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Filimonov D, Tanskanen S, Revonsuo A, Koivisto M. Is auditory awareness graded or dichotomous: Electrophysiological correlates of consciousness at different depths of stimulus processing. Conscious Cogn 2024; 123:103720. [PMID: 38901129 DOI: 10.1016/j.concog.2024.103720] [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: 11/15/2023] [Revised: 06/12/2024] [Accepted: 06/12/2024] [Indexed: 06/22/2024]
Abstract
The level-of-processing (LoP) hypothesis postulates that transition from unaware to aware visual stimuli is either graded or dichotomous depending on the depth of stimulus processing. Humans can be progressively aware of the low-level features, such as colors or shapes, while the high-level features, such as semantic category, enter consciousness in an all-or none fashion. Unlike in vision, sounds always unfold in time, which might require mechanisms dissimilar from visual processing. We tested the LoP hypothesis in hearing for the first time by presenting participants with words of different categories, spoken in different pitches near the perceptual threshold. We also assessed whether different electrophysiological correlates of consciousness, the auditory awareness negativity (AAN) and late positivity (LP), were associated with LoP. Our findings indicate that LoP also applies to the auditory modality. AAN is an early correlate of awareness independent of LoP, while LP was modulated by awareness, performance accuracy and the level of processing.
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Affiliation(s)
- Dmitri Filimonov
- Department of Psychology, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland.
| | - Sampo Tanskanen
- Faculty of Medicine, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland
| | - Antti Revonsuo
- Department of Psychology, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland; Division of Cognitive Neuroscience and Philosophy, University of Skövde, Sweden
| | - Mika Koivisto
- Department of Psychology, University of Turku, Finland; Turku Brain and Mind Centre, University of Turku, Finland
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2
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Altmayer V, Sangare A, Calligaris C, Puybasset L, Perlbarg V, Naccache L, Sitt JD, Rohaut B. Functional and structural brain connectivity in disorders of consciousness. Brain Struct Funct 2024:10.1007/s00429-024-02839-8. [PMID: 39052096 DOI: 10.1007/s00429-024-02839-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 07/12/2024] [Indexed: 07/27/2024]
Abstract
Brain connectivity, allowing information to be shared between distinct cortical areas and thus to be processed in an integrated way, has long been considered critical for consciousness. However, the relationship between functional intercortical interactions and the structural connections thought to underlie them is poorly understood. In the present work, we explore both functional (with an EEG-based metric: the median weighted symbolic mutual information in the theta band) and structural (with a brain MRI-based metric: fractional anisotropy) connectivities in a cohort of 78 patients with disorders of consciousness. Both metrics could distinguish patients in a vegetative state from patients in minimally conscious state. Crucially, we discovered a significant positive correlation between functional and structural connectivities. Furthermore, we showed that this structure-function relationship is more specifically observed when considering structural connectivity within the intra- and inter-hemispheric long-distance cortico-cortical bundles involved in the Global Neuronal Workspace (GNW) theory of consciousness, thus supporting predictions of this model. Altogether, these results support the interest of multimodal assessments of brain connectivity in refining the diagnostic evaluation of patients with disorders of consciousness.
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Affiliation(s)
- Victor Altmayer
- Sorbonne University, Paris, F-75013, France
- Department of Neurology, AP-HP, Pitié-Salpêtrière Hospital, Neuro-ICU, Paris, F-75013, France
| | - Aude Sangare
- Sorbonne University, Paris, F-75013, France
- Department of Neurophysiology, AP-HP, Pitié-Salpêtrière Hospital, Paris, F-75013, France
- PICNIC-Lab, Paris Brain Institute, (ICM), INSERM, CNRS, Hôpital Pitié Salpêtrière, 47 bvd de l'hôpital, Paris, F-75013, France
| | - Charlotte Calligaris
- Sorbonne University, Paris, F-75013, France
- Department of Neurology, AP-HP, Pitié-Salpêtrière Hospital, Neuro-ICU, Paris, F-75013, France
| | - Louis Puybasset
- Sorbonne University, Paris, F-75013, France
- Department of Neuro-anesthesiology and Neurocritical Care, AP-HP, Pitié-Salpêtrière Hospital, Paris, F-75013, France
| | | | - Lionel Naccache
- Sorbonne University, Paris, F-75013, France
- Department of Neurophysiology, AP-HP, Pitié-Salpêtrière Hospital, Paris, F-75013, France
- PICNIC-Lab, Paris Brain Institute, (ICM), INSERM, CNRS, Hôpital Pitié Salpêtrière, 47 bvd de l'hôpital, Paris, F-75013, France
| | - Jacobo Diego Sitt
- PICNIC-Lab, Paris Brain Institute, (ICM), INSERM, CNRS, Hôpital Pitié Salpêtrière, 47 bvd de l'hôpital, Paris, F-75013, France
| | - Benjamin Rohaut
- Sorbonne University, Paris, F-75013, France.
- Department of Neurology, AP-HP, Pitié-Salpêtrière Hospital, Neuro-ICU, Paris, F-75013, France.
- PICNIC-Lab, Paris Brain Institute, (ICM), INSERM, CNRS, Hôpital Pitié Salpêtrière, 47 bvd de l'hôpital, Paris, F-75013, France.
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3
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Chis-Ciure R, Melloni L, Northoff G. A measure centrality index for systematic empirical comparison of consciousness theories. Neurosci Biobehav Rev 2024; 161:105670. [PMID: 38615851 DOI: 10.1016/j.neubiorev.2024.105670] [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: 02/03/2024] [Revised: 03/15/2024] [Accepted: 04/08/2024] [Indexed: 04/16/2024]
Abstract
Consciousness science is marred by disparate constructs and methodologies, making it challenging to systematically compare theories. This foundational crisis casts doubts on the scientific character of the field itself. Addressing it, we propose a framework for systematically comparing consciousness theories by introducing a novel inter-theory classification interface, the Measure Centrality Index (MCI). Recognizing its gradient distribution, the MCI assesses the degree of importance a specific empirical measure has for a given consciousness theory. We apply the MCI to probe how the empirical measures of the Global Neuronal Workspace Theory (GNW), Integrated Information Theory (IIT), and Temporospatial Theory of Consciousness (TTC) would fare within the context of the other two. We demonstrate that direct comparison of IIT, GNW, and TTC is meaningful and valid for some measures like Lempel-Ziv Complexity (LZC), Autocorrelation Window (ACW), and possibly Mutual Information (MI). In contrast, it is problematic for others like the anatomical and physiological neural correlates of consciousness (NCC) due to their MCI-based differential weightings within the structure of the theories. In sum, we introduce and provide proof-of-principle of a novel systematic method for direct inter-theory empirical comparisons, thereby addressing isolated evolution of theories and confirmatory bias issues in the state-of-the-art neuroscience of consciousness.
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Affiliation(s)
- Robert Chis-Ciure
- New York University (NYU), New York, USA; International Center for Neuroscience and Ethics (CINET), Tatiana Foundation, Madrid, Spain; Wolfram Physics Project, USA.
| | - Lucia Melloni
- Max Planck Institute for Empirical Aesthetics, Frankfurt am Main, Germany
| | - Georg Northoff
- University of Ottawa, Institute of Mental Health Research at the Royal Ottawa Hospital, Ottawa, Canada
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4
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Naccache L, Munoz-Musat E. A global neuronal workspace model of functional neurological disorders. DIALOGUES IN CLINICAL NEUROSCIENCE 2024; 26:1-23. [PMID: 38767966 PMCID: PMC11107854 DOI: 10.1080/19585969.2024.2340131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 04/03/2024] [Indexed: 05/22/2024]
Abstract
We introduce here a general model of Functional Neurological Disorders based on the following hypothesis: a Functional Neurological Disorder could correspond to a consciously initiated voluntary top-down process causing involuntary lasting consequences that are consciously experienced and subjectively interpreted by the patient as involuntary. We develop this central hypothesis according to Global Neuronal Workspace theory of consciousness, that is particularly suited to describe interactions between conscious and non-conscious cognitive processes. We then present a list of predictions defining a research program aimed at empirically testing their validity. Finally, this general model leads us to reinterpret the long-debated links between hypnotic suggestion and functional neurological disorders. Driven by both scientific and therapeutic goals, this theoretical paper aims at bringing closer the psychiatric and neurological worlds of functional neurological disorders with the latest developments of cognitive neuroscience of consciousness.
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Affiliation(s)
- Lionel Naccache
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France- Sorbonne Université, UPMC Univ Paris 06, Faculté de Médecine Pitié-Salpêtrière, Sorbonne Université, Paris, France
- Department of Neurology, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, DMU Neurosciences, Paris, France
- Department of Clinical Neurophysiology, AP-HP, Hôpital Groupe hospitalier Pitié-Salpêtrière, DMU Neurosciences, Paris, France
| | - Esteban Munoz-Musat
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France- Sorbonne Université, UPMC Univ Paris 06, Faculté de Médecine Pitié-Salpêtrière, Sorbonne Université, Paris, France
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5
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Lacalli T. Mental causation: an evolutionary perspective. Front Psychol 2024; 15:1394669. [PMID: 38741757 PMCID: PMC11089241 DOI: 10.3389/fpsyg.2024.1394669] [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: 03/01/2024] [Accepted: 04/16/2024] [Indexed: 05/16/2024] Open
Abstract
The relationship between consciousness and individual agency is examined from a bottom-up evolutionary perspective, an approach somewhat different from other ways of dealing with the issue, but one relevant to the question of animal consciousness. Two ways are identified that would decouple the two, allowing consciousness of a limited kind to exist without agency: (1) reflex pathways that incorporate conscious sensations as an intrinsic component (InCs), and (2) reflexes that are consciously conditioned and dependent on synaptic plasticity but not memory (CCRs). Whether InCs and CCRs exist as more than hypothetical constructs is not clear, and InCs are in any case limited to theories where consciousness depends directly on EM field-based effects. Consciousness with agency, as we experience it, then belongs in a third category that allows for deliberate choice of alternative actions (DCs), where the key difference between this and CCR-level pathways is that DCs require access to explicit memory systems whereas CCRs do not. CCRs are nevertheless useful from a heuristic standpoint as a conceptual model for how conscious inputs could act to refine routine behaviors while allowing evolution to optimize phenomenal experience (i.e., qualia) in the absence of individual agency, a somewhat counterintuitive result. However, so long as CCRs are not a required precondition for the evolution of memory-dependent DC-level processes, the later could have evolved first. If so, the adaptive benefit of consciousness when it first evolved may be linked as much to the role it plays in encoding memories as to any other function. The possibility that CCRs are more than a theoretical construct, and have played a role in the evolution of consciousness, argues against theories of consciousness focussed exclusively on higher-order functions as the appropriate way to deal with consciousness as it first evolved, as it develops in the early postnatal period of life, or with the conscious experiences of animals other than ourselves. An evolutionary perspective also resolves the problem of free will, that it is best treated as a property of a species rather than the individuals belonging to that species whereas, in contrast, agency is an attribute of individuals.
