Scientific Reports
October 13, 2020
Lucie Bréchet, Denis Brunet, Lampros Perogamvros et al.
92 citations
During non-rapid eye movement (NREM) sleep, brief brain states lasting less than a second, called EEG microstates, determine whether a person will recall a dream upon waking. Two microstates (3 and 4) dominated NREM sleep compared to wakefulness. Within NREM sleep, microstate 3 was more present before dream recall, while microstate 4 was less present. Microstate 3 involved the medial frontal lobe, suggesting deeper local deactivation and executive disconnection that keeps the brain asleep. Microstate 4 involved the occipital cortex, thalamus, and brainstem, and its reduced presence may indicate local activation enabling rich perceptual dream content. The temporal dynamics of these alternating brain states determine whether conscious experience arises during NREM sleep.
Frontiers in Psychology
January 1, 2013
Lampros Perogamvros, Thien Thanh Dang‐Vu, Martin Desseilles et al.
79 citations
Sleep and dreaming activate emotional and reward systems, including the amygdala and mesolimbic dopaminergic regions during REM sleep, which likely consolidates memory traces with high emotional or motivational value. Coordinated hippocampal-striatal replay during NREM sleep may selectively strengthen memories for important events. Via activation of emotional and motivational circuits, sleep and dreaming provide a neurobehavioral substrate for offline reprocessing of emotions, associative learning, and exploratory behaviors, improving memory organization, emotion regulation, social skills, and creativity. Dysregulation from sleep disturbances such as insomnia or sleep deprivation may predispose individuals to reward-related disorders like mood disorders, increased risk-taking, and compulsive behaviors, with major health implications for vulnerable populations.
Journal of Cognitive Neuroscience
May 31, 2017
Lampros Perogamvros, Benjamin Baird, Mitja Seibold et al.
76 citations
Spontaneous thoughts occur during wakefulness, NREM sleep, and REM sleep, and all share activation in the midcingulate cortex. Waking thoughts additionally involve a medial prefrontal region linked to metacognition and have more metacognitive content than sleep thoughts. REM sleep thoughts are more social in content. The findings suggest a core neural substrate for thoughts across behavioral states, with medial prefrontal regions contributing to metacognitive qualities during wake.
May 16, 2023
William Wong, Kátia C. Andrade, Thomas Andrillon et al.
21 citations
preprint
A new open-access database, DREAM, combines sleep magneto/electroencephalography (M/EEG) recordings with standardized dream reports to enable large-scale neurocognitive research on dreaming. The initial release includes 20 datasets from 561 participants and 2649 awakenings, each with at least 20 seconds of high-frequency M/EEG data and a classification of the subject's experience. Analyses demonstrate that features extracted from EEG can predict whether a person reports having had a conscious experience during both REM and NREM sleep. The database aims to overcome the limitations of small sample sizes and methodological variability in dream research, allowing new questions to be addressed at a scale unattainable by individual labs.
Nature Communications
August 13, 2025
William Wong, Rubén Herzog, Kátia Cristine Andrade et al.
10 citations
A new open database, the DREAM database, combines standardized sleep magneto/electroencephalography (M/EEG) recordings with dream reports from 505 participants across 20 datasets, totaling 2,643 awakenings. Each awakening includes at least 20 seconds of high-resolution sleep EEG (≥100 Hz, ≥2 electrodes) and a classification of the sleeper's reported experience. Analyses showed that reports of conscious experiences during sleep can be predicted from objective EEG features in both REM and NREM sleep. The database aims to overcome limitations of small sample sizes and methodological variability in dream research, enabling larger-scale investigations of the neurocognitive basis of dreaming.
Journal of Sleep Research
February 9, 2025
Lampros Perogamvros, Vincent Rochas, Jean‐Baptiste Beau et al.
5 citations
Dreams may help regulate emotions by reducing negative feelings. A new concept, the cathartic dream, is defined as a dream with a dynamic plot and emotional twists where negative emotions are expressed and ultimately decreased, reflecting psychological relief akin to Aristotelian catharsis. Using a large language model to categorize dream diaries, researchers detected cathartic dreams in both healthy individuals and patients with nightmares. Their prevalence increased during two weeks of imagery rehearsal therapy and targeted memory reactivation during REM sleep. The increase in cathartic dreams correlated with decreased depression scores in nightmare patients, suggesting a functional role in well-being.
May 17, 2023
David R. Samson, Alice Clerget, Noor H. Abbas et al.
2 citations
preprint
Dreams in two small-scale forager groups, the BaYaka and Hadza, contain more threat-related content than dreams in Global North populations, yet the Hadza show low negative emotions in their dreams, suggesting emotion regulation through linking threats with non-fearful contexts. The BaYaka display more community-oriented dream content. In contrast, a Global North Nightmare Disorder group shows increased negative emotion content, and a Canadian student sample during COVID-19 shows the highest anxiety dream content. The findings support the idea that dreams in non-clinical populations can reduce anxiety and negative emotions via emotional release, contributing to understanding the evolutionary function of dreaming.
