Infants' representations of physical events are surprisingly flexible. Brief exposure to one event can immediately enhance infants' representations of another event. The present experiments tested two potential mechanisms underlying this priming: enhanced encoding or improved retrieval. Five-month-olds saw a target block become hidden inside a container, followed by priming events that involved a second block. The target was subsequently withdrawn from the container. Infants noticed a change to the target's height after seeing priming events involving occlusion, but they failed to so do if priming events involved no occlusion (Experiment 1). Infants noticed the change even when the priming and target blocks were not identical (Experiment 2). Because the target became fully hidden before the priming events started, priming must have arisen from improved retrieval, not enhanced encoding, of information about the target. The results add to our understanding of how brief observation of one event can affect infants' processing of subsequent events, thereby elucidating fine-grained aspects of the representational process.