First-episode psychosis (FEP), primarily characterized by positive symptoms such as delusions and hallucinations, can be perceived as an embedding failure of metacognition. Metacognition refers to the ability to monitor, control, and regulate one's own cognitive processes, from subtle mechanisms to more integrative functions essential for daily life. Impairments in metacognition are observed...
Understanding the neural mechanisms underlying the impact of psychedelics on social perception and cognition may be instrumental to unravel their therapeutic potential. We conducted a pharmacoimaging study to examine ayahuasca's effects on a key theory of mind region, at the core of the third visual pathway (TVP) - the posterior superior temporal sulcus (pSTS), which is involved in facial...
Reward processing is a broad psychological construct that can be parsed into distinct components known as "reinforcement learning" (learning), "reward responsiveness" (liking), and "motivation to obtain a reward" (wanting). Dysfunctions in reward processing in mesolimbic and mesocortical pathways are a core feature of many pathologies. Psychedelics have been proposed as a treatment option for...
Abstract Reward processing is a broad psychological construct that can be parsed into distinct components known as “reinforcement learning” (learning), “reward responsiveness” (liking), and “motivation to obtain a reward” (wanting). Dysfunctions in reward processing in mesolimbic and mesocortical pathways, are a core feature of many pathologies. Psychedelics have been proposed as a treatment...
Recent years have witnessed an unprecedented increase in the search for the use of psychedelics in improving physical and mental health. Anaesthesia has evolved since very early times, born from the need to eliminate pain and reduce suffering and there are reports of the use of anaesthetics to achieve mystical states since the nineteenth century. Nowadays, the renaissance of psychedelics in...
N, N-dimethyltryptamine (DMT) is a psychedelic tryptamine acting on 5-HT2A serotonin receptors, which is associated with intense visual hallucinatory phenomena and perceptual changes such as distortions in visual space. The neural underpinnings of these effects remain unknown. We hypothesised that changes in population receptive field (pRF) properties in the primary visual cortex (V1) might...
The modulation of social cognition is suggested as a possible mechanism contributing to the potential clinical efficacy of psychedelics in disorders involving socio-emotional and reward processing deficits. Resting-state functional Magnetic Resonance Imaging (rs-fMRI) can be used to detect changes in brain connectivity during psychedelic-induced states. Thus, this pharmacoimaging study...
Network NeuroscienceSeptember 15, 2023Daniela Jardim Pereira, João Pereira, Alexandre Sayal et al.5 citations
Abstract Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback (NF), a training method for the self-regulation of brain activity, has shown promising results as a neurorehabilitation tool, depending on the ability of the patient to succeed in neuromodulation. This study explores connectivity-based structural and functional success predictors in an NF n-back working memory...
The Default Mode Network (DMN) and the Theory of Mind (ToM) networks play a crucial role in our understanding of the neurocognition of the self. The DMN is commonly associated with introspection, while the ToM is involved in perspective-taking. There is no research investigating the overlap between the DMN and ToM in relation to causal effects such as induced by psychedelics, and their precise...
Psychoactive natural products: Potential in the treatment of brain diseases and strategies to improve delivery For this special issue, focusing on psychoactive natural products with therapeutic potential for the treatment of brain diseases, we have invited authors to contribute with research and review articles illustrating and stimulating the continuing effort in drug discovery and drug...
There is an increasing interest in the neural effects of psychoactive drugs, in particular tryptamine psychedelics, which has been incremented by the proposal that they have potential therapeutic benefits, based on their molecular mimicry of serotonin. It is widely believed that they act mainly through 5HT2A receptors but their effects on neural activation of distinct brain systems are not...
3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) is known to produce euphoric states, but may also cause adverse consequences in humans, such as hyperthermia and neurocognitive deficits. Although MDMA consumption has been associated with visual problems, the effects of this recreational drug in retinal physiology have not been addressed hitherto. In this work, we evaluated the effect of a...
Abstract Ayahuasca, an amazonian brew containing the serotonergic psychedelic substance N,N-dimethyltryptamine (DMT), induces distinctive visual perceptual phenomenology, yet the neural mechanisms underlying the interplay between external visual drive and internal imagery remain unknown. Using a placebo-controlled, within-subject fMRI design, the present study investigated the impact of...