This neuroimaging study (n=49) compared psilocybin and placebo effects on brain patterns and subjective experiences using ultra-high field 7T MRI. Participants who took psilocybin (12mg/70kg, n=22) displayed increased average functional connectivity and a hyperconnected-hyperarousal brain pattern, correlated with profound changes in consciousness, notably feelings of oceanic boundlessness and visionary restructuralization, as measured by the 5D-ASC Rating Scale. This study links these brain dynamics to the phenomenological experiences during the psychedelic state for the first time.
Abstract of Dynamic Functional Hyperconnectivity after Psilocybin … Oceanic Boundlessness
“Background: Psilocybin is a widely studied psychedelic substance, which leads to the psychedelic state, a specific altered state of consciousness. To date, the relationship between the psychedelic state’s neurobiological and experiential patterns remains under-characterized as they are often analyzed separately. We investigated the relationship between neurobiological and experiential patterns after psilocybin by focusing on the link between dynamic cerebral connectivity and retrospective questionnaire assessment.
Methods: Healthy participants were randomized to receive either psilocybin (n=22) or placebo (n=27) and scanned for six minutes in eyes open resting state during the peak subjective drug effect (102 minutes post-treatment) in ultra-high field 7T MRI. The 5D-ASC Rating Scale was administered 360 minutes after drug intake.
Results: Under psilocybin, there were alterations across all dimensions of the 5D-ASC scale, and widespread increases in averaged brain functional connectivity. Further time-varying functional connectivity analysis unveiled a recurrent hyperconnected pattern characterized by low BOLD signal amplitude, suggesting heightened cortical arousal. In terms of neuro-experiential links, canonical correlation analysis showed higher transition probabilities to the hyperconnected pattern with feelings of oceanic boundlessness, and secondly with visionary restructuralization.
Conclusions: Psilocybin generates profound alterations both at the brain and at the experiential level. We suggest that the brain’s tendency to enter a hyperconnected-hyperarousal pattern under psilocybin represents the potential to entertain variant mental associations. These findings illuminate the intricate interplay between brain dynamics and subjective experience under psilocybin, providing insights into the neurophysiology and neuro-experiential qualities of the psychedelic state.”
Authors: Sepehr Mortaheb, Larry D. Fort, Natasha L. Mason, Pablo Mallaroni, Johannes G. Ramaekers & Athena Demertzi
Summary of Dynamic Functional Hyperconnectivity after Psilocybin … Oceanic Boundlessness
Hallucinogens are psychoactive drugs that alter conscious experience. Psilocybin has been studied for its potential contribution in treating various disorders, such as obsessive-compulsive disorder, death-related anxiety, depression, treatment-resistant depression, major depressive disorder, and smoking and alcohol and tobacco addiction. Psilocybin administration leads to the psychedelic state, which is a combination of neurobiological and phenomenological patterns that include ego dissolution, unconstrained and hyper-associative cognition, profound alterations in the perception of time, space and selfhood, perceptual alterations, synesthesia, amplification of emotional state, and emotional volatility.
Psilocybin alters brain function by decreasing connectivity in the default mode network, visual network, and executive control network, and increasing the likelihood of the brain to configure into transient functional patterns with low stability. A neurophenomenological approach was adopted after psilocybin intake to quantify its effects on cerebral functional dynamics and link these dynamic spatiotemporal fingerprints with reported experiential alterations measured with psychometric instruments.
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https://doi.org/10.1101/2023.09.18.558309
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Cite this paper (APA)
Mortaheb, S., Fort, L. D., Mason, N. L., Mallaroni, P., Ramaekers, J. G., & Demertzi, A. (2023). Dynamic Functional Hyperconnectivity after Psilocybin Intake is Primarily Associated with Oceanic Boundlessness. bioRxiv, 2023-09.
Study details
Compounds studied
Psilocybin
Topics studied
Neuroscience
Study characteristics
Original Re-analysis
Placebo-Controlled
Double-Blind
Participants
49
Humans
Authors
Authors associated with this publication with profiles on Blossom
Johannes RamaekersJohannes Ramaekers is a professor at Maastricht University his work focuses on behavioral toxicology of drugs and combines methods from psychopharmacology, forensic toxicology and neuroscience to determine drug-induced changes in human performance. Some of this research is done with DMT.
Compound Details
The psychedelics given at which dose and how many times
Psilocybin 12 mg | 1xLinked Research Papers
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