RUI: Understanding How Offline Wake and Sleep Jointly Shape Memory

A critical question about memory centers on why some things are remembered and why others are forgotten over time. New memories are fragile, and they must be strengthened and reorganized to last. This happens both during moments of resting wakefulness throughout the day and during sleep at night. This project aims to discover exactly how resting wake and sleep work together to improve memory. To this end the project is designed to track memory through multiple brain states in wake and sleep measured by electroencephalography (EEG). Understanding how wake and sleep work together to shape memory is an important step toward explaining how long-term memories are formed. This research tests the hypothesis that offline wake and sleep are part of a coordinated multistep process unfolding across the 24-hour day. Specifically, the researchers propose that new memories are first temporarily stabilized during resting awake periods, but that these changes become long-lasting only when people sleep. The project has three main goals. First, an initial study aims to confirm the state(s) of wakefulness during which memory is optimally consolidated in the first few minutes just after learning with a focus on states with slow EEG oscillations. Subsequent studies aim to determine the time window during which resting wake best optimizes subsequent sleep consolidation, and to track how salience cues affect the evolution of memory across wake and sleep. Together, these studies test the hypothesis that memory consolidation during sleep depends on earlier stages of processing during wakefulness. Support for this hypothesis can improve understanding of long-term memory formation that has been obscured in research examining only one brain state, one timepoint, or one memory process at a time. Beyond its scientific goals, this project also intends to provide high-impact research training in neuroscience for approximately 12 undergraduate students across the course of 3 years at a predominantly undergraduate institution. 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.