Dynamic Functional Hyperconnectivity after Psilocybin Intake is Primarily Associated with Oceanic Boundlessness

This pre-print 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

To provide insights into neurophenomenological richness after psilocybin intake, we investigated the link between dynamical brain patterns and the ensuing phenomenological pattern after psilocybin intake. Healthy participants received either psilocybin (n=22) or placebo (n=27) while in ultra-high field 7T MRI scanning. Changes in the phenomenological patterns were quantified using the 5-Dimensional Altered States of Consciousness (5D-ASC) Rating Scale, revealing alterations across all dimensions under psilocybin. Changes in the neurobiological patterns displayed that psilocybin induced widespread increases in averaged functional connectivity. Time-varying connectivity analysis unveiled a recurrent hyperconnected pattern characterized by low BOLD signal amplitude, suggesting heightened cortical arousal. In terms of neurophenomenology, canonical correlation analysis primarily linked the transition probabilities of the hyperconnected pattern with feelings of oceanic boundlessness (OBN), and secondly with visionary restructuralization. We suggest that the brain’s tendency to enter a hyperconnected-hyperarousal pattern under psilocybin represents the potential to entertain variant mental associations. For the first time, these findings link brain dynamics with phenomenological alterations, providing new insights into the neurophenomenology and neurophysiology 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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Dynamic Functional Hyperconnectivity after Psilocybin Intake is Primarily Associated with Oceanic Boundlessness


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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

Topics studied

Study characteristics
Original Re-analysis Placebo-Controlled Double-Blind

49 Humans


Authors associated with this publication with profiles on Blossom

Johannes Ramaekers
Johannes 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 | 1x

Linked Research Papers

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