Lucid Dreaming

Aristotle noted that “often when one is asleep, there is something in consciousness which declares that what then presents itself is but a dream” (On Dreams, 462a); van Eeden named the state in 1913; the laboratories dismissed it until Keith Hearne at Hull (1978) and then Stephen LaBerge at Stanford (1981) had sleepers signal from inside REM with an agreed pattern of eye movements, the one muscle group REM leaves free, and the polygraph recorded the signal in the middle of unbroken REM sleep. The dreamer could report from inside while the instruments watched from outside.

What the lucid brain looks like: Voss et al. (2009) found a hybrid of REM and waking, with fast gamma activity (around 40 Hz) over the frontal cortex laid on the REM pattern; Dresler (2012) found in fMRI the frontopolar and parietal regions, the ones that carry self-reflection and are quiet in ordinary dreaming, switched on. In 2014 Voss stimulated the frontal scalp at 25 and 40 Hz in sleepers who had never had a lucid dream and induced the awareness. The state is, by every measure, a dream with the waking monitor partly restored, which is what the dreamer reports.

How common, and how learned: Saunders et al. (2016) pooled fifty years of surveys and found 55 per cent of people have had at least one lucid dream and 23 per cent have one a month or more. Stumbrys et al. (2012) reviewed 35 induction studies and found two techniques with evidence: reality testing through the day (asking, repeatedly, “am I dreaming?” and checking), and the mnemonic induction (MILD) of setting an intention on waking in the small hours and returning to sleep; Aspy (2017) combined them in a national Australian study and raised the rate from a baseline of about a tenth of nights to a fifth. Most techniques work modestly and most studies are small.

What it is for: the nightmare, above all, since the dreamer who knows can turn and face the pursuer, and case series and small trials (Spoormaker and van den Bout, 2006) found it reduced nightmare frequency; motor practice, since Erlacher and Schredl (2010) found dreamed practice of a coin-toss task improved waking performance; and the laboratory, since Konkoly et al. (2021), in four laboratories on three continents, posed arithmetic and yes–no questions to lucid dreamers in REM sleep and received correct answers by eye movements and facial muscles, which opens the dream to question for the first time.

Sources

• LaBerge, S., Nagel, L. E., Dement, W. C., and Zarcone, V. P. (1981). “Lucid dreaming verified by volitional communication during REM sleep.” Perceptual and Motor Skills 52.
• Voss, U., et al. (2014). “Induction of self awareness in dreams through frontal low current stimulation of gamma activity.” Nature Neuroscience 17.
• Dresler, M., et al. (2012). “Neural correlates of dream lucidity obtained from contrasting lucid versus non-lucid REM sleep: a combined EEG/fMRI case study.” Sleep 35.
• Stumbrys, T., Erlacher, D., Schädlich, M., and Schredl, M. (2012). “Induction of lucid dreams: a systematic review of evidence.” Consciousness and Cognition 21.
• Aspy, D. J., Delfabbro, P., Proeve, M., and Mohr, P. (2017). “Reality testing and the mnemonic induction of lucid dreams: findings from the national Australian lucid dream induction study.” Dreaming 27.
• Konkoly, K. R., et al. (2021). “Real-time dialogue between experimenters and dreamers during REM sleep.” Current Biology 31.
• Saunders, D. T., et al. (2016). “Lucid dreaming incidence: a quality effects meta-analysis of 50 years of research.” Consciousness and Cognition 43.

A review of the literature for readers; not medical advice.