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Sidarta Ribeiro

Universidade Federal do Rio Grande do Norte, Instituto Federal do Rio Grande do Norte

36 papers in the library · 1,934 citations · publishing 2011-2026

Papers

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Dream content and slow waves benefit prey against predator in a video game confrontation

Scientific Reports March 13, 2026 Daniel Soares Brandão, Rafael N. B. Scott, Ernesto Soares et al.

Every studied animal species exhibits some form of sleep, a state evolved under the sustained influence of prey and predator behaviors. Dreams have been proposed to have evolved as offline mental simulations able to warn against impending threats from the environment, such as predators. To assess how the ecological roles of prey and predator interact with sleep and dreaming, we used a...

Visuoaffective day residue in hypnagogia involves sequential bihemispheric interactions between cortical, subcortical, and cerebellar structures.

Communications Biology July 4, 2025 George Vagner Souza, Natália Bezerra Mota, Allan Kardec Barros et al.

The intricate interplay between visual perception and emotion determines how waking experience influences mentation through a 'day residue' at once conspicuous yet hard to predict. Here we set out to map the neural sources associated with the visuo-affective processing of the 'day residue' during hypnagogic sleep. To this end, we assessed 28 healthy participants on a combined nap protocol with...

DOI: 10.1038/s42003-025-08429-6 (opens in new tab) Full text (opens in new tab) Cerebellum Humans Electroencephalography Emotions +5

Electrophysiological Correlates of Lucid Dreaming: Sensor and Source Level Signatures.

Journal of Neuroscience May 14, 2025 Çağatay Demirel, Jarrod Gott, Kristoffer Appel et al. 8 citations

Lucid dreaming (LD) is a state of conscious awareness of the ongoing oneiric state, predominantly linked to REM sleep. Progress in understanding its neurobiological basis has been hindered by small sample sizes, diverse EEG setups, and artifacts like saccadic eye movements. To address these challenges in characterizing the electrophysiological correlates of LD, we introduced an adaptive...

O relatório da DEA sobre os riscos da ayahuasca: a “ciência” a serviço do proibicionismo?

Ponto Urbe December 27, 2024 Beatriz Caiuby Labate, Anna O. Ermakova, Jordan Sloshower et al.

Em fevereiro de 2023, a Drug Enforcement Administration (DEA) divulgou um documento para a equipe jurídica que representa a Church of the Eagle and the Condor (“CEC”). Essa divulgação ocorreu dois anos depois que a igreja, em conjunto com o Chacruna Institute, enviou duas solicitações baseadas na lei de liberdade de informação [Freedom Of Information Act] à DEA e ao Departamento de Justiça...

Author Correction: 5-MeO-DMT induces sleep-like LFP spectral signatures in the hippocampus and prefrontal cortex of awake rats

Scientific Reports July 14, 2024 Annie C. Souza, Bryan C. Souza, Arthur França et al. 1 citation

The original version of this Article contained an error in Affiliation 6, which was incorrectly given as ‘Brain Network Dynamics Unit, University of Oxford, Oxford, UK.’ The correct affiliation is listed below:

5-MeO-DMT induces sleep-like LFP spectral signatures in the hippocampus and prefrontal cortex of awake rats.

Scientific Reports May 17, 2024 Annie C. Souza, Bryan C. Souza, Arthur França et al. 7 citations

5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a potent classical psychedelic known to induce changes in locomotion, behaviour, and sleep in rodents. However, there is limited knowledge regarding its acute neurophysiological effects. Local field potentials (LFPs) are commonly used as a proxy for neural activity, but previous studies investigating psychedelics have been hindered by confounding...

DOI: 10.1038/s41598-024-61474-9 (opens in new tab) Full text (opens in new tab) 5-MEO-DMT Hippocampal oscillations Prefrontal cortex Psychedelics hallucinogens +5

Brazilian Psychedelic Science and the Frontiers of Psychiatry

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

The use of psychedelic substances has intrigued, benefited, and challenged humanity for millennia. These substances, found regularly in nature, are known to induce non-ordinary states of consciousness. They provide heightened sensory, emotional and cognitive experiences, which include augmented visual imagery, changes in thought, mood, and awareness, perception of space-time and reality and, in...

The DEA report on ayahuasca risks: “Science” in service of prohibition?

Journal of Psychedelic Studies June 9, 2023 Beatriz Caiuby Labate, Anna O. Ermakova, Jordan Sloshower et al. 1 citation

Abstract On February 2023, the Drug Enforcement Administration (DEA) released a document to the legal team representing the Church of the Eagle and the Condor (“CEC”). This disclosure came two years after the church, in conjunction with Chacruna Institute, submitted two FOIA requests to the DEA and the Department of Justice requesting all records pertaining to ayahuasca. This report, titled...

Speech graph analysis in obsessive-compulsive disorder: The relevance of dream reports.

Journal of Psychiatric Research March 28, 2023 Matilde Gomes, Maria Picó Pérez, Inês Castro et al.

