Brain oscillations represent frequency-specific neural phenomena essential for coordinating distributed brain activity and supporting cognition. The endocannabinoid system (ECS), particularly via cannabinoid receptor 1 (CB1R), plays a pivotal role in modulating neural oscillations through inhibitory circuit modulation, synaptic plasticity regulation, and long-range connectivity coordination....
Research on the pharmacokinetic influence of cannabidiol (CBD) on delta-9-tetrahydrocannabinol (THC) has produced equivocal results. We conducted a systematic search following PRISMA guidelines (last search: 24th November 2025, PROSPERO: CRD42023480695). Included studies were acute dosing trials that administered a) a single, fixed dose of THC and b) a matched dose of THC co-administered with...
Subacute and long-term changes in cognitive functioning after administration of classic psychedelics, MDMA and ketamine: A systematic review of clinical and preclinical evidence.
Consciousness can persist, transform, and dissolve across wakefulness, sleep, and advanced meditation. Despite empirical and theoretical advances within each domain, these states are rarely examined within an integrated scientific framework. An interdisciplinary perspective reveals converging phenomena that challenge binary accounts of consciousness and highlight its graded, dynamic, and...
As neuroscientific theories of consciousness continue to proliferate, the need to assess their similarities and differences - as well as their predictive and explanatory power - becomes ever more pressing. Recently, a number of structured adversarial collaborations have been devised to test the competing predictions of several candidate theories of consciousness. In this review, we compare and...
David Marr's tri-level analysis has organized cognitive neuroscience for four decades. We argue that it has also constrained it. The framework rests on three assumptions: that cognitive goals can be specified a priori, that neural processes implement algorithms, and that physical substrates are interchangeable realizers of abstract functions. Each assumption was defensible in 1982. Each is now...
The question of whether consciousness persists after decapitation has fascinated scientists, philosophers, and the public for over two centuries, from 18th-century debates over the guillotine to modern neurophysiological studies of cerebral ischemia. This review synthesizes historical controversies-such as the anecdotal reports of facial movements in severed heads and early galvanism...
Classic psychedelics have re-emerged as compelling probes of neural plasticity, raising interest in their potential relevance for behavioral and circuit-level features associated with autism spectrum disorder (ASD). Although only a limited number of studies have examined these compounds in validated animal models of ASD, a growing body of preclinical work has investigated their effects on...
We examine a seldom-discussed characteristic of scientific theories of human consciousness: the extent to which an adequate theory requires a big-tent or integrated, global neural substrate for consciousness or a more limited, small-tent or localized neural substrate. Most current theories of consciousness are big-tent, with the assumption that consciousness must integrate many different types...
Setting up a psychedelic study can be a long, arduous, and Kafkaesque process. Researchers are faced with a host of challenges in this rapidly evolving field, necessitating a range of considerations that remain largely unstandardised. Many of the complexities inherent to psychedelic research also challenge existing assumptions around, for example, approaches to psychiatric prescribing, the...
Serotonergic psychedelics induce profound alterations in consciousness, giving rise to an altered state commonly referred to as the psychedelic state. The entropic brain hypothesis proposes that brain entropy (i.e., the degree of uncertainty in the distribution of brain states) is elevated during the psychedelic state, as well as in other states characterized by an expanded breadth of...
This review integrates anthropological and neuroscientific perspectives to elucidate music-induced trance processes and their relevance to non-ordinary states of consciousness (NSCs). The objectives are to deepen the understanding of trance phenomena, delineate links across diverse trance expressions, and inform future neuroscientific research. Drawing on anthropological insights, we examine...
The study of meditation has grown considerably in academic research, including robust findings demonstrating its positive impact on several domains of psychological well-being. Functional magnetic resonance imaging (fMRI) studies have provided evidence for neural correlates underlying these effects; however, there has not yet been a comprehensive whole-brain meta-analytic synthesis across...
Classical serotonergic psychedelics primarily exert their profound effects through agonism at the serotonin 2A (5-HT2A) receptor, which is abundantly expressed in many cortical regions, particularly in layer V pyramidal neurons of associative and visual areas. At the cellular level, these receptors are predominantly localized postsynaptically on the soma and apical dendrites. This review...
Aberrations of inner speech have been linked to psychotic symptoms such as thought insertion and auditory verbal hallucinations. These symptoms may reflect failures of prediction and source monitoring. Normally, efference copies of speech motor commands are sent to auditory cortices and suppressed, helping distinguish self-generated from external input. If suppression malfunctions, predicted...
Suicide, the individual desire to take one's own life, at whose core lies the unbearable psychological pain Shneidman called psychache, is a uniquely human experience. Unlike depression, suicidality has no preclinical analog. Suicidality and chronic depression, long treated as a single clinical entity, are increasingly recognized as partly separable in neurobiology and treatment response....
Global shifts towards the liberalisation of cannabis policies have increased the potency of cannabis products, alongside their accessibility, diversity, and the number of inexperienced cannabis consumers. There is a lack of systematic evidence on the subjective effects of cannabis' main psychoactive compound, Δ9-tetrahydrocannabinol (THC). We systematically reviewed and meta-analysed data from...
Serotonergic psychedelics are known for their profound effects on consciousness and are gaining renewed interest as potential psychiatric treatments. These advances underscore the need to clarify the mechanisms of action of these compounds. This systematic review compiles and critically evaluates 23 in vitro and 26 in vivo electrophysiological studies on psychedelic compounds, with an emphasis...
Metaphors have long played multiple roles in conceptualizing the mind and brain, guiding the development and refinement of theoretical models and empirical questions. Early analogies (comparing the brain to hydraulic systems, telephone exchanges, factories, or libraries) offered shortcuts to understanding aspects of cognition, memory, and brain dynamics. From theoretical frameworks, metaphors...
Although research on psychedelics (hallucinogenic serotonin 2 A or 5-HT2A agonists) has shown initial promise in ameliorating a range of psychiatric conditions, the mechanisms by which psychedelics promote therapeutic benefits have yet to be elucidated. Researchers have posited enhancements in cognitive flexibility as a transdiagnostic mechanism through which psychedelics could disrupt...
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...
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder characterized by amyloid-β (Aβ) accumulation, tau pathology, synaptic dysfunction, and neuroinflammation, which collectively drive progressive memory loss, cognitive decline, and behavioral changes. Increasing evidence implicates epigenetic dysregulation as a key contributor to these pathological processes by altering gene...
A large body of work has investigated the effect of various pharmacological compounds on aversive memory formation, retrieval, and modification in humans. A broad overview across signalling pathways and memory models is currently lacking. Here, we systematically review publications that tested the impact of acute pharmacological interventions on aversive memory in healthy humans, following...
Current models of post-traumatic stress disorder (PTSD) predominantly focus on emotional dysregulation, avoidance behaviors, and intrusive symptoms, with limited attention to disturbances in bodily self-consciousness. These frameworks do not fully account for how trauma may disrupt the integration of interoceptive and exteroceptive signals underlying the sense of embodied self. Building on...
Computational phenomenology has emerged as a powerful framework for investigating advanced meditation states and stages, and meditative development and endpoints. Various models have been proposed to mechanistically explain the diverse experiences associated with these practices, including enhanced well-being, shifts in attentional control, the loosening or 'defabrication' of perceptual...