1
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Cushing CA, Lau H, Hofmann SG, LeDoux JE, Taschereau-Dumouchel V. Metacognition as a window into subjective affective experience. Psychiatry Clin Neurosci 2024; 78:430-437. [PMID: 38884177 DOI: 10.1111/pcn.13683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/10/2024] [Accepted: 05/02/2024] [Indexed: 06/18/2024]
Abstract
When patients seek professional help for mental disorders, they often do so because of troubling subjective affective experiences. While these subjective states are at the center of the patient's symptomatology, scientific tools for studying them and their cognitive antecedents are limited. Here, we explore the use of concepts and analytic tools from the science of consciousness, a field of research that has faced similar challenges in having to develop robust empirical methods for addressing a phenomenon that has been considered difficult to pin down experimentally. One important strand is the operationalization of some relevant processes in terms of metacognition and confidence ratings, which can be rigorously studied in both humans and animals. By assessing subjective experience with similar approaches, we hope to develop new scientific approaches for studying affective processes and promoting psychological resilience in the face of debilitating emotional experiences.
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Affiliation(s)
- Cody A Cushing
- Department of Psychology, UCLA, Los Angeles, California, USA
| | - Hakwan Lau
- RIKEN Center for Brain Science, Wako, Japan
| | - Stefan G Hofmann
- Department of Psychology, Philipps-University Marburg, Marburg, Germany
| | - Joseph E LeDoux
- Center for Neural Science and Department of Psychology, New York University, New York, New York, USA
- Emotional Brain Institute, Nathan Kline Institute, Orangeburg, New York, USA
- Department of Psychiatry, and Department of Child and Adolescent Psychiatry, New York University Langone Medical School, New York, New York, USA
- Max-Planck-NYU Center for Language, Music, and Emotion (CLaME), New York University, New York, New York, USA
| | - Vincent Taschereau-Dumouchel
- Department of Psychiatry and Addictology, Université de Montréal, Montreal, Quebec, Canada
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Montreal, Quebec, Canada
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2
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Salti M, Gabay O, Bergerbest D. Beyond task response - A key to the subjective aspects of consciousness. Phys Life Rev 2024; 50:98-99. [PMID: 39003939 DOI: 10.1016/j.plrev.2024.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 07/04/2024] [Accepted: 07/04/2024] [Indexed: 07/16/2024]
Affiliation(s)
- Moti Salti
- Department of Cognitive and Brain Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.
| | - Omer Gabay
- Department of Psychology, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Dafna Bergerbest
- School of Behavioral Sciences, The Academic College of Tel-Aviv Yaffo, Tel-Aviv Yaffo 61083, Israel
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3
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Gonçalves ÓF, Sayal J, Lisboa F, Palhares P. The experimental study of consciousness: Is psychology travelling back to the future? Int J Clin Health Psychol 2024; 24:100475. [PMID: 39021679 PMCID: PMC11253270 DOI: 10.1016/j.ijchp.2024.100475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 05/29/2024] [Indexed: 07/20/2024] Open
Abstract
It was with the promise of rendering an experimental approach to consciousness that psychology started its trajectory as an independent science more than 150 years ago. Here, we will posit that the neurosciences were instrumental in leading psychology to resume the study of consciousness by projecting an empirical agenda for the future. First, we will start by showing how scientists were able to venture into the consciousness of supposedly unconscious patients, opening the door for the identification of important neural correlates of distinct consciousness states. Then, we will describe how different technological advances and elegant experimental paradigms helped in establishing important neuronal correlates of global consciousness (i.e., being conscious at all), perceptual consciousness (i.e., being conscious of something), and self-consciousness (i.e., being conscious of itself). Finally, we will illustrate how the study of complex consciousness experiences may contribute to the clarification of the mechanisms associated with global consciousness, the relationship between perceptual and self-consciousness, and the interface among distinct self-consciousness domains. In closing, we will elaborate on the road ahead of us for re-establishing psychology as a science of consciousness.
