NeuroImage
January 11, 2019
Michele Colombo, Martino Napolitani, Mélanie Boly et al.
359 citations
During anesthesia, people may still be conscious even though they do not respond. A marker of consciousness based on the decay rate of the power spectral density (PSD) of resting EEG—measured by the spectral exponent β—was tested in healthy participants under xenon, propofol, or ketamine anesthesia (n=5 per group). Delayed reports indicated whether consciousness was present or absent. Xenon and propofol, which abolish consciousness, caused a steeper PSD decay (more negative β) compared to wakefulness. Ketamine, which preserves consciousness, showed a PSD decay similar to wakefulness overall but a flattening in high frequencies (20–40 Hz). The spectral exponent correlated strongly with the Perturbational Complexity Index (PCI), supporting its use as a marker of consciousness.
Nature Communications
February 25, 2022
Minji Lee, Leandro Sanz, Alice Barra et al.
120 citations
A deep-learning-based explainable consciousness indicator (ECI) uses EEG responses to transcranial magnetic stimulation and resting-state EEG to separately quantify arousal and awareness. Tested during sleep (n=6), general anesthesia (n=16), and severe brain injury (n=34), ECI distinguishes states such as ketamine-induced anesthesia and rapid eye movement sleep, which combine low arousal with high awareness. Parietal brain regions are most relevant for these measurements. The indicator offers a way to disentangle the two components of consciousness across physiological, pharmacological, and pathological conditions.
Scientific Reports
December 6, 2018
Benjamin Baird, Anna Castelnovo, Olivia Gosseries et al.
74 citations
People who have frequent lucid dreams—three or more per week—show stronger functional connections between the left anterior prefrontal cortex and several brain regions, including the angular gyrus, middle temporal gyrus, and inferior frontal gyrus, compared to people who rarely or never lucid dream. These connections involve areas that are normally less active during sleep. No differences in brain structure were found. The findings suggest that frequent lucid dreaming is linked to how certain brain networks communicate, not to structural differences.
Communications biology
August 5, 2024
Charlotte Maschke, Jordan O'Byrne, Michele Angelo Colombo et al.
50 citations
Consciousness may depend on brain activity poised at criticality—a state with complex patterns and high sensitivity to disruption. Analyzing resting-state EEG from healthy volunteers under propofol, xenon, or ketamine anesthesia, the study found that unconsciousness (from propofol or xenon) shifted brain dynamics away from avalanche criticality and the edge of chaos. Ketamine anesthesia preserved consciousness (vivid dreams) and criticality. Dynamical properties from resting EEG accurately predicted individual values of the perturbational complexity index (PCI), a TMS-based consciousness measure. The findings link perturbational complexity to criticality and suggest criticality is necessary for consciousness.
Brain sciences
July 14, 2021
Charlotte Martial, Géraldine Fontaine, Olivia Gosseries et al.
37 citations
People who have had a near-death experience often report a disturbed sense of having a distinct self. In a survey of 100 individuals who scored 27 or higher out of 80 on the Near-Death-Experience Content scale, 80 had their experience in a life-threatening situation and 20 did not. Participants completed inventories measuring ego dissolution and ego inflation during their NDE, as well as a scale of nature-relatedness. Ego-dissolution scores were higher than ego-inflation scores. Total NDE intensity positively correlated with ego dissolution and, more weakly, with ego inflation and nature-relatedness. Ego dissolution also correlated with the intensity of out-of-body experiences and a sense of unity. The findings suggest that dissolved ego-boundaries are a common feature of NDEs.
Scientific reports
October 1, 2019
Charlotte Martial, Armand Mensen, Vanessa Charland-Verville et al.
36 citations
A proof-of-concept study induced near-death experience (NDE)-like features in five volunteers who had previously had a pleasant NDE by having them recall the memory under hypnosis while their brain activity was recorded with high-density EEG. The hypnosis protocol recreated NDE-like features without adverse effects and increased absorption and dissociation compared to normal consciousness recall. Recalling the NDE phenomenology was associated with increased alpha brain activity in frontal and posterior regions. The methodology offers a controlled way to prospectively study NDE-like features and their EEG correlates.
NeuroImage
June 1, 2024
Pradeep Kumar G, Rajanikant Panda, Kanishka Sharma et al.
