Bilingualism modulates functional connectivity induced by a domain-general artificial grammar learning task.

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 post-task alterations to connectivity involving increased involvement of occipital regions, reduced involvement of frontal and central regions, and faster reaction times to stimuli at higher levels of bilingual experience. Crucially, the regions implicated post-task appear to reflect task-relevant regions which are involved in the language and executive control networks, reflecting greater short-term task-driven flexibility. These findings have important implications for our understanding of how domain-general processing and connectivity are shaped by linguistic experience.