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Affiliation(s)
- Thurston Lacalli
- Department of Biology, University of Victoria, Victoria, BC, Canada
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6
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Evers K, Farisco M, Pennartz CMA. Assessing the commensurability of theories of consciousness: On the usefulness of common denominators in differentiating, integrating and testing hypotheses. Conscious Cogn 2024; 119:103668. [PMID: 38417198 DOI: 10.1016/j.concog.2024.103668] [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: 05/24/2023] [Revised: 02/07/2024] [Accepted: 02/12/2024] [Indexed: 03/01/2024]
Abstract
How deep is the current diversity in the panoply of theories to define consciousness, and to what extent do these theories share common denominators? Here we first examine to what extent different theories are commensurable (or comparable) along particular dimensions. We posit logical (and, when applicable, empirical) commensurability as a necessary condition for identifying common denominators among different theories. By consequence, dimensions for inclusion in a set of logically and empirically commensurable theories of consciousness can be proposed. Next, we compare a limited subset of neuroscience-based theories in terms of commensurability. This analysis does not yield a denominator that might serve to define a minimally unifying model of consciousness. Theories that seem to be akin by one denominator can be remote by another. We suggest a methodology of comparing different theories via multiple probing questions, allowing to discern overall (dis)similarities between theories. Despite very different background definitions of consciousness, we conclude that, if attention is paid to the search for a common methological approach to brain-consciousness relationships, it should be possible in principle to overcome the current Babylonian confusion of tongues and eventually integrate and merge different theories.
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Affiliation(s)
- K Evers
- Centre for Research Ethics and Bioethics, Uppsala University, Uppsala, Sweden.
| | - M Farisco
- Centre for Research Ethics and Bioethics, Uppsala University, Uppsala, Sweden; Bioethics Unit, Biogem, Molecular Biology and Molecular Genetics Research Institute, Ariano Irpino (AV), Italy
| | - C M A Pennartz
- Department of Cognitive and Systems Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherland; Research Priority Area, Brain and Cognition, University of Amsterdam, Amsterdam, Netherlands
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7
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Ji X, Elmoznino E, Deane G, Constant A, Dumas G, Lajoie G, Simon J, Bengio Y. Sources of richness and ineffability for phenomenally conscious states. Neurosci Conscious 2024; 2024:niae001. [PMID: 38487679 PMCID: PMC10939345 DOI: 10.1093/nc/niae001] [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: 05/01/2023] [Revised: 01/03/2024] [Accepted: 01/23/2024] [Indexed: 03/17/2024] Open
Abstract
Conscious states-state that there is something it is like to be in-seem both rich or full of detail and ineffable or hard to fully describe or recall. The problem of ineffability, in particular, is a longstanding issue in philosophy that partly motivates the explanatory gap: the belief that consciousness cannot be reduced to underlying physical processes. Here, we provide an information theoretic dynamical systems perspective on the richness and ineffability of consciousness. In our framework, the richness of conscious experience corresponds to the amount of information in a conscious state and ineffability corresponds to the amount of information lost at different stages of processing. We describe how attractor dynamics in working memory would induce impoverished recollections of our original experiences, how the discrete symbolic nature of language is insufficient for describing the rich and high-dimensional structure of experiences, and how similarity in the cognitive function of two individuals relates to improved communicability of their experiences to each other. While our model may not settle all questions relating to the explanatory gap, it makes progress toward a fully physicalist explanation of the richness and ineffability of conscious experience-two important aspects that seem to be part of what makes qualitative character so puzzling.
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Affiliation(s)
- Xu Ji
- Mila - Quebec AI Institute, Montreal, Quebec H2S 3H1, Canada
- Department of Computer science and operations Research, University of Montreal, Pavillon André-Aisenstadt 2920, chemin de la Tour, Montreal, Quebec H3T 1J4, Canada
| | - Eric Elmoznino
- Mila - Quebec AI Institute, Montreal, Quebec H2S 3H1, Canada
- Department of Computer science and operations Research, University of Montreal, Pavillon André-Aisenstadt 2920, chemin de la Tour, Montreal, Quebec H3T 1J4, Canada
| | - George Deane
- Department of Philosophy, University of Montreal, Pavillon 2910, boul. Édouard-Montpetit, Montreal, Quebec H3C 3J7, Canada
| | - Axel Constant
- School of Engineering and Informatics, University of Sussex, Sussex House, Falmer, East Sussex BN1 9RH, United Kingdom
| | - Guillaume Dumas
- Mila - Quebec AI Institute, Montreal, Quebec H2S 3H1, Canada
- Department of Psychiatry and Addiction, University of Montreal, Pavillon Roger-Gaudry 2900, boul. Édouard-Montpetit, Montreal, Quebec H3T 1J4, Canada
| | - Guillaume Lajoie
- Mila - Quebec AI Institute, Montreal, Quebec H2S 3H1, Canada
- Department of Mathematics and Statistics, University of Montreal, Pavillon André-Aisenstadt (AA-5190) 2920, chemin de la Tour, Montreal, Quebec H3T 1J4, Canada
| | - Jonathan Simon
- Department of Philosophy, University of Montreal, Pavillon 2910, boul. Édouard-Montpetit, Montreal, Quebec H3C 3J7, Canada
| | - Yoshua Bengio
- Mila - Quebec AI Institute, Montreal, Quebec H2S 3H1, Canada
- Department of Computer science and operations Research, University of Montreal, Pavillon André-Aisenstadt 2920, chemin de la Tour, Montreal, Quebec H3T 1J4, Canada
- CIFAR - Canadian Institute for Advanced Research, MaRS Centre, West Tower 661 University Ave., Suite 505, Toronto, Ontario M5G 1M1, Canada
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8
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Levy R. The prefrontal cortex: from monkey to man. Brain 2024; 147:794-815. [PMID: 37972282 PMCID: PMC10907097 DOI: 10.1093/brain/awad389] [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: 06/05/2023] [Revised: 10/01/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023] Open
Abstract
The prefrontal cortex is so important to human beings that, if deprived of it, our behaviour is reduced to action-reactions and automatisms, with no ability to make deliberate decisions. Why does the prefrontal cortex hold such importance in humans? In answer, this review draws on the proximity between humans and other primates, which enables us, through comparative anatomical-functional analysis, to understand the cognitive functions we have in common and specify those that distinguish humans from their closest cousins. First, a focus on the lateral region of the prefrontal cortex illustrates the existence of a continuum between rhesus monkeys (the most studied primates in neuroscience) and humans for most of the major cognitive functions in which this region of the brain plays a central role. This continuum involves the presence of elementary mental operations in the rhesus monkey (e.g. working memory or response inhibition) that are constitutive of 'macro-functions' such as planning, problem-solving and even language production. Second, the human prefrontal cortex has developed dramatically compared to that of other primates. This increase seems to concern the most anterior part (the frontopolar cortex). In humans, the development of the most anterior prefrontal cortex is associated with three major and interrelated cognitive changes: (i) a greater working memory capacity, allowing for greater integration of past experiences and prospective futures; (ii) a greater capacity to link discontinuous or distant data, whether temporal or semantic; and (iii) a greater capacity for abstraction, allowing humans to classify knowledge in different ways, to engage in analogical reasoning or to acquire abstract values that give rise to our beliefs and morals. Together, these new skills enable us, among other things, to develop highly sophisticated social interactions based on language, enabling us to conceive beliefs and moral judgements and to conceptualize, create and extend our vision of our environment beyond what we can physically grasp. Finally, a model of the transition of prefrontal functions between humans and non-human primates concludes this review.
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Affiliation(s)
- Richard Levy
- AP–HP, Groupe Hospitalier Pitié-Salpêtrière, Department of Neurology, Sorbonne Université, Institute of Memory and Alzheimer’s Disease, 75013 Paris, France
- Sorbonne Université, INSERM U1127, CNRS 7225, Paris Brain Institute- ICM, 75013 Paris, France
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9
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Young MJ, Fecchio M, Bodien YG, Edlow BL. Covert cortical processing: a diagnosis in search of a definition. Neurosci Conscious 2024; 2024:niad026. [PMID: 38327828 PMCID: PMC10849751 DOI: 10.1093/nc/niad026] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 10/22/2023] [Accepted: 12/10/2023] [Indexed: 02/09/2024] Open
Abstract
Historically, clinical evaluation of unresponsive patients following brain injury has relied principally on serial behavioral examination to search for emerging signs of consciousness and track recovery. Advances in neuroimaging and electrophysiologic techniques now enable clinicians to peer into residual brain functions even in the absence of overt behavioral signs. These advances have expanded clinicians' ability to sub-stratify behaviorally unresponsive and seemingly unaware patients following brain injury by querying and classifying covert brain activity made evident through active or passive neuroimaging or electrophysiologic techniques, including functional MRI, electroencephalography (EEG), transcranial magnetic stimulation-EEG, and positron emission tomography. Clinical research has thus reciprocally influenced clinical practice, giving rise to new diagnostic categories including cognitive-motor dissociation (i.e. 'covert consciousness') and covert cortical processing (CCP). While covert consciousness has received extensive attention and study, CCP is relatively less understood. We describe that CCP is an emerging and clinically relevant state of consciousness marked by the presence of intact association cortex responses to environmental stimuli in the absence of behavioral evidence of stimulus processing. CCP is not a monotonic state but rather encapsulates a spectrum of possible association cortex responses from rudimentary to complex and to a range of possible stimuli. In constructing a roadmap for this evolving field, we emphasize that efforts to inform clinicians, philosophers, and researchers of this condition are crucial. Along with strategies to sensitize diagnostic criteria and disorders of consciousness nosology to these vital discoveries, democratizing access to the resources necessary for clinical identification of CCP is an emerging clinical and ethical imperative.
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Affiliation(s)
- Michael J Young
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA 02114, USA
| | - Matteo Fecchio
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA 02114, USA
| | - Yelena G Bodien
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA 02114, USA
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, 300 1st Ave, Charlestown, Boston, MA 02129, USA
| | - Brian L Edlow
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA 02114, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, 149 13th St, Charlestown, Charlestown, MA 02129, USA
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10
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Jiang Y, Sleigh J. Consciousness and General Anesthesia: Challenges for Measuring the Depth of Anesthesia. Anesthesiology 2024; 140:313-328. [PMID: 38193734 DOI: 10.1097/aln.0000000000004830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
The optimal consciousness level required for general anesthesia with surgery is unclear, but in existing practice, anesthetic oblivion, may be incomplete. This article discusses the concept of consciousness, how it is altered by anesthetics, the challenges for assessing consciousness, currently used technologies for assessing anesthesia levels, and future research directions. Wakefulness is marked by a subjective experience of existence (consciousness), perception of input from the body or the environment (connectedness), the ability for volitional responsiveness, and a sense of continuity in time. Anesthetic drugs may selectively impair some of these components without complete extinction of the subjective experience of existence. In agreement with Sanders et al. (2012), the authors propose that a state of disconnected consciousness is the optimal level of anesthesia, as it likely avoids both awareness and the possible dangers of oversedation. However, at present, there are no reliably tested indices that can discriminate between connected consciousness, disconnected consciousness, and complete unconsciousness.
