Sleep resolves competition between explicit and implicit memory systemsK. Kleespies, P. Paulus, H. Zhu, F. Pargent, M. Jakob, J. Werle, M. Czisch, J. Boedecker, S. Gais, and M. Schoenauer Manuscript, February 2025. Sleep supports stabilization of explicit, declarative memory and benefits implicit, procedural memory. In addition, sleep may change the quality of memories. Explicit and implicit learning systems, usually linked to hippocampus and striatum, can compete during learning. Whether they continue to interact during offline periods remains unclear. Here, we investigate for feedback-driven classification learning, whether sleep integrates explicit and implicit aspects of memory. We find that over sleep, but not wakefulness, the negative relationship between implicit and explicit memory components is resolved. Additionally, performance in a task that allows the cooperative use of both types of memory improves and participants show superior performance in generalizing their knowledge to unseen exemplars. A reinforcement learning (RL) model suggests that this can be explained by better transfer of the learned exemplar value representations in participants who slept. Thus, sleep combines information learned by different routes and helps us respond optimally to everyday life contingencies. |