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Affiliation(s)
| | - Joana Sayal
- Proaction Lab – CINEICC, Faculty of Psychology and Educational Sciences, University of Coimbra, Colégio de Jesus, R. Inácio Duarte 65, Coimbra 3000-481, Portugal
| | - Fábio Lisboa
- Proaction Lab – CINEICC, Faculty of Psychology and Educational Sciences, University of Coimbra, Colégio de Jesus, R. Inácio Duarte 65, Coimbra 3000-481, Portugal
| | - Pedro Palhares
- Proaction Lab – CINEICC, Faculty of Psychology and Educational Sciences, University of Coimbra, Colégio de Jesus, R. Inácio Duarte 65, Coimbra 3000-481, Portugal
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4
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Amerio P, Michel M, Goerttler S, Peters MAK, Cleeremans A. Unconscious Perception of Vernier Offsets. Open Mind (Camb) 2024; 8:739-765. [PMID: 38895041 PMCID: PMC11185422 DOI: 10.1162/opmi_a_00145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/15/2024] [Indexed: 06/21/2024] Open
Abstract
The comparison between conscious and unconscious perception is a cornerstone of consciousness science. However, most studies reporting above-chance discrimination of unseen stimuli do not control for criterion biases when assessing awareness. We tested whether observers can discriminate subjectively invisible offsets of Vernier stimuli when visibility is probed using a bias-free task. To reduce visibility, stimuli were either backward masked or presented for very brief durations (1-3 milliseconds) using a modern-day Tachistoscope. We found some behavioral indicators of perception without awareness, and yet, no conclusive evidence thereof. To seek more decisive proof, we simulated a series of Bayesian observer models, including some that produce visibility judgements alongside type-1 judgements. Our data are best accounted for by observers with slightly suboptimal conscious access to sensory evidence. Overall, the stimuli and visibility manipulations employed here induced mild instances of blindsight-like behavior, making them attractive candidates for future investigation of this phenomenon.
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Affiliation(s)
- Pietro Amerio
- Consciousness, Cognition & Computation Group, Center for Research in Cognition & Neurosciences, ULB Neuroscience Institute, Université libre de Bruxelles
| | - Matthias Michel
- Consciousness, Cognition & Computation Group, Center for Research in Cognition & Neurosciences, ULB Neuroscience Institute, Université libre de Bruxelles
- Center for Mind, Brain and Consciousness, New York University
| | - Stephan Goerttler
- Consciousness, Cognition & Computation Group, Center for Research in Cognition & Neurosciences, ULB Neuroscience Institute, Université libre de Bruxelles
| | | | - Axel Cleeremans
- Consciousness, Cognition & Computation Group, Center for Research in Cognition & Neurosciences, ULB Neuroscience Institute, Université libre de Bruxelles
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5
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Mudrik L, Hirschhorn R, Korisky U. Taking consciousness for real: Increasing the ecological validity of the study of conscious vs. unconscious processes. Neuron 2024; 112:1642-1656. [PMID: 38653247 PMCID: PMC11100345 DOI: 10.1016/j.neuron.2024.03.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/23/2024] [Accepted: 03/29/2024] [Indexed: 04/25/2024]
Abstract
The study of consciousness has developed well-controlled, rigorous methods for manipulating and measuring consciousness. Yet, in the process, experimental paradigms grew farther away from everyday conscious and unconscious processes, which raises the concern of ecological validity. In this review, we suggest that the field can benefit from adopting a more ecological approach, akin to other fields of cognitive science. There, this approach challenged some existing hypotheses, yielded stronger effects, and enabled new research questions. We argue that such a move is critical for studying consciousness, where experimental paradigms tend to be artificial and small effect sizes are relatively prevalent. We identify three paths for doing so-changing the stimuli and experimental settings, changing the measures, and changing the research questions themselves-and review works that have already started implementing such approaches. While acknowledging the inherent challenges, we call for increasing ecological validity in consciousness studies.
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Affiliation(s)
- Liad Mudrik
- School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
| | - Rony Hirschhorn
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Uri Korisky
- School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel
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6
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Ladas AI, Gravalas T, Stoneham T, Frantzidis CA. Towards a hybrid approach to unveil the Chimaira of neurosciences: philosophy, aperiodic activity and the neural correlates of consciousness. Front Hum Neurosci 2023; 17:1245868. [PMID: 37900726 PMCID: PMC10603270 DOI: 10.3389/fnhum.2023.1245868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/02/2023] [Indexed: 10/31/2023] Open
Abstract
Contemporary theories of consciousness, although very efficient in postulating testable hypotheses, seem to either neglect its relational aspect or to have a profound difficulty in operationalizing this aspect in a measurable manner. We further argue that the analysis of periodic brain activity is inadequate to reveal consciousness's subjective facet. This creates an important epistemic gap in the quest for the neural correlates of consciousness. We suggest a possible solution to bridge this gap, by analysing aperiodic brain activity. We further argue for the imperative need to inform neuroscientific theories of consciousness with relevant philosophical endeavours, in an effort to define, and therefore operationalise, consciousness thoroughly.
