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Pedro A. M. Mediano

48 papers in the library · 968 citations · publishing 2018-2026

Papers

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Distributed harmonic patterns of structure-function dependence orchestrate human consciousness.

Communications Biology January 28, 2023 Andrea I. Luppi, Jakub Vohryzek, Morten L. Kringelbach et al. 98 citations

A central question in neuroscience is how consciousness arises from the dynamic interplay of brain structure and function. Here we decompose functional MRI signals from pathological and pharmacologically-induced perturbations of consciousness into distributed patterns of structure-function dependence across scales: the harmonic modes of the human structural connectome. We show that...

Canalization and plasticity in psychopathology

Neuropharmacology December 27, 2022 Robin Carhart-Harris, Shamil Chandaria, David Erritzøe et al. 106 citations

This theoretical article revives a classical bridging construct, canalization, to describe a new model of a general factor of psychopathology. To achieve this, we have distinguished between two types of plasticity, an early one that we call 'TEMP' for 'Temperature or Entropy Mediated Plasticity', and another, we call 'canalization', which is close to Hebbian plasticity. These two forms of...

Psychedelics and schizophrenia: Distinct alterations to Bayesian inference.

Neuroimage November 1, 2022 Hardik Rajpal, Pedro A. M. Mediano, Fernando E. Rosas et al. 23 citations

Schizophrenia and states induced by certain psychotomimetic drugs may share some physiological and phenomenological properties, but they differ in fundamental ways: one is a crippling chronic mental disease, while the others are temporary, pharmacologically-induced states presently being explored as treatments for mental illnesses. Building towards a deeper understanding of these different...

A mechanistic model of the neural entropy increase elicited by psychedelic drugs

Research Square October 26, 2022 Rubén Herzog, Pedro A. M. Mediano, Fernando E. Rosas et al. 6 citations

Abstract Psychedelic drugs, including lysergic acid diethylamide (LSD) 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...

Retraction Note: A mechanistic model of the neural entropy increase elicited by psychedelic drugs.

Sci Rep September 15, 2022 Rubén Herzog, Pedro A. M. Mediano, Fernando E. Rosas et al. 3 citations

s attention that there was a typo in the script used to calculate the differential entropy. Therefore, the reported entropy estimations are invalid and do not produce the expected increase in entropy when using

From Relaxed Beliefs Under Psychedelics (REBUS) to Revised Beliefs After Psychedelics (REBAS): Preliminary Development of the RElaxed Beliefs Questionnaire (REB-Q)

July 7, 2022 Richard J. Zeifman, Meg J. Spriggs, Hannes Kettner et al. 13 citations preprint

Background: The Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs, and offers a unified account of the acute and therapeutic action of psychedelics. Although REBUS has received some neuroscientific support, little research has examined its psychological validity. We conducted a...

Metastability, fractal scaling, and synergistic information processing: What phase relationships reveal about intrinsic brain activity

Neuroimage July 1, 2022 Fran Hancock, Joana Cabral, Andrea I. Luppi et al. 40 citations

Dynamic functional connectivity (dFC) in resting-state fMRI holds promise to deliver candidate biomarkers for clinical applications. However, the reliability and interpretability of dFC metrics remain contested. Despite a myriad of methodologies and resulting measures, few studies have combined metrics derived from different conceptualizations of brain functioning within the same analysis -...

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,...

Whole-brain modelling identifies distinct but convergent paths to unconsciousness in anaesthesia and disorders of consciousness

Communications Biology April 20, 2022 Andrea I. Luppi, Pedro A. M. Mediano, Fernando E. Rosas et al.

The human brain entertains rich spatiotemporal dynamics, which are drastically reconfigured when consciousness is lost due to anaesthesia or disorders of consciousness (DOC). Here, we sought to identify the neurobiological mechanisms that explain how transient pharmacological intervention and chronic neuroanatomical injury can lead to common reconfigurations of neural activity. We developed and...

Ketamine and sleep modulate neural complexity dynamics in cats.

The European journal of neuroscience March 1, 2022 Claudia Pascovich, Santiago Castro-Zaballa, Pedro A. M. Mediano et al. 16 citations

There is increasing evidence that the level of consciousness can be captured by neural informational complexity: for instance, complexity, as measured by the Lempel Ziv (LZ) compression algorithm, decreases during anaesthesia and non-rapid eye movement (NREM) sleep in humans and rats, when compared with LZ in awake and REM sleep. In contrast, LZ is higher in humans under the effect of...

What it is like to be a bit: an integrated information decomposition account of emergent mental phenomena

Neuroscience of Consciousness November 1, 2021 Andrea I. Luppi, Pedro A. M. Mediano, Fernando E. Rosas et al. 42 citations

Abstract A central question in neuroscience concerns the relationship between consciousness and its physical substrate. Here, we argue that a richer characterization of consciousness can be obtained by viewing it as constituted of distinct information-theoretic elements. In other words, we propose a shift from quantification of consciousness—viewed as integrated information—to its...

Fluctuations in Neural Complexity During Wakefulness Relate To Conscious Level and Cognition

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...

RETRACTED ARTICLE: A mechanistic model of the neural entropy increase elicited by psychedelic drugs

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...

Whole-brain models to explore altered states of consciousness from the\n bottom up

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...

Whole-brain models to explore altered states of consciousness from the bottom up

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...

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...

Spectrally and temporally resolved estimation of neural signal diversity

Pedro A. M. Mediano, Fernando E. Rosas, Andrea I. Luppi et al. 10 citations

Abstract Quantifying the complexity of neural activity has provided fundamental insights into cognition, consciousness, and clinical conditions. However, the most widely used approach to estimate the complexity of neural dynamics, Lempel-Ziv complexity (LZ), has fundamental limitations that substantially restrict its domain of applicability. In this article we leverage the information-theoretic...

Accurate and Interpretable Prediction of Antidepressant Treatment Response from Receptor-informed Neuroimaging

bioRxiv (Cold Spring Harbor Laboratory) Hanna M. Tolle, Andrea I. Luppi, Timothy Lawn et al. 1 citation preprint

Conventional antidepressants show moderate efficacy in treating major depressive disorder. Psychedelic-assisted therapy holds promise, yet individual responses vary, underscoring the need for predictive tools to guide treatment selection. Here, we present graphTRIP (graph-based Treatment Response Interpretability and Prediction) – a geometric deep learning architecture that enables three...

Phi-monads are conceptually problematic and mathematically undefined in Integrated Information Theory 4.0

Ignacio Cea, Niccolò Negro, Pedro A. M. Mediano et al. preprint

The Integrated Information Theory (IIT) 4.0 is an influential framework aiming to explain consciousness mathematically in terms of intrinsic existence, namely what exists for itself in a specific, maximally irreducible, structured form. IIT thus posits that the minimal substrates of consciousness are also the ultimate building blocks of what exists. These are called ‘monads’, and are defined as...

Compatibilist emergence for the science of consciousness

George Blackburne, Alberto Liardi, Jeremy I Skipper et al. preprint

The relationship between subjectivity and its substrate can be understood via the notion of compatibilist emergence, accounting for the plurality of ways nature can host new dynamical laws at higher scales. We discuss how the autopoietic character of life may require and promote the kind of emergence necessary, albeit not sufficient, for consciousness.