Communications Biology
January 28, 2023
Andrea I. Luppi, Jakub Vohryzek, Morten L. Kringelbach et al.
98 citations
Consciousness depends on how tightly brain function follows the brain's physical wiring. Using MRI scans, researchers measured structure-function coupling across spatial scales in people who were unconscious from anesthesia or brain injury and in people under psychedelics (LSD or ketamine). During loss of consciousness, function more closely tracked the brain's structural connections, a signature that could distinguish behaviorally similar brain-injured patients and detect covert consciousness. In contrast, psychedelics decoupled function from structure, and this decoupling correlated with physiological and subjective scores. The findings suggest that connectome harmonic decomposition reveals how neuromodulation and network architecture jointly shape consciousness.
Communications Biology
June 29, 2022
Anira Escrichs, Yonatan Sanz Perl, Carme Uribe et al.
67 citations
Different brain states—resting, meditating, deep sleep, and disorders of consciousness after coma—are underpinned by distinct spatiotemporal dynamics that can be characterized using turbulence theory. Non-conscious states tend to be more synchronous, while conscious states are more asynchronous, but the work goes beyond this simple dichotomy. A model-free analysis of human neuroimaging data applied Kuramoto's turbulence framework with coupled oscillators and measured information cascades across spatial scales. A complementary model-based approach used exhaustive computer simulations of whole-brain models fitted to those measures to study information encoding. The framework shows that turbulence theory provides excellent tools for describing and differentiating between brain states.
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.
Communications Biology
May 9, 2023
Philipp Klar, Yasir Çatal, Robert Langner et al.
35 citations
Scale-free physiological processes are common in the human body. Resting-state fMRI studies found that anesthesia eliminates scale-free dynamics. This study examines scale-free dynamics in the cerebral cortex's unimodal periphery and transmodal core during rest and tasks at three conscious levels (awake, sedation, anesthesia), complemented by computational modeling. The results show that anesthesia transforms pink noise into white noise, disrupting the brain's alignment with a task's temporal structure. The model indicates that stimuli with pink noise, unlike brown or white noise, modulate task-related activity. The findings support two mechanisms of consciousness—temporo-spatial nestedness and alignment—proposed by the Temporo-Spatial Theory of Consciousness.
Communications Biology
July 26, 2023
Ivani Brys, Sebastian A Barrientos, Jon Ezra Ward et al.
33 citations
Psychedelics like LSD, DOI, ketamine, and PCP produce profound changes in perception and cognition by inducing synchronized high-frequency oscillations across multiple brain regions. In rats, these drugs caused near-zero phase delays (<1 ms) in the ventral striatum and cortical areas, indicating hypersynchrony that likely disrupts information integration across neural systems. This shared pattern, despite different firing rate effects on interneurons and principal cells, suggests a key mechanism behind altered states of consciousness. Similar hypersynchrony may contribute to hallucinations and delusions in psychotic disorders, offering potential targets for new antipsychotic treatments.
Communications Biology
September 30, 2024
Pablo Castro, Andrea I. Luppi, Enzo Tagliazucchi et al.
21 citations
Brain activity during unconsciousness, whether from general anaesthesia or slow wave sleep, is dominated by a recurrent functional connectivity pattern primarily mediated by structural connectivity and with a reduced capacity to transition to other patterns. Conscious awareness is characterized by richer brain dynamics measured by entropy and a greater repertoire of connectivity states. These findings suggest that the dynamic exploration of functional connectivity states provides robust and generalizable markers for the state of consciousness across different conditions.
Communications Biology
September 19, 2024
I Mindlin, R Herzog, L Belloli et al.
18 citations
Combining whole-brain models with deep learning, researchers mapped the low-dimensional space of patients with disorders of consciousness and simulated pharmacological interventions by altering neuromodulatory levels. Serotonergic and opioid receptor activation shifted the models toward brain dynamics seen in healthier states, with improvements correlating with the mean density of activated receptors across the brain. This approach provides a way to explore therapeutic potential of psychedelic drugs within ethical and methodological constraints, marking progress toward treatments for disorders of consciousness and other brain diseases.
