This pre-print cross-sectional fMRI study (n=67) found that experienced psychedelic users (≥10 lifetime experiences) showed faster and more accurate recognition of angry facial expressions alongside diminished neural responses to anger in limbic and salience network regions, enhanced responses to happiness in parietal and sensorimotor areas, and reduced emotional differentiation in default mode network regions compared to non-users.
Abstract of Investigating Emotional Reactivity in Experienced Users of Psychedelics
“Classic psychedelics profoundly influence emotional states, eliciting intense acute emotional experiences followed by subtle, sustained changes in emotional reactivity lasting up to several weeks. While clinical studies with controlled participant screening, dosing, and settings provide evidence for these effects, the impact of psychedelics is highly context-dependent. Thus, it remains unclear whether naturalistic, less-controlled psychedelic use similarly modulates emotional reactivity. To address this, our preregistered, cross-sectional fMRI study compared experienced psychedelic users (≥10 lifetime experiences; N = 33) with a matched group of non-users (N = 34) on behavioral and neural responses to emotional facial expressions. Psychedelic users demonstrated faster and more accurate recognition of angry facial expressions, suggesting reduced interference from threat-related stimuli during task performance. Whole-brain fMRI analyses revealed diminished neural responses to anger in limbic and salience network regions, coupled with enhanced responses to happiness in parietal and sensorimotor areas, consistent with prior clinical findings. Additionally, users showed increased precuneus activation in response to fearful facial expressions. Region-of-interest analyses further indicated reduced differentiation of emotional categories in two default mode network regions-the frontal medial cortex and parahippocampal gyrus. In conclusion, our study provides a nuanced view of neurofunctional alterations in emotional processing associated with naturalistic psychedelic use, advancing our understanding of its potential long-term effects.“
Authors: Pawel Orlowski, Aleksandra Domagalik & Michał Bola
Summary of Investigating Emotional Reactivity in Experienced Users of Psychedelics
Classic psychedelics such as psilocybin, LSD and DMT are reported to shift perception, mood, self-reference and cognition, with follow-on changes in emotional processing that can persist beyond the acute experience. Earlier research in controlled settings has shown reduced sensitivity to negative affect, greater positive affect, and modulation of large-scale brain networks involved in emotion. Network terms used here: the default mode network (DMN) supports self-focused thought and autobiographical memory; the salience network helps detect and prioritise emotionally relevant cues; both can be tracked with functional MRI (fMRI), which measures blood-oxygen-level dependent (BOLD) signal as a proxy for neural activity.
However, most evidence comes from clinical or tightly supervised environments (“set and setting” optimised; fixed dose; psychological support). Naturalistic use—variable doses, motivations and environments—is far more common globally, yet under-studied. The authors previously found, using surveys and EEG, that experienced users reported higher positive and lower negative emotional reactivity and showed attenuated early neural responses to fearful faces. The present preregistered study tests whether experienced users (≥10 lifetime psychedelic experiences) differ from non-users in behavioural performance and brain responses during explicit recognition of emotional facial expressions, predicting attenuated neural reactivity to negative emotions.
Methods
Design and preregistration
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https://doi.org/10.31234/osf.io/y5m8d_v1
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Cite this paper (APA)
Orłowski, P., Domagalik, A., & Bola, M. Investigating Emotional Reactivity in Experienced Users of Psychedelics: a cross-sectional fMRI study.
Study details
Participants
67
Humans