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.
Sci Rep
July 9, 2025
Stephanie Müller, Federico Cavanna, Laura De la Fuente et al.
2 citations
High doses of psilocybin mushrooms caused people to look more locally at paintings, with less spread in where their eyes fixated, compared with low doses. Psilocybin increased subjective emotional intensity and feelings of flow but did not change how people rated the paintings aesthetically, indicating a separation between perceptual and evaluative parts of aesthetic experience. The gaze changes may stem from altered perception of low-level visual features such as textures, shapes, and colors. The work demonstrates that eye tracking can objectively measure psychedelic effects on behavior in naturalistic settings.
Neuroscience of Consciousness
January 1, 2025
Stephanie Müller, 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 Preprint Server
April 22, 2026
Nicolás Bruno, Federico Cavanna, Federico Zamberlán 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.