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Affiliation(s)
- Aristea I. Ladas
- Department of Psychology, CITY College, University of York Europe Campus, Thessaloniki, Greece
| | - Triantafyllos Gravalas
- Department of Psychology, CITY College, University of York Europe Campus, Thessaloniki, Greece
| | - Tom Stoneham
- Department of Philosophy, University of York, York, United Kingdom
| | - Christos A. Frantzidis
- School of Computer Science, University of Lincoln, Lincoln, United Kingdom
- Laboratory of Medical Physics and Digital Innovation, Biomedical Engineering and Aerospace Neuroscience (BEAN), Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
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7
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Simione L, Raffone A, Kirov R, Overgaard M, Berkovich-Ohana A, Cleeremans A. Editorial: Methodological issues in consciousness research. Front Psychol 2023; 14:1217732. [PMID: 37346419 PMCID: PMC10280984 DOI: 10.3389/fpsyg.2023.1217732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 05/18/2023] [Indexed: 06/23/2023] Open
Affiliation(s)
- Luca Simione
- Institute of Cognitive Sciences and Technologies, CNR, Rome, Italy
- Faculty of Interpreting and Translation, Università degli Studi Internazionali, UNINT, Rome, Italy
| | - Antonino Raffone
- Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Roumen Kirov
- Institute of Neurobiology, Bulgarian Academy of Sciences (BAS), Sofia, Bulgaria
| | - Morten Overgaard
- CFIN, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Aviva Berkovich-Ohana
- Faculty of Education, University of Haifa, and Brain and Behavior Hub, Haifa, Israel
| | - Axel Cleeremans
- Center for Research in Cognition and Neuroscience (CRCN), ULB Neuroscience Institute (UNI), Université libre de Bruxelles, Brussels, Belgium
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8
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Akcay G, Luttge R. Microenvironments Matter: Advances in Brain-on-Chip. BIOSENSORS 2023; 13:551. [PMID: 37232912 PMCID: PMC10216565 DOI: 10.3390/bios13050551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/04/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023]
Abstract
To highlight the particular needs with respect to modeling the unique and complex organization of the human brain structure, we reviewed the state-of-the-art in devising brain models with engineered instructive microenvironments. To acquire a better perspective on the brain's working mechanisms, we first summarize the importance of regional stiffness gradients in brain tissue, varying per layer and the cellular diversities of the layers. Through this, one can acquire an understanding of the essential parameters in emulating the brain in vitro. In addition to the brain's organizational architecture, we addressed also how the mechanical properties have an impact on neuronal cell responses. In this respect, advanced in vitro platforms emerged and profoundly changed the methods of brain modeling efforts from the past, mainly focusing on animal or cell line research. The main challenges in imitating features of the brain in a dish are with regard to composition and functionality. In neurobiological research, there are now methods that aim to cope with such challenges by the self-assembly of human-derived pluripotent stem cells (hPSCs), i.e., brainoids. Alternatively, these brainoids can be used stand-alone or in conjunction with Brain-on-Chip (BoC) platform technology, 3D-printed gels, and other types of engineered guidance features. Currently, advanced in vitro methods have made a giant leap forward regarding cost-effectiveness, ease-of-use, and availability. We bring these recent developments together into one review. We believe our conclusions will give a novel perspective towards advancing instructive microenvironments for BoCs and the understanding of the brain's cellular functions either in modeling healthy or diseased states of the brain.
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Affiliation(s)
- Gulden Akcay
- Neuro-Nanoscale Engineering, Department of Mechanical Engineering/Microsystems, Institute of Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
| | - Regina Luttge
- Neuro-Nanoscale Engineering, Department of Mechanical Engineering/Microsystems, Institute of Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Eindhoven Artificial Intelligence Systems Institute, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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9
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Havlík M, Hlinka J, Klírová M, Adámek P, Horáček J. Towards causal mechanisms of consciousness through focused transcranial brain stimulation. Neurosci Conscious 2023; 2023:niad008. [PMID: 37089451 PMCID: PMC10120840 DOI: 10.1093/nc/niad008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/10/2023] [Accepted: 03/30/2023] [Indexed: 04/25/2023] Open
Abstract
Conscious experience represents one of the most elusive problems of empirical science, namely neuroscience. The main objective of empirical studies of consciousness has been to describe the minimal sets of neural events necessary for a specific neuronal state to become consciously experienced. The current state of the art still does not meet this objective but rather consists of highly speculative theories based on correlates of consciousness and an ever-growing list of knowledge gaps. The current state of the art is defined by the limitations of past stimulation techniques and the emphasis on the observational approach. However, looking at the current stimulation technologies that are becoming more accurate, it is time to consider an alternative approach to studying consciousness, which builds on the methodology of causal explanations via causal alterations. The aim of this methodology is to move beyond the correlates of consciousness and focus directly on the mechanisms of consciousness with the help of the currently focused brain stimulation techniques, such as geodesic transcranial electric neuromodulation. This approach not only overcomes the limitations of the correlational methodology but will also become another firm step in the following science of consciousness.