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Affiliation(s)
- Yandong Jiang
- Department of Anesthesiology, Critical Care and Pain Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Jamie Sleigh
- Department of Anesthesiology, University of Auckland, Hamilton, New Zealand
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11
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Hartung T, Morales Pantoja IE, Smirnova L. Brain organoids and organoid intelligence from ethical, legal, and social points of view. Front Artif Intell 2024; 6:1307613. [PMID: 38249793 PMCID: PMC10796793 DOI: 10.3389/frai.2023.1307613] [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: 10/04/2023] [Accepted: 12/07/2023] [Indexed: 01/23/2024] Open
Abstract
Human brain organoids, aka cerebral organoids or earlier "mini-brains", are 3D cellular models that recapitulate aspects of the developing human brain. They show tremendous promise for advancing our understanding of neurodevelopment and neurological disorders. However, the unprecedented ability to model human brain development and function in vitro also raises complex ethical, legal, and social challenges. Organoid Intelligence (OI) describes the ongoing movement to combine such organoids with Artificial Intelligence to establish basic forms of memory and learning. This article discusses key issues regarding the scientific status and prospects of brain organoids and OI, conceptualizations of consciousness and the mind-brain relationship, ethical and legal dimensions, including moral status, human-animal chimeras, informed consent, and governance matters, such as oversight and regulation. A balanced framework is needed to allow vital research while addressing public perceptions and ethical concerns. Interdisciplinary perspectives and proactive engagement among scientists, ethicists, policymakers, and the public can enable responsible translational pathways for organoid technology. A thoughtful, proactive governance framework might be needed to ensure ethically responsible progress in this promising field.
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Affiliation(s)
- Thomas Hartung
- Center for Alternatives to Animal Testing (CAAT), Health and Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
- CAAT-Europe, University of Konstanz, Konstanz, Germany
| | - Itzy E. Morales Pantoja
- Center for Alternatives to Animal Testing (CAAT), Health and Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Lena Smirnova
- Center for Alternatives to Animal Testing (CAAT), Health and Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
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12
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Brown SAB. How to get rich from inflation. Conscious Cogn 2024; 117:103624. [PMID: 38150781 DOI: 10.1016/j.concog.2023.103624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 12/29/2023]
Abstract
We seem to have rich experience across our visual field. Yet we are surprisingly poor at tasks involving the periphery and low spatial attention. Recently, Lau and collaborators have argued that a phenomenon known as "subjective inflation" allows us to reconcile these phenomena. I show inflation is consistent with multiple interpretations, with starkly different consequences for richness and for theories of consciousness more broadly. What's more, we have only weak reasons favouring any of these interpretations over the others. I provisionally argue for an interpretation on which subjective experience is genuinely rich, but (in peripheral/unattended areas) unreliable as a guide to the external world. The main challenge for this view is that it appears to imply that experience in the periphery is not just unreliable but unstable. However, I argue that this consequence, while initially appearing unintuitive, is in fact plausible.
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13
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Sangare A, Quirins M, Marois C, Valente M, Weiss N, Perez P, Ben Salah A, Munoz-Musat E, Demeret S, Rohaut B, Sitt JD, Eymond C, Naccache L. Pupil dilation response elicited by violations of auditory regularities is a promising but challenging approach to probe consciousness at the bedside. Sci Rep 2023; 13:20331. [PMID: 37989756 PMCID: PMC10663629 DOI: 10.1038/s41598-023-47806-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 11/18/2023] [Indexed: 11/23/2023] Open
Abstract
Pupil dilation response (PDR) has been proposed as a physiological marker of conscious access to a stimulus or its attributes, such as novelty. In a previous study on healthy volunteers, we adapted the auditory "local global" paradigm and showed that violations of global regularity elicited a PDR. Notably without instructions, this global effect was present only in participants who could consciously report violations of global regularities. In the present study, we used a similar approach in 24 non-communicating patients affected with a Disorder of Consciousness (DoC) and compared PDR to ERPs regarding diagnostic and prognostic performance. At the group level, global effect could not be detected in DoC patients. At the individual level, the only patient with a PDR global effect was in a MCS and recovered consciousness at 6 months. Contrasting the most regular trials to the most irregular ones improved PDR's diagnostic and prognostic power in DoC patients. Pupillometry is a promising tool but requires several methodological improvements to enhance the signal-to-noise ratio and make it more robust for probing consciousness and cognition in DoC patients.
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Affiliation(s)
- Aude Sangare
- Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Charles Foix, Département de Neurophysiologie, Sorbonne Université, Paris, France.
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France.
| | - Marion Quirins
- Département de Neurologie, Hôpital Fondation Adolphe de Rothschild, Paris, France
| | - Clémence Marois
- AP-HP.Sorbonne Université, Hôpital Pitié-Salpêtrière, Département de Neurologie, Unité de Médecine Intensive et Réanimation à Orientation Neurologique & Groupe de Recherche Clinique en REanimation et Soins Intensifs du Patient en Insuffisance Respiratoire aiguE (GRC-RESPIRE) Sorbonne Université, Sorbonne Université, Paris, France
| | - Mélanie Valente
- Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Charles Foix, Département de Neurophysiologie, Sorbonne Université, Paris, France
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France
| | - Nicolas Weiss
- AP-HP.Sorbonne Université, Hôpital Pitié-Salpêtrière, Département de Neurologie, Unité de Médecine Intensive et Réanimation à Orientation Neurologique & Groupe de Recherche Clinique en REanimation et Soins Intensifs du Patient en Insuffisance Respiratoire aiguE (GRC-RESPIRE) Sorbonne Université, Sorbonne Université, Paris, France
- Brain Liver Pitié-Salpêtrière (BLIPS) Study Group, INSERM UMR_S 938, Centre de Recherche Saint-Antoine (CRSA), Maladies Métaboliques, Biliaires et Fibro-Inflammatoire du Foie & Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Pauline Perez
- Anesthesia and Intensive Care Unit, Lyon Medical Intensive Care Unit, Edouard, Herriot Hospital, Hospices Civils de Lyon, 69437, Lyon, France
| | - Amina Ben Salah
- Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Charles Foix, Département de Neurophysiologie, Sorbonne Université, Paris, France
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France
| | - Esteban Munoz-Musat
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France
| | - Sophie Demeret
- AP-HP.Sorbonne Université, Hôpital Pitié-Salpêtrière, Département de Neurologie, Unité de Médecine Intensive et Réanimation à Orientation Neurologique & Groupe de Recherche Clinique en REanimation et Soins Intensifs du Patient en Insuffisance Respiratoire aiguE (GRC-RESPIRE) Sorbonne Université, Sorbonne Université, Paris, France
| | - Benjamin Rohaut
- Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Charles Foix, Département de Neurophysiologie, Sorbonne Université, Paris, France
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France
| | - Jacobo D Sitt
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France
| | - Cecile Eymond
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France
| | - Lionel Naccache
- Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Charles Foix, Département de Neurophysiologie, Sorbonne Université, Paris, France.
- INSERM U 1127, PICNIC, Lab, Institut du Cerveau et de la Moelle Épinière, ICM, 75013, Paris, France.
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14
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Türker B, Musat EM, Chabani E, Fonteix-Galet A, Maranci JB, Wattiez N, Pouget P, Sitt J, Naccache L, Arnulf I, Oudiette D. Behavioral and brain responses to verbal stimuli reveal transient periods of cognitive integration of the external world during sleep. Nat Neurosci 2023; 26:1981-1993. [PMID: 37828228 PMCID: PMC10620087 DOI: 10.1038/s41593-023-01449-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/05/2023] [Indexed: 10/14/2023]
Abstract
Sleep has long been considered as a state of behavioral disconnection from the environment, without reactivity to external stimuli. Here we questioned this 'sleep disconnection' dogma by directly investigating behavioral responsiveness in 49 napping participants (27 with narcolepsy and 22 healthy volunteers) engaged in a lexical decision task. Participants were instructed to frown or smile depending on the stimulus type. We found accurate behavioral responses, visible via contractions of the corrugator or zygomatic muscles, in most sleep stages in both groups (except slow-wave sleep in healthy volunteers). Across sleep stages, responses occurred more frequently when stimuli were presented during high cognitive states than during low cognitive states, as indexed by prestimulus electroencephalography. Our findings suggest that transient windows of reactivity to external stimuli exist during bona fide sleep, even in healthy individuals. Such windows of reactivity could pave the way for real-time communication with sleepers to probe sleep-related mental and cognitive processes.
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Affiliation(s)
- Başak Türker
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Esteban Munoz Musat
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Emma Chabani
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | | | - Jean-Baptiste Maranci
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Nicolas Wattiez
- Sorbonne Université, INSERM, Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - Pierre Pouget
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Jacobo Sitt
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Lionel Naccache
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière, Service de Neurophysiologie Clinique, Paris, France
| | - Isabelle Arnulf
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Delphine Oudiette
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France.
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France.
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15
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Humans can intermittently respond to verbal stimuli when sleeping. Nat Neurosci 2023; 26:1840-1841. [PMID: 37828229 DOI: 10.1038/s41593-023-01450-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
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16
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Amir YZ, Assaf Y, Yovel Y, Mudrik L. Experiencing without knowing? Empirical evidence for phenomenal consciousness without access. Cognition 2023; 238:105529. [PMID: 37393795 DOI: 10.1016/j.cognition.2023.105529] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 06/16/2023] [Indexed: 07/04/2023]
Abstract
Can one have a phenomenal experience to which one does not have access? That is, can you experience something without knowing? The dissociation between phenomenal (P) and access (A) consciousness is widely debated. A major challenge to the supporters of this dissociation is the apparent inability to experimentally demonstrate that P-without-A consciousness exists; once participants report having a P-experience, they already have access to it. Thus, all previous empirical support for this dissociation is indirect. Here, using a novel paradigm, we create a situation where participants (Experiment 1, N = 40) lack online access to the stimulus yet are nevertheless able to retrospectively form judgements on its phenomenal, qualitative aspects. We further show that their performance cannot be fully explained by unconscious processing or by a response to stimulus offset (Experiment 2, N = 40). This suggests that P and A consciousness are not only conceptually distinct, but might also be teased apart empirically. STATEMENT OF RELEVANCE: A critical question in the scientific quest towards solving the problem of consciousness focuses on the ability to isolate conscious experiences at their purity, without any accompanying cognitive processes. This challenge has been augmented by a highly influential - yet controversial - dissociation suggested by the philosopher Ned Block between Phenomenal consciousness, or the "what it is like" to have an experience, and Access consciousness, indexing the ability to report that one has that experience. Critically, these two types of consciousness most typically go together, making it highly difficult - if not impossible - to isolate Phenomenal consciousness. Our work shows that the dissociation between phenomenal and access consciousness is not merely conceptual, but can also be empirically demonstrated. It further opens the gate to future studies pinpointing the neural correlates of the two types of consciousness.
