Sleep consolidation potentiates skill maintenance

Contrary to its well-established role in declarative learning the impact of sleep on motor memory consolidation remains a subject of debate. Motor learning involves skill acquisition and skill maintenance, two critical aspects in achieving movement precision. Current literature suggests that whereas motor skill acquisition benefits from sleep, consolidation of skill maintenance depends solely on the passage of time. This has led to the proposal that skill maintenance may be an exception to other types of memories. Here, we address this ongoing controversy in humans through three comprehensive experiments. We found that when training occurs throughout the day consolidation of skill maintenance proceeds independently of sleep. However, when it takes place closely before bedtime so that sleep aligns with the memory stabilization window, a 30% memory enhancement emerges along with a distinct modulation of neural markers of sleep consolidation. Our findings reconcile seemingly conflicting perspectives on the active role of sleep in procedural motor learning, and offer the potential to accelerate motor recovery in rehabilitation programs through the synchronization of training sessions with sleep.