Scientific Reports
October 2, 2023
David R. Samson, Alice Clerget, Noor H. Abbas et al.
Dreams in two small-scale foraging societies—the BaYaka of the Republic of Congo and the Hadza of Tanzania—show patterns that support an emotion regulation function, contrasting with dreams in Global North populations. Analyzing 896 dreams from 234 individuals, the BaYaka had more community-oriented content, while both foraging groups showed heightened threat dream content. Yet the Hadza displayed low negative emotions in their dreams, suggesting a link between potential threats and non-fearful contexts that reduces anxiety. In comparison, a Global North Nightmare Disorder group had increased negative emotion content, and a Canadian student sample during the COVID-19 pandemic showed the highest anxiety dream content. These findings support the idea that dreams can effectively regulate emotions through catharsis, contributing to understanding the evolutionary significance of dreaming.
Current biology : CB
November 21, 2022
Sophie Schwartz, Alice Clerget, Lampros Perogamvros
Pairing a sound with imagery rehearsal therapy during REM sleep reduces nightmare frequency and increases positive dream emotions more than therapy alone. Thirty-six patients with nightmare disorder performed one initial therapy session where half heard a sound while generating a positive nightmare outcome; the other half did not. All patients then practiced therapy nightly at home for two weeks while a wireless headband played the sound during REM sleep. After two weeks, the group that heard the sound reported fewer nightmares and more positive dream emotions, and the reduction in nightmares persisted at three months. The results indicate that targeted memory reactivation during REM sleep can strengthen therapy effects and modulate dream emotions.
iScience
December 25, 2020
Anjali Tarun, Danyal Wainstein Andriano, Virginie Sterpenich et al.
During non-rapid eye movement (NREM) sleep, the brain's large-scale functional networks show a surprising pattern: nearly all networks are most active during NREM stage 2, then abruptly lose activity in NREM stage 3. However, despite this high activity in stage 2, the functional connections and mutual dependencies between networks progressively break down as sleep deepens. This means that even though networks attempt to communicate during stage 2, the efficiency of information transfer is low. The findings advance neural models of sleep and consciousness by showing that network integrity, not just activity levels, is crucial for conscious awareness.
NeuroImage. Clinical
January 1, 2019
Lampros Perogamvros, Hyeong-Dong Park, Laurence Bayer et al.
Patients with nightmare disorder show heightened heartbeat-evoked potentials (HEPs) during REM sleep compared to healthy controls, indicating increased emotional arousal and brain-body interaction specifically in REM sleep. No differences were found in cardiac control measures like heart rate variability. These findings suggest that nightmares are primarily a REM sleep pathology and that elevated emotional arousal during REM, as indexed by HEP, may underlie frequent nightmares. HEP could serve as a biomarker for increased emotional and sensory processing during REM sleep in these patients.
Psychopathology
January 1, 2014
Lampros Perogamvros
A neurophilosophical model proposes that psychotic hallucinations represent intrusions of subjective idealism—the view that reality depends on the mind—into a normally realist perspective where reality is mind-independent. Delusions then arise as the person's attempt to make sense of these intrusions. The model integrates phenomenological evidence of increased self-relatedness in hallucinations and delusions with neurobiological findings on the reward system, default mode network, and corollary discharge circuit in positive symptoms. This framework has implications for clinical practice, research, and therapy, and illustrates how philosophical theories can inform and be enhanced by scientific results.
Vincent Rochas, Kevin Mammeri, Laurence Bayer et al.
preprint
Having a conscious experience with recall during N2 sleep is linked to increased beta/gamma brain activity across widespread cortical areas, with peak activity in posterior occipital-temporal regions in the 30-second window before awakening and in parietal regions in the 20-second window. This effect was significant for high-perceptual dreams but not for low-perceptual dreams, suggesting that the neural activity is driven by sensory experiences such as vision and audition. The findings emphasize the need to distinguish content-specific neural correlates of dreaming and to study their temporal dynamics.
Sophie Schwartz, Alice Clerget, Lampros Perogamvros
preprint
Pairing a sound with a positive imagery rehearsal therapy (IRT) session and then replaying that sound during REM sleep reduces nightmare frequency and increases positive dream emotions more than IRT alone. Thirty-six patients with nightmare disorder performed an initial IRT session; half were exposed to a sound while generating a positive outcome (TMR group), and the other half were not (control group). All patients did IRT at home for two weeks and heard the sound during REM sleep via a wireless headband. The TMR group had fewer nightmares per week after two weeks and sustained improvement at three months. The results suggest TMR can potentiate therapy and modulate dream emotions.