This project explores several aspects of learning and sleep. Memories we have acquired during the day are reactivated during sleep, causing changes in memory storage in brain networks. Dreams in particular may contribute to language learning and problem solving, but one problem with the scientific study of dreaming is that we gain knowledge of a dream only after an individual has awoken. In the waking state, dreams may be recalled in a fragmentary or distorted way, or barely remembered at all. This research will overcome those limitations by allowing dreamers to communicate about their dream experiences while they are having the dreams. For example, using eye-movement and muscle-twitch signals, dreamers can indicate that they are aware of dreaming, and an experimenter can communicate with a dreamer with softly spoken words or other sounds. This strategy will open up new avenues for understanding more about the importance of sleep, with many important implications for society.
The project uses a set of innovative methods to advance knowledge of the various cognitive benefits of sleep. Prior studies showed that spatial memory could be changed during sleep through the method of Targeted Memory Reactivation (TMR). This approach of strategically presenting soft sounds during sleep will be modified to investigate whether vocabulary learning and problem solving can be improved in association with REM sleep or in association with a dream. To enable this novel perspective on dreaming, people will be interviewed from within a dream. Experimenters will issue softly spoken questions, and volunteers will communicate back with a code based on specific eye movements and muscle twitches, readily measured electrophysiologically, all while REM sleep is maintained. People typically experience a dream with a high degree of acceptance and a lack of critical evaluation - they fail to realize that the experience is merely a dream. In a lucid dream, one gains the elusive insight of being in a dream. However, lucid dreams can seldom be summoned at will, and on the rare occasions when people succeed in having a lucid dream in a lab, they often forget pre-assigned goals. These challenges will be overcome by: (a) pre-sleep training to strategically link specific sound cues with action plans; (b) monitoring sleep physiology to coordinate stimulation; and (c) presenting sounds to remind dreamers to evaluate their experience to determine if they are dreaming, and to then engage in specific activities such as rehearsing recently learned foreign words or attempting to reach a solution to a cognitive puzzle. Increasing the frequency of lucid dreams through these methods will make it possible to examine cognition during the course of interactive dreaming. Results from this project will expand understanding of cognitive capabilities during sleep, and will provide new information on the extent to which sleep cognition can assist with language learning, problem solving, and other tasks.
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.
