JAMA Psychiatry
June 1, 2026
Ben Deverett, Duan Li, Theresa R. Lii et al.
1 citation
Ketamine has well-known dissociative, analgesic, and antidepressant properties, but it is unknown whether the neurophysiologic effects that are associated with these properties can be modulated separately from one another. Considering that specific cortical oscillations have been associated with specific therapeutic effects, modulating selective aspects of ketamine neurophysiology could inform...
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...
medRxiv
August 7, 2025
Ben Deverett, Duan Li, Theresa R. Lii et al.
preprint
Structured Abstract Importance Ketamine has well known dissociative, analgesic, and antidepressant properties, but it is unknown whether the neurophysiologic effects that are associated with these properties can be modulated separately from one another. Given prior studies that link specific cortical oscillations with specific therapeutic effects, it is likely that modulating selective aspects...
Neuroimage
July 18, 2025
Xin Wen, Yu Chang, Sijie Li et al.
1 citation
The search for neurophysiological markers of consciousness and their neural substrates remains a focal point in neuroscience research. The integrated information theory (IIT) provides a promising quantitative framework for consciousness assessment, but computational limitations of existing Φ estimation methods hinder an in-depth understanding of large-scale cortical integration. Here, we...
Sleep
May 26, 2025
Alejandra Mondino, Amir Jadidian, Brandon A Toth et al.
4 citations
The preoptic area of the hypothalamus is key for the control of sleep onset and sleep homeostasis. Although traditionally considered exclusively somnogenic, recent studies identified a group of preoptic glutamatergic neurons that promote wakefulness. Specifically, our previous investigations demonstrated that chemogenetic stimulation of glutamatergic neurons within the medial-lateral preoptic...
Anesthesiology
June 1, 2024
George A. Mashour, UnCheol Lee, Dinesh Pal et al.
8 citations
The near-death experience has been reported since antiquity and is often characterized by the perception of light, interactions with other entities, and life recall. Near-death experiences can occur in a variety of situations, but they have been studied systematically after in-hospital cardiac arrest, with an incidence of 10 to 20%. Long attributed to metaphysical or supernatural causes, there...
Anesthesiology
May 1, 2024
Zhenhu Liang, Bo Tang, Yu Chang et al.
13 citations
Identifying the state-related "neural correlates of consciousness" for anesthetics-induced unconsciousness is challenging. Spatiotemporal complexity is a promising tool for investigating consciousness. The authors hypothesized that spatiotemporal complexity may serve as a state-related but not drug-related electroencephalography (EEG) indicator during an unconscious state induced by different...
British Journal of Anaesthesia
March 1, 2024
Zhenhu Liang, Yu Chang, Xiaoge Liu et al.
10 citations
Information integration and network science are important theories for quantifying consciousness. However, whether these theories propose drug- or conscious state-related changes in EEG during anaesthesia-induced unresponsiveness remains unknown. A total of 72 participants were randomised to receive i.v. infusion of propofol, dexmedetomidine, or ketamine at a constant infusion rate until loss...
Anesthesia and analgesia
June 1, 2022
Michael A. Brito, Duan Li, Christopher W Fields et al.
Neurophysiologic complexity has been shown to decrease during states characterized by a depressed level of consciousness, such as sleep or anesthesia. Conversely, neurophysiologic complexity is increased during exposure to serotonergic psychedelics or subanesthetic doses of dissociative anesthetics. However, the neurochemical substrates underlying changes in neurophysiologic complexity are...
Neuroimage
January 7, 2022
Duan Li, Phillip E. Vlisides, George A. Mashour
24 citations
Recent neuroimaging studies have demonstrated that spontaneous brain activity exhibits rich spatiotemporal structure that can be characterized as the exploration of a repertoire of spatially distributed patterns that recur over time. The repertoire of brain states may reflect the capacity for consciousness, since general anesthetics suppress and psychedelic drugs enhance such dynamics. However,...
Frontiers in Systems Neuroscience
August 11, 2020
Michael A. Brito, Duan Li, George A. Mashour et al.
15 citations
There is an ongoing debate as to whether ketamine anesthesia suppresses neurophysiologic complexity at doses sufficient for surgical anesthesia, with previous human studies reporting surrogates of both suppressed and preserved levels of cortical complexity. However, these studies have not assessed cortical dynamics in higher gamma frequencies, which have previously been demonstrated to...
IEEE transactions on neural systems and rehabilitation engineering
January 8, 2020
Zhenhu Liang, Shuai Shao, Zhe Lv et al.
Objective: Constructing a framework to evaluate consciousness is an important issue in neuroscience research and clinical practice. However, there is still no systematic framework for quantifying altered consciousness along the dimensions of both level and content. This study builds a framework to differentiate the following states: coma, general anesthesia, minimally conscious state (MCS), and...
Neuroimage
April 5, 2019
Duan Li, George A. Mashour
103 citations
Ketamine is a unique drug that has psychedelic and anesthetic properties in a dose-dependent manner. Recent studies have shown that ketamine anesthesia appears to maintain the spatiotemporal complexity of cortical activation evoked by transcranial magnetic stimulation, while a psychedelic dose of ketamine is associated with increased spontaneous magnetoencephalographic signal diversity....
Frontiers in Systems Neuroscience
March 23, 2017
Duan Li, Viviane S. Hambrecht‐Wiedbusch, George A. Mashour
33 citations
Recent data from our laboratory demonstrate that high-frequency gamma connectivity across the cortex is present during consciousness and depressed during unconsciousness. However, these data were derived from static and well-defined states of arousal rather than during transitions that would suggest functional relevance. We also recently found that subanesthetic ketamine administered during...