An Activation Likelihood Estimation Meta-Analysis of How Language Balance Impacts the Neural Basis of Bilingual Language Control

Abstract

Background: Neurological networks involved in bilingual language control have been extensively investigated. Among the factors that influence bilingual language control, language balance has recently been proposed as a critical one. Nevertheless, it remains understudied how the neural basis of bilingual language control is affected by language balance. Methods: To address this gap, we conducted a meta-analysis of functional magnetic resonance imaging (fMRI) studies on bilingual language control using Ginger ALE, with language balance as a moderating factor. Results: Conjunction analyses revealed a domain-general pattern of neural activities shared by balanced and unbalanced bilinguals, with convergent activation observed in the left precentral gyrus and left medial frontal gyrus. Regarding domain-specificity, contrast analyses did not identify stronger activation convergence in balanced bilinguals compared to unbalanced bilinguals. However, unbalanced bilinguals exhibited significantly stronger convergence of activation in the left middle frontal gyrus, left inferior frontal gyrus, and left precuneus. Conclusions: These findings suggest that language balance can modify the neural mechanisms of bilingual language control, with unbalanced bilinguals relying on more domain-general cognitive control resources during bilingual language control.

Keywords: bilingual language control; fMRI; language balance; meta-analysis.

Figure 1

PRISMA flow diagram of the literature search for the meta-analysis.

Figure 2

Results of functional imaging meta-analyses. (A) Single-dataset analysis of studies on balanced bilinguals. (B) Single-dataset analysis of studies on unbalanced bilinguals. (C) Conjunction analysis between studies of balanced and unbalanced bilinguals. (D) Contrast analysis between balanced bilinguals and unbalanced bilinguals (unbalanced bilinguals > balanced bilinguals).