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.
Scientific Reports
September 22, 2023
Victor Oswald, Audrey Vanhaudenhuyse, Jitka Annen et al.
24 citations
Self-induced cognitive trance (SICT) is a voluntary non-ordinary state of consciousness involving narrowed awareness, hyper-focused immersion, and altered perception. This study examined autonomic nervous system changes during SICT by measuring heart rate variability and respiration rate variability in 25 proficient participants across three conditions: resting state, SICT, and a mental imagery task. During SICT, participants showed increased heart rate, decreased high-frequency heart rate variability, and specific increases in respiratory amplitude, phase ratio, and respiration rate variability compared to control conditions. These findings suggest SICT is associated with reduced parasympathetic activity, indicating a hyperarousal state of the autonomic nervous system.
Frontiers in Neuroscience
February 2, 2024
Antea D’Andrea, Pierpaolo Croce, Jordan O’Byrne et al.
13 citations
Theravada Buddhist monks with extensive meditation experience underwent magnetoencephalography during focused attention meditation, open monitoring meditation, and resting states. Brain microstate coverage and occurrence differed between meditation and rest and between the two meditation styles. The Hurst exponent, a measure of long-range memory in brain dynamics, was lower during both meditation conditions than during rest. Lempel-Ziv complexity, which quantifies signal complexity, increased progressively from rest to focused attention meditation to open monitoring meditation. These changes in brain criticality indices suggest that meditation shifts brain dynamics toward a more critical state, paralleling changes in cognitive state.
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.
Int J Clin Health Psychol
January 1, 2025
Victor Oswald, Karim Jerbi, Corine Sombrun et al.
4 citations
People vary widely in their experiences during non-ordinary states of consciousness, and this variation is linked to measurable differences in the autonomic nervous system. The study shows that subjective experiences—such as changes in perception, emotion, or sense of self—correspond with distinct patterns of physiological responses, like heart rate or skin conductance. These findings suggest that the body's nervous system plays a key role in shaping how individuals experience altered states, highlighting a direct connection between inner, subjective phenomena and physiological processes.
The Journal of Creative Behavior
December 24, 2024
Antoine Bellemare‐Pepin, Karim Jerbi
4 citations
Creativity relies not only on divergent thinking but also on perceptual flexibility, especially when engaging with ambiguous stimuli. The authors propose a framework linking creativity to perception through sensory affordances, highlighting pareidolia—seeing familiar patterns in noise—as a key mechanism for generating novel ideas. They introduce "divergent perception" to describe active engagement with ambiguous sensory information, suggesting this process may explain heightened creativity in psychedelic and psychotic states. The role of attention in this process is explored, and future research directions are outlined, including manipulating stimulus characteristics and examining interactions between bottom-up and top-down cognitive processes.
bioRxiv (Cold Spring Harbor Laboratory)
January 29, 2026
Venkatesh Subramani, Timothy Nest, Annalisa Pascarella et al.
1 citation
LSD alters brain activity by increasing alpha and beta brain-wave frequencies while genuinely reducing oscillatory power, with these effects showing distinct cortical patterns. The drug also flattens the aperiodic 1/f spectral slope and increases neural signal fractality and complexity, particularly in sensory, language, emotion, and imagery-related networks, while sparing motor cortex. Machine learning identified peak-frequency shifts, aperiodic parameters, and complexity measures as key discriminators of the psychedelic state. Music did not amplify these neural signatures and showed a trend toward attenuation. These findings provide a comprehensive account of how LSD reorganizes large-scale human brain dynamics.
bioRxiv (Cold Spring Harbor Laboratory)
March 5, 2026
Venkatesh Subramani, Annalisa Pascarella, Jérémy Brunel et al.
Lysergic acid diethylamide (LSD) loosens the brain's usual alignment between anatomical structure and neural activity in a frequency-dependent way. Low-frequency brain waves (theta, alpha, beta) become less constrained by the structural connectome, indicating a global relaxation of large-scale dynamics. High-frequency gamma activity shows selective reorganization rather than uniform disruption. Greater gamma-band decoupling within core default-mode network regions predicts the intensity of ego dissolution across individuals. LSD does not cause indiscriminate disintegration but drives system-specific rebalancing: visual and attentional systems decouple while auditory networks strengthen coupling. These findings suggest psychedelic states emerge from frequency-dependent relaxation of structural constraints, with default-mode reorganization as a neural correlate of ego dissolution.
arXiv (Cornell University)
September 23, 2025
Victor Oswald, Karim Jerbi, Corine Sombrun et al.
A self-induced, substance-free trance state called Auto-Induced Cognitive Trance (AICT) engages frontal regions, the posterior cingulate cortex, and the left parietal cortex, brain areas linked to rich subjective experiences. Analysis of EEG recordings from 27 trained participants showed that the aperiodic component of the power spectrum, entropy, and complexity measures distinguished AICT from rest, with the aperiodic component being the strongest discriminator. Baseline neural activity in frontal and parietal regions predicted how much brain activity changed when entering the trance. These results suggest that self-induced trance states alter neural functioning in ways that may explain their intense and unique subjective qualities.