Finding the self by losing the self: Neural correlates of ego-dissolution under psilocybin
Alexander V. Lebedev, Martin Lövdén, Gidon Rosenthal, Amanda Feilding, David Nutt, Robin Carhart-Harris
Human Brain Mapping May 22, 2015 DOI: 10.1002/hbm.22833 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Placebo-controlled study Peer reviewed |
|---|---|
| Sample size | 15 |
| Population | Healthy subjects |
| Intervention | Psilocybin |
| Dose | 2 mg |
| Duration | Twelve-minute functional MRI scans on two occasions |
| Topics | Psilocybin Ego dissolution |
| Keywords | Salience neuroscience Hallucinogen |
| Citations | 347 |
| Key points | Psilocybin-induced ego-dissolution was associated with decreased functional connectivity between the medial temporal lobe and high-level cortical regions, disintegration of the salience network, and reduced interhemispheric communication. |
Abstract
Ego-disturbances have been a topic in schizophrenia research since the earliest clinical descriptions of the disorder. Manifesting as a feeling that one's "self," "ego," or "I" is disintegrating or that the border between one's self and the external world is dissolving, "ego-disintegration" or "dissolution" is also an important feature of the psychedelic experience, such as is produced by psilocybin (a compound found in "magic mushrooms"). Fifteen healthy subjects took part in this placebo-controlled study. Twelve-minute functional MRI scans were acquired on two occasions: subjects received an intravenous infusion of saline on one occasion (placebo) and 2 mg psilocybin on the other. Twenty-two visual analogue scale ratings were completed soon after scanning and the first principal component of these, dominated by items referring to "ego-dissolution", was used as a primary measure of interest in subsequent analyses. Employing methods of connectivity analysis and graph theory, an association was found between psilocybin-induced ego-dissolution and decreased functional connectivity between the medial temporal lobe and high-level cortical regions. Ego-dissolution was also associated with a "disintegration" of the salience network and reduced interhemispheric communication. Addressing baseline brain dynamics as a predictor of drug-response, individuals with lower diversity of executive network nodes were more likely to experience ego-dissolution under psilocybin. These results implicate MTL-cortical decoupling, decreased salience network integrity, and reduced inter-hemispheric communication in psilocybin-induced ego disturbance and suggest that the maintenance of "self"or "ego," as a perceptual phenomenon, may rest on the normal functioning of these systems.
In the evidence
This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.
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Psilocybin-induced ego dissolution was associated with decreased medial temporal-to-cortical connectivity, salience network disintegration, and reduced interhemispheric communication.
Synthesized
Comparable studies
Other randomized controlled trials on ego dissolution, most cited first.
Citations in the library
Cited by 271
- REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics Pharmacological Reviews June 20, 2019
- Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proceedings of the National Academy of Sciences April 11, 2016
- Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression Frontiers in Pharmacology January 17, 2018
- Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution. Current Biology April 13, 2016
- Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function. Pharmacology & Therapeutics May 1, 2019
and 266 more in the library
Cites 39
- Interoceptive inference, emotion, and the embodied self Trends in Cognitive Sciences October 12, 2013
- The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs Frontiers in Human Neuroscience 2014
- Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin Proceedings of the National Academy of Sciences January 23, 2012
- Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action Neuroreport December 1, 1998
- Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects. Psychopharmacology December 1, 2011
and 34 more in the library