Communications Biology
June 20, 2023
Joel Frohlich, Pedro A. M. Mediano, Francesco Bavato et al.
16 citations
Low-frequency delta-band neural activity is typically associated with loss of consciousness and cortical down states, especially when diffuse and high amplitude. However, several classes of pharmacological agents—including antiepileptic drugs, GABA B receptor activators, acetylcholine receptor blockers, and psychedelics—can produce neural activity resembling cortical down states while participants remain conscious. Among these substances safe for healthy volunteers, some may serve as valuable research tools for determining which neural activity patterns are sufficient for consciousness or its absence.
Communications Biology
April 18, 2025
S Parker Singleton, Christopher Timmermann, Andrea I. Luppi et al.
7 citations
After DMT injection, the brain requires less control energy to transition between states compared to placebo, indicating a more flexible and less constrained brain dynamic. These energy changes track with EEG signal diversity and subjective intensity of the drug experience. The regional pattern of DMT's effects aligns with serotonin 2a receptor density, and a model using receptor distribution and pharmacokinetics can predict the drug's impact on brain energy trajectories.
Communications Biology
March 11, 2025
Juan Ignacio Piccinini, Yonatan Sanz Perl, Carla Pallavicini et al.
6 citations
The transition into a psychedelic brain state is often overlooked in favor of static descriptions of acute effects. Using a time-dependent whole-brain model and fMRI data from 15 volunteers given intravenous DMT, the work shows that a transient of heightened reactivity in fronto-parietal regions and visual cortices correlates with serotonin 5HT2a receptor density. Simulated perturbations suggest that minimal disturbances can achieve maximal effects during this brief period, and the temporal evolution of these features aligns with pharmacokinetics. These findings indicate a mechanism for how short psychedelic episodes may exert a lasting influence over time.
Communications Biology
November 6, 2025
Alex Jinich-Diamant, Sierra Simpson, Juan Pablo Zuniga-Hertz et al.
4 citations
A 7-day retreat combining meditation, reconceptualization, and open-label placebo healing rituals produced broad short-term neural and molecular changes in 20 healthy participants. Meditation reduced functional integration in the default mode and salience networks and decreased whole-brain modularity. Post-intervention plasma increased neurite outgrowth, enhanced glycolytic metabolism, and induced upregulation of BDNF, inflammatory, anti-inflammatory, and endogenous opioid pathways, while modulating tryptophan metabolism and neurotransmission-associated exosome miRNA transcripts. These changes suggest enhanced neuroplasticity, metabolic reprogramming, and modulation of functional cell signaling pathways, highlighting the potential of mind-body techniques to affect neural circuits and pathways important to health and well-being.
Communications Biology
August 13, 2025
Steven Kotler, Michael Mannino, Karl Friston et al.
2 citations
Intuition, often inconsistently defined, is reframed as an evolutionarily grounded pathfinding mechanism that emerges from the brain's optimization of its relationship with the environment. A review of empirical findings identifies relevant brain networks and links intuition to cognitive states like insight. Unsolved problems dynamically alter attractor landscapes, guiding future intuitions. The concept of 'opportunistic assimilation' is explored through nonlinear neurodynamics, and hippocampal sharp wave ripples are identified as potential neural correlates of intuition, given their role in creativity, choice, action planning, and abstract thinking. Two complementary frameworks—the free energy principle and metastable coordination dynamics—together provide a comprehensive neurodynamical account of intuition's neurophenomenology.
Communications Biology
March 26, 2026
Veronica Mäki-marttunen
1 citation
Psilocybin, a psychedelic compound that activates 5HT2a serotonin receptors, alters the speed and pattern of traveling waves of neural activity across the cortex. Using fMRI data from a publicly available dataset, researchers found that psilocybin increased the propagation speed of infraslow cortical activity, which was linked to greater overall functional connectivity and a contraction of the principal gradient—a measure of how brain regions are organized along a sensory-to-association axis. The distribution of 5HT2a receptors in the cortex may help explain these changes. The results connect large-scale brain activity patterns, global neural events, and receptor action, offering insights into how psychedelics produce their effects.
