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Laura Alethia de la Fuente

Instituto de Física de Buenos Aires

7 papers in the library · 160 citations · publishing 2020-2025

Papers

Microdosing with psilocybin mushrooms: a double-blind placebo-controlled study

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.

Neural and subjective effects of inhaled DMT in natural settings

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.

Microevidence for microdosing with psilocybin mushrooms: a double-blind placebo-controlled study of subjective effects, behavior, creativity, perception, cognition, and brain activity

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.

Time-resolved Neural and Experience Dynamics of Medium- and High-dose N,N-Dimethyltryptamine

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.

Psilocybin-induced modulation of visual salience processing

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.

Time-resolved Neural and Experience Dynamics of Medium- and High-dose N,N-Dimethyltryptamine.

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.

A Naturalistic Study on the Combined Neural and Psychological Effects of Psilocybin and Compassion Focused Imagery

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.