Contemporary evidence suggests that sleep contributes to theextraction of gist from previously encoded experiences, aprocess that relies on compressed memory replay. While thefunctional significance of the time compression is not fullyunderstood, a recent ‘temporal scaffolding’ model suggestedthat compression allows associating encoded events thathappened in disparate times, a critical feature when extractinggist of a temporal nature. We examined this hypothesis usinga novel behavioral paradigm. Subjects were first presentedwith word pairs that could form a new composite word ifcombined (e.g., car, pet --> carpet), and then tested onwhether they falsely recognize seeing the composite word.When subjects napped in between exposure and testing, falsememories of composite words increased, with reaction timesfor false recognition correlating to time spent in slow wavesleep. These results confirm the functional role of timecompression in memory replay, supporting the temporalscaffolding model.