Increased interbrain synchronization of the left middle frontal gyrus benefits learning word formation rules in social interaction: An fNIRS hyperscanning study

Communication during interactions affects the acquisition of new knowledge, which can be shared and understood by others. However, the effects of such communication on learning word formation rules have gone relatively underexplored, particularly in the context of social interaction. The current study uses functional near-infrared spectroscopy-based hyperscanning techniques to capture how communication about word formation rules influences word learning. The materials consisted of pseudowords that were either lower or higher on the Perceptual Saliency Hierarchy. Perceptual saliency refers to the way our brains prioritize what we perceive. The hierarchy holds that color is perceived more easily than shape, and shape more easily than texture (i.e., color > shape > texture). Dyads of learners showed increased accuracy of learning word formation rules after communicating about relevant topics, which also elicited increased interbrain synchronization and high representation similarity in the left middle frontal gyrus and right superior frontal gyrus, thereby improving collaborative and coordination skills, particularly when learning difficult word formation rules. In all, these findings suggest that communicating about relevant topics is beneficial to word learning in social interaction.