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...
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...
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...
Introduction Fibromyalgia (FM) is the prototypical nociplastic pain condition, characterized by widespread pain and issues with cognition, mood, and sleep. Currently, there are limited treatment options available that effectively treat FM symptoms. Psilocybin-assisted therapy (PAT) is an emerging combined drug-therapy intervention, but no studies to-date have investigated PAT for FM. Methods...
Despite the longstanding use of nitrous oxide and descriptions of its psychological effects more than a century ago, there is a paucity of neurobiological investigation of associated psychedelic experiences. We measure the brain's functional geometry (through analysis of cortical gradients) and temporal dynamics (through analysis of co-activation patterns) using human resting-state functional...
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...
The development of sophisticated computational tools to quantify changes in the brain's oscillatory dynamics across states of consciousness have included both envelope- and phase-based measures of functional connectivity (FC), but there are very few direct comparisons of these techniques using the same dataset. The goal of this study was to compare an envelope-based (i.e. Amplitude Envelope...
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...
Motifs are patterns of inter-connections between nodes of a network, and have been investigated as building blocks of directed networks. This study explored the re-organization of 3-node motifs during loss and recovery of consciousness. Nine healthy subjects underwent a 3-h anesthetic protocol while 128-channel electroencephalography (EEG) was recorded. In the alpha (8-13 Hz) band, 5-min epochs...
BackgroundDespite its designation as a 'dissociative anaesthetic,' the dissociative and psychoactive effects of ketamine remain incompletely understood. The goal of this study was to characterise the subjective experiences and accompanying EEG changes with subanaesthetic doses of ketamine.MethodsHigh-density EEG was recorded in 15 human volunteers before, during, and after subanaesthetic...