Predicting and exploring ayahuasca effects: Perception, mind-wandering, and EEG oscillations
Natan Silva-Costa, Jéssica Andrade Pessoa, Kátia Cristina Andrade, Sérgio Mota-Rolim, Fernanda Palhano-Fontes, Dráulio Barros de Araújo, Isabel Wießner
Journal of Psychopharmacology December 4, 2025 DOI: 10.1177/02698811251389563 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized, double-blind, placebo-controlled, parallel-arm design Peer reviewed |
|---|---|
| Sample size | 50 |
| Population | Healthy volunteers |
| Intervention | Ayahuasca |
| Dose | 1 mL/kg |
| Topics | Ayahuasca Mysticism |
| Keywords | Interoception Electroencephalography Consciousness Cognitive psychology Neuroimaging Theta rhythm Brain mapping |
| Key points | Ayahuasca decreases global alpha oscillations and increases frontomedial delta and right posterior theta and beta; lower acute theta correlates with stronger mystical experiences, while lower baseline theta and beta predict greater interoception and positive emotionality. |
Abstract
Background: Psychedelics induce profound changes in perception and thinking; however, little is known about the neural mechanisms and prediction of these effects.
Aims: Investigating ayahuasca-induced experiences, mind-wandering, and electroencephalogram (EEG) oscillations, beyond the prediction of subjective experiences by baseline EEG.
Methods: In a randomised, double-blind, placebo-controlled, parallel-arm design, 50 healthy volunteers received 1 mL/kg of ayahuasca or placebo. We measured subjective psychedelic experiences (Hallucinogen Rating Scale (HRS), Mystical Experience Questionnaire (MEQ)) and mind-wandering (Amsterdam Resting-State Questionnaire (ARSQ)). EEG signals were assessed before administration (+0h), and 2 hours (+2h) and 4 hours (+4h) post-administration. Relationships between subjective and EEG effects were examined.
Results: Ayahuasca, compared to placebo, induced subjective experiences, including changed perception, cognition, emotion (HRS), mystical experiences (MEQ), and visual, discontinuous, and content-laden thinking (ARSQ). Ayahuasca, compared to placebo, changed EEG oscillations, including decreased global alpha as well as increased frontomedial delta and right posterior theta and beta. Under ayahuasca, lower theta correlated with higher mystical experiences (MEQ) and higher alpha correlated with lower Thoughts about Nothing (ARSQ). Baseline global EEG oscillations predicted ayahuasca-induced experiences, with lower theta linked to higher interoception (HRS Heart Beat, HRS Rush, ARSQ Somatic Awareness) and lower beta linked to higher positive emotionality (HRS Happy).
Conclusion: Ayahuasca induced consciousness alterations, visual, bodily, emotional, and mystical experiences, chaotic and meaningful mind-wandering, and decreased especially alpha. While acute theta seems inversely related to mystical experiences, baseline theta and beta seem to inversely predict interoception and emotionality.
Comparable studies
Other randomized controlled trials on ayahuasca, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial Patients with treatment-resistant depression | 2018 | Randomized controlled trial | n = 29 |
| Human Pharmacology of Ayahuasca: Subjective and Cardiovascular Effects, Monoamine Metabolite Excretion, and Pharmacokinetics Volunteers with prior experience in the use of psychedelics | 2003 | Double-blind placebo-controlled clinical trial | n = 18 |
| Subjective effects and tolerability of the South American psychoactive beverage Ayahuasca in healthy volunteers Healthy male volunteers with prior experience using ayahuasca | 2001 | Single-blind crossover placebo-controlled clinical trial | n = 6 |
| Increased frontal and paralimbic activation following ayahuasca, the pan-amazonian inebriant Male volunteers with prior experience in the use of psychedelics | 2006 | Randomized controlled trial | n = 15 |
| Human brain effects of DMT assessed via EEG-fMRI. Healthy volunteers | 2023 | Within-subjects, placebo-controlled design | n = 20 |
Citations in the library
Cites 60
- Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proceedings of the National Academy of Sciences April 11, 2016
- Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial Psychological Medicine June 15, 2018
- Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression Frontiers in Pharmacology January 17, 2018
- Psychedelics and the essential importance of context. Journal of Psychopharmacology February 15, 2018
- Acute, subacute and long-term subjective effects of psilocybin in healthy humans: a pooled analysis of experimental studies Journal of Psychopharmacology September 20, 2010
and 55 more in the library