Neuroimage
November 1, 2020
Gerald J. Hahn, Gorka Zamora-López, Lynn Uhrig et al.
55 citations
During the sleep-wake cycle, the brain undergoes profound dynamical changes, which manifest subjectively as transitions between conscious experience and unconsciousness. Yet, neurophysiological signatures that can objectively distinguish different consciousness states based are scarce. Here, we show that differences in the level of brain-wide signals can reliably distinguish different stages of...
Scientific Reports
October 20, 2020
Rubén Herzog, Pedro A. M. Mediano, Fernando E. Rosas et al.
60 citations
Retracted
Abstract Psychedelic drugs, including lysergic acid diethylamide and other agonists of the serotonin 2A receptor (5HT2A-R), induce drastic changes in subjective experience, and provide a unique opportunity to study the neurobiological basis of consciousness. One of the most notable neurophysiological signatures of psychedelics, increased entropy in spontaneous neural activity, is thought to be...
bioRxiv (Cold Spring Harbor Laboratory)
August 20, 2020
Carla Pallavicini, Federico Cavanna, Federico Zamberlán et al.
17 citations
preprint
Abstract Background N,N-Dimethyltryptamine (DMT) is a short acting psychedelic tryptamine found naturally in many plants and animals. Few studies to date addressed the neural and psychological effects of DMT alone, either administered intravenously or inhaled in freebase form, and none conducted in natural settings. Aims Our primary aim was to study the acute effects of inhaled DMT in natural...
arXiv (Cornell University)
August 6, 2020
Rodrigo Cofré, Rubén Herzog, Pedro A. M. Mediano et al.
The scope of human consciousness includes states departing from what most of\nus experience as ordinary wakefulness. These altered states of consciousness\nconstitute a prime opportunity to study how global changes in brain activity\nrelate to different varieties of subjective experience. We consider the problem\nof explaining how global signatures of altered consciousness arise from...
arXiv Preprint Archive
August 6, 2020
Rodrigo Cofré, Rubén Herzog, Pedro A. M. Mediano et al.
The scope of human consciousness includes states departing from what most of us experience as ordinary wakefulness. These altered states of consciousness constitute a prime opportunity to study how global changes in brain activity relate to different varieties of subjective experience. We consider the problem of explaining how global signatures of altered consciousness arise from the interplay...
Journal of Cannabis Research
July 17, 2020
Laura Alethia de la Fuente, Federico Zamberlán, Andrés Sánchez Ferrán et al.
30 citations
BACKGROUND: Widespread commercialization of cannabis has led to the introduction of brand names based on users' subjective experience of psychological effects and flavors, but this process has occurred in the absence of agreed standards. The objective of this work was to leverage information extracted from large databases to evaluate the consistency and validity of these subjective reports, and...
bioRxiv Preprint Server
July 2, 2020
Yonatan Sanz Perl, Carla Pallavicini, Ignacio Perez-Ipina et al.
preprint
Consciousness transiently fades away during deep sleep, more stably under anesthesia, and sometimes permanently due to brain injury. The development of an index to quantify the level of consciousness across these different states is regarded as a key problem both in basic and clinical neuroscience. We argue that this problem is ill-defined since such an index would not exhaust all the relevant...
UNC Libraries
April 22, 2020
Peter J. Hellyer, Luke T. J. Williams, Ben Sessa et al.
1 citation
Lysergic acid diethylamide (LSD), the prototypical “psychedelic,” may be unique among psychoactive substances. In the decades that followed its discovery, the magnitude of its effect on science, the arts, and society was unprecedented. LSD produces profound, sometimes life-changing experiences in microgram doses, making it a particularly powerful scientific tool. Here we sought to examine its...
Neuroimage
April 11, 2020
Ignacio Perez-Ipina, Patricio Donnelly Kehoe, Morten L. Kringelbach et al.
81 citations
Global brain states are frequently placed within a unidimensional continuum by correlational studies, ranging from states of deep unconsciousness to ordinary wakefulness. An alternative is their multidimensional and mechanistic characterization in terms of different cognitive capacities, using computational models to reproduce the underlying neural dynamics. We explore this alternative by...
Neuroscience
February 4, 2020
Rocío Martínez Vivot, Carla Pallavicini, Federico Zamberlán et al.
116 citations
We address the hypothesis that the entropy of neural dynamics indexes the intensity and quality of conscious content. Previous work established that serotonergic psychedelics can have a dysregulating effect on brain activity, leading to subjective effects that present a considerable overlap with the phenomenology of certain meditative states. Here we propose that the prolonged practice of...
bioRxiv (Cold Spring Harbor Laboratory)
September 8, 2019
Laura Alethia de la Fuente, Federico Zamberlán, Andrés Sánchez Ferrán et al.
1 citation
preprint
Abstract Background Commercially available cannabis strains have multiplied in recent years as a consequence of regional changes in legislation for medicinal and recreational use. Lack of a standardized system to label plants and seeds hinders the consistent identification of particular strains with their elicited psychoactive effects. The objective of this work was to leverage information...
Neuroimage
June 24, 2019
Carla Pallavicini, Martina G. Vilas, Mirta Villarreal et al.
66 citations
Classic serotonergic psychedelics are remarkable for their capacity to induce reversible alterations in consciousness of the self and the surroundings, mediated by agonism at serotonin 5-HT2A receptors. The subjective effects elicited by dissociative drugs acting as N-methyl-D-aspartate (NMDA) antagonists (e.g. ketamine and phencyclidine) overlap in certain domains with those of serotonergic...