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Affiliation(s)
- Yoni Zion Amir
- Sagol School for Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Yaniv Assaf
- Sagol School for Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel; School of neurobiology, biochemistry and biophysics, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yossi Yovel
- Sagol School for Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel; School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Liad Mudrik
- Sagol School for Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel; School of Psychological Sciences, Tel-Aviv University, Tel Aviv 69978, Israel.
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17
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Farisco M, Changeux JP. About the compatibility between the perturbational complexity index and the global neuronal workspace theory of consciousness. Neurosci Conscious 2023; 2023:niad016. [PMID: 37342235 PMCID: PMC10279414 DOI: 10.1093/nc/niad016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/18/2023] [Accepted: 05/31/2023] [Indexed: 06/22/2023] Open
Abstract
This paper investigates the compatibility between the theoretical framework of the global neuronal workspace theory (GNWT) of conscious processing and the perturbational complexity index (PCI). Even if it has been introduced within the framework of a concurrent theory (i.e. Integrated Information Theory), PCI appears, in principle, compatible with the main tenet of GNWT, which is a conscious process that depends on a long-range connection between different cortical regions, more specifically on the amplification, global propagation, and integration of brain signals. Notwithstanding this basic compatibility, a number of limited compatibilities and apparent differences emerge. This paper starts from the description of brain complexity, a notion that is crucial for PCI, to then summary of the main features of PCI and the main tenets of GNWT. Against this background, the text explores the compatibility between PCI and GNWT. It concludes that GNWT and PCI are fundamentally compatible, even though there are some partial disagreements and some points to further examine.
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Affiliation(s)
- Michele Farisco
- *Corresponding author. Centre for Research Ethics & Bioethics (CRB), Uppsala University, Box 564, Uppsala SE-751 22. E-mail:
| | - Jean-Pierre Changeux
- Neuroscience Department, Institut Pasteur, 25-28 Rue du Dr Roux, Paris 75015, France
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18
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Yurchenko SB. A systematic approach to brain dynamics: cognitive evolution theory of consciousness. Cogn Neurodyn 2023; 17:575-603. [PMID: 37265655 PMCID: PMC10229528 DOI: 10.1007/s11571-022-09863-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/29/2022] [Accepted: 07/21/2022] [Indexed: 12/18/2022] Open
Abstract
The brain integrates volition, cognition, and consciousness seamlessly over three hierarchical (scale-dependent) levels of neural activity for their emergence: a causal or 'hard' level, a computational (unconscious) or 'soft' level, and a phenomenal (conscious) or 'psyche' level respectively. The cognitive evolution theory (CET) is based on three general prerequisites: physicalism, dynamism, and emergentism, which entail five consequences about the nature of consciousness: discreteness, passivity, uniqueness, integrity, and graduation. CET starts from the assumption that brains should have primarily evolved as volitional subsystems of organisms, not as prediction machines. This emphasizes the dynamical nature of consciousness in terms of critical dynamics to account for metastability, avalanches, and self-organized criticality of brain processes, then coupling it with volition and cognition in a framework unified over the levels. Consciousness emerges near critical points, and unfolds as a discrete stream of momentary states, each volitionally driven from oldest subcortical arousal systems. The stream is the brain's way of making a difference via predictive (Bayesian) processing. Its objective observables could be complexity measures reflecting levels of consciousness and its dynamical coherency to reveal how much knowledge (information gain) the brain acquires over the stream. CET also proposes a quantitative classification of both disorders of consciousness and mental disorders within that unified framework.
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19
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White PA. Time marking in perception. Neurosci Biobehav Rev 2023; 146:105043. [PMID: 36642288 DOI: 10.1016/j.neubiorev.2023.105043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/21/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
Several authors have proposed that perceptual information carries labels that identify temporal features, including time of occurrence, ordinal temporal relations, and brief durations. These labels serve to locate and organise perceptual objects, features, and events in time. In some proposals time marking has local, specific functions such as synchronisation of different features in perceptual processing. In other proposals time marking has general significance and is responsible for rendering perceptual experience temporally coherent, just as various forms of spatial information render the visual environment spatially coherent. These proposals, which all concern time marking on the millisecond time scale, are reviewed. It is concluded that time marking is vital to the construction of a multisensory perceptual world in which things are orderly with respect to both space and time, but that much more research is needed to ascertain its functions in perception and its neurophysiological foundations.
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Affiliation(s)
- Peter A White
- School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff CF10 3YG, Wales, UK.
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20
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Fesce R. Imagination: The dawn of consciousness: Fighting some misconceptions in the discussion about consciousness. Physiol Behav 2023; 259:114035. [PMID: 36403782 DOI: 10.1016/j.physbeh.2022.114035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/26/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022]
Abstract
Several theories of consciousness (ToC) have been proposed, but it is hard to integrate them into a consensus theory. Each theory has its merits, in dealing with some aspects of the question, but the terminology is inconsistent, each ToC aims at answering a different question, and there is not even a reasonable agreement about what 'consciousness' is in the first place. Some common implicit assumptions, and the way some critical words - such as 'sensation', 'perception', 'neural correlate of consciousness' (NCC) - are thought to relate to consciousness, have introduced a series of misconceptions that make it difficult to pinpoint what consciousness consists in and how it arises in the brain. The purpose of this contribution is twofold: firstly, to discern the various steps that lead from the detection of a stimulus to a conscious experience, by redefining terms such as sensation and perception with an adequate operative meaning; secondly, to emphasize the inevitable contribution of emotions and the active role of imagination in this process. The diffuse view, for the layperson but among scientists as well, is that the brain produces an internal 'representation' of the external reality and of oneself. This tends to consign one to a Cartesian perspective, i.e., the idea that some entity must be there to witness and interpret such representation. This approach splits the conscious experience into brain activity, which generates a (possible) content of consciousness (still unconscious), and a vaguely defined entity or process that 'generates' consciousness and injects (or sheds the light of) consciousness onto the content of brain activity. This way, however, we learn nothing about how such consciousness would arise. We propose here that consciousness is the function that generates a subjectively relevant and emotionally coloured internal image of the experience one is living. In this process, endogenous, spontaneous activity (imaginative activity, consisting in recalling and reviving memories, prefiguring consequences, analysing conjectures) produces many vague and ambiguous hints, rich of symbolic links, which compete in giving rise to an implicit, emotionally characterized, and semantically pleiotropic, internal experience. Cognitive elaboration may extract from this a defined and univocal, complete and consistent, explicit experience, that can be verbally reported ('what it is like to...').
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Affiliation(s)
- Riccardo Fesce
- Department of Biomedical Sciences - Humanitas University Medical School.
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21
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Chiarella SG, Simione L, D'Angiò M, Raffone A, Di Pace E. The mechanisms of selective attention in phenomenal consciousness. Conscious Cogn 2023; 107:103446. [PMID: 36508897 DOI: 10.1016/j.concog.2022.103446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 10/15/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022]
Abstract
In three experiments we investigated the effects of selective attention in iconic memory and fragile-visual short-term memory (VSTM), which have been related to phenomenal consciousness. We used a novel retro-cue paradigm with different delays (early vs late) and object priorities (high vs equal vs low), to investigate (a) attentional costs and benefits and the role of (b) bottom-up factors and (c) fragile-VSTM in feature-based attentional selection. Experiment 1 showed that attentional costs modulate visual maintenance at longer delays, while Experiment 2 showed that by reducing the time exposure of the memory array from 250 ms to 100 ms, as a bottom-up factor, participants were not able to select the objects based on their priorities. Finally, Experiment 3 showed that a pattern mask presented before the transfer in visual working memory, attenuates the overall performance while preserving the priority effect. The implications for phenomenal consciousness before conscious access are discussed.
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Affiliation(s)
- Salvatore G Chiarella
- Sapienza University of Rome, Department of Psychology, Rome, Italy; Institute of Cognitive Sciences and Technologies (ISTC), National Research Council (CNR), Rome, Italy.
| | - Luca Simione
- Institute of Cognitive Sciences and Technologies (ISTC), National Research Council (CNR), Rome, Italy
| | - Monia D'Angiò
- Sapienza University of Rome, Department of Psychology, Rome, Italy
| | - Antonino Raffone
- Sapienza University of Rome, Department of Psychology, Rome, Italy; ECONA, Interuniversity Center, Rome, Italy; School of Buddhist Studies, Philosophy, and Comparative Religions, Nalanda University, Rajgir, India
| | - Enrico Di Pace
- Sapienza University of Rome, Department of Psychology, Rome, Italy
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22
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Yurchenko SB. From the origins to the stream of consciousness and its neural correlates. Front Integr Neurosci 2022; 16:928978. [PMID: 36407293 PMCID: PMC9672924 DOI: 10.3389/fnint.2022.928978] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 10/12/2022] [Indexed: 09/22/2023] Open
Abstract
There are now dozens of very different theories of consciousness, each somehow contributing to our understanding of its nature. The science of consciousness needs therefore not new theories but a general framework integrating insights from those, yet not making it a still-born "Frankenstein" theory. First, the framework must operate explicitly on the stream of consciousness, not on its static description. Second, this dynamical account must also be put on the evolutionary timeline to explain the origins of consciousness. The Cognitive Evolution Theory (CET), outlined here, proposes such a framework. This starts with the assumption that brains have primarily evolved as volitional subsystems of organisms, inherited from primitive (fast and random) reflexes of simplest neural networks, only then resembling error-minimizing prediction machines. CET adopts the tools of critical dynamics to account for metastability, scale-free avalanches, and self-organization which are all intrinsic to brain dynamics. This formalizes the stream of consciousness as a discrete (transitive, irreflexive) chain of momentary states derived from critical brain dynamics at points of phase transitions and mapped then onto a state space as neural correlates of a particular conscious state. The continuous/discrete dichotomy appears naturally between the brain dynamics at the causal level and conscious states at the phenomenal level, each volitionally triggered from arousal centers of the brainstem and cognitively modulated by thalamocortical systems. Their objective observables can be entropy-based complexity measures, reflecting the transient level or quantity of consciousness at that moment.
