How our brains capture and store new information is heavily influenced by what we already know. While prior work demonstrates that existing memories are spontaneously reactivated and strengthened in the brain during passive rest periods, the prospective benefits of spontaneous offline reactivation for future learning remain unknown. Here, we use functional MRI to interrogate how reactivation and interregional coupling support the ability to learn related content in later situations. We find that offline processing of prior memories is associated with better subsequent learning. Our results provide a mechanistic account of the circumstances under which prior knowledge can come to facilitate—as opposed to interfere with—new learning, serving as a strong foundation upon which new content is encoded.
Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face–object associations were scanned during passive rest and during encoding of new related and unrelated pairs of objects. Spontaneous reactivation of established memories and enhanced hippocampal–neocortical functional connectivity during rest was related to better subsequent learning, specifically of related content. Moreover, the degree of functional coupling during rest was predictive of neural engagement during the new learning experience itself. These results suggest that through rest-phase reactivation and hippocampal–neocortical interactions, existing memories may come to facilitate encoding during subsequent related episodes.