Communications Biology
July 30, 2025
Johan Nakuci, Kanika Bansal
1 citation
A neuroreceptor-based modeling framework using cortical density maps of 19 neuroreceptors and transporters from PET scans can reconstruct BOLD-derived brain activity. The framework identified two neuroreceptor modules: one linked to higher-order associative networks and another to somatomotor and visual networks. Applied to independent datasets, it recovered the binding profiles of LSD and Modafinil, consistent with known pharmacology. It also uncovered associations between neuroreceptors and altered brain activity in neuropsychiatric disorders. The findings suggest the framework can elucidate neuromodulatory mechanisms and advance understanding of brain function across diverse states and conditions.
Communications Biology
October 13, 2024
Nora A Bradford, Angela Shen, Brian Odegaard et al.
1 citation
A workshop and subawards program aimed to align United States federal funding mechanisms with consciousness research is described, including its motivation, execution, and outcomes, to encourage similar efforts locally and globally.
Communications Biology
July 3, 2026
Fengkai He, Xiaojun Xu, Y Y Zhu et al.
Depression involves disrupted communication across brain circuits, and ketamine can rapidly alleviate depressive symptoms. A new analytical framework, the frequency-varying multilayer brain functional network (FMBFN), was developed to examine how brain regions coordinate activity both within and across different frequency bands. Using local field potential recordings from eight brain regions in male mice subjected to chronic social defeat stress (a model of depression), the framework revealed that stress led to frequency-specific hyperconnectivity and altered network integration during social interaction. Ketamine reversed social avoidance and reorganized the multilayer network topology, with the lateral habenula showing a response pattern opposite to other regions. Exploratory analysis also linked ketamine-associated gut microbial changes to global network topology, suggesting possible gut-brain associations.
Communications Biology
June 12, 2026
Saketh Malipeddi, Arun Sasidharan, Bianca Ventura et al.
Advanced meditators from the Isha Yoga tradition report stronger non-dual experiences—where the boundary between self and environment dissolves—during breath-watching meditation compared to novices and meditation-naïve controls. Using EEG-based intrinsic neural timescales (INT), researchers found that across all participants, INTs are longer during internal attention (breath-watching) than during an external cognitive task. However, advanced meditators show similar INT durations between internal and external attention, and this reduced difference correlates with stronger reported non-dual experiences. The findings suggest that similar intrinsic neural timescale durations across internal and external attention may be a neural signature of non-duality.
Communications Biology
April 24, 2026
Tatum Askey, Daniel Allen-Ross, Daniil Luzyanin et al.
A single dose of psilocybin produces a sustained anti-nociceptive effect in chronic neuropathic pain models in male and female mice, mediated primarily by 5-HT2A receptors. Psilocybin significantly potentiates the analgesic efficacy of gabapentin, a standard-of-care treatment, representing the first preclinical evidence that a psychedelic can serve as a pain-network primer for existing analgesics. This finding suggests a novel therapeutic strategy, particularly for the 30-50% of neuropathic pain patients who fail gabapentin monotherapy. The data demonstrate that a single psilocybin injection produces sustained month-long changes that enhance gabapentin efficacy in a preclinical model.
Communications Biology
February 26, 2026
Tianjie Li, Erin. E. Reynolds, Ziqi Wang et al.
A fungal enzyme called PcncAAAD, which decarboxylates aromatic amino acids, is activated by calcium through two metal-binding sites. The primary activation site (site A) lies between the N-terminal domain and a unique C-terminal appendage; binding calcium there stabilizes a 'lid-rim' structure that preserves the substrate-binding pocket. A secondary site (site B) within the C-terminal domain helps stabilize the enzyme's overall structure. Computer simulations and lab tests show that disrupting site A or the lid-rim severely distorts the active site and reduces or eliminates activity. Sodium does not activate the enzyme. The work clarifies how calcium activates this enzyme and may guide engineering of similar enzymes for making aromatic amino acid derivatives.
Communications Biology
December 18, 2025
Fa Lu, Juan Wang, Xuewei Qin et al.