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23
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Signorelli CM, Boils JD, Tagliazucchi E, Jarraya B, Deco G. From Brain-Body Function to Conscious Interactions. Neurosci Biobehav Rev 2022; 141:104833. [PMID: 36037978 DOI: 10.1016/j.neubiorev.2022.104833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/06/2022] [Accepted: 08/18/2022] [Indexed: 11/15/2022]
Abstract
In this review, we discuss empirical results inspiring the introduction of a formal mathematical multilayer model for the biological neuroscience of conscious experience. First, we motivate the discussion through evidence regarding the dynamic brain. Second, we review different brain-body couplings associated with conscious experience and its potential role in driving brain dynamics. Third, we introduce the machinery of multilayer networks to account for several types of interactions in brain-body systems. Then, a multilayer structure consists of two main generalizations: a formal semantic to study biological systems, and an integrative account for several signatures and models of consciousness. Finally, under this framework, we define composition of layers to account for entangled features of brain-body systems related to conscious experience. As such, a multilayer mathematical framework is highly integrative and thus may be more complete than other models. In this short review, we discuss a variety of empirical results inspiring the introduction of a formal mathematical multilayer model for the biological neuroscience of conscious experience.
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Affiliation(s)
- Camilo Miguel Signorelli
- Department of Computer Science, University of Oxford, Oxford, 7 Parks Rd, OxfordOX1 3QG, United Kingdom; Physiology of Cognition, GIGA-CRC In Vivo Imaging, Allée du 6 Août, 8 (B30), 4000 Sart Tilman, University of Liège, Belgium; Cognitive Neuroimaging Unit, INSERM, CEA, CNRS, Université Paris-Saclay, NeuroSpin center, 91191 Gif/Yvette, France; Computational Neuroscience Group, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain.
| | - Joaquín Díaz Boils
- Universidad Internacional de La Rioja, Avda La Paz, 137, Logroño, La Rioja, Spain
| | - Enzo Tagliazucchi
- Physics Department, University of Buenos Aires, Buenos Aires, Argentina
| | - Bechir Jarraya
- Cognitive Neuroimaging Unit, INSERM, CEA, CNRS, Université Paris-Saclay, NeuroSpin center, 91191 Gif/Yvette, France
| | - Gustavo Deco
- Computational Neuroscience Group, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain
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24
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Neural responses to sensory novelty with and without conscious access. Neuroimage 2022; 262:119516. [PMID: 35931308 DOI: 10.1016/j.neuroimage.2022.119516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/11/2022] [Accepted: 07/24/2022] [Indexed: 11/23/2022] Open
Abstract
Detection of novel stimuli that violate statistical regularities in the sensory scene is of paramount importance for the survival of biological organisms. Event-related potentials, phasic increases in pupil size, and evoked changes in oscillatory power have been proposed as markers of sensory novelty detection. However, how conscious access to novelty modulates these different brain responses is not well understood. Here, we studied the neural responses to sensory novelty in the auditory modality with and without conscious access. We identified individual thresholds for conscious auditory discrimination and presented to our participants sequences of tones, where the last stimulus could be another standard, a subthreshold target or a suprathreshold target. Participants were instructed to report whether the last tone of each sequence was the same or different from those preceding it. Results indicate that attentional orientation to behaviorally relevant stimuli and overt decision-making mechanisms, indexed by the P3 event-related response and reaction times, best predict whether a novel stimulus will be consciously accessed. Theta power and pupil size do not predict conscious access to novelty, but instead reflect information maintenance and unexpected sensory uncertainty. These results highlight the interplay between bottom-up and top-down mechanisms and how the brain weights neural responses to novelty and uncertainty during perception and goal-directed behavior.
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25
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Falsaperla R, Collotta AD, Spatuzza M, Familiari M, Vitaliti G, Ruggieri M. Evidences of emerging pain consciousness during prenatal development: a narrative review. Neurol Sci 2022; 43:3523-3532. [PMID: 35246816 PMCID: PMC9120116 DOI: 10.1007/s10072-022-05968-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/22/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND The study of consciousness has always been considered a challenge for neonatologists, even more when considering the uterine period. Our review aimed to individuate at what gestational age the fetus, which later became a premature infant, can feel the perception of external stimuli. Therefore, the aim of our review was to study the onset of consciousness during the fetal life. MATERIALS AND METHODS A literature search was performed in Medline-PubMed database. We included all papers found with the following MeSH words: "consciousness or cognition or awareness or comprehension or cognitive or consciousness of pain" in combination with "embryo or fetus or fetal life or newborn." Studies were selected if titles and/or abstracts suggested an association between formation of consciousness (the basics of neurodevelopment) and preterm infant or fetus. Titles and abstracts were first screened by three independent reviewers according to Cochrane Collaboration's recommendations. RESULTS From the literature review, we found only 8 papers describing the onset of consciousness in the transition period from fetus to premature newborn. Therefore, according to these papers, we temporally analyzed the formation of the thalamocortical connections that are the basis of consciousness. CONCLUSIONS We can conclude that from a neuroanatomical point of view, it is rather unlikely that the infant can be seen as a conscious human before 24 weeks of gestational age, thus before all the thalamocortical connections are established. Further literature data have to confirm this hypothesis.
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Affiliation(s)
- Raffaele Falsaperla
- Neonatal Intensive Care Unit and Neonatal Accompaniment Unit, Azienda Ospedaliero-Universitaria Policlinico "Rodolico-San Marco," San Marco Hospital, University of Catania, Catania, Italy.
- Unit of Clinical PaediatricsAzienda Ospedaliero-Universitaria Policlinico"Rodolico-San Marco", San Marco Hospital, Catania, Italy.
| | - Ausilia Desiree Collotta
- Postgraduate Training Program in Pediatrics, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Michela Spatuzza
- Institute for Biomedical Research and Innovation - The National Research Council of Italy (IRIB-CNR), Catania, Italy
| | - Maria Familiari
- Postgraduate Training Program in Pediatrics, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Giovanna Vitaliti
- Unit of Pediatrics, Department of Medical Sciences, Section of Pediatrics, University Hospital Sant'Anna, University of Ferrara, Ferrara, Italy.
| | - Martino Ruggieri
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, AOU "Policlinico," PO "G. Rodolico," Via S. Sofia, 87, 95128, Catania, Italy
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Abstract
Recent years have seen a blossoming of theories about the biological and physical basis of consciousness. Good theories guide empirical research, allowing us to interpret data, develop new experimental techniques and expand our capacity to manipulate the phenomenon of interest. Indeed, it is only when couched in terms of a theory that empirical discoveries can ultimately deliver a satisfying understanding of a phenomenon. However, in the case of consciousness, it is unclear how current theories relate to each other, or whether they can be empirically distinguished. To clarify this complicated landscape, we review four prominent theoretical approaches to consciousness: higher-order theories, global workspace theories, re-entry and predictive processing theories and integrated information theory. We describe the key characteristics of each approach by identifying which aspects of consciousness they propose to explain, what their neurobiological commitments are and what empirical data are adduced in their support. We consider how some prominent empirical debates might distinguish among these theories, and we outline three ways in which theories need to be developed to deliver a mature regimen of theory-testing in the neuroscience of consciousness. There are good reasons to think that the iterative development, testing and comparison of theories of consciousness will lead to a deeper understanding of this most profound of mysteries.
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Mason GJ, Lavery JM. What Is It Like to Be a Bass? Red Herrings, Fish Pain and the Study of Animal Sentience. Front Vet Sci 2022; 9:788289. [PMID: 35573409 PMCID: PMC9094623 DOI: 10.3389/fvets.2022.788289] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 02/25/2022] [Indexed: 11/13/2022] Open
Abstract
Debates around fishes' ability to feel pain concern sentience: do reactions to tissue damage indicate evaluative consciousness (conscious affect), or mere nociception? Thanks to Braithwaite's discovery of trout nociceptors, and concerns that current practices could compromise welfare in countless fish, this issue's importance is beyond dispute. However, nociceptors are merely necessary, not sufficient, for true pain, and many measures held to indicate sentience have the same problem. The question of whether fish feel pain - or indeed anything at all - therefore stimulates sometimes polarized debate. Here, we try to bridge the divide. After reviewing key consciousness concepts, we identify "red herring" measures that should not be used to infer sentience because also present in non-sentient organisms, notably those lacking nervous systems, like plants and protozoa (P); spines disconnected from brains (S); decerebrate mammals and birds (D); and humans in unaware states (U). These "S.P.U.D. subjects" can show approach/withdrawal; react with apparent emotion; change their reactivity with food deprivation or analgesia; discriminate between stimuli; display Pavlovian learning, including some forms of trace conditioning; and even learn simple instrumental responses. Consequently, none of these responses are good indicators of sentience. Potentially more valid are aspects of working memory, operant conditioning, the self-report of state, and forms of higher order cognition. We suggest new experiments on humans to test these hypotheses, as well as modifications to tests for "mental time travel" and self-awareness (e.g., mirror self-recognition) that could allow these to now probe sentience (since currently they reflect perceptual rather than evaluative, affective aspects of consciousness). Because "bullet-proof" neurological and behavioral indicators of sentience are thus still lacking, agnosticism about fish sentience remains widespread. To end, we address how to balance such doubts with welfare protection, discussing concerns raised by key skeptics in this debate. Overall, we celebrate the rigorous evidential standards required by those unconvinced that fish are sentient; laud the compassion and ethical rigor shown by those advocating for welfare protections; and seek to show how precautionary principles still support protecting fish from physical harm.
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Affiliation(s)
- G. J. Mason
- Integrative Biology, University of Guelph, Guelph, ON, Canada
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Munoz Musat E, Rohaut B, Sangare A, Benhaiem JM, Naccache L. Hypnotic Induction of Deafness to Elementary Sounds: An Electroencephalography Case-Study and a Proposed Cognitive and Neural Scenario. Front Neurosci 2022; 16:756651. [PMID: 35368254 PMCID: PMC8969744 DOI: 10.3389/fnins.2022.756651] [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: 08/10/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Hypnosis can be conceived as a unique opportunity to explore how top-down effects can influence various conscious and non-conscious processes. In the field of perception, such modulatory effects have been described in distinct sensory modalities. In the present study we focused on the auditory channel and aimed at creating a radical deafness to elementary sounds by a specific hypnotic suggestion. We report here a single case-study in a highly suggestible healthy volunteer who reported a total hypnotically suggested deafness. We recorded high-density scalp EEG during an auditory odd-ball paradigm before and after hypnotic deafness suggestion. While both early auditory event-related potentials to sounds (P1) and mismatch negativity component were not affected by hypnotic deafness, we observed a total disappearance of the late P3 complex component when the subject reported being deaf. Moreover, a centro-mesial positivity was present exclusively during the hypnotic condition prior to the P3 complex. Interestingly, source localization suggested an anterior cingulate cortex (ACC) origin of this neural event. Multivariate decoding analyses confirmed and specified these findings. Resting state analyses confirmed a similar level of conscious state in both conditions, and suggested a functional disconnection between auditory areas and other cortical areas. Taken together these results suggest the following plausible scenario: (i) preserved early processing of auditory information unaffected by hypnotic suggestion, (ii) conscious setting of an inhibitory process (ACC) preventing conscious access to sounds, (iii) functional disconnection between the modular and unconscious representations of sounds and global neuronal workspace. This single subject study presents several limits that are discussed and remains open to alternative interpretations. This original proof-of-concept paves the way to a larger study that will test the predictions stemming from our theoretical model and from this first report.
