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Bayne T, Seth AK, Massimini M, Shepherd J, Cleeremans A, Fleming SM, Malach R, Mattingley JB, Menon DK, Owen AM, Peters MAK, Razi A, Mudrik L. Tests for consciousness in humans and beyond. Trends Cogn Sci 2024; 28:454-466. [PMID: 38485576 DOI: 10.1016/j.tics.2024.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 05/12/2024]
Abstract
Which systems/organisms are conscious? New tests for consciousness ('C-tests') are urgently needed. There is persisting uncertainty about when consciousness arises in human development, when it is lost due to neurological disorders and brain injury, and how it is distributed in nonhuman species. This need is amplified by recent and rapid developments in artificial intelligence (AI), neural organoids, and xenobot technology. Although a number of C-tests have been proposed in recent years, most are of limited use, and currently we have no C-tests for many of the populations for which they are most critical. Here, we identify challenges facing any attempt to develop C-tests, propose a multidimensional classification of such tests, and identify strategies that might be used to validate them.
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Affiliation(s)
- Tim Bayne
- Department of Philosophy, Monash University, Melbourne, VIC, Australia; Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada.
| | - Anil K Seth
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; Sussex Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, Brighton, UK
| | - Marcello Massimini
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; Department of Biomedical and Clinical Science, University of Milan, Milan, Italy; IRCCS Fondazione Don Gnocchi
| | - Joshua Shepherd
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; Universitat Autònoma de Barcelona, Belleterra, Spain; ICREA, Barcelona, Spain
| | - Axel Cleeremans
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; Center for Research in Cognition and Neuroscience, ULB Institute of Neuroscience, Université libre de Bruxelles, Brussels, Belgium
| | - Stephen M Fleming
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; Department of Experimental Psychology, University College London, London, UK; Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Rafael Malach
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; The Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Jason B Mattingley
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; Queensland Brain Institute and School of Psychology, The University of Queensland, Brisbane, QLD, Australia
| | - David K Menon
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; University of Cambridge, Cambridge, UK
| | - Adrian M Owen
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; University of Western Ontario, London, ON, Canada
| | - Megan A K Peters
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; University of California, Irvine, Irvine, CA, USA
| | - Adeel Razi
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia; Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Liad Mudrik
- Canadian Institute for Advanced Research (CIFAR), Brain, Mind, and Consciousness Program, Toronto, ON, Canada; School of Psychological Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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2
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Mediano PAM, Rosas FE, Timmermann C, Roseman L, Nutt DJ, Feilding A, Kaelen M, Kringelbach ML, Barrett AB, Seth AK, Muthukumaraswamy S, Bor D, Carhart-Harris RL. Effects of External Stimulation on Psychedelic State Neurodynamics. ACS Chem Neurosci 2024; 15:462-471. [PMID: 38214686 PMCID: PMC10853937 DOI: 10.1021/acschemneuro.3c00289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/26/2023] [Indexed: 01/13/2024] Open
Abstract
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 sleep). However, little is known about how context impacts the entropy-enhancing effect of psychedelics, which carries important implications for how it can be exploited in, for example, psychedelic psychotherapy. This article investigates how brain entropy is modulated by stimulus manipulation during a psychedelic experience by studying participants under the effects of lysergic acid diethylamide (LSD) or placebo, either with gross state changes (eyes closed vs open) or different stimuli (no stimulus vs music vs video). Results show that while brain entropy increases with LSD under all of the experimental conditions, it exhibits the largest changes when subjects have their eyes closed. Furthermore, brain entropy changes are consistently associated with subjective ratings of the psychedelic experience, but this relationship is disrupted when participants are viewing a video─potentially due to a "competition" between external stimuli and endogenous LSD-induced imagery. Taken together, our findings provide strong quantitative evidence of the role of context in modulating neural dynamics during a psychedelic experience, underlining the importance of performing psychedelic psychotherapy in a suitable environment.
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Affiliation(s)
- Pedro A. M. Mediano
- Department
of Computing, Imperial College London, London SW7 2AZ, U.K.
- Department
of Psychology, University of Cambridge, Cambridge CB2 3EB, U.K.
| | - Fernando E. Rosas
- Department
of Informatics, University of Sussex, Brighton BN1 9RH, U.K.
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
- Centre
for Complexity Science, Imperial College
London, London SW7 2AZ, U.K.
- Centre for
Eudaimonia and Human Flourishing, University
of Oxford, Oxford OX1 2JD, U.K.
| | - Christopher Timmermann
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
| | - Leor Roseman
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
| | - David J. Nutt
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
| | | | | | - Morten L. Kringelbach
- Centre for
Eudaimonia and Human Flourishing, University
of Oxford, Oxford OX1 2JD, U.K.
- Department
of Psychiatry, University of Oxford, Oxford OX1 2JD, U.K.
- Center
for Music in the Brain, Department of Clinical Medicine, Aarhus University, Aarhus 8000, Denmark
| | - Adam B. Barrett
- Sussex
Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton BN1 9RH, U.K.
| | - Anil K. Seth
- Sussex
Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton BN1 9RH, U.K.
- CIFAR Program on Brain, Mind, and Consciousness, Toronto M5G 1M1, Canada
| | - Suresh Muthukumaraswamy
- School
of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Daniel Bor
- Department
of Psychology, University of Cambridge, Cambridge CB2 3EB, U.K.
- Department
of Psychology, Queen Mary University of
London, London E1 4NS, U.K.
| | - Robin L. Carhart-Harris
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
- Psychedelics
Division, Neuroscape, University of California
San Francisco, San Francisco, California 94117-1080, United States
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3
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Aundhia C, Parmar G, Talele C, Talele D, Seth AK. Light Sensitive Liposomes: A Novel Strategy for Targeted Drug Delivery. Pharm Nanotechnol 2024; 12:PNT-EPUB-137941. [PMID: 38279711 DOI: 10.2174/0122117385271651231228073850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 11/10/2023] [Accepted: 12/13/2023] [Indexed: 01/28/2024]
Abstract
Light-sensitive liposomes have emerged as a promising platform for drug delivery, offering the potential for precise control over drug release and targeted therapy. These lipid-based nanoparticles possess photoresponsive properties, allowing them to undergo structural changes or release therapeutic payloads upon exposure to specific wavelengths of light. This review presents an overview of the design principles, fabrication methods, and applications of light-sensitive liposomes in drug delivery. Further, this article also discusses the incorporation of light-sensitive moieties, such as azobenzene, spiropyran, and diarylethene, into liposomal structures, enabling spatiotemporal control over drug release. The utilization of photosensitizers and imaging agents to enhance the functionality and versatility of light-sensitive liposomes is also highlighted. Finally, the recent advances, challenges, and future directions in the field, emphasizing the potential for these innovative nanocarriers to revolutionize targeted therapeutics, are also discussed.
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Affiliation(s)
- Chintan Aundhia
- Department of Pharmacy, Sumandeep Vidyapeeth Deemed to be University, Piparia, Waghodia, Vadodara, 391760, Gujarat, India
| | - Ghanshyam Parmar
- Department of Pharmacy, Sumandeep Vidyapeeth Deemed to be University, Piparia, Waghodia, Vadodara, 391760, Gujarat, India
| | - Chitrali Talele
- Department of Pharmacy, Sumandeep Vidyapeeth Deemed to be University, Piparia, Waghodia, Vadodara, 391760, Gujarat, India
| | - Dipali Talele
- Faculty of Pharmacy, Vishwakarma University, Survey No. 2,3,4 Laxmi Nagar, Kondhwa Budruk, Pune, India
| | - A K Seth
- Department of Pharmacy, Sumandeep Vidyapeeth Deemed to be University, Piparia, Waghodia, Vadodara, 391760, Gujarat, India
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Suzuki K, Seth AK, Schwartzman DJ. Modelling phenomenological differences in aetiologically distinct visual hallucinations using deep neural networks. Front Hum Neurosci 2024; 17:1159821. [PMID: 38234594 PMCID: PMC10791985 DOI: 10.3389/fnhum.2023.1159821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 09/11/2023] [Indexed: 01/19/2024] Open
Abstract
Visual hallucinations (VHs) are perceptions of objects or events in the absence of the sensory stimulation that would normally support such perceptions. Although all VHs share this core characteristic, there are substantial phenomenological differences between VHs that have different aetiologies, such as those arising from Neurodegenerative conditions, visual loss, or psychedelic compounds. Here, we examine the potential mechanistic basis of these differences by leveraging recent advances in visualising the learned representations of a coupled classifier and generative deep neural network-an approach we call 'computational (neuro)phenomenology'. Examining three aetiologically distinct populations in which VHs occur-Neurodegenerative conditions (Parkinson's Disease and Lewy Body Dementia), visual loss (Charles Bonnet Syndrome, CBS), and psychedelics-we identified three dimensions relevant to distinguishing these classes of VHs: realism (veridicality), dependence on sensory input (spontaneity), and complexity. By selectively tuning the parameters of the visualisation algorithm to reflect influence along each of these phenomenological dimensions we were able to generate 'synthetic VHs' that were characteristic of the VHs experienced by each aetiology. We verified the validity of this approach experimentally in two studies that examined the phenomenology of VHs in Neurodegenerative and CBS patients, and in people with recent psychedelic experience. These studies confirmed the existence of phenomenological differences across these three dimensions between groups, and crucially, found that the appropriate synthetic VHs were rated as being representative of each group's hallucinatory phenomenology. Together, our findings highlight the phenomenological diversity of VHs associated with distinct causal factors and demonstrate how a neural network model of visual phenomenology can successfully capture the distinctive visual characteristics of hallucinatory experience.
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Affiliation(s)
- Keisuke Suzuki
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Center for Human Nature, Artificial Intelligence and Neuroscience (CHAIN), Hokkaido University, Sapporo, Japan
| | - Anil K. Seth
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Program on Brain, Mind, and Consciousness, Canadian Institute for Advanced Research, Toronto, ON, Canada
| | - David J. Schwartzman
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
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5
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Abstract
Predictive coding is an influential model of cortical neural activity. It proposes that perceptual beliefs are furnished by sequentially minimising "prediction errors"-the differences between predicted and observed data. Implicit in this proposal is the idea that successful perception requires multiple cycles of neural activity. This is at odds with evidence that several aspects of visual perception-including complex forms of object recognition-arise from an initial "feedforward sweep" that occurs on fast timescales which preclude substantial recurrent activity. Here, we propose that the feedforward sweep can be understood as performing amortized inference (applying a learned function that maps directly from data to beliefs) and recurrent processing can be understood as performing iterative inference (sequentially updating neural activity in order to improve the accuracy of beliefs). We propose a hybrid predictive coding network that combines both iterative and amortized inference in a principled manner by describing both in terms of a dual optimization of a single objective function. We show that the resulting scheme can be implemented in a biologically plausible neural architecture that approximates Bayesian inference utilising local Hebbian update rules. We demonstrate that our hybrid predictive coding model combines the benefits of both amortized and iterative inference-obtaining rapid and computationally cheap perceptual inference for familiar data while maintaining the context-sensitivity, precision, and sample efficiency of iterative inference schemes. Moreover, we show how our model is inherently sensitive to its uncertainty and adaptively balances iterative and amortized inference to obtain accurate beliefs using minimum computational expense. Hybrid predictive coding offers a new perspective on the functional relevance of the feedforward and recurrent activity observed during visual perception and offers novel insights into distinct aspects of visual phenomenology.
