The brain in conversation: Mapping the neural correlates of turn-taking, production, and comprehension using fMRI

Sammanfattning: Conversation is the primary mode of language use. A key feature of conversation is turn-taking, during which interlocutors rapidly switch between speaker and listener roles without conscious effort. As previous neuroimaging studies have investigated language comprehension in isolated contexts, little is known regarding the neurocognitive bases of language use in reciprocal interaction. The present fMRI study investigates turn-taking, production, and comprehension processes, by utilizing existing conversational data between participants (N = 23) and a confederate outside the scanner. Turn initiations were associated with regions (the medial prefrontal cortex and the middle frontal gyrus) outside of the perisylvian core language network. Production and comprehension were both associated with core language regions in the temporal lobes, but activation in the left inferior frontal gyrus was mainly associated with production. Activation in the fusiform face area was linked to comprehension. The current findings suggest that (1) the coordination of speaker change is dependent on pragmatic processes that have been relatively overlooked in models of speech preparation, and (2) listeners are aided by their interlocutor's facial gestures when processing speech input during conversation. In addition, the results indicate that production and comprehension processes may differ (e.g., on the syntactic level), even in conversation.