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Affiliation(s)
- Esteban Munoz Musat
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
- *Correspondence: Esteban Munoz Musat, ,
| | - Benjamin Rohaut
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
- Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique–Hôpitaux de Paris, Paris, France
| | - Aude Sangare
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
| | | | - Lionel Naccache
- INSERM U1127, CNRS 7225, Paris Brain Institute, Paris, France
- Sorbonne Université, Paris, France
- Department of Neurophysiology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique–Hôpitaux de Paris, Paris, France
- Lionel Naccache,
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29
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Hermann B, Sangaré A, Munoz-Musat E, Salah AB, Perez P, Valente M, Faugeras F, Axelrod V, Demeret S, Marois C, Pyatigorskaya N, Habert MO, Kas A, Sitt JD, Rohaut B, Naccache L. Importance, limits and caveats of the use of “disorders of consciousness” to theorize consciousness. Neurosci Conscious 2022; 2021:niab048. [PMID: 35369675 PMCID: PMC8966966 DOI: 10.1093/nc/niab048] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 12/21/2021] [Accepted: 01/27/2022] [Indexed: 11/13/2022] Open
Abstract
The clinical and fundamental exploration of patients suffering from disorders of consciousness (DoC) is commonly used by researchers both to test some of their key theoretical predictions and to serve as a unique source of empirical knowledge about possible dissociations between consciousness and cognitive and/or neural processes. For instance, the existence of states of vigilance free of any self-reportable subjective experience [e.g. “vegetative state (VS)” and “complex partial epileptic seizure”] originated from DoC and acted as a cornerstone for all theories by dissociating two concepts that were commonly equated and confused: vigilance and conscious state. In the present article, we first expose briefly the major achievements in the exploration and understanding of DoC. We then propose a synthetic taxonomy of DoC, and we finally highlight some current limits, caveats and questions that have to be addressed when using DoC to theorize consciousness. In particular, we show (i) that a purely behavioral approach of DoC is insufficient to characterize the conscious state of patients; (ii) that the comparison between patients in a minimally conscious state (MCS) and patients in a VS [also coined as unresponsive wakefulness syndrome (UWS)] does not correspond to a pure and minimal contrast between unconscious and conscious states and (iii) we emphasize, in the light of original resting-state positron emission tomography data, that behavioral MCS captures an important but misnamed clinical condition that rather corresponds to a cortically mediated state and that MCS does not necessarily imply the preservation of a conscious state.
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Affiliation(s)
| | - Aude Sangaré
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
- Department of Neurophysiology, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris 75006, France
| | - Esteban Munoz-Musat
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
| | - Amina Ben Salah
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
| | - Pauline Perez
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
| | - Mélanie Valente
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
- Department of Neurophysiology, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris 75006, France
| | - Frédéric Faugeras
- Department of Neurology, AP-HP, Hôpital Henri-Mondor-Albert Chenevier, Université Paris Est Creteil, Créteil 94 000, France
- Département d’Etudes Cognitives, École normale supérieure, PSL University, Paris 75005, France
- Inserm U955, Institut Mondor de Recherche Biomédicale, Equipe E01 NeuroPsychologie Interventionnelle, Créteil 94000, France
| | - Vadim Axelrod
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Sophie Demeret
- Department of Neurology, Neuro-ICU, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris 75006, France
| | - Clémence Marois
- Department of Neurology, Neuro-ICU, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris 75006, France
| | - Nadya Pyatigorskaya
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
- Department of Neuroradiology, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris 75006, France
| | - Marie-Odile Habert
- Department of Nuclear Medicine, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
- Laboratoire d’Imagerie Biomédicale, LIB, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Aurélie Kas
- Department of Nuclear Medicine, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
- Laboratoire d’Imagerie Biomédicale, LIB, INSERM, CNRS, Sorbonne Université, Paris, France
| | - Jacobo D Sitt
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
| | - Benjamin Rohaut
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
- Department of Neurology, Neuro-ICU, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris 75006, France
| | - Lionel Naccache
- Brain institute-ICM, Inserm U1127, CNRS UMR 7225, Sorbonne Université, Paris 75013, France
- Department of Neurophysiology, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris 75006, France
- Medical Intensive Care Unit, AP-HP, Hôpital Européen Georges Pompidou, Paris 75015, France
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30
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Raffone A. Grand Challenges in Consciousness Research Across Perception, Cognition, Self, and Emotion. Front Psychol 2021; 12:770360. [PMID: 34899519 PMCID: PMC8660851 DOI: 10.3389/fpsyg.2021.770360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 11/02/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Antonino Raffone
- Department of Psychology, Sapienza University of Rome, Rome, Italy
- School of Buddhist Studies, Philosophy and Comparative Religions, Nalanda University, Rajgir, India
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31
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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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32
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Signorelli CM, Szczotka J, Prentner R. Explanatory profiles of models of consciousness - towards a systematic classification. Neurosci Conscious 2021; 2021:niab021. [PMID: 34457353 PMCID: PMC8396118 DOI: 10.1093/nc/niab021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/27/2021] [Accepted: 08/18/2021] [Indexed: 11/14/2022] Open
Abstract
Models of consciousness aim to inspire new experimental protocols and aid interpretation of empirical evidence to reveal the structure of conscious experience. Nevertheless, no current model is univocally accepted on either theoretical or empirical grounds. Moreover, a straightforward comparison is difficult for conceptual reasons. In particular, we argue that different models explicitly or implicitly subscribe to different notions of what constitutes a satisfactory explanation, use different tools in their explanatory endeavours and even aim to explain very different phenomena. We thus present a framework to compare existing models in the field with respect to what we call their 'explanatory profiles'. We focus on the following minimal dimensions: mode of explanation, mechanisms of explanation and target of explanation. We also discuss the empirical consequences of the discussed discrepancies among models. This approach may eventually lead to identifying driving assumptions, theoretical commitments, experimental predictions and a better design of future testing experiments. Finally, our conclusion points to more integrative theoretical research, where axiomatic models may play a critical role in solving current theoretical and experimental contradictions.
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Affiliation(s)
- Camilo Miguel Signorelli
- Cognitive Neuroimaging Unit, INSERM U992, NeuroSpin, CEA, Gif sur Yvette F-91191, France
- Department of Computer Science, University of Oxford, 15 Parks Rd, Oxford OX1 3QD, UK
- Center for Brain and Cognition, Universitat Pompeu Fabra, Edifici Merce Rodereda, Carrer de Ramon Trias Fargas, 25, Barcelona 08018, Spain
| | - Joanna Szczotka
- Center for Sleep and Consciousness, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison WI 53719, USA
- Consciousness Lab, Institute of Psychology, Jagiellonian University, 6 Ingardena, Kraków 30-060, Poland
| | - Robert Prentner
- Department of Cognitive Sciences, University of California, 3151 Social Science Plaza, Irvine CA 92697-5100, USA
- Center for the Future Mind, Florida Atlantic University, 777 Glades Road - SO 283, Boca Raton FL 33431-0991, USA
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Drane DL, Pedersen NP, Sabsevitz DS, Block C, Dickey AS, Alwaki A, Kheder A. Cognitive and Emotional Mapping With SEEG. Front Neurol 2021; 12:627981. [PMID: 33912122 PMCID: PMC8072290 DOI: 10.3389/fneur.2021.627981] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/04/2021] [Indexed: 02/05/2023] Open
Abstract
Mapping of cortical functions is critical for the best clinical care of patients undergoing epilepsy and tumor surgery, but also to better understand human brain function and connectivity. The purpose of this review is to explore existing and potential means of mapping higher cortical functions, including stimulation mapping, passive mapping, and connectivity analyses. We examine the history of mapping, differences between subdural and stereoelectroencephalographic approaches, and some risks and safety aspects, before examining different types of functional mapping. Much of this review explores the prospects for new mapping approaches to better understand other components of language, memory, spatial skills, executive, and socio-emotional functions. We also touch on brain-machine interfaces, philosophical aspects of aligning tasks to brain circuits, and the study of consciousness. We end by discussing multi-modal testing and virtual reality approaches to mapping higher cortical functions.
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Affiliation(s)
- Daniel L. Drane
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Emory Epilepsy Center, Atlanta, GA, United States
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
- Department of Neurology, University of Washington School of Medicine, Seattle, WA, United States
| | - Nigel P. Pedersen
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Emory Epilepsy Center, Atlanta, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - David S. Sabsevitz
- Department of Psychology and Psychiatry, Mayo Clinic, Jacksonville, FL, United States
- Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, United States
| | - Cady Block
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
| | - Adam S. Dickey
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
| | - Abdulrahman Alwaki
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
| | - Ammar Kheder
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
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Kim C, Chong SC. Partial awareness can be induced by independent cognitive access to different spatial frequencies. Cognition 2021; 212:104692. [PMID: 33773425 DOI: 10.1016/j.cognition.2021.104692] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 01/15/2023]
Abstract
Partial awareness-an intermediate state between complete consciousness and unconsciousness-has been explained by independent cognitive access to different levels of representation in hierarchical visual processing. This account, however, cannot explain graded visual experiences in low levels. We aimed to explain partial awareness in low levels of visual processing by independent cognitive access to different spatial frequencies. To observe partial awareness stably, we used a novel method. Stimuli were presented briefly (12 ms) and repeatedly with a specific inter-stimulus interval, ranging from 0 to 235 ms. By using various stimuli containing high and low spatial frequencies (superimposed sinusoidal gratings, Navon letters, and scenes), we found that conscious percept was degraded with increasing inter-stimulus intervals. However, the degree of degradation was smaller for low spatial frequency than for high spatial frequency information. Our results reveal that cognitive access to different spatial frequencies can occur independently and this can explain partial awareness in low levels of visual processing.