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Affiliation(s)
- Alexander Tscshantz
- Sussex AI Group, Department of Informatics, University of Sussex, Brighton, United Kingdom
- VERSES Research Lab, Los Angeles, California, United States of America
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
| | - Beren Millidge
- Sussex AI Group, Department of Informatics, University of Sussex, Brighton, United Kingdom
- VERSES Research Lab, Los Angeles, California, United States of America
- Brain Networks Dynamics Unit, University of Oxford, Oxford, United Kingdom
| | - Anil K. Seth
- Sussex AI Group, Department of Informatics, University of Sussex, Brighton, United Kingdom
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
| | - Christopher L. Buckley
- Sussex AI Group, Department of Informatics, University of Sussex, Brighton, United Kingdom
- VERSES Research Lab, Los Angeles, California, United States of America
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6
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Barnett L, Seth AK. Dynamical independence: Discovering emergent macroscopic processes in complex dynamical systems. Phys Rev E 2023; 108:014304. [PMID: 37583178 DOI: 10.1103/physreve.108.014304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 06/15/2023] [Indexed: 08/17/2023]
Abstract
We introduce a notion of emergence for macroscopic variables associated with highly multivariate microscopic dynamical processes. Dynamical independence instantiates the intuition of an emergent macroscopic process as one possessing the characteristics of a dynamical system "in its own right," with its own dynamical laws distinct from those of the underlying microscopic dynamics. We quantify (departure from) dynamical independence by a transformation-invariant Shannon information-based measure of dynamical dependence. We emphasize the data-driven discovery of dynamically independent macroscopic variables, and introduce the idea of a multiscale "emergence portrait" for complex systems. We show how dynamical dependence may be computed explicitly for linear systems in both time and frequency domains, facilitating discovery of emergent phenomena across spatiotemporal scales, and outline application of the linear operationalization to inference of emergence portraits for neural systems from neurophysiological time-series data. We discuss dynamical independence for discrete- and continuous-time deterministic dynamics, with potential application to Hamiltonian mechanics and classical complex systems such as flocking and cellular automata.
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Affiliation(s)
- L Barnett
- Sussex Centre for Consciousness Science, Department of Informatics, University of Sussex, Falmer, Brighton BN1 9QJ, United Kingdom
| | - A K Seth
- Sussex Centre for Consciousness Science, Department of Informatics, University of Sussex, Falmer, Brighton BN1 9QJ, United Kingdom
- Canadian Institute for Advanced Research, Program on Brain, Mind, and Consciousness, Toronto, Ontario M5G 1M1, Canada
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7
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Otten M, Seth AK, Pinto Y. Seeing Ɔ, remembering C: Illusions in short-term memory. PLoS One 2023; 18:e0283257. [PMID: 37018224 PMCID: PMC10075405 DOI: 10.1371/journal.pone.0283257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 03/05/2023] [Indexed: 04/06/2023] Open
Abstract
Perception can be shaped by our expectations, which can lead to perceptual illusions. Similarly, long-term memories can be shaped to fit our expectations, which can generate false memories. However, it is generally assumed that short-term memory for percepts formed just 1 or 2 seconds ago accurately represents the percepts as they were at the time of perception. Here 4 experiments consistently show that within this timeframe, participants go from reliably reporting what was there (perceptual inference accurately reflecting the bottom-up input), to erroneously but with high confidence reporting what they expected to be there (memory report strongly influenced by top-down expectations). Together, these experiments show that expectations can reshape perceptual representations over short time scales, leading to what we refer to as short-term memory (STM) illusions. These illusions appeared when participants saw a memory display which contained real and pseudo-letters (i.e. mirrored letters). Within seconds after the memory display disappeared, high confidence memory errors increased substantially. This increase in errors over time indicates that the high confidence errors do not (purely) result from incorrect perceptual encoding of the memory display. Moreover, high confidence errors occurred mainly for pseudo-to-real letter memories, and much less often for real-to-pseudo-letter memories, indicating that visual similarity is not the primary cause of this memory-bias. Instead 'world knowledge' (e.g., which orientation letters usually have) appear to drive these STM illusions. Our findings support a predictive processing view of the formation and maintenance of memory in which all memory stages, including STM, involve integration of bottom-up memory input with top-down predictions, such that prior expectations can shape memory traces.
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Affiliation(s)
- Marte Otten
- Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands
| | - Anil K Seth
- Sussex Centre for Consciousness Science, School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
- Canadian Institute for Advanced Research, Program on Brain, Mind, and Consciousness, Toronto, Ontario, Canada
| | - Yair Pinto
- Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands
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8
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Suzuki K, Mariola A, Schwartzman DJ, Seth AK. Using Extended Reality to Study the Experience of Presence. Curr Top Behav Neurosci 2023; 65:255-285. [PMID: 36592275 DOI: 10.1007/7854_2022_401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Extended reality (XR), encompassing various forms of virtual reality (VR) and augmented reality (AR), has become a powerful experimental tool in consciousness research due to its capability to create holistic and immersive experiences of oneself and surrounding environments through simulation. One hallmark of a successful XR experience is when it elicits a strong sense of presence, which can be thought of as a subjective sense of reality of the self and the world. Although XR research has shed light on many factors that may influence presence (or its absence) in XR environments, there remains much to be discovered about the detailed and diverse phenomenology of presence, and the neurocognitive mechanisms that underlie it. In this chapter, we analyse the concept of presence and relate it to the way in which humans may generate and maintain a stable sense of reality during both natural perception and virtual experiences. We start by reviewing the concept of presence as developed in XR research, covering both factors that may influence presence and potential ways of measuring presence. We then discuss the phenomenological characteristics of presence in human consciousness, drawing on clinical examples where presence is disturbed. Next, we describe two experiments using XR that investigated the effects of sensorimotor contingency and affordances on a specific form of presence related to the sense of objects as really existing in the world, referred to as 'objecthood'. We then go beyond perceptual presence to discuss the concept of 'conviction about reality', which corresponds to people's beliefs about the reality status of their perceptual experiences. We finish by exploring how the novel XR method of 'Substitutional Reality' can allow experimental investigation of these topics, opening new experimental directions for studying presence beyond the 'as-if' experience of fully simulated environments.
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Affiliation(s)
- Keisuke Suzuki
- Center for Human Nature, Artificial Intelligence and Neuroscience (CHAIN), Hokkaido University, Sapporo, Hokkaido, Japan.
- Sackler Centre for Consciousness Science, School of Engineering and Informatics, University of Sussex, Brighton, UK.
| | - Alberto Mariola
- Sackler Centre for Consciousness Science, School of Engineering and Informatics, University of Sussex, Brighton, UK
- School of Engineering and Informatics, University of Sussex, Brighton, UK
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
| | - David J Schwartzman
- Sackler Centre for Consciousness Science, School of Engineering and Informatics, University of Sussex, Brighton, UK
- School of Engineering and Informatics, University of Sussex, Brighton, UK
| | - Anil K Seth
- Sackler Centre for Consciousness Science, School of Engineering and Informatics, University of Sussex, Brighton, UK
- School of Engineering and Informatics, University of Sussex, Brighton, UK
- Program on Brain, Mind, and Consciousness, Canadian Institute for Advanced Research, Toronto, ON, Canada
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Rajpal H, Mediano PAM, Rosas FE, Timmermann CB, Brugger S, Muthukumaraswamy S, Seth AK, Bor D, Carhart-Harris RL, Jensen HJ. Psychedelics and schizophrenia: Distinct alterations to Bayesian inference. Neuroimage 2022; 263:119624. [PMID: 36108798 DOI: 10.1016/j.neuroimage.2022.119624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/11/2022] [Accepted: 09/10/2022] [Indexed: 11/28/2022] Open
Abstract
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 alterations of normal consciousness, here we compare the changes in neural dynamics induced by LSD and ketamine (in healthy volunteers) against those associated with schizophrenia, as observed in resting-state M/EEG recordings. While both conditions exhibit increased neural signal diversity, our findings reveal that this is accompanied by an increased transfer entropy from the front to the back of the brain in schizophrenia, versus an overall reduction under the two drugs. Furthermore, we show that these effects can be reproduced via different alterations of standard Bayesian inference applied on a computational model based on the predictive processing framework. In particular, the effects observed under the drugs are modelled as a reduction of the precision of the priors, while the effects of schizophrenia correspond to an increased precision of sensory information. These findings shed new light on the similarities and differences between schizophrenia and two psychotomimetic drug states, and have potential implications for the study of consciousness and future mental health treatments.
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Affiliation(s)
- Hardik Rajpal
- Centre for Complexity Science, Imperial College London, South Kensington, London, United Kingdom; Department of Mathematics, Imperial College London, South Kensington, London, United Kingdom; Public Policy Program, The Alan Turing Institute, London, United Kingdom.
| | - Pedro A M Mediano
- Department of Computing, Imperial College London, South Kensington, London, United Kingdom; Department of Psychology, University of Cambridge, Cambridge, United Kingdom; Department of Psychology, Queen Mary University of London, London, United Kingdom.
| | - Fernando E Rosas
- Centre for Complexity Science, Imperial College London, South Kensington, London, United Kingdom; Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, United Kingdom; Data Science Institute, Imperial College London, London, United Kingdom; Department of Informatics, University of Sussex, Brighton, United Kingdom
| | - Christopher B Timmermann
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Stefan Brugger
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, United Kingdom; Centre for Academic Mental Health, Bristol Medical School, University of Bristol, United Kingdom
| | | | - Anil K Seth
- School of Engineering and Informatics, University of Sussex, United Kingdom; CIFAR Program on Brain, Mind, and Consciousness, Toronto, Canada
| | - Daniel Bor
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom; Department of Psychology, Queen Mary University of London, London, United Kingdom
| | - Robin L Carhart-Harris
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, United Kingdom; Psychedelics Division, Neuroscape, Department of Neurology, University of California San Francisco, US
| | - Henrik J Jensen
- Centre for Complexity Science, Imperial College London, South Kensington, London, United Kingdom; Department of Mathematics, Imperial College London, South Kensington, London, United Kingdom; Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
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10
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Francken JC, Beerendonk L, Molenaar D, Fahrenfort JJ, Kiverstein JD, Seth AK, van Gaal S. An academic survey on theoretical foundations, common assumptions and the current state of consciousness science. Neurosci Conscious 2022; 2022:niac011. [PMID: 35975240 PMCID: PMC9374479 DOI: 10.1093/nc/niac011] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 05/13/2022] [Accepted: 07/27/2022] [Indexed: 11/24/2022] Open
Abstract
We report the results of an academic survey into the theoretical and methodological foundations, common assumptions, and the current state of the field of consciousness research. The survey consisted of 22 questions and was distributed on two different occasions of the annual meeting of the Association of the Scientific Study of Consciousness (2018 and 2019). We examined responses from 166 consciousness researchers with different backgrounds (e.g. philosophy, neuroscience, psychology, and computer science) and at various stages of their careers (e.g. junior/senior faculty and graduate/undergraduate students). The results reveal that there remains considerable discussion and debate between the surveyed researchers about the definition of consciousness and the way it should be studied. To highlight a few observations, a majority of respondents believe that machines could have consciousness, that consciousness is a gradual phenomenon in the animal kingdom, and that unconscious processing is extensive, encompassing both low-level and high-level cognitive functions. Further, we show which theories of consciousness are currently considered most promising by respondents and how supposedly different theories cluster together, which dependent measures are considered best to index the presence or absence of consciousness, and which neural measures are thought to be the most likely signatures of consciousness. These findings provide us with a snapshot of the current views of researchers in the field and may therefore help prioritize research and theoretical approaches to foster progress.
