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Adam B. Barrett

16 papers in the library · 1,125 citations · publishing 2011-2026

Papers

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Integrated information theory: the good, the bad and the misunderstood

arXiv Preprint Archive April 13, 2026 Adam B. Barrett, Borjan Milinkovic, Pedro A. M. Mediano et al.

The integrated information theory of consciousness (IIT) is uniquely ambitious in proposing a mathematical formula, derived from apparently fundamental properties of conscious experience, to describe the quantity and quality of consciousness for any physical system that possesses it. IIT has generated considerable debate, which has engendered some misunderstandings and misrepresentations. Here...

Mapping of Subjective Accounts into Interpreted Clusters (MOSAIC): Topic Modelling and LLM applied to Stroboscopic Phenomenology

arXiv Preprint Archive February 25, 2025 Romy Beauté, David J. Schwartzman, Guillaume Dumas et al.

Stroboscopic light stimulation (SLS) on closed eyes typically induces simple visual hallucinations (VHs), characterised by vivid, geometric and colourful patterns. A dataset of 862 sentences, extracted from 422 open subjective reports, was recently compiled as part of the Dreamachine programme (Collective Act, 2022), an immersive multisensory experience that combines SLS and spatial sound in a...

Effects of External Stimulation on Psychedelic State Neurodynamics.

ACS Chemical Neuroscience February 7, 2024 Pedro A. M. Mediano, Fernando E. Rosas, Christopher Timmermann et al. 60 citations

Recent findings have shown that psychedelics reliably enhance brain entropy (understood as neural signal diversity), and this effect has been associated with both acute and long-term psychological outcomes, such as personality changes. These findings are particularly intriguing, given that a decrease of brain entropy is a robust indicator of loss of consciousness (e.g., from wakefulness to...

Statistical diversity distinguishes global states of consciousness

bioRxiv December 7, 2023 Joseph Starkey, Robin Carhart-Harris, Andrea Pigorini et al. preprint

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...

The strength of weak integrated information theory

Trends in Cognitive Sciences June 1, 2022 Pedro A. M. Mediano, Fernando E. Rosas, Daniel Bor et al. 109 citations

The integrated information theory of consciousness (IIT) is unprecedentedly ambitious in that it proposes a universal mathematical formula, derived from fundamental properties of conscious experience, to describe the quality of consciousness that it the of consciousness of in the the of in the the a of the that a from a of a the of the The integrated information theory of consciousness (IIT) is...

Greater than the parts: a review of the information decomposition approach to causal emergence

Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences May 23, 2022 Pedro A. M. Mediano, Fernando E. Rosas, Andrea I. Luppi et al. 73 citations

Emergence is a profound subject that straddles many scientific disciplines, including the formation of galaxies and how consciousness arises from the collective activity of neurons. Despite the broad interest that exists on this concept, the study of emergence has suffered from a lack of formalisms that could be used to guide discussions and advance theories. Here, we summarize, elaborate on,...

The Phi measure of integrated information is not well-defined for general physical systems

arXiv Preprint Archive February 12, 2019 Adam B. Barrett, Pedro A. M. Mediano

According to the Integrated Information Theory of Consciousness, consciousness is a fundamental observer-independent property of physical systems, and the measure Phi of integrated information is identical to the quantity or level of consciousness. For this to be plausible, there should be no alternative formulae for Phi consistent with the axioms of IIT, and there should not be cases of Phi...

Measuring Integrated Information: Comparison of Candidate Measures in Theory and Simulation.

Entropy (Basel, Switzerland) December 25, 2018 Pedro A. M. Mediano, Anil K. Seth, Adam B. Barrett

Integrated Information Theory (IIT) is a prominent theory of consciousness that has at its centre measures that quantify the extent to which a system generates more information than the sum of its parts. While several candidate measures of integrated information (" Φ ") now exist, little is known about how they compare, especially in terms of their behaviour on non-trivial network models. In...

Measuring Integrated Information: Comparison of Candidate Measures in Theory and Simulation

arXiv Preprint Archive June 25, 2018 Pedro A. M. Mediano, Anil K. Seth, Adam B. Barrett

Integrated Information Theory (IIT) is a prominent theory of consciousness that has at its centre measures that quantify the extent to which a system generates more information than the sum of its parts. While several candidate measures of integrated information (`$Φ$') now exist, little is known about how they compare, especially in terms of their behaviour on non-trivial network models. In...

Loss of consciousness is related to hyper-correlated gamma-band activity in anesthetized macaques and sleeping humans.

Neuroimage February 15, 2018 Michał Bola, Adam B. Barrett, Andrea Pigorini et al.

Loss of consciousness can result from a wide range of causes, including natural sleep and pharmacologically induced anesthesia. Important insights might thus come from identifying neuronal mechanisms of loss and re-emergence of consciousness independent of a specific manipulation. Therefore, to seek neuronal signatures of loss of consciousness common to sleep and anesthesia we analyzed...

Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin

Scientific Reports April 19, 2017 Michael Schartner, Robin Carhart-Harris, Adam B. Barrett et al. 450 citations

Abstract What is the level of consciousness of the psychedelic state? Empirically, measures of neural signal diversity such as entropy and Lempel-Ziv (LZ) complexity score higher for wakeful rest than for states with lower conscious level like propofol-induced anesthesia. Here we compute these measures for spontaneous magnetoencephalographic (MEG) signals from humans during altered states of...

Global and local complexity of intracranial EEG decreases during NREM sleep

Neuroscience of Consciousness January 27, 2017 Michael Schartner, Andrea Pigorini, Steve A. Gibbs et al. 158 citations

Key to understanding the neuronal basis of consciousness is the characterization of the neural signatures of changes in level of consciousness during sleep. Here we analysed three measures of dynamical complexity on spontaneous depth electrode recordings from 10 epilepsy patients during wakeful rest (WR) and different stages of sleep: (i) Lempel-Ziv complexity, which is derived from how...

An extended case study on the phenomenology of sequence-space synesthesia

Frontiers in Human Neuroscience July 3, 2014 Cassandra Gould van Praag, Tom Froese, Adam B. Barrett et al. 29 citations

Investigation of synesthesia phenomenology in adults is needed to constrain accounts of developmental trajectories of this trait. We report an extended phenomenological investigation of sequence-space synesthesia in a single case (AB). We used the Elicitation Interview (EI) method to facilitate repeated exploration of AB's synesthetic experience. During an EI the subject's attention is...

An Integration of Integrated Information Theory with Fundamental Physics

arXiv Preprint Archive July 3, 2014 Adam B. Barrett

To truly eliminate Cartesian ghosts from the science of consciousness, we must describe consciousness as an aspect of the physical. Integrated Information Theory states that consciousness arises from intrinsic information generated by dynamical systems; however existing formulations of this theory are not applicable to standard models of fundamental physical entities. Modern physics has shown...

Practical Measures of Integrated Information for Time-Series Data

PLoS Computational Biology January 20, 2011 Adam B. Barrett, Anil K. Seth 243 citations

A recent measure of 'integrated information', Φ(DM), quantifies the extent to which a system generates more information than the sum of its parts as it transitions between states, possibly reflecting levels of consciousness generated by neural systems. However, Φ(DM) is defined only for discrete Markov systems, which are unusual in biology; as a result, Φ(DM) can rarely be measured in practice....