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Affiliation(s)
- Cheongil Kim
- Graduate Program in Cognitive Science, Yonsei University, South Korea
| | - Sang Chul Chong
- Graduate Program in Cognitive Science, Department of Psychology, Yonsei University, South Korea.
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35
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Svrakic DM, Zorumski CF. Neuroscience of Object Relations in Health and Disorder: A Proposal for an Integrative Model. Front Psychol 2021; 12:583743. [PMID: 33790822 PMCID: PMC8005655 DOI: 10.3389/fpsyg.2021.583743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 01/08/2021] [Indexed: 11/13/2022] Open
Abstract
Recent advances in the neuroscience of episodic memory provide a framework to integrate object relations theory, a psychoanalytic model of mind development, with potential neural mechanisms. Object relations are primordial cognitive-affective units of the mind derived from survival- and safety-level experiences with caretakers during phase-sensitive periods of infancy and toddlerhood. Because these are learning experiences, their neural substrate likely involves memory, here affect-enhanced episodic memory. Inaugural object relations are encoded by the hippocampus-amygdala synaptic plasticity, and systems-consolidated by medial prefrontal cortex (mPFC). Self- and object-mental representations, extracted from these early experiences, are at first dichotomized by contradictory affects evoked by frustrating and rewarding interactions ("partial object relations"). Such affective dichotomization appears to be genetically hardwired the amygdala. Intrinsic propensity of mPFC to form schematic frameworks for episodic memories may pilot non-conscious integration of dichotomized mental representations in neonates and infants. With the emergence of working memory in toddlers, an activated self- and object-representation of a particular valence can be juxtaposed with its memorized opposites creating a balanced cognitive-affective frame (conscious "integration of object relations"). Specific events of object relations are forgotten but nevertheless profoundly influence the mental future of the individual, acting (i) as implicit schema-affect templates that regulate attentional priorities, relevance, and preferential assimilation of new information based on past experience, and (ii) as basic units of experience that are, under normal circumstances, integrated as attractors or "focal points" for interactive self-organization of functional brain networks that underlie the mind. A failure to achieve integrated object relations is predictive of poor adult emotional and social outcomes, including personality disorder. Cognitive, cellular-, and systems-neuroscience of episodic memory appear to support key postulates of object relations theory and help elucidate neural mechanisms of psychodynamic psychotherapy. Derived through the dual prism of psychoanalysis and neuroscience, the gained insights may offer new directions to enhance mental health and improve treatment of multiple forms of psychopathology.
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Affiliation(s)
- Dragan M. Svrakic
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Charles F. Zorumski
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
- Department of Psychiatry, Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
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36
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Edlow BL, Naccache L. Unmasking Covert Language Processing in the Intensive Care Unit with Electroencephalography. Ann Neurol 2021; 89:643-645. [PMID: 33491250 PMCID: PMC8048541 DOI: 10.1002/ana.26030] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 01/16/2023]
Affiliation(s)
- Brian L Edlow
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
| | - Lionel Naccache
- PICNIC Lab Team, INSERM, U 1127, CNRS UMR 7225, Faculté de Médecine de Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Hôpital Pitié-Salpêtrière, Paris, France.,APHP, Departments of Neurology and of Clinical Neurophysiology, Hôpital de la Salpêtriere, Paris, France
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37
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Fu Y, Yan W, Shen M, Chen H. Does consciousness overflow cognitive access? Novel insights from the new phenomenon of attribute amnesia. SCIENCE CHINA-LIFE SCIENCES 2021; 64:847-860. [DOI: 10.1007/s11427-020-1831-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 10/09/2020] [Indexed: 01/01/2023]
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Naccache L. Hard but so valuable to define hard criteria for empirical theories of consciousness. Cogn Neurosci 2020; 12:79-81. [PMID: 33196376 DOI: 10.1080/17588928.2020.1839038] [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: 10/23/2022]
Abstract
I congratulate Doerig, Schurger, and Herzog for their stimulating contribution for an empirical approach to theories of consciousness. I must also admit that the excellent way Global Neuronal Workspace Theory (GNWT) I've contributed to since 2001 passes the test they designed may contribute to my enthusiasm (see Table 1 of their article). In this Comment, I focus on two points: highlighting a potential epistemological weakness of their approach, and proposing how GNWT can solve the 'small network argument.'
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Affiliation(s)
- Lionel Naccache
- Department of Neurology and Neurophysiology, INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
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Bourdillon P, Hermann B, Guénot M, Bastuji H, Isnard J, King JR, Sitt J, Naccache L. Brain-scale cortico-cortical functional connectivity in the delta-theta band is a robust signature of conscious states: an intracranial and scalp EEG study. Sci Rep 2020; 10:14037. [PMID: 32820188 PMCID: PMC7441406 DOI: 10.1038/s41598-020-70447-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 07/22/2020] [Indexed: 11/17/2022] Open
Abstract
Long-range cortico-cortical functional connectivity has long been theorized to be necessary for conscious states. In the present work, we estimate long-range cortical connectivity in a series of intracranial and scalp EEG recordings experiments. In the two first experiments intracranial-EEG (iEEG) was recorded during four distinct states within the same individuals: conscious wakefulness (CW), rapid-eye-movement sleep (REM), stable periods of slow-wave sleep (SWS) and deep propofol anaesthesia (PA). We estimated functional connectivity using the following two methods: weighted Symbolic-Mutual-Information (wSMI) and phase-locked value (PLV). Our results showed that long-range functional connectivity in the delta-theta frequency band specifically discriminated CW and REM from SWS and PA. In the third experiment, we generalized this original finding on a large cohort of brain-injured patients. FC in the delta-theta band was significantly higher in patients being in a minimally conscious state (MCS) than in those being in a vegetative state (or unresponsive wakefulness syndrome). Taken together the present results suggest that FC of cortical activity in this slow frequency band is a new and robust signature of conscious states.
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Affiliation(s)
- Pierre Bourdillon
- Department of Neurophysiology, Hospital for Neurology and Neurosurgery, Hospices Civils de Lyon, Lyon, France.
- Faculté de médecine Claude Bernard, Université de Lyon, Lyon, France.
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France.
- Sorbonne Université, Paris, France.
| | - Bertrand Hermann
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France
- Sorbonne Université, Paris, France
- Neuro Intensive Care Unit, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Marc Guénot
- Department of Neurophysiology, Hospital for Neurology and Neurosurgery, Hospices Civils de Lyon, Lyon, France
- Faculté de médecine Claude Bernard, Université de Lyon, Lyon, France
- Neuropain Team, Centre de Recherche en Neurosciences de Lyon, INSERM U1028, Lyon, France
| | - Hélène Bastuji
- Neuropain Team, Centre de Recherche en Neurosciences de Lyon, INSERM U1028, Lyon, France
- Functional Neurology Department and Sleep Center, Hospices Civils de Lyon, Lyon, France
| | - Jean Isnard
- Functional Neurology Department and Sleep Center, Hospices Civils de Lyon, Lyon, France
| | - Jean-Rémi King
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France
| | - Jacobo Sitt
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France
| | - Lionel Naccache
- Brain and Spine Institue, INSERM U1127, CNRS 7225, 47 boulevard de l'Hôpital, 75013, Paris, France.
- Sorbonne Université, Paris, France.
- Department of Neurophysiology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique Hôpitaux de Paris, Paris, France.
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40
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Northoff G, Lamme V. Neural signs and mechanisms of consciousness: Is there a potential convergence of theories of consciousness in sight? Neurosci Biobehav Rev 2020; 118:568-587. [PMID: 32783969 DOI: 10.1016/j.neubiorev.2020.07.019] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/03/2020] [Accepted: 07/16/2020] [Indexed: 11/18/2022]
Abstract
Various theories for the neural basis of consciousness have been proposed, suggesting a diversity of neural signs and mechanisms. We ask to what extent this diversity is real, or whether many theories share the same basic ideas with a potential for convergence towards a more unified theory of the neural basis of consciousness. For that purpose, we review and compare the various neural signs, measures, and mechanisms proposed in the different theories. We demonstrate that different theories focus on neural signs and measures of distinct aspects of neural activity including stimulus-related, prestimulus, and resting state activity as well as on distinct features of consciousness. Therefore, the various mechanisms proposed in the different theories may, in part, complement each other. Together, we provide insight into the shared basis and convergences (and, in part, discrepancies) of the different theories of consciousness. We conclude that the different theories concern distinct aspects of both neural activity and consciousness which, as we suppose, may be integrated and nested within the brain's overall temporo-spatial dynamics.
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Affiliation(s)
- Georg Northoff
- Mental Health Center, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Mind, Brain Imaging and Neuroethics, Institute of Mental Health Research, University of Ottawa, Ottawa, Canada; Centre for Research Ethics & Bioethics, University of Uppsala, Uppsala, Sweden.
| | - Victor Lamme
- Amsterdam Brain and Cognition (ABC), Department of Psychology, University of Amsterdam, the Netherlands
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Abstract
Consciousness is now a well-established field of empirical research. A large body of experimental results has been accumulated and is steadily growing. In parallel, many Theories of Consciousness (ToCs) have been proposed. These theories are diverse in nature, ranging from computational to neurophysiological and quantum theoretical approaches. This contrasts with other fields of natural science, which host a smaller number of competing theories. We suggest that one reason for this abundance of extremely different theories may be the lack of stringent criteria specifying how empirical data constrains ToCs. First, we argue that consciousness is a well-defined topic from an empirical point of view and motivate a purely empirical stance on the quest for consciousness. Second, we present a checklist of criteria that, we propose, empirical ToCs need to cope with. Third, we review 13 of the most influential ToCs and subject them to the criteria. Our analysis helps to situate these different ToCs in the theoretical landscapeand sheds light on their strengths and weaknesses from a strictly empirical point of view.
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Affiliation(s)
- Adrien Doerig
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale De Lausanne (EPFL), Lausanne, Switzerland
| | - Aaron Schurger
- Department of Psychology, Crean College of Health and Behavioral Sciences, Chapman University, Orange, CA, USA.,Institute for Interdisciplinary Brain and Behavioral Sciences, Chapman University, Irvine, CA, USA.,INSERM, Cognitive Neuroimaging Unit, Gif sur Yvette 91191, France.,Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, I2BM, NeuroSpin center, Gif sur Yvette 91191, France
| | - Michael H Herzog
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale De Lausanne (EPFL), Lausanne, Switzerland
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Blundon EG, Gallagher RE, Ward LM. Electrophysiological evidence of preserved hearing at the end of life. Sci Rep 2020; 10:10336. [PMID: 32587364 PMCID: PMC7316981 DOI: 10.1038/s41598-020-67234-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 06/04/2020] [Indexed: 11/17/2022] Open
Abstract
This study attempts to answer the question: “Is hearing the last to go?” We present evidence of hearing among unresponsive actively dying hospice patients. Individual ERP (MMN, P3a, and P3b) responses to deviations in auditory patterns are reported for conscious young, healthy control participants, as well as for hospice patients, both when the latter were conscious, and again when they became unresponsive to their environment. Whereas the MMN (and perhaps too the P3a) is considered an automatic response to auditory irregularities, the P3b is associated with conscious detection of oddball targets. All control participants, and most responsive hospice patients, evidenced a “local” effect (either a MMN, a P3a, or both) and some a “global” effect (P3b) to deviations in tone, or deviations in auditory pattern. Importantly, most unresponsive patients showed evidence of MMN responses to tone changes, and some showed a P3a or P3b response to either tone or pattern changes. Thus, their auditory systems were responding similarly to those of young, healthy controls just hours from end of life. Hearing may indeed be one of the last senses to lose function as humans die.
