How does the brain process continuous experiences so they can be remembered? Evidence suggests that people perceive their experience as a series of distinct and meaningful events. Information encountered within the same event shows greater temporal integration in memory, as well as enhanced neural representational similarity. Although these data support the theory that the brain builds and maintains a mental model of the current event that represents recently encountered stimulus information, this hypothesis has not been directly tested. We used fMRI in humans (N = 21, 13 female) to test whether within-event neural similarity indicates the persistence of stimulus representations in a mental model. Participants viewed trial-unique visual images that were grouped into events. We calculated neural pattern similarity across time in category-selective visual cortex to measure stimulus persistence. Pattern similarity was enhanced within, compared to between, events in object-sensitive left lateral occipital cort...