Altered consciousness—from anesthesia and sleep to disorders of consciousness—involves distinct changes in thalamic nuclei. Analyzing fMRI data across these states, the authors found that propofol anesthesia disrupted pulvinar-cortical connections, sleep transitions affected specific nuclei (VLp, medial geniculate, centromedian), and disorders of consciousness showed widespread disconnections. Five key nuclei showed state-specific alterations, with higher-order nuclei (pulvinar, centromedian, mediodorsal) more consistently involved. Decreased local brain signal complexity occurred in 4–6 nuclei during anesthesia and 4–5 in patients with disorders of consciousness. The coupling between local fluctuation and connectivity varied systematically with consciousness state, suggesting potential therapeutic targets.
Communications Biology
September 30, 2025
Yun Zhao, Naotsugu Tsuchiya, Mario Boley et al.
Consciousness depends on complex brain structures and processes, but how it is regulated neurobiologically is uncertain. Using magnetoencephalography (MEG) data from 15 participants under Xenon-induced anesthesia, researchers developed interconnected neural mass models to infer time-evolving regional neurophysiological variables and inter-regional connectivity strengths. Significant correlations emerged between consciousness levels and connectivity, especially in posterior parietal, occipital, and prefrontal regions. Results support a parietal, rather than frontal, network backbone for global consciousness. Reductions in consciousness were linked to stabilized cortical dynamics, reflected by changes in the system's eigenmodes. This framework offers a time-resolved perspective on neural mechanisms during altered states.
Communications Biology
July 5, 2023
Idan E Nemirovsky, Nicholas J M Popiel, Jorge Rudas et al.
Integrated Information Theory aims to explain and measure consciousness by quantifying how integrated a system's causal properties are. This work implemented version 3.0 of the theory on functional MRI data from 17 healthy volunteers sedated with propofol. Using the PyPhi software, the measure Φmax was computed and compared with other proposed consciousness metrics: an earlier integrated information version, Granger causality, and correlation-based functional connectivity. Φmax showed varied responses to sedation across different brain networks. Changes in Φmax closely tracked changes in conscious level within the frontoparietal and dorsal attention networks, which support higher-order cognition. The findings offer guidance for future use of these measures in neuroimaging.
Communications Biology
November 3, 2022
Peter Coppola, Judith Allanson, Lorina Naci et al.
Consciousness is associated with short-term brain connectivity transitions that are less predictable, quicker, but on average more constant than those in unconscious states. By combining modern consciousness theories with phenomenology and dynamical systems theory, the authors created an individual-specific landscape of brain connectivity dynamics as a proxy for the stream of consciousness. They found that temporally-specific connectivity states are less easily describable by network patterns distant in time, suggesting a richer space of possible states. The cortex, cerebellum, and subcortex all display consciousness-relevant dynamics.
Communications Biology
September 8, 2022
Angeliki Zarkali, Andrea I. Luppi, Emmanuel A. Stamatakis et al.
People with Parkinson's disease who experience hallucinations spend more time in a brain state where regions are functionally segregated from one another and make fewer transitions between brain states. The shift from an integrated to a segregated state requires less energy in those who hallucinate, making that state potentially preferable. The regional energy needed for this transition correlates with neurotransmitter density and gene expression for serotoninergic, GABAergic, noradrenergic, and cholinergic receptors, but not dopaminergic receptors. The findings suggest that neurochemistry and brain structure together shape the dynamic brain states that underlie hallucinations.
Communications Biology
April 20, 2022
A. Luppi, P. Mediano, F. Rosas et al.
A neurobiologically realistic computational model of whole-brain haemodynamic signals, perturbed to simulate loss of consciousness, reveals two distinct neurobiological paths to unconscious brain activity. Incorporating PET data on GABA receptor distribution shows that spatially-specific local inhibition reproduces fMRI activity observed during propofol anaesthesia. Incorporating diffusion MRI data from patients with disorders of consciousness shows that randomized neuroanatomical connectivity can also produce the dynamics characteristic of loss of consciousness. The results generalize across anaesthesia and injury datasets, suggesting that increased inhibition and connectome perturbation are distinct routes to the same functional brain dynamics.