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Affiliation(s)
- Marek Havlík
- Center for Advanced Studies of Brain and Consciousness, National Institute of Mental Health, Topolová 748, Klecany 250 67, Czech Republic
| | - Jaroslav Hlinka
- Center for Advanced Studies of Brain and Consciousness, National Institute of Mental Health, Topolová 748, Klecany 250 67, Czech Republic
- Department of Complex Systems, Institute of Computer Science of the Czech Academy of Sciences, Pod Vodárenskou věží 271/2, Prague 182 07, Czech Republic
| | - Monika Klírová
- Center for Advanced Studies of Brain and Consciousness, National Institute of Mental Health, Topolová 748, Klecany 250 67, Czech Republic
- Third Faculty of Medicine, Charles University, Ruská 87, Prague 10 100 00, Czech Republic
| | - Petr Adámek
- Center for Advanced Studies of Brain and Consciousness, National Institute of Mental Health, Topolová 748, Klecany 250 67, Czech Republic
- Third Faculty of Medicine, Charles University, Ruská 87, Prague 10 100 00, Czech Republic
| | - Jiří Horáček
- Center for Advanced Studies of Brain and Consciousness, National Institute of Mental Health, Topolová 748, Klecany 250 67, Czech Republic
- Third Faculty of Medicine, Charles University, Ruská 87, Prague 10 100 00, Czech Republic
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10
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Michel M. Confidence in consciousness research. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2023; 14:e1628. [PMID: 36205300 DOI: 10.1002/wcs.1628] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 09/14/2022] [Accepted: 09/21/2022] [Indexed: 11/06/2022]
Abstract
To study (un)conscious perception and test hypotheses about consciousness, researchers need procedures for determining whether subjects consciously perceive stimuli or not. This article is an introduction to a family of procedures called "confidence-based procedures," which consist in interpreting metacognitive indicators as indicators of consciousness. I assess the validity and accuracy of these procedures, and answer a series of common objections to their use in consciousness research. I conclude that confidence-based procedures are valid for assessing consciousness, and, in most cases, accurate enough for our practical and scientific purposes. This article is categorized under: Psychology > Perception and Psychophysics Philosophy > Consciousness.
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Affiliation(s)
- Matthias Michel
- Center for Mind, Brain and Consciousness, New York University, New York, New York, USA
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11
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Abstract
In the study of consciousness, qualia, the individual subjective experience, is
neglected. It remains impenetrable because the objective perspective used for
scientific investigations misses its subjective nature. In 1974, Thomas Nagel
suggested that studying qualia requires an “objective phenomenology method”
whose goal would be to describe the subjective character of experiences in an
independent manner. We introduce a corresponding theoretical and experimental
framework based on the “idiosyncrasy principle.” Accordingly, subjectivity
depends on the idiosyncratic composition of physical properties to qualia. This
allows conceptualizing an idiosyncratic transfer function between the world and
its representation. The main challenge in delineating such a transfer function
is to come up with an objective measure for another person’s perspective.
Numerosity, as opposed to other perceived contents of the physical world, allows
reporting subjective experience in an objective manner. On the basis of this
unique attribute of numerosity, we suggest a tentative neurocognitive research
plan aimed at delineating such idiosyncratic transfer functions, permitting one
person to adopt the perspective of another and linking qualia to its
mechanism.