Obsessive-compulsive disorder (OCD) is a distressing disorder characterized by the presence of intrusive thoughts, images or urges (obsessions) and/or behavioral efforts to reduce the anxiety (compulsions). OCD lifetime prevalence varies between 1% and 3% in the general population and there are no reliable markers that support the diagnosis. In order to fill this gap, Computational Psychiatry...

LSD, madness and healing: Mystical experiences as possible link between psychosis model and therapy model.

Psychological Medicine March 1, 2023 Isabel Wießner, Marcelo Falchi, Fernanda Palhano-Fontes et al. 53 citations

For a century, psychedelics have been investigated as models of psychosis for demonstrating phenomenological similarities with psychotic experiences and as therapeutic models for treating depression, anxiety, and substance use disorders. This study sought to explore this paradoxical relationship connecting key parameters of the psychotic experience, psychotherapy, and psychedelic experience. In...

LSD and language: Decreased structural connectivity, increased semantic similarity, changed vocabulary in healthy individuals.

European Neuropsychopharmacology March 1, 2023 Isabel Wießner, Marcelo Falchi, Dimitri Daldegan-Bueno et al. 6 citations

Language has been explored as a window into the mind. Psychedelics, known to affect perception and cognition, seem to change language, but a systematic, time-dependent exploration is lacking. Therefore, we aimed at mapping the psychedelic effects on language over the time course of the acute and sub-acute effects in an explorative manner. For this, 24 healthy volunteers (age [mean±SD, range]:...

Imagetic and affective measures of memory reverberation diverge at sleep onset in association with theta rhythm

Neuroimage October 17, 2022 Natália Bezerra Mota, Ernesto Soares, Edgar Altszyler et al. 5 citations

The 'day residue' - the presence of waking memories into dreams - is a century-old concept that remains controversial in neuroscience. Even at the psychological level, it remains unclear how waking imagery cedes into dreams. Are visual and affective residues enhanced, modified, or erased at sleep onset? Are they linked, or dissociated? What are the neural correlates of these transformations? To...

DOI: 10.1016/j.neuroimage.2022.119690 (opens in new tab) Affect linguistics Audiology Electroencephalography Mental image +3

Nootropic effects of LSD: Behavioral, molecular and computational evidence.

Experimental Neurology June 1, 2022 Isis M. Ornelas, F. A. Cini, Isabel Wießner et al. 37 citations

The therapeutic use of classical psychedelic substances such as d-lysergic acid diethylamide (LSD) surged in recent years. Studies in rodents suggest that these effects are produced by increased neural plasticity, including stimulation of the mTOR pathway, a key regulator of metabolism, plasticity, and aging. Could psychedelic-induced neural plasticity be harnessed to enhance cognition? Here we...

Low-dose LSD and the stream of thought: Increased Discontinuity of Mind, Deep Thoughts and abstract flow.

Psychopharmacology June 1, 2022 Isabel Wießner, Marcelo Falchi, Fernanda Palhano-Fontes et al. 22 citations

Stream of thought describes the nature of the mind when it is freely roaming, a mental state that is continuous and highly dynamic as in mind-wandering or free association. Classic serotonergic psychedelics are known to profoundly impact perception, cognition and language, yet their influence on the stream of thought remains largely unexplored. To elucidate the effects of LSD on the stream of...

DOI: 10.1007/s00213-021-06006-3 (opens in new tab) Full text (opens in new tab) LSD Abstract thinking Forward flow Free association +4

LSD, afterglow and hangover: Increased episodic memory and verbal fluency, decreased cognitive flexibility.

European Neuropsychopharmacology May 1, 2022 Isabel Wießner, Rodolfo Olivieri, Marcelo Falchi et al. 42 citations

Psychedelics acutely impair cognitive functions, but these impairments decline with growing experiences with psychedelics and microdoses may even exert opposing effects. Given the recent evidence that psychedelics induce neuroplasticity, this explorative study aimed at investigating the potential of psychedelics to sub-acutely change cognition. For this, we applied a randomized, double-blind,...

DOI: 10.1016/j.euroneuro.2022.01.114 (opens in new tab) Full text (opens in new tab) Cognitive flexibility Executive functions Phonological verbal fluency Psycholytic dose +2

LSD and creativity: Increased novelty and symbolic thinking, decreased utility and convergent thinking

Journal of Psychopharmacology February 1, 2022 Isabel Wießner, Marcelo Falchi-Carvalho, Lucas Oliveira Maia et al. 43 citations

Background: Controversy surrounds psychedelics and their potential to boost creativity. To date, psychedelic studies lack a uniform conceptualization of creativity and methodologically rigorous designs. Aims: This study aimed at addressing previous issues by examining the effects of lysergic acid diethylamide (LSD) on creativity using multimodal tasks and multidimensional approaches. Methods:...

DOI: 10.1177/02698811211069113 (opens in new tab) Creativity Divergent thinking Originality Cognitive psychology +9

Lucid dreaming increased during the COVID-19 pandemic: An online survey.

