Guillermo Cecchi

IBM Research - Thomas J. Watson Research Center

2 papers in the library · 274 citations · publishing 2011-2020

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.

DOI: 10.1002/hbm.21381 Ayahuasca Hallucinogen Mental image Perception +2

Detection of acute 3,4-methylenedioxymethamphetamine (MDMA) effects across protocols using automated natural language processing

Neuropsychopharmacology January 24, 2020 Carla Agurto, Guillermo Cecchi, Raquel Norel et al. 33 citations

Computer-extracted speech features from acoustic, semantic, and psycholinguistic domains can detect mental states after controlled administration of MDMA and intranasal oxytocin. In a double-blind, placebo-controlled study with 31 healthy adults, speech tasks during peak drug effects yielded cross-validated accuracies up to 87% in the training/validation set and 92% in independent datasets for classifying drug conditions. Oxytocin-driven changes were mostly captured by acoustic features related to emotion and prosody, while MDMA-related mental states manifested across multiple speech domains. The experimental task—whether involving interaction with another individual—also affected speech responses. These results suggest speech analysis can provide objective markers of drug-induced mental states.

DOI: 10.1038/s41386-020-0620-4 Full text MDMA Ecstasy Audiology Placebo +6