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Affiliation(s)
| | - Romayne E Gallagher
- Department of Family Medicine, Vancouver, Canada.,Department of Family and Community Medicine, Providence Health Care, Vancouver, Canada
| | - Lawrence M Ward
- Department of Psychology, Vancouver, Canada. .,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada.
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43
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Distinguishing the Neural Correlates of Perceptual Awareness and Postperceptual Processing. J Neurosci 2020; 40:4925-4935. [PMID: 32409620 DOI: 10.1523/jneurosci.0120-20.2020] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/10/2020] [Accepted: 05/06/2020] [Indexed: 02/07/2023] Open
Abstract
To identify the neural correlates of perceptual awareness, researchers often compare the differences in neural activation between conditions in which an observer is or is not aware of a stimulus. While intuitive, this approach often contains a critical limitation: to link brain activity with perceptual awareness, observers traditionally report the contents of their perceptual experience. However, relying on observers' reports is problematic because it is difficult to know whether the neural responses being measured are associated with conscious perception or with postperceptual processes involved in the reporting task (e.g., working memory, decision-making). To address this issue, we combined a standard visual masking paradigm with a recently developed "no-report" paradigm in male/female human participants. In the visual masking paradigm, observers saw images of animals and objects that were visible or invisible, depending on their proximity to masks. Meanwhile, on half of the trials, observers reported the contents of their perceptual experience (i.e., report condition), while on the other half of trials they refrained from reporting about their experiences (i.e., no-report condition). We used electroencephalography to examine how visibility interacts with reporting by measuring the P3b event-related potential, one of the proposed canonical "signatures" of conscious processing. Overall, we found a robust P3b in the report condition, but no P3b whatsoever in the no-report condition. This finding suggests that the P3b itself is not a neural signature of conscious processing and highlights the importance of carefully distinguishing the neural correlates of perceptual awareness from postperceptual processing.SIGNIFICANCE STATEMENT What are the neural signatures that differentiate conscious and unconscious processing in the brain? Perhaps the most well established candidate signature is the P3b event-related potential, a late slow wave that appears when observers are aware of a stimulus, but disappears when a stimulus fails to reach awareness. Here, however, we found that the P3b does not track what observers are perceiving, but instead tracks what observers are reporting. When observers are aware of simple visual stimuli, the P3b is nowhere to be found unless observers are reporting the contents of their experience. These results challenge the well established notion of the P3b as a neural marker of awareness and highlight the need for new approaches to the neuroscience of consciousness.
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45
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Panagiotaropoulos TI, Dwarakanath A, Kapoor V. Prefrontal Cortex and Consciousness: Beware of the Signals. Trends Cogn Sci 2020; 24:343-344. [PMID: 32298618 DOI: 10.1016/j.tics.2020.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 02/13/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Theofanis I Panagiotaropoulos
- Cognitive Neuroimaging Unit, CEA, DSV/I2BM, INSERM, Universite Paris-Sud, Universite Paris-Saclay, Neurospin Center, 91191 Gif/Yvette, France.
| | - Abhilash Dwarakanath
- Cognitive Neuroimaging Unit, CEA, DSV/I2BM, INSERM, Universite Paris-Sud, Universite Paris-Saclay, Neurospin Center, 91191 Gif/Yvette, France
| | - Vishal Kapoor
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tübingen 72076, Germany
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46
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Affiliation(s)
- David Rosenthal
- Philosophy and Concentration in Cognitive Science, Graduate Center, City University of New York, New York, NY, USA
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47
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Abstract
Visual functions are reviewed that coincide with conscious as opposed to unconscious vision. Four stages of vision are identified, going from the fully invisible, to subjectively invisible, unattended, and clearly visible. It is proposed that feature extraction, categorization, and some aspects of visual inference occur during full and subjective invisibility. Functions related to perceptual organization, such as grouping and figure-ground segregation, occur during inattention as well as full visibility. It is argued that perceptual organization is the function that is central to understanding the transition from unconscious to conscious seeing. It is discussed what this implies for theories of consciousness such as Recurrent Processing Theory, Higher Order Thought Theory, Integrated Information Theory, and Global Neuronal Workspace Theory.
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Affiliation(s)
- Victor A F Lamme
- Department of Psychology, Amsterdam Brain and Cognition (ABC), University of Amsterdam, Amsterdam, Netherlands
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48
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Eklund R, Gerdfeldter B, Wiens S. Effects of a Manual Response Requirement on Early and Late Correlates of Auditory Awareness. Front Psychol 2019; 10:2083. [PMID: 31551899 PMCID: PMC6747040 DOI: 10.3389/fpsyg.2019.02083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/27/2019] [Indexed: 11/26/2022] Open
Abstract
In hearing, two neural correlates of awareness are the auditory awareness negativity (AAN) and the late positivity (LP). These correlates of auditory awareness are typically observed with tasks in which subjects are required to report their awareness with manual responses. Thus, the correlates may be confounded by this manual response requirement. We manipulated the response requirement in a tone detection task (N = 52). Tones were presented at each subject's individual awareness threshold while high-density electroencephalography (EEG) activity was recorded. In one response condition, subjects pushed a button if they were aware of the tone and withheld responding if they were unaware of the tone. In the other condition, subjects pushed a button if they were unaware of the tone and withheld responding if they were aware of the tone. To capture AAN and LP, difference waves were computed between aware and unaware trials, separately for trials in which responses were required and trials in which responses were not required. Results suggest that AAN and LP are unaffected by the response requirement. These findings imply that in hearing, early and late correlates of awareness are not confounded by a manual response requirement. Furthermore, the results suggest that AAN originates from bilateral auditory cortices, supporting the view that AAN is a neural correlate of localized recurrent processing in early sensory areas.
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Affiliation(s)
| | | | - Stefan Wiens
- Gösta Ekmans Laboratorium, Department of Psychology, Stockholm University, Stockholm, Sweden
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49
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Brown R, Lau H, LeDoux JE. Understanding the Higher-Order Approach to Consciousness. Trends Cogn Sci 2019; 23:754-768. [PMID: 31375408 DOI: 10.1016/j.tics.2019.06.009] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/15/2019] [Accepted: 06/26/2019] [Indexed: 01/28/2023]
Abstract
The higher-order theory (HOT) of consciousness has often been misunderstood by critics. Here, we clarify its position on several issues, and distinguish it from other views, such as the global workspace theory (GWT) and early sensory models (e.g., first-order local recurrency theories). For example, HOT has been criticized for overintellectualizing consciousness. We show that, while higher-order states are cognitively assembled, the requirements are in fact considerably less than often presumed. In this sense, HOT may be viewed as an intermediate position between GWT and early sensory views. We also clarify that most proponents of HOT do not stipulate consciousness as equivalent to metacognition or confidence. Furthermore, compared with other existing theories, HOT can arguably account better for complex everyday experiences, such as emotions and episodic memories. This makes HOT particularly useful as a framework for conceptualizing pathological mental states.
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Affiliation(s)
- Richard Brown
- Philosophy Program LaGuardia Community College, City University of New York, Long Island City, NY, USA
| | - Hakwan Lau
- Department of Psychology and Brain Research Institute, University of California, Los Angeles, CA, USA; Department of Psychology, and State Key Laboratory for Brain and Cognitive Sciences, the University of Hong Kong, Hong Kong, China
| | - Joseph E LeDoux
- Center for Neural Science and Department of Psychology, New York University, New York, NY, USA; Departments of Psychiatry and Child and Adolescent Psychiatry, New York University Langone Medical School, New York, NY, USA; Nathan Kline Institute, Orangeburg, NY, USA.
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50
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Sikkens T, Bosman CA, Olcese U. The Role of Top-Down Modulation in Shaping Sensory Processing Across Brain States: Implications for Consciousness. Front Syst Neurosci 2019; 13:31. [PMID: 31680883 PMCID: PMC6802962 DOI: 10.3389/fnsys.2019.00031] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 07/05/2019] [Indexed: 11/24/2022] Open
Abstract
Top-down, feedback projections account for a large portion of all connections between neurons in the thalamocortical system, yet their precise role remains the subject of much discussion. A large number of studies has focused on investigating how sensory information is transformed across hierarchically-distributed processing stages in a feedforward fashion, and computational models have shown that purely feedforward artificial neural networks can even outperform humans in pattern classification tasks. What is then the functional role of feedback connections? Several key roles have been identified, ranging from attentional modulation to, crucially, conscious perception. Specifically, most of the major theories on consciousness postulate that feedback connections would play an essential role in enabling sensory information to be consciously perceived. Consequently, it follows that their efficacy in modulating target regions should drastically decrease in nonconscious brain states [non-rapid eye movement (REM) sleep, anesthesia] compared to conscious ones (wakefulness), and also in instances when a given sensory stimulus is not perceived compared to when it is. Until recently, however, this prediction could only be tested with correlative experiments, due to the lack of techniques to selectively manipulate and measure the activity of feedback pathways. In this article, we will review the most recent literature on the functions of feedback connections across brain states and based on the presence or absence of perception. We will focus on experiments studying mismatch negativity, a phenomenon which has been hypothesized to rely on top-down modulation but which persists during nonconscious states. While feedback modulation is generally dampened in nonconscious states and enhanced when perception occurs, there are clear deviations from this rule. As we will discuss, this may pose a challenge to most theories of consciousness, and possibly require a change in how the level of consciousness in supposedly nonconscious states is assessed.
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Affiliation(s)
- Tom Sikkens
- Cognitive and Systems Neuroscience Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands.,Research Priority Area Brain and Cognition, University of Amsterdam, Amsterdam, Netherlands
| | - Conrado A Bosman
- Cognitive and Systems Neuroscience Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands.,Research Priority Area Brain and Cognition, University of Amsterdam, Amsterdam, Netherlands
| | - Umberto Olcese
- Cognitive and Systems Neuroscience Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands.,Research Priority Area Brain and Cognition, University of Amsterdam, Amsterdam, Netherlands
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