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Affiliation(s)
- M Salti
- Brain Imaging Research Center, Ben-Gurion University of the Negev.,Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev
| | - D Bergerbest
- School of Behavioral Sciences, The Academic College of Tel-Aviv Yaffo
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12
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Derrien D, Garric C, Sergent C, Chokron S. The nature of blindsight: implications for current theories of consciousness. Neurosci Conscious 2022; 2022:niab043. [PMID: 35237447 PMCID: PMC8884361 DOI: 10.1093/nc/niab043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 11/08/2021] [Accepted: 01/13/2022] [Indexed: 11/16/2022] Open
Abstract
Blindsight regroups the different manifestations of preserved discriminatory visual capacities following the damage to the primary visual cortex. Blindsight types differentially impact objective and subjective perception, patients can report having no visual awareness whilst their behaviour suggests visual processing still occurs at some cortical level. This phenomenon hence presents a unique opportunity to study consciousness and perceptual consciousness, and for this reason, it has had an historical importance for the development of this field of research. From these studies, two main opposing models of the underlying mechanisms have been established: (a) blindsight is perception without consciousness or (b) blindsight is in fact degraded vision, two views that mirror more general theoretical options about whether unconscious cognition truly exists or whether it is only a degraded form of conscious processing. In this article, we want to re-examine this debate in the light of recent advances in the characterization of blindsight and associated phenomena. We first provide an in-depth definition of blindsight and its subtypes, mainly blindsight type I, blindsight type II and the more recently described blindsense. We emphasize the necessity of sensitive and robust methodology to uncover the dissociations between perception and awareness that can be observed in brain-damaged patients with visual field defects at different cognitive levels. We discuss these different profiles of dissociation in the light of both contending models. We propose that the different types of dissociations reveal a pattern of relationship between perception, awareness and metacognition that is actually richer than what is proposed by either of the existing models. Finally, we consider this in the framework of current theories of consciousness and touch on the implications the findings of blindsight have on these.
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Affiliation(s)
- Diane Derrien
- Integrative Neuroscience and Cognition Center, UMR 8002, CNRS & Université de Paris, Paris 75006, France
- Institut de Neuropsychologie, Neurovision, NeuroCognition, Fondation Ophtalmologique Rothschild, Paris 75019, France
| | - Clémentine Garric
- Inserm, CHU Lille, U1172—LilNCog (JPARC)—Lille Neuroscience & Cognition, University of Lille, Lille 59000, France
| | - Claire Sergent
- Integrative Neuroscience and Cognition Center, UMR 8002, CNRS & Université de Paris, Paris 75006, France
| | - Sylvie Chokron
- Integrative Neuroscience and Cognition Center, UMR 8002, CNRS & Université de Paris, Paris 75006, France
- Institut de Neuropsychologie, Neurovision, NeuroCognition, Fondation Ophtalmologique Rothschild, Paris 75019, France
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13
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Revach D, Salti M. Expanding the discussion: Revision of the fundamental assumptions framing the study of the neural correlates of consciousness. Conscious Cogn 2021; 96:103229. [PMID: 34749156 DOI: 10.1016/j.concog.2021.103229] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 10/23/2021] [Accepted: 10/23/2021] [Indexed: 01/10/2023]
Abstract
The way one asks a question is shaped by a-priori assumptions and constrains the range of possible answers. We identify and test the assumptions underlying contemporary debates, models, and methodology in the study of the neural correlates of consciousness, which was framed by Crick and Koch's seminal paper (1990). These premises create a sequential and passive conception of conscious perception: it is considered the product of resolved information processing by unconscious mechanisms, produced by a singular event in time and place representing the moment of entry. The conscious percept produced is then automatically retained to be utilized by post-conscious mechanisms. Major debates in the field, such as concern the moment of entry, the all-or-none vs graded nature, and report vs no-report paradigms, are driven by the consensus on these assumptions. We show how removing these assumptions can resolve some of the debates and challenges and prompt additional questions. The potential non-sequential nature of perception suggests new ways of thinking about consciousness as a dynamic and dispersed process, and in turn about the relationship between conscious and unconscious perception. Moreover, it allows us to present a parsimonious account for conscious perception while addressing more aspects of the phenomenon.
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Affiliation(s)
- Daniel Revach
- Ben Gurion University of the Negev, Beer-Sheva 84105, Israel.
| | - Moti Salti
- Ben Gurion University of the Negev, Beer-Sheva 84105, Israel
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14
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Abstract
Studies of unconscious mental processes often compare a performance measure (e.g., some assessment of perception or memory) with a measure of awareness (e.g., a verbal report or forced-choice response) of the critical cue or contingency taken either concurrently or separately. The resulting patterns of bivariate data across participants lend themselves to several analytic approaches for inferring the existence of unconscious mental processes, but it is rare for researchers to consider the underlying generative processes that might cause these patterns. We show that bivariate data are generally insufficient to discriminate single-process models, with a unitary latent process determining both performance and awareness, from dual-process models, comprising distinct latent processes for performance and awareness. Future research attempting to isolate and investigate unconscious processes will need to employ richer types of data and analyses.
