LEARNING, CREATIVE PROBLEM-SOLVING, REM SLEEP, AND AWARENESS OF DREAMING.

This project explores the relevance of sleep for cognition with two test cases, that of vocabulary learning and problem solving. The project addresses the question: can memory reactivation during sleep contribute to these functions? The contemporary scientific study of cognition largely ignores cognition during sleep. Whereas understanding wake cognition may be paramount, sleep may influence wake cognition much more than commonly assumed, particularly with respect to what we can remember. Sleep may be particularly important for gradual learning over extended periods of time, such as acquiring competency in a foreign language or solving a difficult problem. Sleep cognition is also worthy of study on its own merit, although its scientific study has been hampered by an over-reliance on retrospectively learning about another person's dream content. After waking, dreams may be recalled in a fragmentary or distorted way, or barely remembered at all. Sleep may entail a severely limited memory capacity to keep recent information in mind. Yet, very little information is available about the status of memory abilities in the sleep state. The proposed research will overcome limitations of retrospective dream reporting by producing the first documented demonstrations of interactive dreaming, thereby opening up new horizons for understanding sleep cognition and its role in learning and problem solving. Intellectual Merit: This project will advance knowledge of cognitive benefits of sleep. A novel research approach will be developed for strategically presenting soft sounds during sleep. Prior studies showed that spatial memory could be changed during sleep through the method of Targeted Memory Reactivation (TMR). Here, results will show whether vocabulary learning and problem solving can be improved with auditory cues during REM sleep, and whether improvements can be produced with memory reactivation in the context of a dream. To enable this novel perspective on dreaming, people will be interviewed from within a dream. Steps will be taken to demonstrate the validity of this method, with experimenters issuing softly spoken questions and volunteers communicating back with a code based on specific eye movements readily be measured electrophysiologically 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 then to 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 with 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. Broader Impacts: This research will give direction to future studies