Lucid dreaming during NREM sleep: Two case reports

Lucid dreaming, where the dreamer knows they are dreaming, usually happens during REM sleep, but this sleep laboratory study reports two possible instances of lucidity during NREM sleep. NREM lucid dreaming appears much rarer and harder to achieve, most likely during N1 sleep, less likely during N2 sleep, and not yet observed during N3 sleep. The authors suggest future research on induction methods, neural mechanisms, and perceptual differences between REM and NREM lucid dreams, and call for a consensus definition of lucid dreaming to clarify the psychophysiological states that support self-reflective awareness.

Study at a glance

Abstract

Lucid dreams – dreams in which the dreamer is aware that is dreaming – most frequently occur during REM sleep, yet there is some evidence suggesting that lucid dreaming can occur during NREM sleep as well. By conducting a sleep laboratory study on lucid dreams, we found two possible instances of lucidity during NREM sleep which are reported here. While lucid dreaming during NREM sleep seems to be much rarer and more difficult to achieve, it appears to be possible and is most likely to occur during N1 sleep, somewhat less likely during N2 sleep and yet to be observed during N3 sleep. Future studies should explore induction methods, underlying neural mechanisms and perceptual/dream content differences between REM and NREM lucid dreams. Furthermore, a consensus agreement is needed to define what is meant by lucid dreaming and create a vocabulary that is helpful in clarifying variable psychophysiological states that can support self-reflective awareness.