Weaving a story: narrative formation over prolonged time scales engages social cognition and fronto-parietal networks.

Forming narratives is of key importance to human experience, enabling one to render large amounts of information into relatively compacted stories for future retrieval, giving meaning to otherwise fragmented occurrences. The neural mechanisms that underlie coherent narrative construction of causally-connected information over prolonged temporal periods are yet unclear. Participants in this fMRI study observed consecutive scenes from a full-length movie either in their original order, enabling causal inferences over time, or in reverse order, impeding a key component of coherent narratives - causal inference. In between scenes, we presented short periods of blank screens for examining post-encoding processing effects. Using multivariate pattern analysis (MVPA) followed by seed-base correlation analysis, we hypothesized that networks involved in online monitoring of incoming information on the one hand, and offline processing of previous occurrences on the other would differ between the groups. We found that despite the exposure to the same scenes, the chronological order condition exhibited enhanced functional connectivity in fronto-parietal regions associated with information integration and working-memory. The reverse-order condition yielded offline, post-scene co-activation of neural networks involved in social cognition, and particularly theory-of-mind and action comprehension. These findings shed light on offline processes of narrative construction efforts, highlighting the role of social cognition networks in seeking for narrative coherence.