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Affiliation(s)
- David R Shanks
- Division of Psychology and Language Sciences, University College London, UK
| | - Simone Malejka
- Department of Psychology, University of Cologne, Germany
| | - Miguel A Vadillo
- Departamento de Psicología Básica, Facultad de Psicología, Universidad Autónoma de Madrid, Spain
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15
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Gómez-Ramírez J, González-Rosa JJ. Intra- and interhemispheric symmetry of subcortical brain structures: a volumetric analysis in the aging human brain. Brain Struct Funct 2021; 227:451-462. [PMID: 34089103 DOI: 10.1007/s00429-021-02305-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/19/2021] [Indexed: 12/20/2022]
Abstract
Here, we address the hemispheric interdependency of subcortical structures in the aging human brain. In particular, we investigated whether subcortical volume variations can be explained by the adjacency of structures in the same hemisphere or are due to the interhemispheric development of mirror subcortical structures in the brain. Seven subcortical structures in each hemisphere were automatically segmented in a large sample of 3312 magnetic resonance imaging (MRI) studies of elderly individuals in their 70s and 80s. We performed Eigenvalue analysis, and found that anatomic volumes in the limbic system and basal ganglia show similar statistical dependency whether considered in the same hemisphere (intrahemispherically) or different hemispheres (interhemispherically). Our results indicate that anatomic bilaterality of subcortical volumes is preserved in the aging human brain, supporting the hypothesis that coupling between non-adjacent subcortical structures might act as a mechanism to compensate for the deleterious effects of aging.
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Affiliation(s)
| | - Javier J González-Rosa
- Department of Psychology, Universidad de Cádiz, Cádiz, Spain
- Instituto de Investigación Biomédica de Cádiz (INIBICA), Cádiz, Spain
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16
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Levinson M, Podvalny E, Baete SH, He BJ. Cortical and subcortical signatures of conscious object recognition. Nat Commun 2021; 12:2930. [PMID: 34006884 PMCID: PMC8131711 DOI: 10.1038/s41467-021-23266-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/12/2021] [Indexed: 11/29/2022] Open
Abstract
The neural mechanisms underlying conscious recognition remain unclear, particularly the roles played by the prefrontal cortex, deactivated brain areas and subcortical regions. We investigated neural activity during conscious object recognition using 7 Tesla fMRI while human participants viewed object images presented at liminal contrasts. Here, we show both recognized and unrecognized images recruit widely distributed cortical and subcortical regions; however, recognized images elicit enhanced activation of visual, frontoparietal, and subcortical networks and stronger deactivation of the default-mode network. For recognized images, object category information can be decoded from all of the involved cortical networks but not from subcortical regions. Phase-scrambled images trigger strong involvement of inferior frontal junction, anterior cingulate cortex and default-mode network, implicating these regions in inferential processing under increased uncertainty. Our results indicate that content-specific activity in both activated and deactivated cortical networks and non-content-specific subcortical activity support conscious recognition. Cortical and subcortical neural activity supporting conscious object recognition has not yet been well defined. Here, the authors describe these networks and show recognition-related category information can be decoded from widespread cortical activity but not subcortical activity.
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Affiliation(s)
- Max Levinson
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA
| | - Ella Podvalny
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA
| | - Steven H Baete
- Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Biyu J He
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA. .,Department of Radiology, New York University School of Medicine, New York, NY, USA. .,Department of Neurology, New York University School of Medicine, New York, NY, USA. .,Department of Neuroscience & Physiology, New York University School of Medicine, New York, NY, USA.
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17
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Halligan PW, Oakley DA. Giving Up on Consciousness as the Ghost in the Machine. Front Psychol 2021; 12:571460. [PMID: 33995166 PMCID: PMC8121175 DOI: 10.3389/fpsyg.2021.571460] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Consciousness as used here, refers to the private, subjective experience of being aware of our perceptions, thoughts, feelings, actions, memories (psychological contents) including the intimate experience of a unified self with the capacity to generate and control actions and psychological contents. This compelling, intuitive consciousness-centric account has, and continues to shape folk and scientific accounts of psychology and human behavior. Over the last 30 years, research from the cognitive neurosciences has challenged this intuitive social construct account when providing a neurocognitive architecture for a human psychology. Growing evidence suggests that the executive functions typically attributed to the experience of consciousness are carried out competently, backstage and outside subjective awareness by a myriad of fast, efficient non-conscious brain systems. While it remains unclear how and where the experience of consciousness is generated in the brain, we suggested that the traditional intuitive explanation that consciousness is causally efficacious is wrong-headed when providing a cognitive neuroscientific account of human psychology. Notwithstanding the compelling 1st-person experience (inside view) that convinces us that subjective awareness is the mental curator of our actions and thoughts, we argue that the best framework for building a scientific account is to be consistent with the biophysical causal dependency of prior neural processes. From a 3rd person perspective, (outside view), we propose that subjective awareness lacking causal influence, is (no more) than our experience of being aware, our awareness of our psychological content, knowing that we are aware, and the belief that that such experiences are evidence of an agentive capacity shared by others. While the human mind can be described as comprising both conscious and nonconscious aspects, both ultimately depend on neural process in the brain. In arguing for the counter-intuitive epiphenomenal perspective, we suggest that a scientific approach considers all mental aspects of mind including consciousness in terms of their underlying, preceding (causal) biological changes, in the realization that most brain processes are not accompanied by any discernible change in subjective awareness.
