During the transition from wakefulness to sleep, unusual bodily sensations and out-of-body experiences can be induced. A high-density EEG and neurophenomenology approach reveals specific brain activity patterns associated with these phenomena, suggesting that the brain's altered state during sleep onset may facilitate such experiences.
Unusual bodily experiences (UBEs)—illusory perceptions such as floating, body distortions, or out-of-body sensations—can occur during meditation and sleep. In a controlled sleep laboratory, 20 of 35 healthy participants reported 36 UBEs, primarily during meditation (wakefulness) but also during arousals, REM sleep, and non-REM sleep. Electroencephalography (EEG) analyses revealed that UBEs emerge during intermediate states of consciousness that combine features of wakefulness and sleep. Specifically, UBEs were associated with EEG reactivation: increased high-frequency activity (beta and gamma) and decreased low-frequency activity (delta and theta), especially around temporal regions. These findings offer new insights into the neural correlates of self-consciousness and body perception across sleep and wakefulness.