Recent advances in interventional psychiatry continue to reshape how researchers understand the human brain. A new study published in Cell Reports suggests that dream-like mental states are not limited to sleep and can emerge even while people remain physiologically awake, challenging one of neuroscience’s longest standing assumptions.
Rethinking The Traditional View Of Consciousness
For decades, scientists have treated wakefulness and sleep as separate biological states with fundamentally different patterns of thought. Waking consciousness has generally been associated with deliberate, organized thinking, while dreams have been viewed as products of sleep, particularly during rapid eye movement sleep.
The new findings suggest the distinction is far less rigid. Instead of mental experiences being determined solely by whether someone is awake or asleep, subtle patterns of brain activity may play a much larger role in shaping conscious experience.
This perspective could influence future research into consciousness, sleep medicine, and neurological disorders.
How Researchers Studied Dream-Like Mental States
Investigators at the Paris Brain Institute recruited 92 healthy adults and monitored their brain activity using electroencephalography, or EEG, during two quiet daytime resting sessions designed to encourage the transition from wakefulness into sleep. Participants were periodically interrupted and asked to describe what had been occurring in their minds during the previous ten seconds while also rating their experiences based on factors including spontaneity, fluidity, bizarreness, and perceived wakefulness.
Rather than forcing experiences into predefined categories, researchers used a data driven clustering approach to identify recurring mental states. Four distinct patterns consistently emerged:
Fleeting mental content
Alert mental content
Bizarre dream-like experiences
Voluntary goal directed thinking
Perhaps the most surprising discovery was that each of these mental states appeared across multiple levels of wakefulness and light sleep instead of belonging exclusively to one stage.
Brain Activity Matters More Than Sleep Stage
The investigators compared participants’ reported experiences with EEG recordings collected immediately before each interruption.
They found that the different mental states were associated with unique combinations of spectral power, signal complexity, and functional connectivity. Importantly, these neural signatures remained significant even after accounting for traditional sleep stages.
Dream-like experiences were linked with lower long range functional connectivity and reduced spectral offset, while highly alert experiences demonstrated greater neural complexity.
These findings suggest that fine scale brain dynamics may explain conscious experience more accurately than conventional sleep staging alone.
Why This Study Is Different
Most previous research has attempted to compare wakefulness and sleep as two separate categories. This investigation instead focused on the transition between the two states and analyzed mental experiences without assuming they belonged to either category.
The researchers also incorporated multiple subjective dimensions of experience instead of relying solely on narrative dream reports. Combining these ratings with advanced EEG analysis allowed them to identify mental states that crossed traditional physiological boundaries.
The observation that bizarre, dream-like experiences occurred during EEG confirmed wakefulness represents one of the study’s most notable findings.
Clinical Relevance Beyond Sleep Research
Although this work examined healthy volunteers, the implications extend into several areas relevant to interventional psychiatry.
Many neurological and psychiatric conditions involve altered sleep, consciousness, or spontaneous thought. Disorders such as insomnia, narcolepsy, depression, Parkinson’s disease, and other conditions frequently include complaints that are not fully explained by standard sleep measurements.
If mental states are better characterized by detailed neural activity than by sleep stages alone, clinicians may eventually gain more precise tools for understanding patients’ subjective experiences.
Future studies may determine whether specific psychiatric or neurological disorders produce different distributions of these mental states or distinct EEG signatures that could serve as biomarkers for diagnosis or treatment monitoring.
A New Framework For Understanding Conscious Experience
The study supports the growing idea that consciousness exists along a continuum rather than within sharply divided states of wakefulness and sleep.
Instead of asking whether someone is simply awake or asleep, future neuroscience may increasingly examine the precise patterns of brain activity that give rise to specific forms of conscious experience.
While additional research will be needed to investigate deeper stages of sleep and clinical populations, these findings offer an important step toward a more comprehensive understanding of how the brain generates thought, imagination, and awareness.
As researchers continue refining EEG based approaches to measuring mental states, the boundary between dreaming and waking may prove to be far more fluid than previously believed.
Citations
Decat N, Le Coz A, Sénéchal J, et al. Dream-like mental states can occur during wakefulness. Cell Reports. 2026. https://www.sciencedirect.com/science/article/pii/S2211124726003153
Paris Brain Institute. Dreaming While Awake: Dream-like States Are Not Confined To Sleep. https://parisbraininstitute.org/news/dreaming-while-awake-dream-states-are-not-confined-sleep
Explore more at https://www.interventionalpsychiatry.org/