First-person spoken narratives elicit consistent event structures in the angular gyrus

Abstract

Event segmentation theory explains how we parse a stream of continuous 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 investigated the segmentation of audiovisual stimuli, such as movies, but only a handful of studies focused on how the brain parses auditory-only narrative. Using two stories with rich narrative features, we asked participants to listen to the story-recordings while being scanned with fMRI. We then recruited two separate groups of behavioral participants to parse the stories, either via transcript (visual-only) or recording (audio-only). Annotated boundaries from the two modalities were analyzed and used as behavioral benchmarks for the neural-behavioral comparison of event structures. We examined four regions of interest (angular gyrus, posterior cingulate cortex, early auditory cortex, and early visual cortex) and found that only the angular gyrus produced neural event structures that significantly matched with the behavioral event structures across both modalities and both stories. Our results indicate that activity in the angular gyrus is associated with the neural processes involved in parsing continuous narratives, particularly when these narratives are audio-only and contain ambiguous event transitions, rather than with changes in sensory-related features.