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Affiliation(s)
- Jolien C Francken
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Institute for Interdisciplinary Studies, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
- Faculty of Philosophy, Theology and Religious Sciences, Radboud University, Erasmusplein 1, 6525 HT, Nijmegen, the Netherlands
| | - Lola Beerendonk
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
| | - Dylan Molenaar
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
| | - Johannes J Fahrenfort
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Department of Experimental and Applied Psychology, Vrije Universiteit, Van der Boechorststraat 7, 1081 BT, Amsterdam, the Netherlands
| | - Julian D Kiverstein
- Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | - Anil K Seth
- Department of Informatics, University of Sussex, Sussex House, Falmer, Brighton BN1 9RH, UK
- Sackler Centre for Consciousness Science, University of Sussex, Sussex House, Falmer, Brighton BN1 9RH, UK
- Canadian Institute for Advanced Research (CIFAR) Program on Brain, Mind, and Consciousness, MaRS Centre, West Tower, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Simon van Gaal
- Department of Psychology, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
- Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, the Netherlands
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11
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Mediano PAM, Rosas FE, Luppi AI, Jensen HJ, Seth AK, Barrett AB, Carhart-Harris RL, Bor D. Greater than the parts: a review of the information decomposition approach to causal emergence. Philos Trans A Math Phys Eng Sci 2022; 380:20210246. [PMID: 35599558 PMCID: PMC9125226 DOI: 10.1098/rsta.2021.0246] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/07/2022] [Indexed: 05/28/2023]
Abstract
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, and extend a recent formal theory of causal emergence based on information decomposition, which is quantifiable and amenable to empirical testing. This theory relates emergence with information about a system's temporal evolution that cannot be obtained from the parts of the system separately. This article provides an accessible but rigorous introduction to the framework, discussing the merits of the approach in various scenarios of interest. We also discuss several interpretation issues and potential misunderstandings, while highlighting the distinctive benefits of this formalism. This article is part of the theme issue 'Emergent phenomena in complex physical and socio-technical systems: from cells to societies'.
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Affiliation(s)
- Pedro A M Mediano
- Department of Psychology, University of Cambridge, Cambridge, UK
- Department of Psychology, Queen Mary University of London, London, UK
| | - Fernando E Rosas
- Centre for Psychedelic Research, Imperial College London, London, UK
- Data Science Institute, Imperial College London, London, UK
- Centre for Complexity Science, Imperial College London, London, UK
| | - Andrea I Luppi
- University Division of Anaesthesia, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Leverhulme Centre for the Future of Intelligence, University of Cambridge, Cambridge, UK
- The Alan Turing Institute, London, UK
| | - Henrik J Jensen
- Centre for Complexity Science, Imperial College London, London, UK
- Department of Mathematics, Imperial College London, London, UK
- Institute of Innovative Research, Tokyo Institute of Technology Tokyo, Japan
| | - Anil K Seth
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
- CIFAR Program on Brain, Mind, and Consciousness, Toronto, Canada
| | - Adam B Barrett
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
- The Data Intensive Science Centre, Department of Informatics, University of Sussex, Brighton, UK
| | - Robin L Carhart-Harris
- Centre for Psychedelic Research, Imperial College London, London, UK
- Psychedelics Division, Neuroscape, Department of Neurology, University of California, San Francisco, CA, USA
| | - Daniel Bor
- Department of Psychology, University of Cambridge, Cambridge, UK
- Department of Psychology, Queen Mary University of London, London, UK
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12
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Sherman MT, Fountas Z, Seth AK, Roseboom W. Trial-by-trial predictions of subjective time from human brain activity. PLoS Comput Biol 2022; 18:e1010223. [PMID: 35797365 PMCID: PMC9262235 DOI: 10.1371/journal.pcbi.1010223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 05/17/2022] [Indexed: 11/19/2022] Open
Abstract
Human experience of time exhibits systematic, context-dependent deviations from clock time; for example, time is experienced differently at work than on holiday. Here we test the proposal that differences from clock time in subjective experience of time arise because time estimates are constructed by accumulating the same quantity that guides perception: salient events. Healthy human participants watched naturalistic, silent videos of up to 24 seconds in duration and estimated their duration while fMRI was acquired. We were able to reconstruct trial-by-trial biases in participants’ duration reports, which reflect subjective experience of duration, purely from salient events in their visual cortex BOLD activity. By contrast, salient events in neither of two control regions–auditory and somatosensory cortex–were predictive of duration biases. These results held despite being able to (trivially) predict clock time from all three brain areas. Our results reveal that the information arising during perceptual processing of a dynamic environment provides a sufficient basis for reconstructing human subjective time duration. Our perception of time isn’t like a clock; it varies depending on other aspects of experience, such as what we see and hear in that moment. Previous studies have shown that differences in simple features, such as an image being larger or smaller, or brighter or dimmer, can change how we perceive time for those experiences. But in everyday life, the properties of these simple features can change frequently, presenting a challenge to understanding real-world time perception based on simple lab experiments. To overcome this problem, we developed a computational model of human time perception based on tracking changes in neural activity across brain regions involved in sensory processing (using non-invasive brain imaging). By measuring changes in brain activity patterns across these regions, our approach accommodates the different and changing feature combinations present in natural scenarios, such as walking on a busy street. Our model reproduces people’s duration reports for natural videos (up to almost half a minute long) and, most importantly, predicts whether a person reports a scene as relatively shorter or longer–the biases in time perception that reflect how natural experience of time deviates from clock time.
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Affiliation(s)
- Maxine T. Sherman
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
- * E-mail: (MTS); (WR)
| | - Zafeirios Fountas
- Wellcome Centre for Human Neuroimaging, University College London, London, United Kingdom
| | - Anil K. Seth
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Canadian Institute for Advanced Research, Program on Brain, Mind, and Consciousness, Toronto, Canada
| | - Warrick Roseboom
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- School of Psychology, University of Sussex, Brighton, United Kingdom
- * E-mail: (MTS); (WR)
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13
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Fountas Z, Sylaidi A, Nikiforou K, Seth AK, Shanahan M, Roseboom W. A Predictive Processing Model of Episodic Memory and Time Perception. Neural Comput 2022; 34:1501-1544. [PMID: 35671462 DOI: 10.1162/neco_a_01514] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 03/06/2022] [Indexed: 11/04/2022]
Abstract
Human perception and experience of time are strongly influenced by ongoing stimulation, memory of past experiences, and required task context. When paying attention to time, time experience seems to expand; when distracted, it seems to contract. When considering time based on memory, the experience may be different than what is in the moment, exemplified by sayings like "time flies when you're having fun." Experience of time also depends on the content of perceptual experience-rapidly changing or complex perceptual scenes seem longer in duration than less dynamic ones. The complexity of interactions among attention, memory, and perceptual stimulation is a likely reason that an overarching theory of time perception has been difficult to achieve. Here, we introduce a model of perceptual processing and episodic memory that makes use of hierarchical predictive coding, short-term plasticity, spatiotemporal attention, and episodic memory formation and recall, and apply this model to the problem of human time perception. In an experiment with approximately 13,000 human participants, we investigated the effects of memory, cognitive load, and stimulus content on duration reports of dynamic natural scenes up to about 1 minute long. Using our model to generate duration estimates, we compared human and model performance. Model-based estimates replicated key qualitative biases, including differences by cognitive load (attention), scene type (stimulation), and whether the judgment was made based on current or remembered experience (memory). Our work provides a comprehensive model of human time perception and a foundation for exploring the computational basis of episodic memory within a hierarchical predictive coding framework.
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Affiliation(s)
- Zafeirios Fountas
- Emotech Labs, London, N1 7EU U.K.,Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London WC1N 3AR, U.K.
| | | | | | - Anil K Seth
- Department of Informatics and Sackler Centre for Consciousness Science, University of Sussex, Brighton, BN1 9RH, U.K.,Canadian Institute for Advanced Research Program on Brain, Mind, and Consciousness, Toronto, ON M5G 1M1, Canada
| | - Murray Shanahan
- Department of Computing, Imperial College London, London, SW7 2RH, U.K.
| | - Warrick Roseboom
- Department of Informatics and Sackler Centre for Consciousness Science, University of Sussex, Brighton BN1 9RH, U.K.
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14
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Mediano PAM, Rosas FE, Bor D, Seth AK, Barrett AB. The strength of weak integrated information theory. Trends Cogn Sci 2022; 26:646-655. [PMID: 35659757 DOI: 10.1016/j.tics.2022.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 04/21/2022] [Accepted: 04/21/2022] [Indexed: 12/27/2022]
Abstract
The integrated information theory of consciousness (IIT) is divisive: while some believe it provides an unprecedentedly powerful approach to address the 'hard problem', others dismiss it on grounds that it is untestable. We argue that the appeal and applicability of IIT can be greatly widened if we distinguish two flavours of the theory: strong IIT, which identifies consciousness with specific properties associated with maxima of integrated information; and weak IIT, which tests pragmatic hypotheses relating aspects of consciousness to broader measures of information dynamics. We review challenges for strong IIT, explain how existing empirical findings are well explained by weak IIT without needing to commit to the entirety of strong IIT, and discuss the outlook for both flavours of IIT.
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Affiliation(s)
- Pedro A M Mediano
- Department of Psychology, University of Cambridge, Cambridge, UK; Department of Psychology, Queen Mary University of London, London, UK.
| | - Fernando E Rosas
- Centre for Psychedelic Research, Imperial College London, London, UK; Data Science Institute, Imperial College London, London, UK; Centre for Complexity Science, Imperial College London, London, UK
| | - Daniel Bor
- Department of Psychology, University of Cambridge, Cambridge, UK; Department of Psychology, Queen Mary University of London, London, UK
| | - Anil K Seth
- Sackler Centre for Consciousness Science, Department of Informatics, University of Sussex, Brighton, UK; CIFAR Program on Brain, Mind, and Consciousness, Toronto, Canada
| | - Adam B Barrett
- Sackler Centre for Consciousness Science, Department of Informatics, University of Sussex, Brighton, UK; The Data Intensive Science Centre, Department of Informatics, University of Sussex, Brighton, UK.
