Translational Psychiatry
August 2, 2022
Federico Cavanna, Stephanie Müller, Laura Alethia de la Fuente et al.
130 citations
A double-blind placebo-controlled trial tested the effects of a low (0.5 g) dose of dried psilocybin mushrooms on 34 individuals beginning a microdosing protocol. The active dose produced more intense acute subjective effects than placebo, but only among participants who correctly guessed their condition. These effects coincided with reduced EEG theta-band power and preserved Lempel-Ziv broadband signal complexity. No evidence was found for enhanced well-being, creativity, or cognitive function; instead, small changes toward cognitive impairment appeared. The findings suggest that expectation, not the drug itself, accounts for many anecdotal benefits attributed to psilocybin microdosing.
Journal of Psychedelic Studies
May 6, 2021
Federico Cavanna, Carla Pallavicini, Virginia Milano et al.
31 citations
During the COVID-19 pandemic, people who had used psychedelic drugs at least once in their lives reported higher positive affect and personality traits linked to resilience, such as greater openness and lower conscientiousness, compared to those who had not. Among 5,618 participants (average age 29, 72% female), 32% reported lifetime psychedelic use. The number of past psychedelic experiences predicted higher scores on a measure of plasticity. No evidence linked lifetime psychedelic use to impaired mental health indicators. Other psychoactive drugs showed opposite associations with mental health.
Frontiers in Psychiatry
November 5, 2021
Enzo Tagliazucchi, Federico Zamberlán, Federico Cavanna et al.
23 citations
Inhaled DMT, a classic psychedelic, produces short but profound shifts in consciousness. In 35 healthy volunteers, electroencephalography recorded before and during the drug's acute effects in a natural setting showed marked reductions in alpha and beta brain oscillations and increases in delta, theta, and gamma power, particularly in posterior regions. The power of fronto-temporal theta oscillations inversely correlated with feelings of unity and transcendence—core features of mystical-type experiences. These findings suggest that baseline brain activity prior to psychedelic use may help predict the likelihood of such experiences, which are linked to lasting well-being and improved therapeutic outcomes.
bioRxiv (Cold Spring Harbor Laboratory)
August 20, 2020
Carla Pallavicini, Federico Cavanna, Federico Zamberlán et al.
17 citations
preprint
Inhaled DMT, a short-acting psychedelic found in plants and animals, was studied in 35 experienced participants in natural settings using wireless EEG and questionnaires. DMT reduced alpha brain waves (8-12 Hz) across the scalp while increasing delta (1-4 Hz) and gamma (30-40 Hz) waves. Increases in gamma power correlated with reports of mystical-type experiences. DMT also altered global synchrony and metastability in gamma and alpha bands and increased signal complexity. These findings align with prior psychedelic research and suggest EEG markers for mystical experiences in natural contexts, underscoring the value of studying these compounds in real-world settings.
bioRxiv (Cold Spring Harbor Laboratory)
December 7, 2021
Federico Cavanna, Stephanie Müller, Laura Alethia de la Fuente et al.
8 citations
preprint
A double-blind placebo-controlled trial tested the effects of a low (0.5 g) sub-hallucinogenic dose of dried psilocybin mushrooms in 34 individuals planning to microdose. Acute subjective effects were significantly stronger with the active dose than with placebo, possibly due to unblinding. For other measures—including creativity, perception, cognition, and brain activity—the results were null or showed a trend toward cognitive impairment and, in electroencephalography, reduced theta band spectral power. These findings suggest that expectation effects may account for some of the anecdotal benefits people report from microdosing psilocybin.
Journal of Cognitive Neuroscience
December 30, 2025
Evan Lewis-Healey, Carla Pallavicini, Federico Cavanna et al.
4 citations
The psychedelic drug DMT rapidly reorganizes conscious experience and brain activity, but the link between brain dynamics and subjective effects remains unclear. In a blinded, dose-dependent study, 19 participants received 20 mg or 40 mg of DMT. The higher dose produced more intense visual hallucinations and emotional experiences. Electroencephalography data showed that alpha power and permutation entropy best tracked moment-to-moment changes in subjective experience, while Lempel-Ziv complexity—previously thought to be a strong correlate—showed the weakest association. The findings indicate that the relationship between neural complexity and psychedelic phenomenology is less straightforward than hypothesized.
bioRxiv (Cold Spring Harbor Laboratory)
November 1, 2023
Stephanie Müller, Federico Cavanna, L. de la Fuente et al.
3 citations
preprint
High doses of psilocybin mushrooms cause people to explore paintings with more local, less random eye movements, making their gaze patterns less entropic. Participants also reported stronger emotional responses and a greater state of flow under the high dose. These effects are consistent with psilocybin altering the perception of low-level visual features like textures, shapes, and colors. The findings demonstrate that eye-tracking under naturalistic conditions can objectively measure psychedelic-induced perceptual changes, supporting greater ecological validity.
bioRxiv Preprint Server
March 11, 2021
Enzo Tagliazucchi, Federico Zamberlan, Federico Cavanna et al.
