Naturalistic use of psychedelics does not modulate processing of self-related stimuli (but it might modulate attentional mechanisms): An event-related potentials study
In a preregistered cross‑sectional ERP study comparing experienced naturalistic psychedelic users (N=56) and non‑users (N=57), P300 amplitude to participants' own names did not differ between groups, indicating no persistent change in self‑representation. Psychedelic users did show increased P300 to other‑names and a smaller task‑related P300 enhancement to target names, consistent with altered allocation of attentional resources.
Authors
- Paweł Orłowski
- Michał Bola
Published
Abstract
Classic psychedelics are able to profoundly alter the state of consciousness and lead to acute experiences of ego dissolution – the blurring of the distinction between representations of self and the external world. However, whether repeated use of psychedelics is associated with more prolonged and permanent modifications to the concept of self remains to be investigated. Therefore, we conducted a preregistered, cross‐sectional study in which experienced psychedelics users (15 or more lifetime experiences with psychedelics; N = 56) were compared to nonusers (N = 57) in terms of neural reactivity to a Self‐name (i.e., each participant's own name) stimulus, which is known to robustly activate a representation of self. Two control stimuli were additionally used: an Other‐name stimulus, as a passive control condition in which no reaction was required, and a Target‐name stimulus, to which participants provided a manual response and which thus constituted an active control condition. Analysis of the amplitude of the P300 ERP component evoked by the Self‐ or Target‐names revealed no difference between the psychedelics users and nonusers. However, psychedelic users exhibited increased P300 amplitude during perception of Other‐names. In addition, in comparison to nonusers, psychedelics users exhibited a smaller increase in P300 amplitude when processing the task‐relevant Target‐names (in relation to both Self‐ and Other‐names). Therefore, our data suggests that regular naturalistic use of psychedelics may not be related to long‐term changes in the representation of self, but it might potentially affect the allocation of attentional resources to task‐relevant stimuli.
Research Summary of 'Naturalistic use of psychedelics does not modulate processing of self-related stimuli (but it might modulate attentional mechanisms): An event-related potentials study'
Introduction
Classic psychedelics (for example psilocybin, LSD, mescaline, DMT) are known to acutely alter consciousness and can induce ego dissolution, a transient blurring of boundaries between self and world. Neuroimaging work has linked acute ego-dissolution to reduced activation and altered connectivity within the default mode network and disruptions in salience-network function. While laboratory studies typically probe acute or short-term effects after a single controlled dose, naturalistic use is characterised by repetitive intake in uncontrolled settings, and it remains unclear whether repeated naturalistic use produces longer-lasting changes in self-processing. Orłowski and colleagues conducted a preregistered, cross-sectional EEG study to test whether experienced naturalistic users of classic psychedelics show persistent alterations in neural processing of self-related stimuli. The investigators compared experienced users (≥15 lifetime psychedelic experiences; N = 56) to non-users (N = 57) using each participant's own name (Self), an Other-name (passive control) and a Target-name (active control requiring a button press). The pre-registered primary outcome was P300 amplitude; an exploratory analysis examined stimulus-induced alpha-band desynchronisation. The a priori hypothesis was that users would show reduced P300 (and weaker alpha desynchronisation) to the Self-name, with no group differences for Other or Target stimuli.
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Study Details
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- APA Citation
Orłowski, P., Hobot, J., Ruban, A., Szczypiński, J., & Bola, M. (2024). Naturalistic use of psychedelics does not modulate processing of self-related stimuli (but it might modulate attentional mechanisms): An event-related potentials study. Psychophysiology, 61(8). https://doi.org/10.1111/psyp.14583
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