Schedule of Events | Symposia

The One with the Neural Synchrony: How Long-Term Shared Narrative Experiences Shape Brain Activity Over Time

Poster Session C - Sunday, March 30, 2025, 5:00 – 7:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Joshua Koh¹, Alexander Barnett^2,3; ¹Integrated Program in Neuroscience, McGill University, ²Department of Neurology & Neurosurgery, McGill University, ³The Neuro (Montréal Neurological Institute-Hospital), McGill University

People’s brain activity meaningfully synchronizes during shared experiences, but synchrony in higher-order regions is restricted to coherent events. If higher-order regions represent the abstract features of events that are integrated over longer timescales, then shared prior knowledge should increase their synchrony. However, few studies have examined how the accumulation of shared prior knowledge (for a given context) over extended periods of time (e.g., weeks or months) might influence such shared brain activity. In this study, we examined how shared neural representations evolved over time using a unique dataset in which six participants watched episodes of the TV show Friends (Seasons 1 to 4, in sequence) while undergoing fMRI scanning. In an additional exploratory analysis, we investigated the relationship between these shared neural responses and the IMDb ratings of the Friends episodes. Results indicated that networks responsible for top-down attentional control, motor control, salience detection, and the representation of event-related semantic knowledge showed increased synchrony over long-term shared experiences. A notable exception was regions within the language network, which exhibited decreased neural synchrony over time. Interestingly, all networks exhibited a significant positive relationship between neural synchrony and individual episode IMDb ratings. This was particularly evident in networks associated with attention, visual, and event processing. These findings suggest that collective audience reception and engagement to multi-modal narratives may be reflected in the extent of shared brain activity, as well as offer new insights into how long-term exposure to shared content shapes neural representations.

Topic Area: LONG-TERM MEMORY: Semantic