Improving Conscious Memory Abilities through Unconscious Memory Rehearsal During Sleep

Sleeping and dreaming have long mystified humanity and been a focal point for philosophical and artistic exploration. An intriguing speculation is that we use our time sleeping to organize and regulate memory storage — unlike a computer, which does nothing at all when asleep. Extending this idea, we speculate that the conscious experiences one has when awake are partly a function of what the brain does in sleep. But strategies for understanding sleep are quite limited; reports made upon awakening disclose very little of the complexity of sleep, which includes a series of stages defined by the electrical activity of the brain (Stage 1, 2, etc.). Even with these standard electrophysiological methods, we are still very much in the dark about what happens during sleep. This project will contribute to ushering in a new era in understanding sleep and consciousness. We will systematically alter the functioning of the brain during sleep, with consequences for a person’s conscious experiences after awakening. Unconscious processing can have a striking influence on conscious thoughts. In a recent study, we investigated unconscious bias pertaining to race and gender, which is known to influence conscious decisions made with respect to other people. In the proposed study, we will extend this research through a new study of conscious and unconscious memory processing. People will come to the lab to memorize a set of celebrity faces and famous world locations. After a learning phase, we will test memory accuracy. Then, during a 90-minute period of sleep, we will present sounds linked with this prior learning. Later, we will test memory again to determine whether our procedure selectively alters conscious and/or unconscious memories for the faces and locations. Results will broaden research on the mechanisms whereby memory change during sleep impacts the conscious memory experiences we have when awake.