Thoughts and cortical responses are shaped by the type of change at event boundaries

Ketcheson, S.; Wallace, R. S.; Zhou, S. S.; Hardikar, S.; Mulholland, B.; Chitiz, L.; Gallivan, J.; Leech, R.; Smallwood, J.; Jefferies, E.; Wammes, J. D.

doi:10.64898/2026.10.12.758535

bioRxiv · 10.64898/2026.10.12.758535

Thoughts and cortical responses are shaped by the type of change at event boundaries

Ketcheson, S.·Wallace, R. S.·Zhou, S. S.·Hardikar, S.·Mulholland, B.·Chitiz, L.·Gallivan, J.·Leech, R.·Smallwood, J.·Jefferies, E.·Wammes, J. D.

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Abstract

Continuous experience is divided into discrete and meaningful events, but different kinds of event transitions may shape thought and brain activity in different ways. We examined how perceived event boundaries relate to visual, auditory, and semantic features, ongoing thought, and large-scale cortical states during movie-watching. We combined three independent samples who viewed the same eight movie clips, aligning these measures to a shared stimulus timeline: One marked event boundaries, one reported ongoing thought, and one was scanned with fMRI. Whole-brain spatial correlations showed that event boundaries correlated positively with visual change and negatively with auditory change, but not with any thought pattern. Time-resolved analyses showed that boundaries were associated with a reduction in distracted thoughts and brain states positioned toward visual processing. Clustering boundaries by movie feature change profile identified visual, semantic, interruption, and narrative boundary types. All four types showed a shift toward visual processing in the brain, but their other associations differed. Visual boundaries were associated with less distraction, semantic boundaries with thoughts related to past experience and prior knowledge, and narrative boundaries with more detailed and deliberate thoughts. Visual and semantic boundaries also showed distinct shifts in brain state that were not apparent in the other two types. These findings suggest that event boundaries mark a set of state shifts in ongoing experience, with a shared reorientation toward visual processing and changes in thought and brain state that vary with the type of transition.

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Ketcheson, S., Wallace, R. S., Zhou, S. S., Hardikar, S., Mulholland, B., Chitiz, L., Gallivan, J., Leech, R., Smallwood, J., Jefferies, E., Wammes, J. D.. 2026-10-13. Thoughts and cortical responses are shaped by the type of change at event boundaries. https://doi.org/10.64898/2026.10.12.758535

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