Bilingualism modulates domain-general functional connectivity: insights from EEG and artificial grammar learning

Bilingualism is associated with distinct patterns of resting-state functional brain connectivity – a consequence of ongoing language control demands that do not apply to monolinguals. However, it is not well understood how these patterns affect, and are affected by, brain activation for domain-general cognitively demanding tasks. Here, we employ a novel task-driven resting-state electroencephalography design including an implicit Lindenmayer grammar learning task, which tracks aperiodic and hierarchical dependencies, to determine task-related functional connectivity changes in bilinguals. Quantified bilingual experience was used as a predictor of directional effects, using Generalised Additive Models to account for non-linear patterns. Our results revealed whole-brain post-task alterations to connectivity, including increased involvement of bilateral temporal and posterior regions and reduced involvement of frontal regions. Crucially, greater bilingual experience was associated with more distributed processing, suggesting enhanced efficiency. These findings have important implications for our understanding of how domain-general processing and connectivity are shaped by linguistic experience.