This study combines brain recordings from two people at once with a computational model that treats learning like tracking predictions and surprises. When participants learned by doing, their brains leaned on expected outcomes; when they learned by watching others, surprise signals played a bigger role. The result suggests people weight feedback differently depending on whether they are acting or observing, and that those differences show up both in behavior and in neural rhythms linked to control.
For anyone curious about human potential, this work points to mechanisms that make bilinguals flexible and socially sensitive learners. The findings raise useful questions: how might teachers or teammates shape learning by changing what counts as a helpful reward? Follow the link to see how measuring brains together and fitting models reveals the subtle ways social feedback sculpts language control.
Abstract
Language control is a cognitive ability that bilinguals use to suppress interference from the language they are not currently using to accurately select and use the intended language. Adaptive language control underpins language switching and enables bilinguals to flexibly switch between languages according to context. Reinforcement learning, which models how individuals update their strategies based on reward prediction errors, provides a computational framework for studying adaptive behavior in changing environments. To investigate how bilingual language control is shaped by reward signals in social interactions, we used dual-electroencephalography (EEG) to measure the performance of bilinguals who alternated between active and observational learner roles in voluntary language switching tasks. Computational modeling results indicated that the dual-sensitivity model best captured behavior which showed that bilinguals adaptively updated values by assigning distinct weights to feedback from themselves and others. EEG analyses revealed that bilinguals relied on expected values during active learning and on prediction errors during observational learning to modulate delta band activity. Taken together, these findings reveal how rewards dynamically modulate language control through expected values and prediction errors, providing new evidence for the adaptability of bilingual control during social interaction.