PLoS One 2022 P Kelly, Tainá Macêdo, T Felipe et al. 3 citations

The COVID-19 pandemic changed people's lives all over the world. While anxiety and stress decreased sleep quality for most people, an increase in total sleep time was also observed in certain cohorts. Dream recall frequency also increased, especially for nightmares. However, to date, there are no consistent reports focusing on pandemic-related changes in lucid dreaming, a state during which...

3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for victims of sexual abuse with severe post-traumatic stress disorder: an open label pilot study in Brazil.

Revista Brasileira de Psiquiatria 2021 Alvaro V Jardim, Dora V Jardim, Bruno Rasmussen Chaves et al. 54 citations

To conduct Brazil's first clinical trial employing 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for post-traumatic stress disorder (PTSD), given its high prevalence resulting from epidemic violence. Of 60 volunteers, four matched the inclusion & exclusion criteria. Three patients with PTSD secondary to sexual abuse (diagnosed by the Structured Clinical Interview for DSM-IV...

The entropic tongue: Disorganization of natural language under LSD.

Consciousness and Cognition December 8, 2020 Camila Sanz, Carla Pallavicini, Facundo Carrillo et al. 34 citations

Serotonergic psychedelics have been suggested to mirror certain aspects of psychosis, and, more generally, elicit a state of consciousness underpinned by increased entropy of on-going neural activity. We investigated the hypothesis that language produced under the effects of lysergic acid diethylamide (LSD) should exhibit increased entropy and reduced semantic coherence. Computational analysis...

DOI: 10.1016/j.concog.2020.103070 (opens in new tab) LSD Language Effects Speech disorganization Psychedelic neuroscience

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

The current global threat brought on by the Covid-19 pandemic has led to widespread social isolation, posing new challenges in dealing with metal suffering related to social distancing, and in quickly learning new social habits intended to prevent contagion. Neuroscience and psychology agree that dreaming helps people to cope with negative emotions and to learn from experience, but can dreaming...

DOI: 10.1371/journal.pone.0242903 (opens in new tab) Pandemic 2019-20 coronavirus outbreak Dream Coronavirus infections +2

Structural differences between REM and non-REM dream reports assessed by graph analysis

PLoS One July 23, 2020 Joshua M. Martin, Danyal Wainstein Andriano, Natália Bezerra Mota et al. 41 citations

Dream reports collected after rapid eye movement sleep (REM) awakenings are, on average, longer, more vivid, bizarre, emotional and story-like compared to those collected after non-REM. However, a comparison of the word-to-word structural organization of dream reports is lacking, and traditional measures that distinguish REM and non-REM dreaming may be confounded by report length. This problem...

DOI: 10.1371/journal.pone.0228903 (opens in new tab) Dream Social connectedness Graph Eye movement +2

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

Neuroscience and psychology agree that dreaming helps to cope with negative emotions and learn from experience. The current global threat related to the COVID-19 pandemic led to widespread social isolation. Does dreaming change and/or reflect mental suffering? To address these questions, we applied natural language processing tools to study 239 dream reports from 67 individuals either before...

The Dream of God: How Do Religion and Science See Lucid Dreaming and Other Conscious States During Sleep?

Frontiers in Psychology 2020 Sérgio Mota-Rolim, Kelly Bulkeley, Stephany Campanelli et al. 31 citations

Lucid dreaming (LD) began to be scientifically studied in the last century, but various religions have highlighted the importance of LD in their doctrines for a much longer period. Hindus' manuscripts dating back over 2,000 years ago, for example, divide consciousness in waking, dreaming (including LD), and deep sleep. In the Buddhist tradition, Tibetan monks have been practicing the "Dream...

d-Lysergic acid diethylamide has major potential as a cognitive enhancer

bioRxiv (Cold Spring Harbor Laboratory) December 6, 2019 Felipe Augusto Cini da Silva, Isis M. Ornelas, Encarni Marcos et al. 9 citations preprint

Abstract Psychedelic agonists of serotonin receptors induce neural plasticity and synaptogenesis, but their potential to enhance learning remains uncharted. Here we show that a single dose of d-LSD, a potent serotonergic agonist, increased novel object preference in young and adult rats several days after treatment. d-LSD alone did not increase preference in old animals, but could rescue it to...

Portable Devices to Induce Lucid Dreams—Are They Reliable?

Frontiers in Neuroscience May 8, 2019 Sérgio Mota-Rolim, Achilleas Pavlou, George Nascimento et al. 25 citations

One of the main current challenges in lucid dreaming (LD) research is to develop a simple and reliable way to induce it (Stumbrys et al., 2012). This is because, for most people, LD is very pleasurable but also very rare (LaBerge and Rheingold, 1990; Mota-Rolim et al., 2013). Along with its recreational nature, LD also has potential clinical applications, such as the treatment of recurrent...

DOI: 10.3389/fnins.2019.00428 (opens in new tab) Lucid dream Sleep system call Circadian rhythm Cognitive psychology +1