In the stillness of sleep, some people wake up — without ever opening their eyes.
They become aware, mid-dream, that they’re dreaming. They explore their fantasies with the same sense of self as they have when awake. This uncanny state, called lucid dreaming, has long captivated researchers trying to understand how consciousness works.
Now, researchers led by Çağatay Demirel at the Donders Center for Cognitive Neuroimaging have uncovered the most robust neural evidence yet that lucid dreaming is not just a parlor trick — but rather a distinct state of consciousness.
The work, which used the largest EEG dataset on lucid dreaming to date, suggests that the sleeping brain may enter a form of conscious awareness previously undocumented in neuroscience.
“This research opens the door to a deeper understanding of lucid dreaming as an intricate state of consciousness by pointing to the possibility that conscious experience can arise from within sleep itself,” Demirel said in a press statement.
A New Map of the Sleeping Brain
Unlike the typical REM (rapid eye movement) sleep stage, when most vivid dreaming occurs, lucid dreams include metacognition: the awareness that you are in a dream. This kind of self-awareness is a key ingredient of waking consciousness. But how, exactly, does the dreaming brain support it?
Earlier studies hinted at specific brainwave changes, such as spikes in gamma frequencies, during lucid dreams. But there was a problem. Many of those results may have been distorted by eye movement artifacts, which are notoriously hard to clean from EEG (electroencephalography) data.
To overcome this, Demirel’s team pooled EEG recordings from five international labs, covering 44 lucid dream episodes in 26 experienced dreamers. It might not sound like much, but that’s an unprecedentedly large sample size for this niche field. Then they built a new multi-stage cleaning pipeline to eliminate misleading signals, including those from voluntary and involuntary eye movements and muscle twitches.
After the data was scrubbed, the team compared four conditions: lucid REM sleep, non-lucid REM sleep (from both early and late stages), and relaxed wakefulness.
Regional Differences
At first glance, the differences between lucid and non-lucid REM weren’t dramatic — at least not at the surface level. But when researchers dug deeper, estimating the source of the EEG signals within the brain, they noticed some distinct outcomes.
Lucid dreaming was marked by reduced beta-band activity (12–30 Hz) in the right temporo-parietal junction, an area of the brain tied to self-perception and spatial awareness. At the same time, bursts of gamma-band activity (30–36 Hz) surfaced in the left temporal lobe, an area often associated with language and insight. This, the authors suggest, could reflect a kind of inner dialogue or realization happening inside the dream.
Functional connectivity, measured in the alpha band (8–12 Hz), actually increased during lucid dreams. This is unlike in psychedelic states, where it tends to decline. The team interprets this as a sign of heightened self-awareness, rather than a loss of ego boundaries.
In general, these brain regions, and the patterns of activity within them, are typically associated with alertness and cognitive control. Their activation during lucid dreaming could mean that the brain is reaching a state somewhere between sleep and wakefulness.
“This work offers a perspective that could challenge the traditional binary view of sleep and wakefulness in future research,” Demirel noted.
More Complex Than REM, Yet Not Quite Waking
The researchers also looked at the complexity and unpredictability of brain signals and how these features are linked with levels of consciousness. Lucid dreams showed slightly more complexity than non-lucid REM sleep, but still fell short of waking levels.
The clearest finding came from a measure called the Higuchi fractal dimension — a kind of fingerprint of complexity. Lucid dreams scored higher than non-lucid REM sleep, but lower than waking.
That puts lucid dreaming in an intriguing place: more conscious than a typical dream, but not fully awake.
There’s this idea that consciousness exists on a spectrum, and that dreaming may not be an all-or-nothing phenomenon. Lucid dreaming could represent a unique blend of internal simulation and external awareness, a sort of bridge between sleeping and waking states.
There are also practical implications to all of this. Lucid dreaming is trainable, and some researchers believe it could help with nightmares, trauma, or even creativity training.
The study’s findings, and the EEG tools used to uncover them, could aid research into other altered states — like anesthesia, meditation, or psychedelic experiences. They might also help develop neurofeedback and brain-computer interfaces designed to induce or modulate lucid dreams.
The findings appeared in the journal JNeurosci.