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15
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Ramstead MJD, Seth AK, Hesp C, Sandved-Smith L, Mago J, Lifshitz M, Pagnoni G, Smith R, Dumas G, Lutz A, Friston K, Constant A. From Generative Models to Generative Passages: A Computational Approach to (Neuro) Phenomenology. Rev Philos Psychol 2022; 13:829-857. [PMID: 35317021 PMCID: PMC8932094 DOI: 10.1007/s13164-021-00604-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 10/28/2021] [Indexed: 12/16/2022]
Abstract
This paper presents a version of neurophenomenology based on generative modelling techniques developed in computational neuroscience and biology. Our approach can be described as computational phenomenology because it applies methods originally developed in computational modelling to provide a formal model of the descriptions of lived experience in the phenomenological tradition of philosophy (e.g., the work of Edmund Husserl, Maurice Merleau-Ponty, etc.). The first section presents a brief review of the overall project to naturalize phenomenology. The second section presents and evaluates philosophical objections to that project and situates our version of computational phenomenology with respect to these projects. The third section reviews the generative modelling framework. The final section presents our approach in detail. We conclude by discussing how our approach differs from previous attempts to use generative modelling to help understand consciousness. In summary, we describe a version of computational phenomenology which uses generative modelling to construct a computational model of the inferential or interpretive processes that best explain this or that kind of lived experience.
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Affiliation(s)
- Maxwell J. D. Ramstead
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
- VERSES Research Lab and Spatial Web Foundation, Los Angeles, California USA
| | - Anil K. Seth
- School of Engineering and Informatics, University of Sussex, Brighton, BN1 9QJ UK
- Canadian Institute for Advanced Research (CIFAR), Program on Brain, Mind, and Consciousness, Toronto, Ontario, M5G 1M1 Canada
| | - Casper Hesp
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
- Department of Psychology, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, Netherlands
- Amsterdam Brain and Cognition Centre, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, Netherlands
- Institute for Advanced Study, University of Amsterdam, Oude Turfmarkt 147, 1012 GC Amsterdam, Netherlands
| | - Lars Sandved-Smith
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
- Lyon Neuroscience Research Centre, INSERM U1028, CNRS UMR5292, Lyon 1 University, Lyon, France
| | - Jonas Mago
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
- Integrated Program in Neuroscience, Department of Neuroscience, McGill University, Montreal, Canada
- Division of Social and Transcultural Psychiatry, McGill University, Montreal, Canada
| | - Michael Lifshitz
- Division of Social and Transcultural Psychiatry, McGill University, Montreal, Canada
- Lady Davis Institute for Medical Research, Montreal Jewish General Hospital, Montreal, Canada
| | - Giuseppe Pagnoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - Ryan Smith
- Laureate Institute for Brain Research, Tulsa, Oklahoma USA
| | - Guillaume Dumas
- CHU Sainte-Justine Research Center, Department of Psychiatry, University of Montreal, Montreal, Canada
- Mila – Quebec Artificial Intelligence Institute, University of Montreal, Montreal, Canada
| | - Antoine Lutz
- Lyon Neuroscience Research Centre, INSERM U1028, CNRS UMR5292, Lyon 1 University, Lyon, France
| | - Karl Friston
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
- VERSES Research Lab and Spatial Web Foundation, Los Angeles, California USA
| | - Axel Constant
- Charles Perkins Centre, The University of Sydney, Sydney, Australia
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16
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Lush P, Seth AK. Reply to: No specific relationship between hypnotic suggestibility and the rubber hand illusion. Nat Commun 2022; 13:563. [PMID: 35091580 PMCID: PMC8799699 DOI: 10.1038/s41467-022-28178-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 01/07/2022] [Indexed: 11/16/2022] Open
Affiliation(s)
- P Lush
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK. .,Department of Informatics, Chichester Building, University of Sussex, Falmer, BN1 9RH, UK.
| | - A K Seth
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK.,Department of Informatics, Chichester Building, University of Sussex, Falmer, BN1 9RH, UK.,Canadian Institute for Advanced Research, Program on Brain, Mind, and Consciousness, 661 University Avenue, Toronto, ON, M5G 1M1, Canada
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17
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Tschantz A, Barca L, Maisto D, Buckley CL, Seth AK, Pezzulo G. Simulating homeostatic, allostatic and goal-directed forms of interoceptive control using active inference. Biol Psychol 2022; 169:108266. [DOI: 10.1016/j.biopsycho.2022.108266] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 01/06/2022] [Accepted: 01/14/2022] [Indexed: 12/28/2022]
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18
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Skora LI, Seth AK, Scott RB. Sensorimotor predictions shape reported conscious visual experience in a breaking continuous flash suppression task. Neurosci Conscious 2021; 2021:niab003. [PMID: 33763234 PMCID: PMC7970722 DOI: 10.1093/nc/niab003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 11/12/2022] Open
Abstract
Accounts of predictive processing propose that conscious experience is influenced not only by passive predictions about the world, but also by predictions encompassing how the world changes in relation to our actions-that is, on predictions about sensorimotor contingencies. We tested whether valid sensorimotor predictions, in particular learned associations between stimuli and actions, shape reports about conscious visual experience. Two experiments used instrumental conditioning to build sensorimotor predictions linking different stimuli with distinct actions. Conditioning was followed by a breaking continuous flash suppression task, measuring the speed of reported breakthrough for different pairings between the stimuli and prepared actions, comparing those congruent and incongruent with the trained sensorimotor predictions. In Experiment 1, counterbalancing of the response actions within the breaking continuous flash suppression task was achieved by repeating the same action within each block but having them differ across the two blocks. Experiment 2 sought to increase the predictive salience of the actions by avoiding the repetition within blocks. In Experiment 1, breakthrough times were numerically shorter for congruent than incongruent pairings, but Bayesian analysis supported the null hypothesis of no influence from the sensorimotor predictions. In Experiment 2, reported conscious perception was significantly faster for congruent than for incongruent pairings. A meta-analytic Bayes factor combining the two experiments confirmed this effect. Altogether, we provide evidence for a key implication of the action-oriented predictive processing approach to conscious perception, namely that sensorimotor predictions shape our conscious experience of the world.
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Affiliation(s)
- Lina I Skora
- School of Psychology, University of Sussex, Pevensey Building, Falmer, Brighton BN1 9RH, UK
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, Brighton, Brighton BN1 9RH, UK
| | - Anil K Seth
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, Brighton, Brighton BN1 9RH, UK
- School of Engineering and Informatics, University of Sussex, Falmer, Brighton, Brighton BN1 9RH, UK
- Canadian Institute for Advanced Research, Program on Brain, Mind and Consciousness, 661 University Ave, Toronto, ON M5G 1M1, Canada
| | - Ryan B Scott
- School of Psychology, University of Sussex, Pevensey Building, Falmer, Brighton BN1 9RH, UK
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, Brighton, Brighton BN1 9RH, UK
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19
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Abstract
The theories of consciousness discussed by Doerig and colleagues tend to monolithically identify consciousness with some other phenomenon, process, or mechanism. But by treating consciousness as singular explanatory target, such theories will struggle to account for the diverse properties that conscious experiences exhibit. We propose that progress in consciousness science will best be achieved by elaborating systematic mappings between physical and biological mechanisms, and the functional and (crucially) phenomenological properties of consciousness. This means we need theories for consciousness science, perhaps more so than theories of consciousness. From this perspective, 'predictive processing' emerges as a highly promising candidate.
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Affiliation(s)
- Anil K Seth
- Sackler Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, BN1 9QJ, UK.,CIFAR Program on Brain, Mind, and Consciousness, Toronto, ON, Canada
| | - Jakob Hohwy
- Cognition & Philosophy Lab, Monash University, Melbourne, Australia
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20
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Rosas FE, Mediano PAM, Jensen HJ, Seth AK, Barrett AB, Carhart-Harris RL, Bor D. Reconciling emergences: An information-theoretic approach to identify causal emergence in multivariate data. PLoS Comput Biol 2020; 16:e1008289. [PMID: 33347467 PMCID: PMC7833221 DOI: 10.1371/journal.pcbi.1008289] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 01/25/2021] [Accepted: 08/25/2020] [Indexed: 11/19/2022] Open
Abstract
The broad concept of emergence is instrumental in various of the most challenging open scientific questions-yet, few quantitative theories of what constitutes emergent phenomena have been proposed. This article introduces a formal theory of causal emergence in multivariate systems, which studies the relationship between the dynamics of parts of a system and macroscopic features of interest. Our theory provides a quantitative definition of downward causation, and introduces a complementary modality of emergent behaviour-which we refer to as causal decoupling. Moreover, the theory allows practical criteria that can be efficiently calculated in large systems, making our framework applicable in a range of scenarios of practical interest. We illustrate our findings in a number of case studies, including Conway's Game of Life, Reynolds' flocking model, and neural activity as measured by electrocorticography.
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Affiliation(s)
- Fernando E. Rosas
- Center for Psychedelic Research, Department of Brain Science, Imperial College London, London SW7 2DD, UK
- Data Science Institute, Imperial College London, London SW7 2AZ, UK
- Center for Complexity Science, Imperial College London, London SW7 2AZ, UK
| | | | - Henrik J. Jensen
- Center for Complexity Science, Imperial College London, London SW7 2AZ, UK
- Department of Mathematics, Imperial College London, London SW7 2AZ, UK
- Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8502, Japan
| | - Anil K. Seth
- Sackler Centre for Consciousness Science, Department of Informatics, University of Sussex, Brighton BN1 9QJ, UK
- CIFAR Program on Brain, Mind, and Consciousness, Toronto M5G 1M1, Canada
| | - Adam B. Barrett
- Sackler Centre for Consciousness Science, Department of Informatics, University of Sussex, Brighton BN1 9QJ, UK
- The Data Intensive Science Centre, Department of Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - Robin L. Carhart-Harris
- Center for Psychedelic Research, Department of Brain Science, Imperial College London, London SW7 2DD, UK
| | - Daniel Bor
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
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21
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Lush P, Botan V, Scott RB, Seth AK, Ward J, Dienes Z. Trait phenomenological control predicts experience of mirror synaesthesia and the rubber hand illusion. Nat Commun 2020; 11:4853. [PMID: 32978377 PMCID: PMC7519080 DOI: 10.1038/s41467-020-18591-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 08/24/2020] [Indexed: 01/05/2023] Open
Abstract
In hypnotic responding, expectancies arising from imaginative suggestion drive striking experiential changes (e.g., hallucinations) - which are experienced as involuntary - according to a normally distributed and stable trait ability (hypnotisability). Such experiences can be triggered by implicit suggestion and occur outside the hypnotic context. In large sample studies (of 156, 404 and 353 participants), we report substantial relationships between hypnotisability and experimental measures of experiential change in mirror-sensory synaesthesia and the rubber hand illusion comparable to relationships between hypnotisability and individual hypnosis scale items. The control of phenomenology to meet expectancies arising from perceived task requirements can account for experiential change in psychological experiments.
