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Guillermo Cecchi

4 papers in the library · 352 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.

Dreaming during the Covid-19 pandemic: Computational assessment of dream reports reveals mental suffering related to fear of contagion

PLoS ONE November 30, 2020 Natália Bezerra Mota, Janaína Weissheimer, Marina Ribeiro et al. 71 citations

Dreams during the 2019-20 coronavirus outbreak reveal psychological distress. Analyzing 239 dream reports from 67 individuals, dreams during the Coronavirus disease 2019 (COVID-19) Pandemic showed more anger and sadness words. These dreams also linked to "contamination" and "cleanness." Intriguingly, these dream characteristics explained 40% of the variation in psychological suffering related to social isolation, relevant for Psychiatry and Medicine. This underscores how the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) crisis impacts Sleep and Wakefulness Research, including mind wandering and attention, reflecting widespread Coronavirus Infections' effects.

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.

Dreaming during Covid-19 pandemic: Computational assessment of dreams reveals mental suffering and fear of contagion

medRxiv May 21, 2020 Natália Bezerra Mota, Janaína Weissheimer, Marina Ribeiro et al. 7 citations preprint

Dreams during the COVID-19 pandemic contained a higher proportion of anger and sadness words and were semantically more similar to the terms contamination and cleanness compared to dreams from before the outbreak. These dream features were associated with mental suffering related to social isolation, explaining 39% of the variance in negative symptoms measured by the PANSS scale. The findings suggest that pandemic dreams reflect mental suffering, fear of contagion, and changes in daily habits.