20 citations
High-order interactions between brain regions, measured as synergistic and redundant information, change differently across three non-ordinary states of consciousness. During Rajyoga meditation, synergy increased across the whole brain in delta and theta brainwave bands, while redundancy decreased in frontal, central, and posterior electrodes in delta and beta bands. During hypnosis, synergy decreased in mid-frontal, temporal, and mid-centro-parietal electrodes in the delta band, and in left frontal and right parietal electrodes in the beta2 band. During auto-induced cognitive trance, synergy decreased in delta and theta bands in left-frontal, right-frontocentral, and posterior electrodes, and at the whole brain level in the alpha band. Redundancy changes during hypnosis and auto-induced cognitive trance were not significant. Subjective reports of absorption, dissociation, and mystical experience did not correlate with the high-order measures.
Frontiers in psychology
January 1, 2022
Charlotte Grégoire, Nolwenn Marie, Corine Sombrun et al.
20 citations
A protocol describes a planned trial comparing three group interventions—hypnosis, mindful self-compassion meditation, and self-induced cognitive trance (SICT)—against a no-intervention control for improving quality of life in cancer patients who have completed active treatment within the past year. The study targets cancer-related fatigue, emotional distress, sleep difficulties, pain, and cognitive problems. Each participant chooses their preferred arm. Data from questionnaires, neurobiological measures, and medical records are collected at baseline, immediately after the intervention, and at 3- and 12-month follow-ups. The trial aims to enroll 160 patients and will assess short- and long-term effectiveness.
Nature reviews. Neurology
June 1, 2025
Charlotte Martial, Pauline Fritz, Olivia Gosseries et al.
19 citations
Near-death experiences (NDEs) are episodes of disconnected consciousness with prototypical mystical features, often occurring during actual or perceived physical threat. Various explanatory theories have been proposed, but integration has been limited. Converging evidence from neuroscience—including non-human studies, psychedelic-induced mystical experiences, and research on the dying brain—now offers a comprehensive explanation. This Review discusses psychological and neurophysiological processes underlying NDEs, including cellular and electrophysiological brain network changes and neurotransmitter alterations. The authors propose a model encompassing a cascade of concomitant processes within an evolutionary framework and consider how NDE research informs debates on consciousness emergence near brain death.
Current Opinion in Behavioral Sciences
May 9, 2024
Olivia Gosseries, Nolwenn Marie, Yannick Lafon et al.
16 citations
Trance states, found across cultures from shamanic rituals to contemporary practices, are increasingly studied by researchers and clinicians. This review describes their common phenomenological features, such as altered awareness and perception. Using advanced neuroscientific techniques, it reports on the neural mechanisms underlying these states, including changes in brain connectivity and dynamics. The review also examines clinical applications, suggesting that trance states may be useful in therapeutic settings. By connecting subjective experience, brain function, and practical use, it advances understanding of trance and its potential benefits.
Brain Structure and Function
January 1, 2021
Jitka Annen, Rajanikant Panda, Charlotte Martial et al.
15 citations
A world champion free diver's brain activity and connectivity shift markedly during a 6.5-minute breath-hold. EEG shows increased alpha wave power and connectivity, with decreased delta band connectivity. fMRI reveals heightened connectivity within the default mode network and visual areas, but reduced connectivity in sensorimotor cortices. These changes overlap with some meditation-related brain signatures but also include unique features suggesting altered somatosensory integration. Self-reports indicate that elite free divers may achieve a state of sensory dissociation during prolonged apnea, reflecting their ability to adapt psychologically and physiologically to extreme breath-holding.
BMC complementary medicine and therapies
November 4, 2024
Nolwenn Marie, Yannick Lafon, Aminata Bicego et al.
13 citations
Shamanic trances are non-pathological altered states of consciousness that differ from normal waking states in phenomenology and neurophysiology. A review of 27 studies classified findings into four dimensions: phenomenology, psychology, neuro-physiological functions, and clinical applications. The trances are influenced by multiple personal and environmental variables and may offer therapeutic potential, but the evidence is preliminary and requires rigorous studies to assess effectiveness for complementary therapies. The review highlights shamanic trance as a multifaceted area of study at the intersections of consciousness, spirituality, and therapy.
NeuroImage
September 1, 2024
Charlotte Martial, Andrea Piarulli, Olivia Gosseries et al.
