P300‐mediated modulations in self–other processing under psychedelic psilocybin are related to connectedness and changed meaning: A window into the self–other overlap
Lukasz Smigielski, Michael Kometer, Milan Scheidegger, Cornelia Stress, Katrin H. Preller, Thomas Koenig, Franz X. Vollenweider
Human Brain Mapping August 21, 2020 DOI: 10.1002/hbm.25174 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Placebo-controlled, double-blind, within-subject crossover experiment Peer reviewed |
|---|---|
| Sample size | 17 |
| Population | Human participants |
| Intervention | Psilocybin |
| Dose | 230 μg/kg p.o. |
| Topics | Psilocybin |
| Keywords | Anterior cingulate cortex Cognition Cognitive psychology Perception Insula Optimal distinctiveness theory Stimulus psychology Anhedonia Hallucinogen |
| Citations | 42 |
| Key findings | Psilocybin abolished the distinctiveness of self- and other-related electric field configurations during the P300 timeframe, driven by current source density changes within the supragenual anterior cingulate and right insular cortex. |
Abstract
Abstract The concept of self and self‐referential processing has a growing explanatory value in psychiatry and neuroscience, referring to the cognitive organization and perceptual differentiation of self‐stimuli in health and disease. Conditions in which selfhood loses its natural coherence offer a unique opportunity for elucidating the mechanisms underlying self‐disturbances. We assessed the psychoactive effects of psilocybin (230 μg/kg p.o.), a preferential 5‐HT1A/2A agonist known to induce shifts in self‐perception. Our placebo‐controlled, double‐blind, within‐subject crossover experiment ( n = 17) implemented a verbal self‐monitoring task involving vocalizations and participant identification of real‐time auditory source‐ (self/other) and pitch‐modulating feedback. Subjective experience and task performance were analyzed, with time‐point‐by‐time‐point assumption‐free multivariate randomization statistics applied to the spatiotemporal dynamics of event‐related potentials. Psilocybin‐modulated self‐experience, interacted with source to affect task accuracy, and altered the late phase of self‐stimuli encoding by abolishing the distinctiveness of self‐ and other‐related electric field configurations during the P300 timeframe. This last effect was driven by current source density changes within the supragenual anterior cingulate and right insular cortex. The extent of the P300 effect was associated with the intensity of psilocybin‐induced feelings of unity and changed meaning of percepts. Modulations of late encoding and their underlying neural generators in self‐referential processing networks via 5‐HT signaling may be key for understanding self‐disorders. This mechanism may reflect a neural instantiation of altered self–other and relational meaning processing in a stimulus‐locked time domain. The study elucidates the neuropharmacological foundation of subjectivity, with implications for therapy, underscoring the concept of connectedness.
Comparable studies
Other randomized controlled trials on psilocybin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial Cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety | 2016 | Randomized controlled trial | n = 51 |
| Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial Patients with cancer-related anxiety and depression | 2016 | Double-blind, placebo-controlled, crossover trial | n = 29 |
| Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance Hallucinogen-naïve adults reporting regular participation in religious or spiritual... | 2006 | Double-blind study | n = 36 |
| Trial of Psilocybin versus Escitalopram for Depression Selected group of patients with depression | 2021 | Randomized controlled trial | |
| Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder Adults aged 21 to 75 years with major depressive disorder, not currently using... | 2020 | Randomized controlled trial | n = 24 |
Citations in the library
Cited by 29
- A neurophenomenological approach to non-ordinary states of consciousness: hypnosis, meditation, and psychedelics Trends in Cognitive Sciences December 22, 2022
- Classic Psychedelic Drugs: Update on Biological Mechanisms Pharmacopsychiatry January 25, 2022
- Dose–response relationships of psilocybin-induced subjective experiences in humans Journal of Psychopharmacology March 4, 2021
- Psilocybin-assisted therapy improves psycho-social-spiritual well-being in cancer patients. Journal of Affective Disorders February 15, 2023
- Psychedelics and Consciousness: Distinctions, Demarcations, and Opportunities The International Journal of Neuropsychopharmacology May 10, 2021
and 24 more in the library
Cites 32
- Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance Psychopharmacology July 7, 2006
- Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects. Psychopharmacology December 1, 2011
- Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proceedings of the National Academy of Sciences April 11, 2016
- Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV) PLoS One August 31, 2010
- The Standardized Psychometric Assessment of Altered States of Consciousness (ASCs) in Humans Pharmacopsychiatry July 1, 1998
and 27 more in the library