Auditory Narrative Processing Elicits Consistent Event Structures in the Default Mode Network

Abstract

Event segmentation theory explains how we parse the continuous stream of information into meaningful event models. Narratives are useful stimuli for studying this phenomenon, as the flow of information and the way we make meaning of them mirrors how we comprehend and make sense of our daily lives. Many studies have focused on the segmentation of audiovisual stimuli such as movies. In this study, we investigated how the brain parses narrative information when the input was only auditory, using two story recordings. Behaviorally annotated boundaries of the story text were analyzed and used as the behavioral benchmark for the neural-behavioral comparison of event structures. Our results showed that the angular gyrus and posterior cingulate cortex activity produced neural event structures that significantly matched with the behavioral event structures, while the early auditory and early visual cortices’ neural-behavioral matches were not consistently significant for both stories. This pattern demonstrated that successful matching in the default-mode network regions was related to neural processes involved with parsing the continuous narratives, rather than changes in sensory-related features. Our study also found nuanced differences between AG and PCC’s neural response to audio-only narratives, which suggests a potentially more prominent role for the angular gyrus in processing narratives that are presented solely auditorily than might be expected from data on visuo-auditory stories.