3 citations
preprint
Inhaled DMT, a classic psychedelic, produces brief but profound changes in consciousness that vary with context. Using wireless EEG and source imaging, researchers mapped changes in neural oscillations. Frontal and temporal theta power inversely correlated with feelings of unity and transcendence—hallmarks of mystical-type experiences. A machine learning model confirmed the robustness of these results. The findings align with the idea that pre-drug mindset influences subjective experience. Priming individuals to lower theta power before taking a serotonergic psychedelic might increase the likelihood of mystical-type experiences, potentially enhancing well-being and therapeutic outcomes.
Neuroscience of Consciousness
January 1, 2025
Stephanie Muller, Federico Cavanna, Laura Alethia de la Fuente et al.
1 citation
Psilocybin alters how people process visual salience during natural scene perception, leading to more focused and exploratory gaze patterns. In a self-blinded study, 23 participants viewed natural scenes under low and high doses of psilocybin while their eye movements were tracked. Under the high dose, fixations concentrated more on salient image regions, inter-fixation distance decreased, and the Shannon entropy of fixations on high-saliency areas indicated more exploratory and less predictable scanning. Resting-state electroencephalography showed broadband spectral power reductions and increased Lempel-Ziv complexity, with delta power negatively correlating with salience metrics. These findings suggest psilocybin shifts attentional dynamics, heightening sensitivity to visual salience and altering gaze behavior.
bioRxiv Preprint Server
December 19, 2024
Evan Lewis-Healey, Carla Pallavicini, Federico Cavanna et al.
1 citation
preprint
A dose of the fast-acting psychedelic DMT rapidly reorganizes conscious experience and brain dynamics, but the link between neural complexity and subjective effects is weaker than previously thought. Nineteen participants received 20 mg or 40 mg of DMT in two sessions. The higher dose produced more extreme visual hallucinations and emotionally intense experiences. Contrary to earlier claims, Lempel-Ziv complexity—a measure of neural signal diversity—was the least strongly associated neural marker of the psychedelic state. The findings suggest the relationship between neural complexity and phenomenology during psychedelic experiences is less clear than originally hypothesized.
bioRxiv (Cold Spring Harbor Laboratory)
February 22, 2022
Camila Sanz, Federico Cavanna, Stephanie Müller et al.
1 citation
preprint
Low doses of psilocybin (microdoses) can be detected in natural speech. In a double-blind, placebo-controlled experiment, participants given 0.5 g of psilocybin mushrooms showed significant differences in verbosity and sentiment scores compared to placebo, though semantic variability did not differ. Machine learning classifiers using these speech metrics distinguished between the psilocybin and placebo conditions with high accuracy (AUC≈0.8). These findings suggest that unconstrained natural language may serve as a practical, low-cost tool for monitoring microdosing effects, addressing limitations of existing questionnaires designed for larger psychedelic doses.
bioRxiv Preprint Server
April 22, 2026
Nicolás Bruno, Federico Cavanna, Federico Zamberlan et al.
preprint
Spontaneous thoughts make up most of everyday inner experience, but studying them is difficult because traditional methods disrupt the natural flow of thinking or introduce motor artifacts. An alternative approach combined delayed verbal retrospective free reports with automated ratings from large language models. Twenty-two participants performed an eyes-closed free-thinking task, and their reports were evaluated on ten dimensions by four LLMs and human raters. Machine-learning models trained on EEG features achieved above-chance accuracy for predicting emotional valence. LLMs showed higher inter-rater agreement than humans, supporting their use for scalable annotation and suggesting that affective dimensions of spontaneous thoughts can be decoded from brain activity.
Apollo (University of Cambridge)
December 30, 2025
Evan Lewis-Healey, Carla Pallavicini, Federico Cavanna et al.
A dose of the fast-acting psychedelic drug DMT rapidly reorganizes both conscious experience and brain activity. In a blinded, counterbalanced study, 19 participants received either 20 mg or 40 mg of freebase DMT. The higher dose caused more extreme visual hallucinations and emotionally intense experiences. Electroencephalography showed that changes in alpha brainwave power and a measure of signal irregularity (permutation entropy) were most strongly linked to moment-by-moment changes in subjective experience. Surprisingly, a measure of neural signal complexity (Lempel-Ziv complexity), previously thought to be a robust marker of psychedelic states, showed the weakest link to experience. This suggests the connection between brain complexity and conscious experience during psychedelic states is less straightforward than previously assumed.
bioRxiv (Cold Spring Harbor Laboratory)
December 22, 2025
Carla Pallavicini, Lorena Llobenes, Federico Cavanna et al.
Combining psilocybin with a compassion-focused imagery exercise produces long-term synergistic effects on cognitive absorption, self-compassion, and decentering. In a sample of 105 participants, those who received a compassion imagery prime before taking psilocybin showed distinct changes in brain network interactions—particularly among attentional, executive, and default mode networks—compared to those who simply focused on breathing. fMRI-based classifiers could distinguish the two priming conditions only at a high dose of psilocybin. The findings suggest that pairing psilocybin with compassion-based practices may amplify lasting psychological shifts and reorganize large-scale brain networks, though confirmatory studies are needed.
Open Science Framework
January 1, 2025
Federico Cavanna, Enzo Tagliazucchi
Psilocybin acutely alters probabilistic reinforcement learning in healthy adults. In a double-blind, randomized, within-subject, placebo-controlled study, behavioral data and event-related potentials from EEG recordings will reveal how the psychedelic modulates neural mechanisms of reward processing and decision-making.