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Affiliation(s)
- Peter W Halligan
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - David A Oakley
- Division of Psychology and Language Sciences, University College London, London, United Kingdom
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18
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Malejka S, Vadillo MA, Dienes Z, Shanks DR. Correlation analysis to investigate unconscious mental processes: A critical appraisal and mini-tutorial. Cognition 2021; 212:104667. [PMID: 33975175 DOI: 10.1016/j.cognition.2021.104667] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 11/24/2022]
Abstract
As a method to investigate the scope of unconscious mental processes, researchers frequently obtain concurrent measures of task performance and stimulus awareness across participants. Even though both measures might be significantly greater than zero, the correlation between them might not, encouraging the inference that an unconscious process drives task performance. We highlight the pitfalls of this null-correlation approach and provide a mini-tutorial on ways to avoid them. As reference, we use a recent study by Salvador et al. (2018) reporting a non-significant correlation between the extent to which memory was suppressed by a Think/No-Think cue and an index of cue awareness. In the Null Hypothesis Significance Testing (NHST) framework, it is inappropriate to interpret failure to reject the null hypothesis (i.e., correlation = 0) as evidence for the null. Furthermore, psychological measures are often unreliable, which can dramatically attenuate the size of observed correlations. A Bayesian approach can circumvent both problems and compare the extent to which the data provide evidence for the null versus the alternative hypothesis (i.e., correlation > 0), while considering the usually low reliabilities of the variables. Applied to Salvador et al.'s data, this approach indicates no to moderate support for the claimed unconscious nature of participants' memory-suppression performance-depending on the model of the alternative hypothesis. Hence, more reliable data are needed. When analyzing correlational data, we recommend researchers to employ the Bayesian methods developed here (and made freely available as R scripts), rather than standard NHST methods, to take account of unreliability.
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19
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Stein T, Kaiser D, Fahrenfort JJ, van Gaal S. The human visual system differentially represents subjectively and objectively invisible stimuli. PLoS Biol 2021; 19:e3001241. [PMID: 33951043 PMCID: PMC8128378 DOI: 10.1371/journal.pbio.3001241] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 05/17/2021] [Accepted: 04/20/2021] [Indexed: 11/18/2022] Open
Abstract
The study of unconscious processing requires a measure of conscious awareness. Awareness measures can be either subjective (based on participant's report) or objective (based on perceptual performance). The preferred awareness measure depends on the theoretical position about consciousness and may influence conclusions about the extent of unconscious processing and about the neural correlates of consciousness. We obtained functional magnetic resonance imaging (fMRI) measurements from 43 subjects while they viewed masked faces and houses that were either subjectively or objectively invisible. Even for objectively invisible (perceptually indiscriminable) stimuli, we found significant category information in both early, lower-level visual areas and in higher-level visual cortex, although representations in anterior, category-selective ventrotemporal areas were less robust. For subjectively invisible stimuli, similar to visible stimuli, there was a clear posterior-to-anterior gradient in visual cortex, with stronger category information in ventrotemporal cortex than in early visual cortex. For objectively invisible stimuli, however, category information remained virtually unchanged from early visual cortex to object- and category-selective visual areas. These results demonstrate that although both objectively and subjectively invisible stimuli are represented in visual cortex, the extent of unconscious information processing is influenced by the measurement approach. Furthermore, our data show that subjective and objective approaches are associated with different neural correlates of consciousness and thus have implications for neural theories of consciousness.
