8 papers in the library · 228 citations · publishing 2020-2024
Netw Neurosci December 10, 2024 Thomas F. Varley, Daniel Havert, Leandro Fosque et al. 12 citations
The serotonergic psychedelic N,N-dipropyltryptamine alters information-processing dynamics in in vitro cortical neural circuits.
arXiv Preprint Archive October 31, 2023 Thomas F. Varley, Daniel Havert, Leandro Fosque et al.
Most of the recent work in psychedelic neuroscience has been done using non-invasive neuroimaging, with data recorded from the brains of adult volunteers under the influence of a variety of drugs. While this data provides holistic insights into the effects of psychedelics on whole-brain dynamics, the effects of psychedelics on the meso-scale dynamics of cortical circuits remains much less...
bioRxiv (Cold Spring Harbor Laboratory) September 23, 2021 Pedro A. M. Mediano, Aleksi Ikkala, Rogier Kievit et al. 30 citations preprint
ABSTRACT There has been considerable recent progress in measuring conscious level using neural complexity measures. For instance, such measures can reliably distinguish healthy awake from asleep subjects and vegetative state patients. However, this line of research has never explored the dynamics of conscious level during normal wakefulness. Being able to capture meaningful differences in...
Neuroimage June 30, 2020 Thomas F. Varley, Robin Carhart-Harris, Leor Roseman et al. 91 citations
Psychedelic drugs, such as psilocybin and LSD, represent unique tools for researchers investigating the neural origins of consciousness. Currently, the most compelling theories of how psychedelics exert their effects is by increasing the complexity of brain activity and moving the system towards a critical point between order and disorder, creating more dynamic and complex patterns of neural...
bioRxiv Preprint Server April 4, 2020 Thomas F. Varley, Vanessa Denny, Olaf Sporns et al. 6 citations preprint
Research has found that the vividness of conscious experience is related to brain dynamics. Despite both being anesthetics, propofol and ketamine produce different subjective states: we explore the different effects of these two anaesthetics on the structure of dynamic attractors reconstructed from electrophysiological activity recorded from cerebral cortex of two macaques. We used two methods:...
bioRxiv Preprint Server March 27, 2020 Thomas F. Varley, Olaf Sporns, Aina Puce et al. 3 citations preprint
Whether the brain operates at a critical ‘‘tipping” point is a long standing scientific question, with evidence from both cellular and systems-scale studies suggesting that the brain does sit in, or near, a critical regime. Neuroimaging studies of humans in altered states of consciousness have prompted the suggestion that maintenance of critical dynamics is necessary for the emergence of...
PLoS One February 13, 2020 Thomas F. Varley, Michael M. Craig, Ram Adapa et al.
Recent evidence suggests that the quantity and quality of conscious experience may be a function of the complexity of activity in the brain and that consciousness emerges in a critical zone between low and high-entropy states. We propose fractal shapes as a measure of proximity to this critical point, as fractal dimension encodes information about complexity beyond simple entropy or randomness,...
Scientific Reports January 23, 2020 Thomas F. Varley, Andrea I. Luppi, Ioannis Pappas et al. 86 citations
The brain is possibly the most complex system known to mankind, and its complexity has been called upon to explain the emergence of consciousness. However, complexity has been defined in many ways by multiple different fields: here, we investigate measures of algorithmic and process complexity in both the temporal and topological domains, testing them on functional MRI BOLD signal data obtained...