Explanatory profiles of models of consciousness: towards a systematic classification
TL;DR: It is argued 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.
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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TL;DR: In this article , the authors review four prominent theoretical approaches to consciousness: higher-order theories, global workspace theories, re-entry and predictive processing theories and integrated information theory, and identify 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.
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.
80 citations
TL;DR: In this paper , the authors applied anesthesia to suppress consciousness in nonhuman primates and found that deep brain stimulation of central thalamus might restore both arousal and awareness following consciousness loss.
Abstract: Loss of consciousness is associated with the disruption of long-range thalamocortical and corticocortical brain communication. We tested the hypothesis that deep brain stimulation (DBS) of central thalamus might restore both arousal and awareness following consciousness loss. We applied anesthesia to suppress consciousness in nonhuman primates. During anesthesia, central thalamic stimulation induced arousal in an on-off manner and increased functional magnetic resonance imaging activity in prefrontal, parietal, and cingulate cortices. Moreover, DBS restored a broad dynamic repertoire of spontaneous resting-state activity, previously described as a signature of consciousness. None of these effects were obtained during the stimulation of a control site in the ventrolateral thalamus. Last, DBS restored a broad hierarchical response to auditory violations that was disrupted under anesthesia. Thus, DBS restored the two dimensions of consciousness, arousal and conscious access, following consciousness loss, paving the way to its therapeutical translation in patients with disorders of consciousness.
27 citations
TL;DR: A bird's eye view of studies that interpreted their findings in light of at least one of four leading neuroscientific theories of consciousness is provided, finding that supporting a specific theory can be predicted solely from methodological choices, irrespective of findings.
15 citations
TL;DR: In this article , the theoretical landscape on the potential role of heartbeats in cognition and consciousness is reviewed, as well as the experimental evidence supporting these hypotheses, and the authors advocate for methodological developments on the estimation of brain-heart interactions to uncover the role of cardiac inputs in the origin, levels, and contents of consciousness.
Abstract: Recent experimental evidence on patients with disorders of consciousness revealed that observing brain-heart interactions helps to detect residual consciousness, even in patients with absence of behavioral signs of consciousness. Those findings support hypotheses suggesting that visceral activity is involved in the neurobiology of consciousness, and sum to the existing evidence in healthy participants in which the neural responses to heartbeats reveal perceptual and self-consciousness. More evidence obtained through mathematical modeling of physiological dynamics revealed that emotion processing is prompted by an initial modulation from ascending vagal inputs to the brain, followed by sustained bidirectional brain-heart interactions. Those findings support long-lasting hypotheses on the causal role of bodily activity in emotions, feelings, and potentially consciousness. In this paper, the theoretical landscape on the potential role of heartbeats in cognition and consciousness is reviewed, as well as the experimental evidence supporting these hypotheses. I advocate for methodological developments on the estimation of brain-heart interactions to uncover the role of cardiac inputs in the origin, levels, and contents of consciousness. The ongoing evidence depicts interactions further than the cortical responses evoked by each heartbeat, suggesting the potential presence of non-linear, complex, and bidirectional communication between brain and heartbeat dynamics. Further developments on methodologies to analyze brain-heart interactions may contribute to a better understanding of the physiological dynamics involved in homeostatic-allostatic control, cognitive functions, and consciousness.
14 citations
TL;DR: This paper provided a bird's eye view on studies that interpreted their findings in light of at least one of four leading neuroscientific theories of consciousness (N=412 experiments), asking how methodological choices of the researchers might affect the final conclusions.
Abstract: Understanding how consciousness arises from neural activity remains one of the biggest challenges for neuroscience. Numerous theories have been proposed in recent years, each gaining independent empirical support. Currently, there is no comprehensive, quantitative and theory-neutral overview of the field that enables an evaluation of how theoretical frameworks interact with empirical research. We provide a bird’s eye view on studies that interpreted their findings in light of at least one of four leading neuroscientific theories of consciousness (N=412 experiments), asking how methodological choices of the researchers might affect the final conclusions. We found that supporting a specific theory can be predicted solely from methodological choices, irrespective of findings. Furthermore, most studies interpret their findings post-hoc, rather than a-priori testing critical predictions of the theories. Our results highlight challenges for the field and provide researchers with a unique, open-access website to further analyze trends in the neuroscience of consciousness.
