A new strategy for moving forward in the characterization of the Global Neuronal Workspace (GNW) is proposed. According to Dehaene, Changeux and colleagues, broadcasting is the main function of the GNW. However, the dynamic network properties described by recent graph-theoretic GNW models are consistent with many large-scale communication processes that are different from broadcasting. We propose to apply a different graph-theoretic approach, originally developed for optimizing information dissemination in communication networks, which can be used to identify the (...) pattern of frequency and phase-specific directed functional connections that the GNW would exhibit only if it were a broadcasting network. (shrink)

According to the global neuronal workspace model of consciousness, consciousness results from the global broadcast of information throughout the brain. The global neuronal workspace is mainly constituted by a fronto-parietal network. The anterior insular cortex is part of this global neuronal workspace, but the function of this region has not yet been defined within the global neuronal workspace model of consciousness. In this review, I hypothesize that the (...) anterior insular cortex implements a cross-modal priority map, the function of which is to determine priorities for the processing of information and subsequent entrance in the global neuronal workspace. (shrink)

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. (shrink)

The relationship between attention and consciousness is one that is crucial for understanding perception and different types of conscious experience, and we commend this analysis of the topic by Pitts, Lutsyshyna, and Hillyard (2018). We have also examined this relationship closely (e.g., Montemayor & Haladjian, 2015) and would like to point out a few potential contradictions in the Pitts et al. paper that require clarification, particularly in the attempt to reconcile aspects of recurrent processing theory (RPT) with global (...) class='Hi'>neuronal workspace theory (GNWT). This commentary addresses these points and introduces other considerations important for this topic. (shrink)

Can we ever experimentally disentangle phenomenal consciousness from the cognitive accessibility inherent to conscious reports? In this commentary, we suggest that (1) Block's notion of phenomenal consciousness remains intractably entangled with the need to obtain subjective reports about it; and (2) many experimental paradigms suggest that the intuitive notion of a rich but non-reportable phenomenal world is, to a large extent illusory – in a sense that requires clarification.

This paper explores a remarkable convergence of ideas and evidence, previously presented in separate places by its authors. That convergence has now become so persuasive that we believe we are working within substantially the same broad framework. Taylor's mathematical papers on neuronal systems involved in consciousness dovetail well with work by Newman and Baars on the thalamocortical system, suggesting a brain mechanism much like the global workspace architecture developed by Baars (see references below). This architecture is relational, (...) in the sense that it continuously mediates the interaction of input with memory. While our approaches overlap in a number of ways, each of us tends to focus on different areas of detail. What is most striking, and we believe significant, is the extent of consensus, which we believe to be consistent with other contemporary approaches by Weiskrantz, Gray, Crick and Koch, Edelman, Gazzaniga, Newell and colleagues, Posner, Baddeley, and a number of others. We suggest that cognitive neuroscience is moving toward a shared understanding of consciousness in the brain. (shrink)

This introductory chapter attempts to clarify the philosophical, empirical, and theoretical bases on which a cognitive neuroscience approach to consciousness can be founded. We isolate three major empirical observations that any theory of consciousness should incorporate, namely (1) a considerable amount of processing is possible without consciousness, (2) attention is a prerequisite of consciousness, and (3) consciousness is required for some specific cognitive tasks, including those that require durable information maintenance, novel combinations of operations, or the spontaneous generation of intentional (...) behavior. We then propose a theoretical framework that synthesizes those facts: the hypothesis of a global neuronal workspace. This framework postulates that, at any given time, many modular cerebral networks are active in parallel and process information in an unconscious manner. An information becomes conscious, however, if the neural population that represents it is mobilized by top-down attentional amplification into a brain-scale state of coherent activity that involves many neurons distributed throughout the brain. The long-distance connectivity of these `workspace neurons' can, when they are active for a minimal duration, make the information available to a variety of processes including perceptual categorization, long-term memorization, evaluation, and intentional action. We postulate that this global availability of information through the workspace is what we subjectively experience as a conscious state. A complete theory of consciousness should explain why some cognitive and cerebral representations can be permanently or temporarily inaccessible to consciousness, what is the range of possible conscious contents, how they map onto specific cerebral circuits, and whether a generic neuronal mechanism underlies all of them. We confront the workspace model with those issues and identify novel experimental predictions. Neurophysiological, anatomical, and brain-imaging data strongly argue for a major role of prefrontal cortex, anterior cingulate, and the areas that connect to them, in creating the postulated brain-scale workspace. (shrink)

This paper proposes a brain-inspired cognitive architecture that incorporates approximations to the concepts of consciousness, imagination, and emotion. To emulate the empirically established cognitive efficacy of conscious as opposed to non-conscious information processing in the mammalian brain, the architecture adopts a model of information flow from global workspace theory. Cognitive functions such as anticipation and planning are realised through internal simulation of interaction with the environment. Action selection, in both actual and internally simulated interaction with the environment, is (...) mediated by affect. An implementation of the architecture is described which is based on weightless neurons and is used to control a simulated robot. (shrink)