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Affiliation(s)
- P Lush
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK.
- Department of Informatics, Chichester Building, University of Sussex, Falmer, BN1 9RH, UK.
| | - V Botan
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK
- School of Psychology, Pevensey Building, University of Sussex, Falmer, BN1 9RH, UK
| | - R B Scott
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK
- School of Psychology, Pevensey Building, University of Sussex, Falmer, BN1 9RH, UK
| | - A K Seth
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK
- Department of Informatics, Chichester Building, University of Sussex, Falmer, BN1 9RH, UK
- Canadian Institute for Advanced Research (CIFAR) Program on Brain, Mind, and Consciousness, Toronto, ON, M5G 1M1, Canada
| | - J Ward
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK
- School of Psychology, Pevensey Building, University of Sussex, Falmer, BN1 9RH, UK
| | - Z Dienes
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK
- School of Psychology, Pevensey Building, University of Sussex, Falmer, BN1 9RH, UK
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22
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Boonstra EA, van Schouwenburg MR, Seth AK, Bauer M, Zantvoord JB, Kemper EM, Lansink CS, Slagter HA. Conscious perception and the modulatory role of dopamine: no effect of the dopamine D2 agonist cabergoline on visual masking, the attentional blink, and probabilistic discrimination. Psychopharmacology (Berl) 2020; 237:2855-2872. [PMID: 32621073 PMCID: PMC7501106 DOI: 10.1007/s00213-020-05579-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/03/2020] [Indexed: 11/02/2022]
Abstract
RATIONALE Conscious perception is thought to depend on global amplification of sensory input. In recent years, striatal dopamine has been proposed to be involved in gating information and conscious access, due to its modulatory influence on thalamocortical connectivity. OBJECTIVES Since much of the evidence that implicates striatal dopamine is correlational, we conducted a double-blind crossover pharmacological study in which we administered cabergoline-a dopamine D2 agonist-and placebo to 30 healthy participants. Under both conditions, we subjected participants to several well-established experimental conscious-perception paradigms, such as backward masking and the attentional blink task. RESULTS We found no evidence in support of an effect of cabergoline on conscious perception: key behavioral and event-related potential (ERP) findings associated with each of these tasks were unaffected by cabergoline. CONCLUSIONS Our results cast doubt on a causal role for dopamine in visual perception. It remains an open possibility that dopamine has causal effects in other tasks, perhaps where perceptual uncertainty is more prominent.
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Affiliation(s)
- E A Boonstra
- Department of Experimental and Applied Psychology, Institute for Brain and Behavior Amsterdam (iBBA) Vrije Universiteit, Amsterdam, Netherlands.
- Department of Psychology, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands.
| | - M R van Schouwenburg
- Department of Psychology, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands
| | - A K Seth
- Department of Informatics Sackler Centre for Consciousness Science, University of Sussex, Brighton, BN1 9QJ, UK
- Canadian Institute for Advanced Research, Azrieli Programme on Brain, Mind, and Consciousness, Toronto, Canada
| | - M Bauer
- School of Psychology, University of Nottingham, Nottingham, UK
| | - J B Zantvoord
- Department of Child and Adolescent Psychiatry, The Bascule, Academic Centre for Child and Adolescent Psychiatry Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - E M Kemper
- Department of Pharmacy, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - C S Lansink
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands
| | - H A Slagter
- Department of Experimental and Applied Psychology, Institute for Brain and Behavior Amsterdam (iBBA) Vrije Universiteit, Amsterdam, Netherlands
- Department of Psychology, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands
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23
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Seth AK, Millidge B, Buckley CL, Tschantz A. Curious Inferences: Reply to Sun and Firestone on the Dark Room Problem. Trends Cogn Sci 2020; 24:681-683. [DOI: 10.1016/j.tics.2020.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/22/2020] [Indexed: 10/23/2022]
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24
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Affiliation(s)
- Tim Bayne
- School of Philosophical, Historical, and International Studies, Monash University, Melbourne, Australia; Canadian Institute for Advanced Research, Azrieli Program in Brain, Mind, and Consciousness, Toronto, Canada.
| | - Anil K Seth
- Canadian Institute for Advanced Research, Azrieli Program in Brain, Mind, and Consciousness, Toronto, Canada; School of Engineering and Informatics, University of Sussex, Brighton, UK; Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - Marcello Massimini
- Canadian Institute for Advanced Research, Azrieli Program in Brain, Mind, and Consciousness, Toronto, Canada; Department of Biomedical Clinical Sciences, University of Milan, Milan, Italy; IRCCS, Fondazione Don Gnocchi, Milan, Italy
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25
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Abstract
Converging theories suggest that organisms learn and exploit probabilistic models of their environment. However, it remains unclear how such models can be learned in practice. The open-ended complexity of natural environments means that it is generally infeasible for organisms to model their environment comprehensively. Alternatively, action-oriented models attempt to encode a parsimonious representation of adaptive agent-environment interactions. One approach to learning action-oriented models is to learn online in the presence of goal-directed behaviours. This constrains an agent to behaviourally relevant trajectories, reducing the diversity of the data a model need account for. Unfortunately, this approach can cause models to prematurely converge to sub-optimal solutions, through a process we refer to as a bad-bootstrap. Here, we exploit the normative framework of active inference to show that efficient action-oriented models can be learned by balancing goal-oriented and epistemic (information-seeking) behaviours in a principled manner. We illustrate our approach using a simple agent-based model of bacterial chemotaxis. We first demonstrate that learning via goal-directed behaviour indeed constrains models to behaviorally relevant aspects of the environment, but that this approach is prone to sub-optimal convergence. We then demonstrate that epistemic behaviours facilitate the construction of accurate and comprehensive models, but that these models are not tailored to any specific behavioural niche and are therefore less efficient in their use of data. Finally, we show that active inference agents learn models that are parsimonious, tailored to action, and which avoid bad bootstraps and sub-optimal convergence. Critically, our results indicate that models learned through active inference can support adaptive behaviour in spite of, and indeed because of, their departure from veridical representations of the environment. Our approach provides a principled method for learning adaptive models from limited interactions with an environment, highlighting a route to sample efficient learning algorithms.
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Affiliation(s)
- Alexander Tschantz
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
| | - Anil K. Seth
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Canadian Institute for Advanced Research, Azrieli Programme on Brain, Mind, and Consciousness, Toronto, Ontario, Canada
| | - Christopher L. Buckley
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Evolutionary and Adaptive Systems Research Group, University of Sussex, Falmer, United Kingdom
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26
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Abstract
Researchers often adjudicate between models of memory according to the models' ability to explain impaired patterns of performance (e.g., in amnesia). In contrast, evidence from special groups with enhanced memory is very rarely considered. Here, we explored how people with unusual perceptual experiences (synaesthesia) perform on various measures of memory and test how computational models of memory may account for their enhanced performance. We contrasted direct and indirect measures of memory (i.e., recognition memory, repetition priming, and fluency) in grapheme-colour synaesthetes and controls using a continuous identification with recognition (CID-R) paradigm. Synaesthetes outperformed controls on recognition memory and showed a different reaction-time pattern for identification. The data were most parsimoniously accounted for by a single-system computational model of the relationship between recognition and identification. Overall, the findings speak in favour of enhanced processing as an explanation for the memory advantage in synaesthesia. In general, our results show how synaesthesia can be used as an effective tool to study how individual differences in perception affect cognitive functions.
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Affiliation(s)
- Nicolas Rothen
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK.
- School of Psychology, University of Sussex, Brighton, UK.
- Faculty of Psychology, Swiss Distance University Institute, Brig, Switzerland.
| | | | - Anil K Seth
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
- School of Engineering and Informatics, University of Sussex, Brighton, UK
| | - Sabine Oligschläger
- School of Psychology, University of Sussex, Brighton, UK
- Max Planck Research Group Neuroanatomy & Connectivity, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Faculty of Biosciences, Pharmacy and Psychology University Leipzig, Leipzig, Germany
| | - Jamie Ward
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
- School of Psychology, University of Sussex, Brighton, UK
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27
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Bayne T, Seth AK, Massimini M. Are There Islands of Awareness? Trends Neurosci 2020; 43:6-16. [DOI: 10.1016/j.tins.2019.11.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/30/2019] [Accepted: 11/08/2019] [Indexed: 12/26/2022]
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28
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Seth AK, Hohwy J. Editorial: Open science in consciousness research. Neurosci Conscious 2019; 2019:niz018. [PMID: 31850148 PMCID: PMC6910075 DOI: 10.1093/nc/niz018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 11/26/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Anil K Seth
- Sackler Centre for Consciousness Science, School of Engineering and Informatics, University of Sussex, Brighton, BN1 9QJ, UK and Canadian Institute for Advanced Research, Azrieli Programme on Brain, Mind, and Consciousness
| | - Jakob Hohwy
- Department of Philosophy, Monash University, Cognition & Philosophy Lab 20 Chancellor's Walk, RmE672, Melbourne, VIC, Australia
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29
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Abstract
People with synaesthesia have additional perceptual experiences, which are automatically and consistently triggered by specific inducing stimuli. Synaesthesia therefore offers a unique window into the neurocognitive mechanisms underlying conscious perception. A long-standing question in synaesthesia research is whether it is possible to artificially induce non-synaesthetic individuals to have synaesthesia-like experiences. Although synaesthesia is widely considered a congenital condition, increasing evidence points to the potential of a variety of approaches to induce synaesthesia-like experiences, even in adulthood. Here, we summarize a range of methods for artificially inducing synaesthesia-like experiences, comparing the resulting experiences to the key hallmarks of natural synaesthesia which include consistency, automaticity and a lack of 'perceptual presence'. We conclude that a number of aspects of synaesthesia can be artificially induced in non-synaesthetes. These data suggest the involvement of developmental and/or learning components in the acquisition of synaesthesia, and they extend previous reports of perceptual plasticity leading to dramatic changes in perceptual phenomenology in adults. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.
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Affiliation(s)
- David J. Schwartzman
- Sackler Centre for Consciousness Science, University of Sussex, Brighton BN1 9QJ, UK
- Department of Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - Daniel Bor
- Department of Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK
| | - Nicolas Rothen
- Sackler Centre for Consciousness Science, University of Sussex, Brighton BN1 9QJ, UK
- Faculty of Psychology, Swiss Distance University Institute, 3900 Brig, Switzerland
| | - Anil K. Seth
- Sackler Centre for Consciousness Science, University of Sussex, Brighton BN1 9QJ, UK
- Department of Informatics, University of Sussex, Brighton BN1 9QJ, UK
- Azrieli Programme on Brain, Mind, and Consciousness, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
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30
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Lush P, Roseboom W, Cleeremans A, Scott RB, Seth AK, Dienes Z. Intentional binding as Bayesian cue combination: Testing predictions with trait individual differences. ACTA ACUST UNITED AC 2019; 45:1206-1217. [DOI: 10.1037/xhp0000661] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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31
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Abstract
The experience of authorship over one’s actions and their consequences—sense of agency—is a fundamental aspect of conscious experience. In recent years, it has become common to use intentional binding as an implicit measure of the sense of agency. However, it remains contentious whether reported intentional-binding effects indicate the role of intention-related information in perception or merely represent a strong case of multisensory causal binding. Here, we used a novel virtual-reality setup to demonstrate identical magnitude-binding effects in both the presence and complete absence of intentional action, when perceptual stimuli were matched for temporal and spatial information. Our results demonstrate that intentional-binding-like effects are most simply accounted for by multisensory causal binding without necessarily being related to intention or agency. Future studies that relate binding effects to agency must provide evidence for effects beyond that expected for multisensory causal binding by itself.