12 citations
References
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TL;DR: It is argued that the most plausible candidate is the formation of dynamic links mediated by synchrony over multiple frequency bands.
Abstract: The emergence of a unified cognitive moment relies on the coordination of scattered mosaics of functionally specialized brain regions. Here we review the mechanisms of large-scale integration that counterbalance the distributed anatomical and functional organization of brain activity to enable the emergence of coherent behaviour and cognition. Although the mechanisms involved in large-scale integration are still largely unknown, we argue that the most plausible candidate is the formation of dynamic links mediated by synchrony over multiple frequency bands.
4,485 citations
Book•
01 Jan 1995TL;DR: The fourth edition of The Cognitive Neurosciences continues to chart new directions in the study of the biologic underpinnings of complex cognition -the relationship between the structural and physiological mechanisms of the nervous system and the psychological reality of the mind as discussed by the authors.
Abstract: Each edition of this classic reference has proved to be a benchmark in the developing field of cognitive neuroscience. The fourth edition of The Cognitive Neurosciences continues to chart new directions in the study of the biologic underpinnings of complex cognition -- the relationship between the structural and physiological mechanisms of the nervous system and the psychological reality of the mind. The material in this edition is entirely new, with all chapters written specifically for it. Since the publication of the third edition, the field of cognitive neuroscience has made rapid and dramatic advances; fundamental stances are changing and new ideas are emerging. This edition reflects the vibrancy of the field, with research in development and evolution that finds a dynamic growth pattern becoming specific and fixed, and research in plasticity that sees the neuronal systems always changing; exciting new empirical evidence on attention that also verifies many central tenets of longstanding theories; work that shows the boundaries of the motor system pushed further into cognition; memory research that, paradoxically, provides insight into how humans imagine future events; pioneering theoretical and methodological work in vision; new findings on how genes and experience shape the language faculty; new ideas about how the emotional brain develops and operates; and research on consciousness that ranges from a novel mechanism for how the brain generates the baseline activity necessary to sustain conscious experience to a bold theoretical attempt to make the problem of qualia more tractable.
4,285 citations
Book•
01 Jan 1988
TL;DR: In this article, the basic model of conscious representations are internally consistent and globally distributed, and the neural basis of conscious experience is explained, including the fundamental role of context, goal contexts, spontaneous problem solving and the stream of consciousness.
Abstract: List of figures and tables Preface Part I Introduction: 1 What is to be explained? some preliminaries Part II The Basic Model: 2 Model 1: conscious representations are internally consistent and globally distributed 3 The neural basis of conscious experience Part III The Fundamental Role of Context: 4 Model 2: unconscious contexts shape conscious experience 5 Model 3: conscious experience is informative - it always demands some degree of adaptation Part IV Goals and Voluntary Control: 6 Model 4: Goal contexts, spontaneous problem solving, and the stream of consciousness 7 Model 5: volition as ideomotor control of thought and action Part V Attention, self, and conscious self-monitoring: 8 Model 6: attention as control of access to consciousness 9 Model 7 Self as the dominant context of experience and action Part VI Consciousness is Functional: 10 The functions of consciousness Part VII Conclusion: 11 A summary and some future directions Glossary and guide to theoretical claims References Name index, Subject index
2,722 citations
TL;DR: In this article, a non-reductive theory based on principles of structural coherence and organizational invariance and a double-aspect theory of information is proposed to explain the complexity of the problem of consciousness.
Abstract: To make progress on the problem of consciousness, we have to confront it directly. In this paper, I first isolate the truly hard part of the problem, separating it from more tractable parts and giving an account of why it is so difficult to explain. I critique some recent work that uses reductive methods to address consciousness, and argue that such methods inevitably fail to come to grips with the hardest part of the problem. Once this failure is recognized, the door to further progress is opened. In the second half of the paper, I argue that if we move to a new kind of nonreductive explanation, a naturalistic account of consciousness can be given. I put forward my own candidate for such an account: a nonreductive theory based on principles of structural coherence and organizational invariance, and a double-aspect theory of information.
2,046 citations