Inducing unusual bodily sensations and out-of-body experiences across the wake-sleep cycle: a high-density EEG and neurophenomenology study
Teresa Campillo-Ferrer, Antonella Iadarola, Ramona Cordani, Marco Veneruso, Çağatay Demirel, Lino Nobili, Robert Oostenveld
PsyArXiv April 13, 2025 preprint DOI: 10.31234/osf.io/pz7x4_v1 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study in a controlled sleep laboratory |
|---|---|
| Sample size | 35 |
| Population | Healthy participants |
| Interventions | Meditation Light stimulation |
| Topics | Philosophy of mind |
| Citations | 1 |
| Key findings | Twenty of 35 participants reported 36 unusual bodily experiences, occurring primarily during meditation but also during sleep arousals, REM sleep, and non-REM sleep. Exploratory EEG analyses suggest these experiences emerge during intermediate states of consciousness, associated with wake-like reactivation: increased beta and gamma activity and decreased delta and theta activity, particularly around temporal regions. |
Abstract
Unusual bodily experiences (UBEs) are illusory perceptions involving the body and its surroundings, such as body distortions and out-of-body experiences. This study examines UBEs in a controlled sleep laboratory using meditation and light stimulation to facilitate their occurrence. A total of N=35 healthy participants underwent high-density EEG with additional EMG, EOG, and ECG recordings. Participants signalled UBEs by performing left-right-left-right eye movements, providing an objective marker for analysis. Interviews adapted from the micro-phenomenological technique were conducted to capture detailed subjective reports and to guide subsequent sleep and EEG analyses. Of the 35 participants, N=20 reported a total of n=36 UBEs, occurring primarily during meditation (wakefulness) but also during sleep arousals, rapid eye-movement (REM) sleep and non-REM sleep. Spectral EEG analyses and generalized linear mixed models were used to investigate the neural dynamics of these experiences, suggesting that UBEs emerge during intermediate states of consciousness combining EEG features of both wakefulness and sleep. Specifically, exploratory EEG analyses showed that UBEs across sleep and wakefulness were associated with a wake-like EEG reactivation marked by increased high-frequency activity (beta and gamma) and decreased low-frequency activity (delta and theta), with a particularly pronounced effect around temporal regions. Collectively, these results provide novel insights into the electrophysiological mechanisms underlying UBEs and contribute to a deeper understanding of self-consciousness and body perception across sleep and wakefulness.
Comparable studies
Other observational and cohort studies on philosophy of mind, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| The phenomenology of near-death experiences Subjects who reported near-death experiences | 1980 | Retrospective study | n = 78 |
| Visual Phenomenology of the LSD Flashback Persons with a history of LSD use | 1983 | Observational cohort | n = 123 |
| The neurophenomenology of neutral hypnosis. Individuals of high, medium, and low hypnotizability | 2013 | Observational cohort | n = 37 |
| The Phenomenology of Acute Organic Psychosis Patients with acute organic psychosis and acute schizophrenics | 1987 | Observational cohort | n = 148 |
| EEG oscillatory states as neuro-phenomenology of consciousness as revealed from patients in vegetative and minimally conscious states. Brain-damaged patients with disorders of consciousness and healthy-conscious subjects | 2012 | Observational cohort |