This double-blind, randomized, placebo-controlled, and crossover study (n=15) investigated the effects of oral psilocybin (14mg/70kg) on the predictive processing of somatosensory tactile stimulation using simultaneous EEG–fMRI recording. Psilocybin produced robust perceptual alterations of bodily awareness and self-experience that were related to decreased brain response to surprising tactile stimuli.
Abstract
“Introduction: As source of sensory information, the body provides a sense of agency and self/non-self-discrimination. The integration of bodily states and sensory inputs with prior beliefs has been linked to the generation of bodily self-consciousness. The ability to detect surprising tactile stimuli is essential for the survival of an organism and for the formation of mental body representations. Despite the relevance for a variety of psychiatric disorders characterized by altered body and self-perception, the neurobiology of these processes is poorly understood.
Methods: We therefore investigated the effect of psilocybin (Psi), known to induce alterations in self-experience, on tactile mismatch responses by combining pharmacological manipulations with simultaneous electroencephalography–functional magnetic resonance imaging (EEG–fMRI) recording.
Results: Psi reduced activity in response to tactile surprising stimuli in frontal regions, the visual cortex, and the cerebellum. Furthermore, Psi reduced tactile mismatch negativity EEG responses at frontal electrodes, associated with alterations of body- and self-experience.
Discussion: This study provides first evidence that Psi alters the integration of tactile sensory inputs through aberrant prediction error processing and highlights the importance of the 5-HT2A system in tactile deviancy processing as well as in the integration of bodily and self-related stimuli. These findings may have important implications for the treatment of psychiatric disorders characterized by aberrant bodily self-awareness.”
Authors: Patricia Duerler, Silvia Brem, Gorka Fraga-González, Tiffany Neef, Micah Allen, Peter Zeidman, Philipp Stämpfli, Franz X. Vollenweider & Katrin H. Preller
Summary of Psilocybin Induces Aberrant Prediction Error Processing of Tactile Mismatch Responses-A Simultaneous EEG-FMRI Study
Introduction
The skin is the body’s largest organ, is central to the processing of boundaries and self/non-self discrimination, and is the starting point of our self-awareness. Altered bodily self-perception is a core symptom of many psychiatric disorders.
The ability to react to novel or surprising environmental stimuli is essential for survival and for the mental and physical health of an organism.
Study details
Compounds studied
Psilocybin
Topics studied
Neuroscience
Study characteristics
Placebo-Controlled
Double-Blind
Within-Subject
Randomized
Re-analysis
Participants
15
Humans
Authors
Authors associated with this publication with profiles on Blossom
Katrin PrellerKatrin Preller is one of the upcoming researchers, currently at the University of Zurich and Yale University, and is focused on the neurobiology and pharmacology of psychedelics.
Franz Vollenweider
Franz X. Vollenweider is one of the pioneering psychedelics researchers, currently at the University of Zurich. He is also the director of the Heffter (sponsored) Research Center Zürich for Consciousness Studies (HRC-ZH).
Institutes
Institutes associated with this publication
University of BaselThe University of Basel Department of Biomedicine hosts the Liechti Lab research group, headed by Matthias Liechti.
Linked Clinical Trial
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