in bilinguals: A quantitative meta-analysis of functional neuroimaging studies

TLDR

Bilingual language production relies on neural control mechanisms, with prior studies highlighting key regions involved in language switching. The study aimed to evaluate the bilingual cognitive control model by quantitatively meta‑analyzing neuroimaging data on language switching. The authors performed an activation likelihood estimation meta‑analysis on ten neuroimaging studies, contrasting language‑switching trials with baseline single‑language conditions. The meta‑analysis identified eight reliably activated regions—left inferior frontal, left middle temporal, left middle frontal, right precentral, right superior temporal, pre‑SMA, and bilateral caudate—supporting caudate/prefrontal involvement in switching and extending prior qualitative models.

Abstract

In a quantitative meta-analysis, using the activation likelihood estimation method, we examined the neural regions involved in bilingual cognitive control, particularly when engaging in switching between languages. The purpose of this study was to evaluate the bilingual cognitive control model based on a qualitative analysis [Abutalebi, J., & Green, D. W. (2008). Control mechanisms in bilingual language production: Neural evidence from language switching studies. Language and Cognitive Processes, 23, 557-582.] After reviewing 128 peer-reviewed articles, ten neuroimaging studies met our inclusion criteria and in each study, bilinguals switched between languages in response to cues. We isolated regions involved in voluntary language switching, by including reported contrasts between the switching conditions and high level baseline conditions involving similar tasks but requiring the use of only one language. Eight brain regions showed significant and reliable activation: left inferior frontal gyrus, left middle temporal gyrus, left middle frontal gyrus, right precentral gyrus, right superior temporal gyrus, midline pre-SMA and bilateral caudate nuclei. This quantitative result is consistent with bilingual aphasia studies that report switching deficits associated with lesions to the caudate nuclei or prefrontal cortex. It also extends the previously reported qualitative model. We discuss the implications of the findings for accounts of bilingual cognitive control.