Consciousness and Cognition
March 1, 2019
Charlotte Martial, Héléna Cassol, Vanessa Charland-Verville et al.
98 citations
The real or perceived proximity to death often results in a non-ordinary state of consciousness characterized by phenomenological features such as the perception of leaving the body boundaries, feelings of peace, bliss and timelessness, life review, the sensation of traveling through a tunnel and an irreversible threshold. Near-death experiences (NDEs) are comparable among individuals of...
Science Advances
February 1, 2019
Athena Demertzi, Enzo Tagliazucchi, Stanislas Dehaene et al.
545 citations
Adopting the framework of brain dynamics as a cornerstone of human consciousness, we determined whether dynamic signal coordination provides specific and generalizable patterns pertaining to conscious and unconscious states after brain damage. A dynamic pattern of coordinated and anticoordinated functional magnetic resonance imaging signals characterized healthy individuals and minimally...
Neuroscience of Consciousness
2019
Andrew Peterson, Enzo Tagliazucchi, Charles Weijer
25 citations
This article provides an ethical analysis of psychedelic research involving disorders of consciousness patients. We apply two internationally accepted approaches for analyzing the ethics of human research, the Value-Validity Framework and Component Analysis, to a research program recently proposed by Scott and Carhart-Harris. We focus on Scott and Carhart-Harris's proposal, but the ethical...
Frontiers in Integrative Neuroscience
November 1, 2018
Camila Sanz, Carla Pallavicini, Carla Pallavicini et al.
78 citations
Classic psychedelics are substances of paramount cultural and neuroscientific importance. A distinctive feature of psychedelic drugs is the wide range of potential subjective effects they can elicit, known to be deeply influenced by the internal state of the user (“set”) and the surroundings (“setting”). The observation of cross-tolerance and a series of empirical studies in humans and animal...
Frontiers in Integrative Neuroscience
November 1, 2018
Camila Sanz, Carla Pallavicini, Carla Pallavicini et al.
78 citations
Classic psychedelics are substances of paramount cultural and neuroscientific importance. A distinctive feature of psychedelic drugs is the wide range of potential subjective effects they can elicit, known to be deeply influenced by the internal state of the user (“set”) and the surroundings (“setting”). The observation of cross-tolerance and a series of empirical studies in humans and animal...
Frontiers in Integrative Neuroscience
November 1, 2018
Camila Sanz, Carla Pallavicini, Carla Pallavicini et al.
78 citations
Classic psychedelics are substances of paramount cultural and neuroscientific importance. A distinctive feature of psychedelic drugs is the wide range of potential subjective effects they can elicit, known to be deeply influenced by the internal state of the user (“set”) and the surroundings (“setting”). The observation of cross-tolerance and a series of empirical studies in humans and animal...
Frontiers in Neuroscience
January 22, 2018
Camila Sanz, Federico Zamberlán, Earth Erowid et al.
112 citations
Ever since the modern rediscovery of psychedelic substances by Western society, several authors have independently proposed that their effects bear a high resemblance to the dreams and dreamlike experiences occurring naturally during the sleep-wake cycle. Recent studies in humans have provided neurophysiological evidence supporting this hypothesis. However, a rigorous comparative analysis of...
Frontiers in Neuroscience
2018
Camila Sanz, Federico Zamberlán, Earth Erowid et al.
3 citations
correction
CORRECTION article Front. Neurosci., 11 April 2018Sec. Neuropharmacology Volume 12 - 2018 | https://doi.org/10.3389/fnins.2018.00229
Neuroimage
October 3, 2017
Federico Cavanna, Martina G. Vilas, Matías Palmucci et al.
151 citations
The scientific study of human consciousness has greatly benefited from the development of non-invasive brain imaging methods. The quest to identify the neural correlates of consciousness combined psychophysical experimentation with neuroimaging tools such as functional magnetic resonance imaging (fMRI) to map the changes in neural activity associated with conscious vs. unconscious percepts....
Curr Biol
April 13, 2016
Enzo Tagliazucchi, Leor Roseman, Mendel Kaelen et al.
531 citations
Lysergic acid diethylamide (LSD) is a non-selective serotonin-receptor agonist that was first synthesized in 1938 and identified as (potently) psychoactive in 1943. Psychedelics have been used by indigenous cultures for millennia [1]; however, because of LSD's unique potency and the timing of its discovery (coinciding with a period of major discovery in psychopharmacology), it is generally...
Proc Natl Acad Sci U S A
April 11, 2016
Robin Carhart-Harris, Suresh Muthukumaraswamy, Leor Roseman et al.
887 citations
Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in...
Journal of The Royal Society Interface
2016
Enzo Tagliazucchi, Dante R. Chialvo, Michael Siniatchkin et al.
210 citations
Loss of cortical integration and changes in the dynamics of electrophysiological brain signals characterize the transition from wakefulness towards unconsciousness. In this study, we arrive at a basic model explaining these observations based on the theory of phase transitions in complex systems. We studied the link between spatial and temporal correlations of large-scale brain activity...
Human Brain Mapping
July 3, 2014
Enzo Tagliazucchi, Robin Carhart-Harris, Robert Leech et al.
423 citations
Abstract The study of rapid changes in brain dynamics and functional connectivity (FC) is of increasing interest in neuroimaging. Brain states departing from normal waking consciousness are expected to be accompanied by alterations in the aforementioned dynamics. In particular, the psychedelic experience produced by psilocybin (a substance found in “magic mushrooms”) is characterized by...