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Affiliation(s)
- Keisuke Suzuki
- Department of Informatics, University of Sussex
- Sackler Centre for Consciousness Science, University of Sussex
| | - Peter Lush
- Department of Informatics, University of Sussex
- Sackler Centre for Consciousness Science, University of Sussex
| | - Anil K. Seth
- Department of Informatics, University of Sussex
- Sackler Centre for Consciousness Science, University of Sussex
| | - Warrick Roseboom
- Department of Informatics, University of Sussex
- Sackler Centre for Consciousness Science, University of Sussex
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32
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Broad RJ, Gabel MC, Dowell NG, Schwartzman DJ, Seth AK, Zhang H, Alexander DC, Cercignani M, Leigh PN. Neurite orientation and dispersion density imaging (NODDI) detects cortical and corticospinal tract degeneration in ALS. J Neurol Neurosurg Psychiatry 2019; 90:404-411. [PMID: 30361295 PMCID: PMC6581155 DOI: 10.1136/jnnp-2018-318830] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/30/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Corticospinal tract (CST) degeneration and cortical atrophy are consistent features of amyotrophic lateral sclerosis (ALS). We hypothesised that neurite orientation dispersion and density imaging (NODDI), a multicompartment model of diffusion MRI, would reveal microstructural changes associated with ALS within the CST and precentral gyrus (PCG) 'in vivo'. METHODS 23 participants with sporadic ALS and 23 healthy controls underwent diffusion MRI. Neurite density index (NDI), orientation dispersion index (ODI) and free water fraction (isotropic compartment (ISO)) were derived. Whole brain voxel-wise analysis was performed to assess for group differences. Standard diffusion tensor imaging (DTI) parameters were computed for comparison. Subgroup analysis was performed to investigate for NODDI parameter differences relating to bulbar involvement. Correlation of NODDI parameters with clinical variables were also explored. The results were accepted as significant where p<0.05 after family-wise error correction at the cluster level, clusters formed with p<0.001. RESULTS In the ALS group NDI was reduced in the extensive regions of the CST, the corpus callosum and the right PCG. ODI was reduced in the right anterior internal capsule and the right PCG. Significant differences in NDI were detected between subgroups stratified according to the presence or absence of bulbar involvement. ODI and ISO correlated with disease duration. CONCLUSIONS NODDI demonstrates that axonal loss within the CST is a core feature of degeneration in ALS. This is the main factor contributing to the altered diffusivity profile detected using DTI. NODDI also identified dendritic alterations within the PCG, suggesting microstructural cortical dendritic changes occur together with CST axonal damage.
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Affiliation(s)
- Rebecca J Broad
- Department of Neuroscience, Trafford Centre for Biomedical Research, Brighton and Sussex Medical School, Brighton, UK .,Brighton and Sussex University Hospitals NHS Trust, Princess Royal Hospital, Haywards Heath, UK
| | - Matt C Gabel
- Department of Neuroscience, Trafford Centre for Biomedical Research, Brighton and Sussex Medical School, Brighton, UK
| | - Nicholas G Dowell
- Department of Neuroscience, Trafford Centre for Biomedical Research, Brighton and Sussex Medical School, Brighton, UK
| | | | - Anil K Seth
- Sackler Centre Consciousness Science, University of Sussex, Brighton, UK
| | - Hui Zhang
- Centre for Medical Image Computing and Department of Computer Science, University College London, London, UK
| | - Daniel C Alexander
- Centre for Medical Image Computing and Department of Computer Science, University College London, London, UK
| | - Mara Cercignani
- Department of Neuroscience, Trafford Centre for Biomedical Research, Brighton and Sussex Medical School, Brighton, UK.,Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy
| | - P Nigel Leigh
- Department of Neuroscience, Trafford Centre for Biomedical Research, Brighton and Sussex Medical School, Brighton, UK.,Brighton and Sussex University Hospitals NHS Trust, Princess Royal Hospital, Haywards Heath, UK
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33
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Rae CL, Critchley HD, Seth AK. A Bayesian Account of the Sensory-Motor Interactions Underlying Symptoms of Tourette Syndrome. Front Psychiatry 2019; 10:29. [PMID: 30890965 PMCID: PMC6412155 DOI: 10.3389/fpsyt.2019.00029] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 01/17/2019] [Indexed: 11/17/2022] Open
Abstract
Tourette syndrome is a hyperkinetic movement disorder. Characteristic features include tics, recurrent movements that are experienced as compulsive and "unwilled"; uncomfortable premonitory sensations that resolve through tic release; and often, the ability to suppress tics temporarily. We demonstrate how these symptoms and features can be understood in terms of aberrant predictive (Bayesian) processing in hierarchical neural systems, explaining specifically: why tics arise, their "unvoluntary" nature, how premonitory sensations emerge, and why tic suppression works-sometimes. In our model, premonitory sensations and tics are generated through over-precise priors for sensation and action within somatomotor regions of the striatum. Abnormally high precision of priors arises through the dysfunctional synaptic integration of cortical inputs. These priors for sensation and action are projected into primary sensory and motor areas, triggering premonitory sensations and tics, which in turn elicit prediction errors for unexpected feelings and movements. We propose experimental paradigms to validate this Bayesian account of tics. Our model integrates behavioural, neuroimaging, and computational approaches to provide mechanistic insight into the pathophysiological basis of Tourette syndrome.
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Affiliation(s)
- Charlotte L. Rae
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Neuroscience, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Hugo D. Critchley
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Neuroscience, Brighton and Sussex Medical School, Brighton, United Kingdom
- Sussex Partnership NHS Foundation Trust, Brighton, United Kingdom
| | - Anil K. Seth
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
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34
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Abstract
The metacognitive ability to introspect about self-performance varies substantially across individuals. Given that effective monitoring of performance is deemed important for effective behavioral control, intervening to improve metacognition may have widespread benefits, for example in educational and clinical settings. However, it is unknown whether and how metacognition can be systematically improved through training independently of task performance, or whether metacognitive improvements generalize across different task domains. Across 8 sessions, here we provided feedback to two groups of participants in a perceptual discrimination task: an experimental group (n = 29) received feedback on their metacognitive judgments, while an active control group (n = 32) received feedback on their decision performance only. Relative to the control group, adaptive training led to increases in metacognitive calibration (as assessed by Brier scores), which generalized both to untrained stimuli and an untrained task (recognition memory). Leveraging signal detection modeling we found that metacognitive improvements were driven both by changes in metacognitive efficiency (meta-d′/d′) and confidence level, and that later increases in metacognitive efficiency were positively mediated by earlier shifts in confidence. Our results reveal a striking malleability of introspection and indicate the potential for a domain-general enhancement of metacognitive abilities.
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Affiliation(s)
- Jason Carpenter
- Wellcome Centre for Human Neuroimaging, University College London
| | - Maxine T Sherman
- Sackler Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex
| | - Rogier A Kievit
- Max Planck University College London Centre for Computational Psychiatry and Ageing Research, University College London
| | - Anil K Seth
- Sackler Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex
| | - Hakwan Lau
- Department of Psychology and Brain Research Institute, University of California, Los Angeles
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35
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Andermane N, Bosten JM, Seth AK, Ward J. Individual differences in change blindness are predicted by the strength and stability of visual representations. Neurosci Conscious 2019; 2019:niy010. [PMID: 30697440 PMCID: PMC6345093 DOI: 10.1093/nc/niy010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 08/28/2018] [Accepted: 10/03/2018] [Indexed: 12/02/2022] Open
Abstract
The phenomenon of change blindness reveals that people are surprisingly poor at detecting unexpected visual changes; however, research on individual differences in detection ability is scarce. Predictive processing accounts of visual perception suggest that better change detection may be linked to assigning greater weight to prediction error signals, as indexed by an increased alternation rate in perceptual rivalry or greater sensitivity to low-level visual signals. Alternatively, superior detection ability may be associated with robust visual predictions against which sensory changes can be more effectively registered, suggesting an association with high-level mechanisms of visual short-term memory (VSTM) and attention. We administered a battery of 10 measures to explore these predictions and to determine, for the first time, the test–retest reliability of commonly used change detection measures. Change detection performance was stable over time and generalized from displays of static scenes to video clips. An exploratory factor analysis revealed two factors explaining performance across the battery, that we identify as visual stability (loading on change detection, attention measures, VSTM and perceptual rivalry) and visual ability (loading on iconic memory, temporal order judgments and contrast sensitivity). These results highlight the importance of strong, stable representations and the ability to resist distraction, in order to successfully incorporate unexpected changes into the contents of visual awareness.
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Affiliation(s)
- Nora Andermane
- School of Psychology, University of Sussex, Brighton, UK
| | - Jenny M Bosten
- School of Psychology, University of Sussex, Brighton, UK
| | - Anil K Seth
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - Jamie Ward
- School of Psychology, University of Sussex, Brighton, UK
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36
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Roseboom W, Fountas Z, Nikiforou K, Bhowmik D, Shanahan M, Seth AK. Activity in perceptual classification networks as a basis for human subjective time perception. Nat Commun 2019; 10:267. [PMID: 30655543 PMCID: PMC6336826 DOI: 10.1038/s41467-018-08194-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 12/09/2018] [Indexed: 01/17/2023] Open
Abstract
Despite being a fundamental dimension of experience, how the human brain generates the perception of time remains unknown. Here, we provide a novel explanation for how human time perception might be accomplished, based on non-temporal perceptual classification processes. To demonstrate this proposal, we build an artificial neural system centred on a feed-forward image classification network, functionally similar to human visual processing. In this system, input videos of natural scenes drive changes in network activation, and accumulation of salient changes in activation are used to estimate duration. Estimates produced by this system match human reports made about the same videos, replicating key qualitative biases, including differentiating between scenes of walking around a busy city or sitting in a cafe or office. Our approach provides a working model of duration perception from stimulus to estimation and presents a new direction for examining the foundations of this central aspect of human experience.
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Affiliation(s)
- Warrick Roseboom
- Department of Informatics, University of Sussex, Falmer, Brighton, BN1 9QJ, UK.
