A common neural code for meaning in discourse production and comprehension

Abstract

AbstractHow does the brain code the meanings conveyed by language? Neuroimaging studies have investigated this by linking neural activity patterns during discourse comprehension to semantic models of language content. Here, we applied this approach to the production of discourse for the first time. Participants underwent fMRI while producing and listening to discourse on a range of topics. We quantified the semantic similarity of different speech passages and identified where similarity in neural activity was predicted by semantic similarity. A widely distributed and bilateral network, similar to that found for comprehension, showed such effects when participants produced their own discourse. Critically, cross-task neural similarities between comprehension and production were also predicted by similarities in semantic content. These results indicate that discourse semantics engages a common neural code during both comprehension and production. Furthermore, common coding in right-hemisphere regions challenges the idea that language production processes are strongly left-lateralised.