bioRxivAugust 24, 2025Yinan Xu, C. Prat, Florian Sense et al.
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Despite the importance of memories in everyday life and the progress made in understanding how they are encoded and retrieved, the neural processes by which declarative memories are maintained or forgotten remain elusive. Part of the problem is that it is empirically difficult to measure the rate at which memories fade, even between repeated presentations of the source of the memory. Without...
Ketamine, a psychoactive medication, exerts both analgesic and dissociative effects. However, whether its analgesic effect stems from its dissociative properties is a topic of debate. Our study aimed to determine whether ketamine’s analgesic and dissociative effects are supported by distinct neural mechanisms. In a within-subject, placebo-controlled study, 37 healthy volunteers were...
Introduction: Psychedelics are emerging as potential treatments for neuropsychiatric conditions, with evidence suggesting a single administration can lead to enduring behavioural changes. While the underlying putative mechanism(s) remain unclear, there is evidence supporting altered learning as a key candidate. Aim: This systematic review examined studies assessing the effects of psychedelics...
The objective of the present study was to characterize the effects of long-term meditation (LTM) on directed connectivity patterns during resting-state and meditative brain states. Specifically, it was aimed to identify major cortical sources of information flow and target regions of information influx, and to reveal which frequency-specific oscillatory networks are critically involved in...
bioRxivJune 14, 2025Michael Gruenwald, Sebastien De Landtsheer, Thomas Huebl et al.
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Psychological trauma is associated with significant alterations of biological functions and is correlated with epigenetic changes specifically of DNA methylation. Trauma therapy is aiming at relieving the impact of trauma and is in initial studies also correlated with changes in DNA methylation. In this study we explored the changes in whole blood DNA methylation of participants of a program...
Dreaming represents a complex and universal aspect of human sleep, yet it remains an intriguing phenomenon, with the neural mechanisms underlying dream experiences and their frequency not fully understood. This study employs a multimodal neuroimaging approach, integrating quantitative multi-parameter mapping, diffusion tensor imaging, and resting-state functional MRI, to investigate the neural...
Abstract 5-MeO-DMT, a potent, short-acting psychedelic, induces profound shifts in cognition, affect, and self-awareness. Because language explicitly expresses these domains and voice implicitly conveys them, both may serve as potential ‘biomarkers’ of behavioural change. This study introduces a novel framework for analysing baseline language and vocal features, pre- to post-psychedelic...
Identifying the neural correlates of consciousness remains a major challenge in neuroscience, requiring theories that bridge between subjective experience and measurable neural correlates. However, theoretical interpretation of empirical evidence is often post hoc and susceptible to confirmation bias. Building upon the adversarial collaboration mediated by the COGITATE Consortium, we present a...
bioRxivMarch 24, 2025Kenneth Shinozuka, Mattia Rosso, Clayton R. Coleman et al.3 citations
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Abstract Lysergic acid diethylamide (LSD) and other psychedelic substances profoundly alter human consciousness. While several studies have demonstrated changes in brain function and connectivity associated with psychedelics, we still have a limited understanding of how LSD reshapes brain networks operating across different frequency bands. In this study, we applied the recently developed...
While the beneficial impacts of meditation are increasingly acknowledged, its underlying neural mechanisms remain poorly understood. We examined the electrophysiological brain signals of expert Buddhist monks during two established meditation methods known as Samatha and Vipassana, which employ focused attention and open monitoring technique. By combining source-space magnetoencephalography...
bioRxivFebruary 12, 2025Nerea L Herrero, Yohann Corfdir, Aylin A Vázquez-Chenlo et al.
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Consciousness does not always fade during sleep. Instead, it can re-emerge, giving rise to lucid dreams (LDs), sleep paralysis (SP), out-of-body experiences (OBEs), and false awakenings (FAs). While some of these states have been studied phenomenologically, their neurophysiological underpinnings remain unclear. Here, we investigate their electrophysiological correlates and distinguish them from...
ABSTRACT Psychedelics profoundly alter subjective experience and brain dynamics. Brain oscillations express signatures of near-critical dynamics, relevant for healthy function. Alterations in the proximity to criticality have been suggested to underlie the experiential and neurological effects of psychedelics. Here, we investigate the effects of a psychedelic substance (DMT) on the criticality...
