Skip to content

Tiago Arruda Sanchez

Universidade Federal do Rio de Janeiro

3 papers in the library · 243 citations · publishing 2011-2025

Papers

Seeing with the eyes shut: Neural basis of enhanced imagery following ayahuasca ingestion

Human Brain Mapping September 16, 2011 Dráulio Barros de Araújo, Sidarta Ribeiro, Guillermo Cecchi et al. 241 citations

Ayahuasca, a hallucinogenic brew containing serotonergic agonists and reuptake inhibitors, triggers vivid visual imagery during ceremonies. Using functional magnetic resonance imaging while participants performed a closed-eyes imagery task, the brew produced a robust increase in activation across occipital, temporal, and frontal brain areas. In the primary visual area, activation levels matched those of natural image viewing with eyes open. This effect correlated with individual perceptual changes measured by psychiatric scales. Activity in areas BA30 and BA37, linked to episodic memory and contextual associations, was also potentiated. Modulation of BA10, involved in prospective imagination and working memory, was detected. The findings suggest Ayahuasca seeings arise from an extensive network for vision, memory, and intention, lending a sense of reality to inner experiences.

Resilience and Brain Changes in Long-Term Ayahuasca Users: Insights From Psychometric and fMRI Pattern Recognition.

Journal of magnetic resonance imaging : JMRI December 1, 2025 Lucas Rego Ramos, Orlando Fernandes, Tiago Arruda Sanchez 1 citation

Long-term ayahuasca use may be associated with altered emotional brain reactivity and increased psychological resilience. In a study of 38 healthy male participants (19 long-term ayahuasca users and 19 non-user controls), users showed significantly higher resilience scores (mean = 43.89) compared to controls (mean = 39.05). A machine learning classifier distinguished users from controls with 75% accuracy, and a regression model significantly predicted individual resilience scores. These findings support neural patterns consistent with long-term adaptations from ayahuasca detectable via fMRI and machine learning.

Brazilian Psychedelic Science and the Frontiers of Psychiatry

Jornal Brasileiro de Psiquiatria January 1, 2024 Dráulio Barros de Araújo, Tiago Arruda Sanchez, Sidarta Ribeiro 1 citation

Psychedelic substances have been used by humanity for millennia to induce non-ordinary states of consciousness, characterized by heightened sensory, emotional, and cognitive experiences, including augmented visual imagery, altered perception of space-time and reality, and profound mystical insights. Many indigenous populations worldwide developed these substances as vital components of healing. In the Amazon, shamans ancestrally used Ayahuasca, a drink made from two plants, to promote physical and psychological healing. The Navajo in North America retain the ancestral use of the peyote cactus as sacred medicine, while the Mazatecs of Mexico used psilocybin-containing mushrooms in their healing rituals.