10 citations
During fainting, some people have dream-like experiences with extraordinary, mystical features similar to near-death experiences. In 22 healthy volunteers who fainted under controlled conditions, eight reported such near-death-like features. Their brain activity showed higher electrical activity in delta, theta, and beta2 frequency bands in temporal and frontal regions, including the insula, right temporoparietal junction, and cingulate cortex. The richer the experience, the stronger the activity in these areas. The brains of those with near-death-like experiences also showed more complex, more connected, and more integrated neural networks compared to those without such experiences. These surges of neural activity may mark disconnected consciousness during fainting.
Neuroscience of consciousness
January 1, 2024
Charlotte Grégoire, Corine Sombrun, Philippe Lenaif et al.
10 citations
Two Western trance practices, auto-induced cognitive trance (AICT) and Mahorikatan® trance (MT), both derived from traditional shamanic training, share core phenomenological features such as emotional expression, perceptual changes, a feeling of unicity, and expanded consciousness. AICT participants commonly reported body movements, vocalizations, increased creativity, visions of entities or places, and interaction with the environment, while MT participants commonly reported body dissolution. Most participants in both groups reported positive effects on personal life. The findings characterize the similarities and differences between these trance states and suggest further research into their potential clinical applications.
iScience
January 17, 2025
Paolo Cardone, Arthur Bonhomme, Vincent Bonhomme et al.
9 citations
In a small double-blind, placebo-controlled, cross-over trial with three adults who had prolonged disorders of consciousness after a coma, an intravenous sub-anesthetic dose of the atypical psychedelic ketamine increased brain complexity as measured by Lempel-Ziv complexity, but did not change the explainable consciousness indicator. Patients showed reduced spastic paresis and spent more time with their eyes open, yet their diagnosis of consciousness did not improve. No adverse effects occurred. The findings suggest a potential therapeutic role for ketamine in disorders of consciousness and support a link between brain complexity and conscious states.
The International journal of clinical and experimental hypnosis
January 1, 2024
Mélanie Louras, Audrey Vanhaudenhuyse, Rajanikant Panda et al.
8 citations
Combining virtual reality with mind-body therapies such as meditation, mindfulness, relaxation, and hypnosis can reduce pain in both healthy volunteers and patients. A scoping review of 43 studies found that the combination is feasible, well-tolerated, and potentially useful for decreasing pain, and also improves anxiety, mood, and relaxation. However, insufficient research and a lack of multidimensional studies limit full understanding of their potential. More randomized controlled trials with usability evaluations are needed to incorporate these approaches into routine clinical practice.
Expert review of neurotherapeutics
June 1, 2025
Rosalie Girard Pepin, Fatemeh Seyfzadeh, David Williamson et al.
7 citations
Pharmacological treatment options for disorders of consciousness (DoC), which range from coma to minimally conscious state, remain limited due to the heterogeneity of causes such as traumatic brain injury, stroke, and infections. A lack of rigorous clinical trials has led to off-label use of drugs—including dopaminergic and GABAergic agents, antidepressants, statins, and anticonvulsants—often without clear mechanistic understanding. Robust longitudinal trials are needed, prioritizing early subacute intervention and better-defined outcomes that consider immediate responses and long-term quality of life. A shift toward personalized medicine and unified functional frameworks is advocated, along with increased use of AI tools to predict treatment responses.
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
May 1, 2025
Paolo Cardone, Pablo Núñez, Naji L N Alnagger et al.
7 citations
A patient in a minimally conscious state plus received psilocybin, a classic psychedelic, for the first time. No increase in overt behavioral repertoire was observed on validated scales, but new spontaneous behavior not previously seen emerged, and brain complexity, measured by the Lempel-Ziv complexity index, increased with changes in underlying periodic rhythms. This case report contributes to future investigations of psychedelics for disorders of consciousness and the link between brain complexity and consciousness.
Neuroscience of consciousness
January 1, 2024
Audrey Vanhaudenhuyse, Marie-Carmen Castillo, Charlotte Martial et al.
