Psychedelics have robust effects on acute brain function and long-term behavior but whether they also cause enduring functional and anatomical brain changes is largely unknown. In an exploratory, placebo-controlled, within-subjects, electroencephalography (EEG), and magnetic resonance imaging (MRI) study in 28 healthy, entirely psychedelic-naive participants...
This article proposes a research agenda for psilocybin-assisted therapy focusing on the correlation between neural entropy and long-term cognitive flexibility.
Psilocybin and other serotonergic drugs acutely alter human brain function and large-scale connectivity as measured with BOLD fMRI, but whether these effects are frequency-specific remains unknown. We applied multitaper spectral and cross-spectral analyses to resting-state fMRI data from 28 healthy volunteers scanned multiple times acutely following oral psi...
Introduced in 2014 and revised in 2018, the entropic brain hypothesis has accrued a wealth of supportive evidence. The hypothesis states that- along a dimension of breadth of conscious experience- ‘expansive states’ reliably exhibit increased brain entropy whereas the inverse applies for states of no or reduced consciousness. Examples of expansive states inc...
Introduced in 2014 and revised in 2018, the entropic brain hypothesis has accrued a wealth of supportive evidence. The hypothesis states that- along a dimension of breadth of conscious experience- ‘expansive states’ reliably exhibit increased brain entropy whereas the inverse applies for states of no or reduced consciousness. Examples of expansive states inc...
Psilocybin, an indoleamine alkaloid derived from various fungal species, is the subject of renewed, rigorous investigation for its therapeutic potential in psychiatry. This compound, a prodrug for the active metabolite psilocin, functions primarily as a partial agonist at the serotonin 2A (5-HT2A) receptor. Its administration within a structured psychotherap...
Electromagnetic field theories of consciousness propose that consciousness emerges from resonant electromagnetic field interactions rather than purely computational neural processes. This paper examines how psychedelic substances-LSD, psilocybin, ketamine, and 5-MeO-DMT-modulate consciousness through their effects on brain electromagnetic fields, as measured...
In this study, we provide the first study to integrate molecular and functional neuroimaging during psychedelic drug effects in humans. Using simultaneous PET-MRI technology, we describe multiple brain actions of lysergic acid diethylamide (LSD) in healthy volunteers. We quantify the occupancy of LSD at cerebral serotonin 2A receptors and show that LSD incre...
Psychedelic compounds significantly reshape conscious perception, yet the implications of these alterations for complex visual-guided behaviors remain poorly understood. We investigated how psilocybin modulates visual salience processing during natural scene perception. Twenty-three participants completed eye-tracking tasks under self-blinded low and high do...
This viewpoint explores the therapeutic potential of psychedelics in treating neuropsychiatric disorders, particularly through the modulation of brain entropy and the experience of ego dissolution. Psychedelics disrupt rigid neural patterns, facilitating enhanced connectivity and fostering profound emotional breakthroughs that may alleviate symptoms of disor...
ABSTRACT Psychedelics have robust effects on acute brain function and long-term behavior but whether they also cause enduring functional and anatomical brain changes is unknown. In a placebo-controlled, within-subjects, electroencephalography, and magnetic resonance imaging study in 28 healthy, entirely psychedelic-naive participants, anatomical and function...
Abstract Psychedelic drugs have profound effects on perception, cognition and mood. How psychedelics affect neural signaling to produce these effects remains poorly understood. We investigated the effect of the classic psychedelic psilocybin on neural activity patterns and spatial encoding in the retrosplenial cortex of head-fixed mice navigating on a treadm...
Protonation is the most frequent adduct found in positive electrospray ionization collision-induced mass spectra (CID-MS/MS). In a parallel report Lee, J. J. Chem. Inf. Model. 2024, 10.1021/acs.jcim.4c00760, we developed a quantum chemistry framework to predict mass spectra by collision-induced dissociation molecular dynamics (CIDMD). As different protonatio...
Psilocybin is a classic psychedelic and a novel treatment for mood disorders. Psilocybin induces dose-dependent transient (4-6 hours) usually pleasant changes in perception, cognition, and emotion by non-selectively agonizing the 5-HT2A receptors and negatively regulating serotonin reuptake, and long-term positive antidepressant effect on mood and well-being...
Exploring the intricate relationship between brain's structure and function, and how this affects subjective experience is a fundamental pursuit in neuroscience. Psychedelic substances offer a unique insight into the influences of specific neurotransmitter systems on perception, cognition and consciousness. Specifically, their impact on brain function propag...
Psychedelic drugs have profound effects on perception, cognition, and mood. How psychedelics affect neural signaling to produce these effects remains poorly understood. We investigated the effect of the classic psychedelic psilocybin on neural activity patterns and spatial encoding in the retrosplenial cortex of head-fixed mice navigating on a treadmill. The...
Psychedelic drugs such as psilocybin and ketamine are returning to clinical research and intervention across several disorders including the treatment of depression. This chapter focusses on psychedelics that specifically target the 5-HT2A receptor such as psilocybin and DMT. These produce plasma-concentration related psychological effects such as hallucinat...
Alcohol Use Disorder (AUD) adversely affects the lives of millions of people, but still lacks effective treatment options. Recent advancements in psychedelic research suggest psilocybin to be potentially efficacious for AUD. However, major knowledge gaps remain regarding (1) psilocybin's general mode of action and (2) AUD-specific alterations of responsivity...
A growing body of work shows that autonomic signals provide a privileged evidence-stream to capture various aspects of subjective and neural states. This work investigates the potential for autonomic markers to track the effects of psychedelics - potent psychoactive drugs with important scientific and clinical value. For this purpose, we introduce a novel Ba...
A prominent theory of psychedelics is that they increase brain entropy. Thirteen studies have evaluated psychedelic effects on fMRI brain entropy; no findings have been replicated. Here we evaluated these metrics in an independent 28-participant healthy cohort with 121 pre- and post-psilocybin fMRI scans. We assessed relations between brain entropy and objec...
