Overview
- Northwestern scientists paired each unsolved puzzle with a unique soundtrack while awake and replayed selected sounds during polysomnography-confirmed REM sleep.
- Of 20 participants, many experienced in lucid dreaming, 12 incorporated the cued puzzles into dreams and doubled next-morning solves on those tasks from about 20% to 40%.
- Across all participants, puzzles that appeared in dreams were solved more often after waking, roughly 40% versus 17% for puzzles not reflected in dreams.
- Several sleepers provided in-dream confirmation using prearranged signals, including left–right eye movements to indicate lucidity and sniff sequences to acknowledge hearing cues.
- The peer-reviewed paper in Neuroscience of Consciousness notes small and selective sampling and unclear causality, and experts raise practical and ethical concerns as the team pursues broader mechanistic studies.