Event segmentation is a spontaneous part of perception, important for processing continuous information and organizing it into memory. Although neural and behavioral event segmentation show a degree of inter-subject consistency, meaningful individual variability exists atop these shared patterns. Here we characterized individual differences in the location of neural event boundaries across four short movies that evoked variable interpretations. Event boundary alignment across subjects followed a posterior-to-anterior gradient that was tightly correlated with the rate of segmentation: slower-segmenting regions that integrate information over longer time periods showed more individual variability in boundary locations. This relationship held irrespective of the stimulus, but the degree to which boundaries in particular regions were shared versus idiosyncratic depended on certain aspects of movie content. Furthermore, this variability was behaviorally significant in that similarity of neural boundary locations during movie-watching predicted similarity in how the movie was ultimately remembered and appraised. In particular, we identified a subset of regions in which neural boundary locations are both aligned with behavioral boundaries during encoding and predictive of stimulus interpretation, suggesting that event segmentation may be a mechanism by which narratives generate variable memories and appraisals of stimuli.

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Event segmentation is a spontaneous part of perception, important for processing continuous information and organizing it into memory. While neural and behavioral event segmentation show a degree of inter-subject consistency, meaningful individual variability exists atop these shared patterns. Here we characterized individual differences in the location of neural and behavioral event boundaries across four short movies that varied in both high- and low-level features and evoked variable interpretations. We studied the same individuals across movies to investigate the extent to which individual segmentation styles are stable irrespective of the stimulus (i.e., "trait-like") versus content-dependent. Results showed that across-subject event boundary alignment follows a posterior-to-anterior gradient that is tightly correlated with the rate of segmentation; slower segmenting regions that integrate information over longer time periods show more individual variability. We found that certain aspects of movie content-namely, continuity editing and social content-drive more shared boundaries and are better suited to pull out individual differences. We identified a subset of regions, specific to each movie, in which neural boundary locations are both aligned with behavioral boundaries during encoding and predictive of stimulus interpretation, suggesting that event segmentation may be a mechanism by which narratives generate variable memories and appraisals of stimuli.