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.
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.
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.
Schizophrenia Bulletin
March 15, 2023
Chi C Chan, Raquel Norel, Carla Agurto et al.
22 citations
Disturbances in self-experience—the sense of being the subject of one's own experiences and actions, and of being distinct from others—are central to schizophrenia. Traditionally assessed by manual interview rating, this study used natural language processing to analyze autobiographical narratives from 167 patients with schizophrenia or schizoaffective disorder and 90 healthy controls, totaling 490,000 words. Topics related to self-experience and agency were significantly more expressed in patients than controls and were decoupled from emotional tone, semantic coherence, and burden-related concepts. A classifier trained on these features discriminated patients from controls with an AUC of 0.80. These findings demonstrate that NLP can automatically detect higher-order metacognitive aspects of self-experience without explicit probing.
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.