Cell Reports
August 1, 2026
Rui Dai, Hyunwoo Jang, A. Hudetz et al.
Understanding the relationship of conscious states to large-scale brain dynamics remains a central challenge in neuroscience. Here, diverse pharmacological and physiological perturbations-including psychedelics, sleep, and propofol sedation-are used to examine integration-segregation organization of brain networks across altered states of consciousness in humans using functional MRI. Across...
bioRxiv : the preprint server for biology
June 1, 2026
Panagiotis Fotiadis, Hyunwoo Jang, Rui Dai et al.
Brain waves are ubiquitous phenomena of human brain activity. As they propagate, they coordinate neural communication, shaping conscious perception. Understanding how brain waves unfold across space and time is thus critical for uncovering the neural mechanisms that support and suppress consciousness. Here, we analyzed data from the Human Connectome Project alongside multiple independent human...
Scientific Data
January 9, 2026
Zirui Huang, Vijay Tarnal, Panagiotis Fotiadis et al.
Anesthesia has revolutionized surgical practice and offers a controlled model to study the neurobiology of consciousness. Functional magnetic resonance imaging (fMRI) studies have shown that anesthesia primarily disrupts connectivity across association cortices, suggesting that impaired integration between higher-order brain regions underlies unconsciousness. However, traditional fMRI paradigms...
bioRxiv
November 26, 2025
Rui Dai, Rodrigo Cofré, Christopher Timmermann et al.
preprint
The mechanism of psychedelic drug action is a dynamic area of neuroscience, with two major lines of investigation: (1) laboratory studies at the molecular and cellular level, and (2) human neuroimaging studies of functional brain networks. Despite considerable progress, there remains insufficient understanding of the link between molecular/cellular substrates of psychedelics and the whole-brain...
Nature Communications
October 24, 2024
Hyunwoo Jang, George A. Mashour, Anthony G. Hudetz et al.
Consciousness requires a dynamic balance of integration and segregation in brain networks. We report an fMRI-based metric, the integration-segregation difference (ISD), which captures two key network properties: network efficiency (integration) and clustering (segregation). With this metric, we quantify brain state transitions from conscious wakefulness to unresponsiveness induced by the...
bioRxiv : the preprint server for biology
October 23, 2024
Rui Dai, Hyunwoo Jang, Anthony G. Hudetz et al.
1 citation
preprint
Understanding neural mechanisms of consciousness remains a challenging question in neuroscience. A central debate in the field concerns whether consciousness arises from global interactions that involve multiple brain regions or focal neural activity, such as in sensory cortex. Additionally, global theories diverge between the Global Neuronal Workspace (GNW) hypothesis, which emphasizes frontal...
Nature Communications
September 9, 2024
Zirui Huang, George A. Mashour, Anthony G. Hudetz
23 citations
Research into the role of thalamocortical circuits in anesthesia-induced unconsciousness is difficult due to anatomical and functional complexity. Prior neuroimaging studies have examined either the thalamus as a whole or focused on specific subregions, overlooking the distinct neuronal subtypes like core and matrix cells. We conducted a study of heathy volunteers and functional magnetic...
Brain Sciences
August 30, 2024
Hyunwoo Jang, Rui Dai, George A. Mashour et al.
Accurate and generalizable classification of brain states is essential for understanding their neural underpinnings and improving clinical diagnostics. Traditionally, functional connectivity patterns and graph-theoretic metrics have been utilized. However, cortical gradient features, which reflect global brain organization, offer a complementary approach. We hypothesized that a machine learning...
bioRxiv
April 15, 2024
Hyunwoo Jang, George A. Mashour, Anthony G. Hudetz et al.
preprint
Consciousness requires a dynamic balance of integration and segregation in functional brain networks. An optimal integration-segregation balance depends on two key aspects of functional connectivity: global efficiency (i.e., integration) and clustering (i.e., segregation). We developed a new fMRI-based measure, termed the integration-segregation difference (ISD), which captures both aspects. We...
Commun Biol
December 19, 2023
Rui Dai, Zirui Huang, Tony E. Larkin et al.
7 citations
Psychedelic concentrations of nitrous oxide reduce functional differentiation in frontoparietal and somatomotor cortical networks.
Cambridge quarterly of healthcare ethics : CQ : the international journal of healthcare ethics committees
October 18, 2023
Matthew Owen, Zirui Huang, Catherine Duclos et al.
Organoids and specifically human cerebral organoids (HCOs) are one of the most relevant novelties in the field of biomedical research. Grown either from embryonic or induced pluripotent stem cells, HCOs can be used as in vitro three-dimensional models, mimicking the developmental process and organization of the developing human brain. Based on that, and despite their current limitations, it...
Neuroimage
June 1, 2023
Rui Dai, Tony E. Larkin, Zirui Huang et al.
49 citations
The neurobiology of the psychedelic experience is not fully understood. Identifying common brain network changes induced by both classical (i.e., acting at the 5-HT2 receptor) and non-classical psychedelics would provide mechanistic insight into state-specific characteristics. We analyzed whole-brain functional connectivity based on resting-state fMRI data in humans, acquired before and during...
Communications Biology
May 9, 2023
Philipp Klar, Yasir Çatal, Robert Langner et al.
