Exploratory study of non-ordinary states of consciousness during sleep show distinct electrophysiological features from wakefulness and canonical sleep stages.

During sleep, consciousness can re-emerge as non-ordinary states such as lucid dreams, sleep paralysis, out-of-body experiences, and false awakenings. In an exploratory study, overnight brainwave recordings were taken from people who frequently experience these states, capturing ten episodes. Eye movement markers identified periods of lucidity. Analysis of brainwave power showed that these states are distinct from wakefulness but share features with both stage 1 and REM sleep. The findings suggest that these non-ordinary states have unique neurophysiological signatures that blend characteristics of different sleep stages.

Study at a glance

Abstract

Consciousness does not always fade during sleep. Instead, it can re-emerge in the form of non-ordinary states of consciousness (NOSC), such as lucid dreams (LDs), sleep paralysis (SP), out-of-body experiences (OBEs), and false awakenings (FAs). While some of these states have been studied phenomenologically, their neurophysiological underpinnings remain unclear. In this exploratory study, we investigate their electrophysiological correlates and distinguish them from standard sleep stages. We conducted overnight polysomnography in frequent experiencers, capturing 10 episodes (3 LDs, 2 SP, 2 OBEs, 3 FAs). Eye movement markers identified periods of lucidity. Relative spectral power was analyzed using principal component analysis (PCA) and permutation-based multivariate analysis of variance (PERMANOVA). Our results indicate that these NOSC are distinct from wakefulness, yet share features with both stage 1 (S1) and rapid eye movement (REM) sleep.