Constructing and expressing the story world: neural correlates of narrative generation.

Narrative generation requires the integration of linguistic, social, and conceptual knowledge to transform internal representations into coherent discourse. Few studies have examined how the distinct stages of comprehension and production are supported by the brain. In this fMRI study, 27 participants viewed a nine-panel cartoon, planned a story, and then orally produced it during scanning. Story comprehension elicited greater activation than fixation within the default mode network (DMN), including medial prefrontal cortex, posterior cingulate cortex, and precuneus, as well as the right insula, regions implicated in situation model construction, emotional inference, and mental simulation. Story production engaged a broader bilateral network encompassing hippocampus, basal ganglia, right temporoparietal junction (TPJ), and left anterior temporal lobe (ATL), reflecting additional demands on lexical selection, memory retrieval, and social-cognitive processes. Exploratory regression analyses revealed that higher lexical diversity (Maas) was associated with reduced activation in the right inferior frontal gyrus during comprehension and increased activation in the precuneus. Regression analysis also showed that a measure of social cognition (TASIT) was associated with cerebellar activation, supporting its emerging role in mentalizing and social prediction. These findings demonstrate that narrative generation relies on dynamic interactions among DMN, language, and cerebellar systems, with comprehension and production sharing a common representational foundation but diverging in their linguistic, memory, and social-cognitive demands. Regression results highlight potential neural mechanisms linking individual differences in lexical and social processing to narrative performance.