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Affiliation(s)
- Timo Stein
- Brain and Cognition, Department of Psychology, University of Amsterdam, the Netherlands
| | - Daniel Kaiser
- Department of Psychology, University of York, United Kingdom
| | - Johannes J. Fahrenfort
- Brain and Cognition, Department of Psychology, University of Amsterdam, the Netherlands
- Cognitive Psychology, Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, the Netherlands
| | - Simon van Gaal
- Brain and Cognition, Department of Psychology, University of Amsterdam, the Netherlands
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20
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Reflections on Eriksen's seminal essay on discrimination, performance and learning without awareness. Atten Percept Psychophys 2020; 83:546-557. [PMID: 32935288 DOI: 10.3758/s13414-020-02098-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Early in his career C.W. Eriksen published in Psychological Review what turned out to be a highly impactful critique on methods and findings on the topic of unconscious influences on discrimination and awareness. His incisive commentary on extant methodology employed at that time - especially the heavy dependence on subjective reports - clearly was heard by others moving forward, as evidenced by the subsequent, lively discussions within the literature concerning the very definition of the notion of unconscious processing. Of equal importance, Eriksen's paper provided an impetus for the development of more refined techniques for manipulating perceptual awareness and for measuring the consequences of those manipulations. My purpose in this essay is to ensure that Eriksen's seminal contributions concerning unconscious phenomena remain within the awareness of the many current investigators working on this popular topic.
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21
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Cognition in some surprising places. Biochem Biophys Res Commun 2020; 564:150-157. [PMID: 32950231 DOI: 10.1016/j.bbrc.2020.08.115] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023]
Abstract
The most widely accepted view in the biopsychological sciences is that the cognitive functions that are diagnostic of mental operations, sentience or, more commonly, consciousness emerged fairly late in evolution, most likely in the Cambrian period. Our position dovetails with James's below - subjectivity, feeling, consciousness has a much longer evolutionary history, one that goes back to the first appearance of life. The Cellular Basis of Consciousness (CBC) model is founded on the presumption that sentience and life are coterminous; that all organisms, based on inherent cellular activities via processes that take place in excitable membranes of their cells, are sentient, have subjective experiences and feelings. These, in turn, guide the context-relevant behaviors essential for their survival in often hostile environments in constant flux. The CBC framework is reductionistic, mechanistic, and calls for bottom-up research programs into the evolutionary origin of biological consciousness.
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22
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Cofré R, Herzog R, Mediano PA, Piccinini J, Rosas FE, Sanz Perl Y, Tagliazucchi E. Whole-Brain Models to Explore Altered States of Consciousness from the Bottom Up. Brain Sci 2020; 10:E626. [PMID: 32927678 PMCID: PMC7565030 DOI: 10.3390/brainsci10090626] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 09/03/2020] [Accepted: 09/07/2020] [Indexed: 01/16/2023] Open
Abstract
The scope of human consciousness includes states departing from what most of us experience as ordinary wakefulness. These altered states of consciousness constitute a prime opportunity to study how global changes in brain activity relate to different varieties of subjective experience. We consider the problem of explaining how global signatures of altered consciousness arise from the interplay between large-scale connectivity and local dynamical rules that can be traced to known properties of neural tissue. For this purpose, we advocate a research program aimed at bridging the gap between bottom-up generative models of whole-brain activity and the top-down signatures proposed by theories of consciousness. Throughout this paper, we define altered states of consciousness, discuss relevant signatures of consciousness observed in brain activity, and introduce whole-brain models to explore the biophysics of altered consciousness from the bottom-up. We discuss the potential of our proposal in view of the current state of the art, give specific examples of how this research agenda might play out, and emphasize how a systematic investigation of altered states of consciousness via bottom-up modeling may help us better understand the biophysical, informational, and dynamical underpinnings of consciousness.
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Affiliation(s)
- Rodrigo Cofré
- CIMFAV-Ingemat, Facultad de Ingeniería, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Rubén Herzog
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso 2360103, Chile;
| | - Pedro A.M. Mediano
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK;
| | - Juan Piccinini
- National Scientific and Technical Research Council, Buenos Aires C1033AAJ, Argentina; (J.P.); (Y.S.P.); (E.T.)
- Buenos Aires Physics Institute and Physics Department, University of Buenos Aires, Buenos Aires C1428EGA, Argentina
| | - Fernando E. Rosas
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London SW7 2DD, UK;
- Data Science Institute, Imperial College London, London SW7 2AZ, UK
- Centre for Complexity Science, Imperial College London, London SW7 2AZ, UK
| | - Yonatan Sanz Perl
- National Scientific and Technical Research Council, Buenos Aires C1033AAJ, Argentina; (J.P.); (Y.S.P.); (E.T.)
- Departamento de Matemáticas y Ciencias, Universidad de San Andrés, Buenos Aires B1644BID, Argentina
| | - Enzo Tagliazucchi
- National Scientific and Technical Research Council, Buenos Aires C1033AAJ, Argentina; (J.P.); (Y.S.P.); (E.T.)
- Buenos Aires Physics Institute and Physics Department, University of Buenos Aires, Buenos Aires C1428EGA, Argentina
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