The Neurocognitive Mechanisms Underlying Narrative Schematic and Paraphrastic Transmission

Narrative transmission serves multiple crucial functions, such as cultural preservation, knowledge accumulation, and consensus building, in human society. However, our understanding of its neurocognitive mechanisms remains limited. In this study, we combined a social transmission chain design with fMRI to investigate the dynamic changes of different narrative components occurring throughout transmission chains and to uncover the factors driving fidelity and distortion. A total of 58 participants were scanned as they listened to and subsequently recalled a story within a social transmission chain. We distinguished two types of transmission modes: schematic transmission, which prioritizes preserving the structural framework of the information, and paraphrastic transmission, which entails rephrasing the content while conveying its meaning. Behavioral results revealed a pattern in which paraphrastic transmission led to distortion and divergence, whereas schematic transmission remained more stable and convergent. Neural findings indicated that the transmission of story structure and content involved subsystems of the Default Mode Network (DMN) and specific subregions of the Hippocampus (HPC). While neural reinstatement between narrative listening and speaking failed to predict across-generation fidelity of content and structure, functional connectivity pattern similarity analysis showed that the DMN and HPC work as an episodic memory system supporting transmission performance. These findings highlight that narrative transmission is supported by distinct neurocognitive representations within episodic memory subsystems, which work collaboratively to sustain the transmission of narratives.