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, Brighton, BN1 9QJ, UK.
| | - Zafeirios Fountas
- Department of Computing, Imperial College London, London, SW7 2RH, UK
| | | | - David Bhowmik
- Department of Computing, Imperial College London, London, SW7 2RH, UK
| | - Murray Shanahan
- Department of Computing, Imperial College London, London, SW7 2RH, UK
- DeepMind, London, N1C 4AG, UK
| | - Anil K Seth
- Department of Informatics, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
- Sackler Centre for Consciousness Science, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
- Canadian Insitutute for Advanced Research (CIFAR), Azrieli Programme on Brain, Mind, and Consciousness, Toronto, ON, Canada
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37
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Suárez-Pinilla M, Nikiforou K, Fountas Z, Seth AK, Roseboom W. Perceptual Content, Not Physiological Signals, Determines Perceived Duration When Viewing Dynamic, Natural Scenes. Collabra: Psychology 2019. [DOI: 10.1525/collabra.234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The neural basis of time perception remains unknown. A prominent account is the pacemaker-accumulator model, wherein regular ticks of some physiological or neural pacemaker are read out as time. Putative candidates for the pacemaker have been suggested in physiological processes (heartbeat), or dopaminergic mid-brain neurons, whose activity has been associated with spontaneous blinking. However, such proposals have difficulty accounting for observations that time perception varies systematically with perceptual content. We examined physiological influences on human duration estimates for naturalistic videos between 1–64 seconds using cardiac and eye recordings. Duration estimates were biased by the amount of change in scene content. Contrary to previous claims, heart rate, and blinking were not related to duration estimates. Our results support a recent proposal that tracking change in perceptual classification networks provides a basis for human time perception, and suggest that previous assertions of the importance of physiological factors should be tempered.
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Affiliation(s)
- Marta Suárez-Pinilla
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
- Department of Informatics, University of Sussex, Brighton, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | | | - Zafeirios Fountas
- Emotech Labs, London, UK
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Anil K. Seth
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
- Department of Informatics, University of Sussex, Brighton, UK
| | - Warrick Roseboom
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
- Department of Informatics, University of Sussex, Brighton, UK
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38
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Mediano PA, Seth AK, Barrett AB. Measuring Integrated Information: Comparison of Candidate Measures in Theory and Simulation. Entropy (Basel) 2018; 21:E17. [PMID: 33266733 PMCID: PMC7514120 DOI: 10.3390/e21010017] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 11/21/2022]
Abstract
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 this article, we provide clear and intuitive descriptions of six distinct candidate measures. We then explore the properties of each of these measures in simulation on networks consisting of eight interacting nodes, animated with Gaussian linear autoregressive dynamics. We find a striking diversity in the behaviour of these measures-no two measures show consistent agreement across all analyses. A subset of the measures appears to reflect some form of dynamical complexity, in the sense of simultaneous segregation and integration between system components. Our results help guide the operationalisation of IIT and advance the development of measures of integrated information and dynamical complexity that may have more general applicability.
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Affiliation(s)
| | - Anil K. Seth
- Sackler Centre for Consciousness Science and Department of Informatics, University of Sussex, Brighton BN1 9RH, UK
| | - Adam B. Barrett
- Sackler Centre for Consciousness Science and Department of Informatics, University of Sussex, Brighton BN1 9RH, UK
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39
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Rothen N, Seth AK, Ward J. Synesthesia improves sensory memory, when perceptual awareness is high. Vision Res 2018; 153:1-6. [DOI: 10.1016/j.visres.2018.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 09/05/2018] [Accepted: 09/08/2018] [Indexed: 10/28/2022]
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40
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Abstract
The mind and brain sciences began with consciousness as a central concern. But for much of the 20th century, ideological and methodological concerns relegated its empirical study to the margins. Since the 1990s, studying consciousness has regained a legitimacy and momentum befitting its status as the primary feature of our mental lives. Nowadays, consciousness science encompasses a rich interdisciplinary mixture drawing together philosophical, theoretical, computational, experimental, and clinical perspectives, with neuroscience its central discipline. Researchers have learned a great deal about the neural mechanisms underlying global states of consciousness, distinctions between conscious and unconscious perception, and self-consciousness. Further progress will depend on specifying closer explanatory mappings between (first-person subjective) phenomenological descriptions and (third-person objective) descriptions of (embodied and embedded) neuronal mechanisms. Such progress will help reframe our understanding of our place in nature and accelerate clinical approaches to a wide range of psychiatric and neurological disorders.
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Affiliation(s)
- Anil K Seth
- Sackler Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, Brighton, UK
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41
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Rae CL, Polyanska L, Gould van Praag CD, Parkinson J, Bouyagoub S, Nagai Y, Seth AK, Harrison NA, Garfinkel SN, Critchley HD. Face perception enhances insula and motor network reactivity in Tourette syndrome. Brain 2018; 141:3249-3261. [PMID: 30346484 PMCID: PMC6202569 DOI: 10.1093/brain/awy254] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/24/2018] [Accepted: 08/15/2018] [Indexed: 11/25/2022] Open
Abstract
Tourette syndrome is a neurodevelopmental disorder, characterized by motor and phonic tics. Tics are typically experienced as avolitional, compulsive, and associated with premonitory urges. They are exacerbated by stress and can be triggered by external stimuli, including social cues like the actions and facial expressions of others. Importantly, emotional social stimuli, with angry facial stimuli potentially the most potent social threat cue, also trigger behavioural reactions in healthy individuals, suggesting that such mechanisms may be particularly sensitive in people with Tourette syndrome. Twenty-one participants with Tourette syndrome and 21 healthy controls underwent functional MRI while viewing faces wearing either neutral or angry expressions to quantify group differences in neural activity associated with processing social information. Simultaneous video recordings of participants during neuroimaging enabled us to model confounding effects of tics on task-related responses to the processing of faces. In both Tourette syndrome and control participants, face stimuli evoked enhanced activation within canonical face perception regions, including the occipital face area and fusiform face area. However, the Tourette syndrome group showed additional responses within the anterior insula to both neutral and angry faces. Functional connectivity during face viewing was then examined in a series of psychophysiological interactions. In participants with Tourette syndrome, the insula showed functional connectivity with a set of cortical regions previously implicated in tic generation: the presupplementary motor area, premotor cortex, primary motor cortex, and the putamen. Furthermore, insula functional connectivity with the globus pallidus and thalamus varied in proportion to tic severity, while supplementary motor area connectivity varied in proportion to premonitory sensations, with insula connectivity to these regions increasing to a greater extent in patients with worse symptom severity. In addition, the occipital face area showed increased functional connectivity in Tourette syndrome participants with posterior cortical regions, including primary somatosensory cortex, and occipital face area connectivity with primary somatosensory and primary motor cortices varied in proportion to tic severity. There were no significant psychophysiological interactions in controls. These findings highlight a potential mechanism in Tourette syndrome through which heightened representation within insular cortex of embodied affective social information may impact the reactivity of subcortical motor pathways, supporting programmed motor actions that are causally implicated in tic generation. Medicinal and psychological therapies that focus on reducing insular hyper-reactivity to social stimuli may have potential benefit for tic reduction in people with Tourette syndrome.
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Affiliation(s)
- Charlotte L Rae
- Sackler Centre for Consciousness Science, University of Sussex, UK
- Department of Neuroscience, Brighton and Sussex Medical School, UK
| | - Liliana Polyanska
- Sackler Centre for Consciousness Science, University of Sussex, UK
- Department of Neuroscience, Brighton and Sussex Medical School, UK
- Department of Education and Psychology, Freie Universität Berlin, Germany
| | - Cassandra D Gould van Praag
- Sackler Centre for Consciousness Science, University of Sussex, UK
- Department of Neuroscience, Brighton and Sussex Medical School, UK
- Department of Psychiatry, University of Oxford, UK
| | - Jim Parkinson
- Sackler Centre for Consciousness Science, University of Sussex, UK
- School of Psychology, University of Sussex, UK
| | - Samira Bouyagoub
- Department of Neuroscience, Brighton and Sussex Medical School, UK
| | - Yoko Nagai
- Department of Neuroscience, Brighton and Sussex Medical School, UK
| | - Anil K Seth
- Sackler Centre for Consciousness Science, University of Sussex, UK
- School of Engineering and Informatics, University of Sussex, UK
| | - Neil A Harrison
- Sackler Centre for Consciousness Science, University of Sussex, UK
- Department of Neuroscience, Brighton and Sussex Medical School, UK
- Sussex Partnership NHS Foundation Trust, UK
| | - Sarah N Garfinkel
- Sackler Centre for Consciousness Science, University of Sussex, UK
- Department of Neuroscience, Brighton and Sussex Medical School, UK
- Sussex Partnership NHS Foundation Trust, UK
| | - Hugo D Critchley
- Sackler Centre for Consciousness Science, University of Sussex, UK
- Department of Neuroscience, Brighton and Sussex Medical School, UK
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Abstract
Modern psychology has long focused on the body as the basis of the self. Recently, predictive processing accounts of interoception (perception of the body 'from within') have become influential in accounting for experiences of body ownership and emotion. Here, we describe embodied selfhood in terms of 'instrumental interoceptive inference' that emphasises allostatic regulation and physiological integrity. We apply this approach to the distinctive phenomenology of embodied selfhood, accounting for its non-object-like character and subjective stability over time. Our perspective has implications for the development of selfhood and illuminates longstanding debates about relations between life and mind, implying, contrary to Descartes, that experiences of embodied selfhood arise because of, and not in spite of, our nature as 'beast machines'.
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Affiliation(s)
- Anil K Seth
- Sackler Centre for Consciousness Science, School of Engineering and Informatics, University of Sussex, Brighton BN1 9QJ, UK.
| | - Manos Tsakiris
- Lab of Action & Body, Department of Psychology, Royal Holloway, University of London, Surrey TW20 0EX, UK; The Warburg Institute, School of Advanced Study, University of London, London WC1H 0AB, UK
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43
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Suárez-Pinilla M, Seth AK, Roseboom W. The Illusion of Uniformity Does Not Depend on the Primary Visual Cortex: Evidence From Sensory Adaptation. Iperception 2018; 9:2041669518800507. [PMID: 30283623 PMCID: PMC6166314 DOI: 10.1177/2041669518800728] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 07/13/2018] [Accepted: 08/22/2018] [Indexed: 11/29/2022] Open
Abstract
Visual experience appears richly detailed despite the poor resolution of the majority of the visual field, thanks to foveal-peripheral integration. The recently described uniformity illusion (UI), wherein peripheral elements of a pattern take on the appearance of foveal elements, may shed light on this integration. We examined the basis of UI by generating adaptation to a pattern of Gabors suitable for producing UI on orientation. After removing the pattern, participants reported the tilt of a single peripheral Gabor. The tilt aftereffect followed the physical adapting orientation rather than the global orientation perceived under UI, even when the illusion had been reported for a long time. Conversely, a control experiment replacing illusory uniformity with a physically uniform Gabor pattern for the same durations did produce an aftereffect to the global orientation. Results indicate that UI is not associated with changes in sensory encoding at V1 but likely depends on higher level processes.
