CAREER: Memory consolidation over multiple nights of sleep

What makes some memories last a lifetime? One factor that determines whether a memory will endure or fade away is how it is processed during sleep. While we sleep, activity in brain networks that represent memories helps some memories survive and thrive. One unknown is whether sleep only helps a memory shortly after it is acquired, or whether it continues to improve memory for a long time thereafter. Previous research generally examines the role of sleep after only one sleep event; this project examines the contribution of multiple nights of sleep to memory, using a combination of behavioral, physiological, and computational methods. Whereas the current public discourse revolves around sleep’s short-term impact (“sleep well before your test”), the findings could highlight sleep’s lasting impact (“sleep well throughout the semester”). The research systematically examines the contribution of multiple nights of sleep to memory, using a combination of behavioral, physiological, and computational methods. There are three distinct research goals: to examine how memory benefits change with time and sleep using a well-established memory task; to consider whether sleep may play a prolonged role specifically for the weakest memories, which are the most sleep-reliant; and to reveal the constraints for multi-night processing by examining how susceptible memories are to being reactivated during sleep. The work resolves the conflict between two views of sleep’s role in memory: Does sleep transform memories over a prolonged process or are its contributions a “one and done” affair, limited to a single night that “clears the decks” for new learning? The knowledge gained through this project will provide valuable and useful information to the public, with potential implications for day-to-day sleep hygiene practices. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.