35 citations
Scale-free physiological processes are ubiquitous in the human organism. Resting-state functional MRI studies observed the loss of scale-free dynamics under anesthesia. In contrast, the modulation of scale-free dynamics during task-related activity remains an open question. We investigate scale-free dynamics in the cerebral cortex's unimodal periphery and transmodal core topography in rest and...
Nature Communications
January 5, 2023
Zirui Huang, George A. Mashour, Anthony G. Hudetz
Consciousness is a multidimensional phenomenon, but key dimensions such as awareness and wakefulness have been described conceptually rather than neurobiologically. We hypothesize that dimensions of consciousness are encoded in multiple neurofunctional dimensions of the brain. We analyze cortical gradients, which are continua of the brain’s overarching functional geometry, to characterize these...
Frontiers in Systems Neuroscience
December 1, 2021
Minkyung Kim, Hyoungkyu Kim, Zirui Huang et al.
Continuous switching between internal and external modes in the brain appears important for generating models of the self and the world. However, how the brain transitions between these two modes remains unknown. We propose that a large synchronization fluctuation of brain networks, emerging only near criticality (i.e., a balanced state between order and disorder), spontaneously creates...
Cell Reports
May 1, 2021
Zirui Huang, Vijay Tarnal, Phillip E. Vlisides et al.
119 citations
Conscious access to sensory information is likely gated at an intermediate site between primary sensory and transmodal association cortices, but the structure responsible remains unknown. We perform functional neuroimaging to determine the neural correlates of conscious access using a volitional mental imagery task, a report paradigm not confounded by motor behavior. Titrating propofol to loss...
Neuroimage
May 1, 2021
Pengmin Qin, Xuehai Wu, Changwei W Wu et al.
51 citations
Consciousness is a mental characteristic of the human mind, whose exact neural features remain unclear. We aimed to identify the critical nodes within the brain's global functional network that support consciousness. To that end, we collected a large fMRI resting state dataset with subjects in at least one of the following three consciousness states: preserved (including the healthy awake...
Science Advances
March 1, 2020
Zirui Huang, Jun Zhang, Jinsong Wu et al.
Neuroimaging suggests that human consciousness relies on frequent access to default mode and dorsal attention brain networks. The ongoing stream of human consciousness relies on two distinct cortical systems, the default mode network and the dorsal attention network, which alternate their activity in an anticorrelated manner. We examined how the two systems are regulated in the conscious brain...
Human Brain Mapping
October 4, 2018
Annemarie Wolff, Daniel A. di Giovanni, Javier Gómez‐Pilar et al.
135 citations
The self is the core of our mental life. Previous investigations have demonstrated a strong neural overlap between self-related activity and resting state activity. This suggests that information about self-relatedness is encoded in our brain's spontaneous activity. The exact neuronal mechanisms of such "rest-self containment," however, remain unclear. The present EEG study investigated...
Entropy
July 10, 2018
Heonsoo Lee, Zirui Huang, Xiaolin Liu et al.
Theoretical consideration predicts that the alteration of local and shared information in the brain is a key element in the mechanism of anesthetic-induced unconsciousness. Ordinal pattern analysis, such as permutation entropy (PE) and symbolic mutual information (SMI), have been successful in quantifying local and shared information in neurophysiological data; however, they have been rarely...
Human Brain Mapping
January 28, 2018
Jianfeng Zhang, Zirui Huang, Yali Chen et al.
70 citations
Which temporal features that can characterize different brain states (i.e., consciousness or unconsciousness) is a fundamental question in the neuroscience of consciousness. Using resting-state functional magnetic resonance imaging (rs-fMRI), we investigated the spatial patterns of two temporal features: the long-range temporal correlations (LRTCs), measured by power-law exponent (PLE), and...
Neuroscience and Biobehavioral Reviews
September 1, 2017
Georg Northoff, Zirui Huang
235 citations
Time and space are the basic building blocks of nature. As a unique existent in nature, our brain exists in time and takes up space. The brain's activity itself also constitutes and spreads in its own (intrinsic) time and space that is crucial for consciousness. Consciousness is a complex phenomenon including different dimensions: level/state, content/form, phenomenal aspects, and cognitive...
Neuropsychologia
January 21, 2016
Zirui Huang, Natsuho Obara, Henry Davis et al.
144 citations
Recent studies have demonstrated an overlap between the neural substrate of resting-state activity and self-related processing in the cortical midline structures (CMS). However, the neural and psychological mechanisms mediating this so-called "rest-self overlap" remain unclear. To investigate the neural mechanisms, we estimated the temporal structure of spontaneous/resting-state activity, e.g....
Annals of Neurology
August 20, 2015
Pengmin Qin, Xuehai Wu, Zirui Huang et al.
144 citations
OBJECTIVE: We aimed to investigate the roles of different resting-state networks in predicting both the actual level of consciousness and its recovery in brain injury patients. METHODS: We investigated resting-state functional connectivity within different networks in patients with varying levels of consciousness: unresponsive wakefulness syndrome (UWS; n = 56), minimally conscious state (MCS;...
Human Brain Mapping
July 1, 2013
Zirui Huang, Rui Dai, Xuehai Wu et al.
104 citations
Recent studies have demonstrated resting-state abnormalities in midline regions in vegetative state/unresponsive wakefulness syndrome and minimally conscious state patients. However, the functional implications of these resting-state abnormalities remain unclear. Recent findings in healthy subjects have revealed a close overlap between the neural substrate of self-referential processing and the...