7 citations
Auto-induced cognitive trance (AICT) produces richer and more distinct subjective experiences than ordinary rest, auditory stimulation, or imagination. In 27 trained participants, free recalls of experiences were longer during AICT than in other conditions. Text mining identified four distinct classes of discourse, with AICT forming its own class clearly separate from ordinary conscious states. Nine content categories emerged, including nature, animals, body modifications, and difficulty describing thoughts. AICT was specifically characterized by reports of nature, animals, body modifications, and difficulty describing thoughts. These findings indicate that AICT generates a unique and richer phenomenology compared to other conscious states.
bioRxiv : the preprint server for biology
October 31, 2023
Charlotte Maschke, Jordan O'Byrne, Michele Angelo Colombo et al.
7 citations
preprint
Consciousness may depend on brain activity poised at criticality, a state with optimal computational properties. Electroencephalograms were recorded from healthy, unresponsive volunteers under propofol, xenon, or ketamine anesthesia. Ketamine spared consciousness (vivid dreams), allowing separation of unresponsiveness from unconsciousness. Unconscious states showed a departure from both the edge of activity propagation and the edge of chaos. The perturbational complexity index (PCI), a sensitive consciousness measure, was predicted from these dynamical properties with a mean absolute error below 7%. Results link PCI to criticality and support criticality's role in consciousness.
Open Repository and Bibliography (University of Liège)
October 13, 2020
Olivia Gosseries, Charlotte Martial
5 citations
An interview with Olivia Gosseries explores the potential of psychedelic drugs, particularly psilocybin, as a treatment for disorders of consciousness such as the persistent vegetative state. While psilocybin is undergoing clinical investigations in healthy volunteers and clinical populations, experts propose extending this research to patients with disorders of consciousness. Gosseries, drawing on her empirical and theoretical work, supports implementing rigorous clinical trials to test efficacy. The interview also touches on ethical and legal challenges and discusses other non-pathological modified states of consciousness.
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference
July 1, 2019
Minji Lee, Benjamin Baird, Olivia Gosseries et al.
4 citations
Cortical networks show differences in functional integration and segregation across states of consciousness, but not in overall connectivity. In the beta frequency band, functional integration during wakefulness exceeded that during NREM sleep. In the theta band, functional segregation (transitivity and clustering coefficient) was stronger in NREM sleep without conscious experience than in wakefulness or REM sleep, while the opposite pattern appeared in the beta band. No significant differences in the weighted phase lag index were found among wakefulness, REM sleep with conscious experience, NREM sleep with conscious experience, and NREM sleep without conscious experience. These findings may relate to cortical bistability and contribute to understanding neural correlates of consciousness.
bioRxiv (Cold Spring Harbor Laboratory)
August 19, 2024
Naji Alnagger, Paolo Cardone, Charlotte Martial et al.
3 citations
preprint
Disorders of consciousness, such as unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), have few treatments. Using whole-brain computational models built from individual patients' fMRI and diffusion-weighted imaging data, this virtual clinical trial simulated the effects of LSD and psilocybin. The psychedelics shifted the brains of patients with disorders of consciousness closer to a critical dynamical state, with a larger effect in MCS patients. In UWS patients, the treatment response depended on structural connectivity, whereas in MCS patients it aligned with baseline functional connectivity. These results provide a computational foundation for considering psychedelics in treating disorders of consciousness and highlight the role of computational modeling in drug discovery and personalized medicine.
International journal of clinical and health psychology : IJCHP
January 1, 2024
Charlotte Martial, Pauline Fritz, Helena Cassol et al.
3 citations
One year after a prolonged intensive care unit (ICU) stay, survivors who reported a near-death experience (NDE) retained vivid, stable memories with many phenomenological details such as visual features and emotions. Among 126 adult ICU survivors, 19 (15%) reported an NDE as identified by the Greyson scale. The most common NDE features were altered time perception, heightened senses, and life review; Greyson scores did not change over the year. One year later, 18% of the NDE group and 24% of the non-NDE group were less afraid of death. The findings suggest that clinicians should interview all ICU patients about their memories.
Advanced Science
November 20, 2025
Paolo Cardone, Charlotte Martial, Yonatan Sanz Perl et al.
2 citations
Simulated administration of LSD and psilocybin in computational models of patients with disorders of consciousness (DoC), including unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), shifted brain activity closer to criticality—the phase transition between order and chaos. The effect was greater in MCS patients. In UWS patients, the treatment response correlated with structural connectivity, while in MCS patients it aligned with baseline functional connectivity. These results provide a computational foundation for using psychedelics in DoC treatment and highlight the potential role of computational modeling in drug discovery and personalized medicine.