Memory traces of specific events are represented by individual neurons in the brain. These neurons are embedded into larger networks, or assemblies, whose activity is characterized by synchronized oscillations at various frequencies as well as by asynchronous activity. In addition, content-specific activity can be analyzed at the level of distributed BOLD responses. Using intracranial EEG recordings in epilepsy patients, we observed that engram patterns are reinstantiated during memory retrieval. Moreover, both intracranial EEG data and simultaneous EEG/fMRI recordings in healthy participants showed that engram patterns are spontaneously replayed during awake resting state and sleep, suggesting a putative mechanism for memory consolidation. These results provide important insights into meso-scale network representations of specific experiences.