Abstract The relationship between the default mode network (DMN) and task-positive networks, such as the frontoparietal control network (FPCN), is a prominent feature of functional connectivity (FC) in the human brain. This relationship is primarily anticorrelated at rest in healthy brains and is disrupted in altered states of consciousness. Although the DMN and FPCN seem to perform distinct...
bioRxivDecember 9, 2024E. Peters, Jakob Pöhlmann, Xin-Lin Wang et al.
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The connection between the dreamed body and the real physical body remains a subject of ongoing investigation. This study explored how the dreamed body responds to somatosensory stimulation of the physical body, aiming to shed light on the sensory processes that shape our dreaming experiences. We employed a novel within-subject design to compare the incorporation of three different types of...
The MindGym, a novel immersive technology utilizing a reflective chamber environment, was developed to create standardized experiential content, including anxiolytic experiences. This study examined whether therapeutic experiences originally created in the MindGym could maintain their efficacy when delivered via 360-degree recordings through virtual reality (VR) headsets. A randomized...
Study Objectives: Nightmares are linked to daytime distress and psychiatric and neurological disorders. However, knowledge about the brain regions involved in nightmare production is sparse. This study aimed to examine the relationship between nightmare frequency and the functional connectivity of the amygdala with the prefrontal cortex, which is central to emotional regulation. Additionally,...
Lucid dreaming occurs when one is aware of dreaming while asleep. While lucid dreaming can occur spontaneously, it remains rare. This multi-center study (Netherlands, Italy, Canada) tested a combined induction approach integrating senses-initiated lucid dreaming (SSILD) with targeted lucidity reactivation in a large sample of participants with varying lucid dreaming experience. Sixty...
Psilocybin, ketamine, and MDMA are psychoactive compounds that exert behavioral effects with distinguishable but also overlapping features. The growing interest in using these compounds as therapeutics necessitates preclinical assays that can accurately screen psychedelics and related analogs. We posit that a promising approach may be to measure drug action on markers of neural plasticity in...
Recent neuroscientific research has advanced our understanding of consciousness, yet the connection between specific qualitative aspects of consciousness, known as “qualia,” and particular brain regions or networks remains elusive. Traditional methods that rely on verbal descriptions from participants pose challenges in neuroimaging studies. To address this, our group has introduced a novel...
Consciousness requires a dynamic balance of integration and segregation in functional brain networks. An optimal integration-segregation balance depends on two key aspects of functional connectivity: global efficiency (i.e., integration) and clustering (i.e., segregation). We developed a new fMRI-based measure, termed the integration-segregation difference (ISD), which captures both aspects. We...
Abstract The transition towards the brain state induced by psychedelic drugs is frequently neglected in favor of a static description of their acute effects. We used a time-dependent whole-brain model to reproduce large-scale brain dynamics measured with fMRI from 15 volunteers under 20 mg intravenous N,N-Dimethyltryptamine (DMT), a short-acting psychedelic. To capture its transient effects, we...
Abstract Application of complexity measures to neurophysiological time series has seen increased use in recent years to identify neural correlates of global states of consciousness. Lempel-Ziv complexity is currently the de-facto complexity measure used in these investigations. However, by simply counting the number of patterns, this measure theoretically takes its maximum value for data that...
Do animals have emotions? Scientists and philosophers have long struggled with this question, with debates ranging from whether animals experience an “internal world” to whether we are capable of studying it. Recently, theoretical, and methodological advances have rekindled this debate, yet, it is unclear where the scientific consensus on these topics lies today. To address this gap, we...
While consciousness never fades during wakefulness, there is a paradoxical coexistence of consciousness during dreaming states. It’s also possible for sensory awareness to be either present or absent when awakened from seemingly-identical states of sedation and anaesthesia. Traditionally, these states have been characterised in terms of their electroencephalographic neural correlates, however,...
bioRxivOctober 2, 2023Roxane Verdikt, Abigail A Armstrong, Jenny Cheng et al.
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Cannabis, the most consumed illicit psychoactive drug in the world, is increasingly used by pregnant women. However, while cannabinoid receptors are expressed in the early embryo, the impact of phytocannabinoids exposure on early embryonic processes is lacking. Here, we leverage a stepwise in vitro differentiation system that captures early embryonic developmental cascade to investigate the...