bioRxiv (Cold Spring Harbor Laboratory)
February 13, 2017
Vanja Dakic, Juliana Nascimento, Rafaela Sartore et al.
preprint
Abstract Dimethyltryptamines are hallucinogenic serotonin-like molecules present in traditional Amerindian medicine (e.g. Ayahuasca) recently associated with cognitive gains, antidepressant effects and changes in brain areas related to attention. Historical and technical restrictions impaired understanding how such substances impact human brain metabolism. Here we used shotgun mass spectrometry...
arXiv Preprint Archive
October 5, 2016
Edgar Altszyler, Mariano Sigman, Sidarta Ribeiro et al.
Word embeddings have been extensively studied in large text datasets. However, only a few studies analyze semantic representations of small corpora, particularly relevant in single-person text production studies. In the present paper, we compare Skip-gram and LSA capabilities in this scenario, and we test both techniques to extract relevant semantic patterns in single-series dreams reports. LSA...
Frontiers in Psychology
March 8, 2016
Natália B. Mota, Adara Resende, Sérgio Mota-Rolim et al.
38 citations
Dreaming and psychosis share important features, such as intrinsic sense perceptions independent of external stimulation, and a general lack of criticism that is associated with reduced frontal cerebral activity. Awareness of dreaming while a dream is happening defines lucid dreaming (LD), a state in which the prefrontal cortex is more active than during regular dreaming. For this reason, LD...
PLoS One
February 18, 2015
Fernanda Palhano-Fontes, Kátia C. Andrade, Luís Fernando Tófoli et al.
461 citations
The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition induced by this class of drugs. A remarkable increase in introspection is at the core of these altered states of consciousness. Self-oriented mental activity has been consistently linked to the Default Mode Network (DMN), a set of brain regions more...
European Neuropsychopharmacology
January 16, 2015
José Carlos Bouso, Fernanda Palhano-Fontes, Antoni Rodrı́guez-fornells et al.
221 citations
Psychedelic agents have a long history of use by humans for their capacity to induce profound modifications in perception, emotion and cognitive processes. Despite increasing knowledge of the neural mechanisms involved in the acute effects of these drugs, the impact of sustained psychedelic use on the human brain remains largely unknown. Molecular pharmacology studies have shown that...
Scientific Reports
January 15, 2014
Natália Bezerra Mota, Raimundo Furtado, Pedro Maia et al.
159 citations
Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search of quantitative insight into the structure of psychotic speech, we investigated speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking and...
Scientific Reports
August 2, 2013
Fábio V. Caixeta, Alianda Maira Cornélio, Robson Scheffer-Teixeira et al.
134 citations
Recent studies show that higher order oscillatory interactions such as cross-frequency coupling are important for brain functions that are impaired in schizophrenia, including perception, attention and memory. Here we investigated the dynamics of oscillatory coupling in the hippocampus of awake rats upon NMDA receptor blockade by ketamine, a pharmacological model of schizophrenia. Ketamine (25,...
Frontiers in Human Neuroscience
2013
Sérgio Mota-Rolim, Zé H. Targino, Bryan C. Souza et al.
42 citations
During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional and lacking in rational judgment of their bizarreness. However, during lucid dreaming (LD), subjects know that they are dreaming, and may control oneiric content. Dreaming and LD features have been studied in North Americans, Europeans and Asians, but not among Brazilians, the...
Human Brain Mapping
September 16, 2011
Dráulio Barros de Araújo, Sidarta Ribeiro, Guillermo Cecchi et al.
241 citations
Abstract The hallucinogenic brew Ayahuasca, a rich source of serotonergic agonists and reuptake inhibitors, has been used for ages by Amazonian populations during religious ceremonies. Among all perceptual changes induced by Ayahuasca, the most remarkable are vivid “seeings.” During such seeings, users report potent imagery. Using functional magnetic resonance imaging during a closed‐eyes...