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Affiliation(s)
- Marta Suárez-Pinilla
- Sackler Centre for Consciousness Science,
University
of Sussex, Brighton, UK; Department of
Informatics, University of Sussex, Brighton, UK
| | - Anil K. Seth
- Sackler Centre for Consciousness Science,
University
of Sussex, Brighton, UK; Department of
Informatics, University of Sussex, Brighton, UK
| | - Warrick Roseboom
- Sackler Centre for Consciousness Science,
University
of Sussex, Brighton, UK; Department of
Informatics, University of Sussex, Brighton, UK
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44
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Barnett L, Barrett AB, Seth AK. Solved problems for Granger causality in neuroscience: A response to Stokes and Purdon. Neuroimage 2018; 178:744-748. [DOI: 10.1016/j.neuroimage.2018.05.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/01/2018] [Accepted: 05/27/2018] [Indexed: 10/14/2022] Open
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45
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Abstract
The recent history of perceptual experience has been shown to influence subsequent perception. Classically, this dependence on perceptual history has been examined in sensory-adaptation paradigms, wherein prolonged exposure to a particular stimulus (e.g., a vertically oriented grating) produces changes in perception of subsequently presented stimuli (e.g., the tilt aftereffect). More recently, several studies have investigated the influence of shorter perceptual exposure with effects, referred to as serial dependence, being described for a variety of low- and high-level perceptual dimensions. In this study, we examined serial dependence in the processing of dispersion statistics, namely variance-a key descriptor of the environment and indicative of the precision and reliability of ensemble representations. We found two opposite serial dependences operating at different timescales, and likely originating at different processing levels: A positive, Bayesian-like bias was driven by the most recent exposures, dependent on feature-specific decision making and appearing only when high confidence was placed in that decision; and a longer lasting negative bias-akin to an adaptation aftereffect-becoming manifest as the positive bias declined. Both effects were independent of spatial presentation location and the similarity of other close traits, such as mean direction of the visual variance stimulus. These findings suggest that visual variance processing occurs in high-level areas but is also subject to a combination of multilevel mechanisms balancing perceptual stability and sensitivity, as with many different perceptual dimensions.
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Affiliation(s)
- Marta Suárez-Pinilla
- Sackler Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton, UK
| | - Anil K Seth
- Sackler Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton, UK
| | - Warrick Roseboom
- Sackler Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton, UK
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46
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Abstract
The recent history of perceptual experience has been shown to influence subsequent perception. Classically, this dependence on perceptual history has been examined in sensory-adaptation paradigms, wherein prolonged exposure to a particular stimulus (e.g., a vertically oriented grating) produces changes in perception of subsequently presented stimuli (e.g., the tilt aftereffect). More recently, several studies have investigated the influence of shorter perceptual exposure with effects, referred to as serial dependence, being described for a variety of low- and high-level perceptual dimensions. In this study, we examined serial dependence in the processing of dispersion statistics, namely variance-a key descriptor of the environment and indicative of the precision and reliability of ensemble representations. We found two opposite serial dependences operating at different timescales, and likely originating at different processing levels: A positive, Bayesian-like bias was driven by the most recent exposures, dependent on feature-specific decision making and appearing only when high confidence was placed in that decision; and a longer lasting negative bias-akin to an adaptation aftereffect-becoming manifest as the positive bias declined. Both effects were independent of spatial presentation location and the similarity of other close traits, such as mean direction of the visual variance stimulus. These findings suggest that visual variance processing occurs in high-level areas but is also subject to a combination of multilevel mechanisms balancing perceptual stability and sensitivity, as with many different perceptual dimensions.
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Affiliation(s)
- Marta Suárez-Pinilla
- Sackler Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton, UK
| | - Anil K Seth
- Sackler Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton, UK
| | - Warrick Roseboom
- Sackler Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton, UK
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47
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Reveley C, Gruslys A, Ye FQ, Glen D, Samaha J, E Russ B, Saad Z, K Seth A, Leopold DA, Saleem KS. Three-Dimensional Digital Template Atlas of the Macaque Brain. Cereb Cortex 2018; 27:4463-4477. [PMID: 27566980 DOI: 10.1093/cercor/bhw248] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 07/20/2016] [Indexed: 11/12/2022] Open
Abstract
We present a new 3D template atlas of the anatomical subdivisions of the macaque brain, which is based on and aligned to the magnetic resonance imaging (MRI) data set and histological sections of the Saleem and Logothetis atlas. We describe the creation and validation of the atlas that, when registered with macaque structural or functional MRI scans, provides a straightforward means to estimate the boundaries between architectonic areas, either in a 3D volume with different planes of sections, or on an inflated brain surface (cortical flat map). As such, this new template atlas is intended for use as a reference standard for macaque brain research. Atlases and templates are available as both volumes and surfaces in standard NIFTI and GIFTI formats.
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Affiliation(s)
- Colin Reveley
- School of Engineering and Informatics, Sackler Center for Consciousness Science, University of Sussex, Brighton BN1 9QJ, UK
| | - Audrunas Gruslys
- Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Frank Q Ye
- Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, and National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Daniel Glen
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institute of Health (NIMH/NIH), Bethesda, MD 20892, USA
| | - Jason Samaha
- School of Engineering and Informatics, Sackler Center for Consciousness Science, University of Sussex, Brighton BN1 9QJ, UK
| | - Brian E Russ
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institute of Health (NIMH/NIH), MD 20892, USA
| | - Ziad Saad
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institute of Health (NIMH/NIH), Bethesda, MD 20892, USA
| | - Anil K Seth
- School of Engineering and Informatics, Sackler Center for Consciousness Science, University of Sussex, Brighton BN1 9QJ, UK
| | - David A Leopold
- Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, and National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Laboratory of Neuropsychology, National Institute of Mental Health, National Institute of Health (NIMH/NIH), MD 20892, USA
| | - Kadharbatcha S Saleem
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institute of Health (NIMH/NIH), MD 20892, USA
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48
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Davies G, Rae CL, Garfinkel SN, Seth AK, Medford N, Critchley HD, Greenwood K. Impairment of perceptual metacognitive accuracy and reduced prefrontal grey matter volume in first-episode psychosis. Cogn Neuropsychiatry 2018; 23:165-179. [PMID: 29485348 DOI: 10.1080/13546805.2018.1444597] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Metacognition, or "thinking about thinking", is a higher-order thought process that allows for the evaluation of perceptual processes for accuracy. Metacognitive accuracy is associated with the grey matter volume (GMV) in the prefrontal cortex (PFC), an area also impacted in schizophrenia. The present study set out to investigate whether deficits in metacognitive accuracy are present in the early stages of psychosis. METHODS Metacognitive accuracy in first-episode psychosis (FEP) was assessed on a perceptual decision-making task and their performance compared to matched healthy control participants (N = 18). A novel signal detection theory approach was used to model metacognitive sensitivity independently from objective perceptual performance. A voxel-based morphometry investigation was also conducted on GMV. RESULTS We found that the FEP group demonstrated significantly worse metacognitive accuracy compared to controls (p = .039). Importantly, GMV deficits were also observed in the superior frontal gyrus. The findings suggest a specific deficit in this processing domain to exist at first episode; however, no relationship was found between GMV and metacognitive accuracy. CONCLUSIONS Our findings support the notion that an inability to accurately scrutinise perception may underpin functional deficits observed in later schizophrenia; however, the exact neural basis of metacognitive deficits in FEP remains elusive.
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Affiliation(s)
- Geoff Davies
- a School of Psychology , University of Sussex , Brighton , UK.,b Sussex Partnership NHS Foundation Trust , Brighton , UK
| | - Charlotte L Rae
- c Sackler Centre for Consciousness Science , University of Sussex , Brighton , UK.,d Neuroscience , Brighton & Sussex Medical School , Brighton , UK
| | - Sarah N Garfinkel
- c Sackler Centre for Consciousness Science , University of Sussex , Brighton , UK.,d Neuroscience , Brighton & Sussex Medical School , Brighton , UK
| | - Anil K Seth
- c Sackler Centre for Consciousness Science , University of Sussex , Brighton , UK.,e School of Engineering & Informatics , University of Sussex , Brighton , UK
| | - Nick Medford
- b Sussex Partnership NHS Foundation Trust , Brighton , UK.,c Sackler Centre for Consciousness Science , University of Sussex , Brighton , UK.,d Neuroscience , Brighton & Sussex Medical School , Brighton , UK
| | - Hugo D Critchley
- b Sussex Partnership NHS Foundation Trust , Brighton , UK.,c Sackler Centre for Consciousness Science , University of Sussex , Brighton , UK.,d Neuroscience , Brighton & Sussex Medical School , Brighton , UK
| | - Kathryn Greenwood
- a School of Psychology , University of Sussex , Brighton , UK.,b Sussex Partnership NHS Foundation Trust , Brighton , UK
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49
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Rothen N, Schwartzman DJ, Bor D, Seth AK. Coordinated neural, behavioral, and phenomenological changes in perceptual plasticity through overtraining of synesthetic associations. Neuropsychologia 2018; 111:151-162. [DOI: 10.1016/j.neuropsychologia.2018.01.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 11/19/2017] [Accepted: 01/19/2018] [Indexed: 10/18/2022]
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50
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Bola M, Barrett AB, Pigorini A, Nobili L, Seth AK, Marchewka A. Loss of consciousness is related to hyper-correlated gamma-band activity in anesthetized macaques and sleeping humans. Neuroimage 2017; 167:130-142. [PMID: 29162522 DOI: 10.1016/j.neuroimage.2017.11.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/14/2017] [Accepted: 11/15/2017] [Indexed: 12/15/2022] Open
Abstract
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 spontaneous electrophysiological activity recorded in two experiments. First, electrocorticography (ECoG) acquired from 4 macaque monkeys anesthetized with different anesthetic agents (ketamine, medetomidine, propofol) and, second, stereo-electroencephalography (sEEG) from 10 epilepsy patients in different wake-sleep stages (wakefulness, NREM, REM). Specifically, we investigated co-activation patterns among brain areas, defined as correlations between local amplitudes of gamma-band activity. We found that resting wakefulness was associated with intermediate levels of gamma-band coupling, indicating neither complete dependence, nor full independence among brain regions. In contrast, loss of consciousness during NREM sleep and propofol anesthesia was associated with excessively correlated brain activity, as indicated by a robust increase of number and strength of positive correlations. However, such excessively correlated brain signals were not observed during REM sleep, and were present only to a limited extent during ketamine anesthesia. This might be related to the fact that, despite suppression of behavioral responsiveness, REM sleep and ketamine anesthesia often involve presence of dream-like conscious experiences. We conclude that hyper-correlated gamma-band activity might be a signature of loss of consciousness common across various manipulations and independent of behavioral responsiveness.
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Affiliation(s)
- Michał Bola
- Laboratory of Brain Imaging, Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland.
| | - Adam B Barrett
- Sackler Centre for Consciousness Science, Department of Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - Andrea Pigorini
- Department of Clinical Sciences, University of Milan, Milan 20157, Italy
| | - Lino Nobili
- Centre of Epilepsy Surgery "C. Munari", Niguarda Hospital, Milan, 20162, Italy
| | - Anil K Seth
- Sackler Centre for Consciousness Science, Department of Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - Artur Marchewka
- Laboratory of Brain Imaging, Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
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