Consciousness is scientifically challenging to study because of its subjective aspect. This leads researchers to rely on report-based experimental paradigms in order to discover neural correlates of consciousness (NCCs). I argue that the reliance on reports has biased the search for NCCs, thus creating what I call 'methodological artefacts'. This paper has three main goals: first, describe the measurement problem in consciousness science and argue that this problem led to the emergence of methodological artefacts. Second, provide a critical assessment of (...) the NCCs put forward by the global neuronal workspace theory. Third, provide the means of dissociating genuine NCCs from methodological artefacts. (shrink)

This chapter seeks to recover an approach to consciousness from a general theory of brain function, namely the prediction error minimization theory. The way this theory applies to mental and developmental disorder demonstrates its relevance to consciousness. The resulting view is discussed in relation to a contemporary theory of consciousness, namely the idea that conscious perception depends on Bayesian metacognition; this theory is also supported by considerations of psychopathology. This Bayesian theory is first disconnected from the higher-order thought theory, and (...) then, via a prediction error conception of action, connected instead to the global neuronal workspace theory. Considerations of mental and developmental disorder therefore show that a very general theory of brain function is relevant to explaining the structure of conscious perception; furthermore, this theory can subsume and unify two contemporary approaches to consciousness, in a move that seeks to elucidate the fundamental mechanism for selection of representational content into consciousness. (shrink)

Human cerebral organoids are three-dimensional biological cultures grown in the laboratory to mimic as closely as possible the cellular composition, structure, and function of the corresponding organ, the brain. For now, cerebral organoids lack blood vessels and other characteristics of the human brain, but are also capable of having coordinated electrical activity. They have been usefully employed for the study of several diseases and the development of the nervous system in unprecedented ways. Research on human cerebral organoids is proceeding at (...) a very fast pace and their complexity is bound to improve. This raises the question of whether cerebral organoids will also be able to develop the unique feature of the human brain, consciousness. If this is the case, some ethical issues would arise. In this article, we discuss the necessary neural correlates and constraints for the emergence of consciousness according to some of the most debated neuroscientific theories. Based on this, we consider what the moral status of a potentially conscious brain organoid might be, in light of ethical and ontological arguments. We conclude by proposing a precautionary principle and some leads for further investigation. In particular, we consider the outcomes of some very recent experiments as entities of a potential new kind. (shrink)

Amidst the many brain events evoked by a visual stimulus, which are specifically associated with conscious perception, and which merely reflect non-conscious processing? Several recent neuroimaging studies have contrasted conscious and non-conscious visual processing, but their results appear inconsistent. Some support a correlation of conscious perception with early occipital events, others with late parieto-frontal activity. Here we attempt to make sense of those dissenting results. On the basis of a minimal neuro-computational model, the global neuronal workspace hypothesis, (...) we propose a taxonomy which distinguishes between vigilance and access to conscious report, as well as between subliminal, preconscious and conscious processing. We suggest that these distinctions map onto different neural mechanisms, and that conscious perception is systematically associated with a sudden surge of parieto-frontal activity causing top-down amplification. (shrink)

Theorists are converging from quite different quarters on a version of the global neuronal workspace model of consciousness, but there are residual confusions to be dissolved. In particular, theorists must resist the temptation to see global accessibility as the cause of consciousness (as if consciousness were some other, further condition); rather, it is consciousness. A useful metaphor for keeping this elusive idea in focus is that consciousness is rather like fame in the brain. It is not (...) a privileged medium of representation, or an added property some states have; it is the very mutual accessibility that gives some informational states the powers that come with a subject's consciousness of that information. Like fame, consciousness is not a momentary condition, or a purely dispositional state, but rather a matter of actual influence over time. Theorists who take on the task of accounting for the aftermath that is critical for consciousness often appear to be leaving out the Subject of consciousness, when in fact they are providing an analysis of the Subject, a necessary component in any serious theory of consciousness. (shrink)

There are two broad classes of empirical theories of consciousness, which I will call the biological and the functional. The biological approach is based on empirical correlations between experience and the brain. For example, there is a great deal of evidence that the neural correlate of visual experience is activity in a set of occipetotemporal pathways, with special emphasis on the infero-temporal cortex. The functionalist approach is a successor of behaviorism, the view that mentality can be seen as tendencies to (...) emit certain behavioral outputs given certain sensory inputs. The trouble with behaviorism is that it did not allow that mental states were causes and effects, but functionalists do allow this. They characterize consciousness in terms of its causal role: the causal influence on it from inputs and other mental states, and its causal efficacy with respect to other mental states and behavior. The central idea of functionalism is a proposal about the concept of consciousness, but scientific functionalists have filled the view in with empirical details—the idea is that a representation is conscious if it is broadcast in a global neuronal workspace. The functional approach says consciousness is a role, whereas the biological approach says consciousness is a realizer of that role. For example, one could take solubility to be a role—dissolving in certain circumstances—or, as with the biological view of consciousness, the physico-chemical configuration that has that role. The. (shrink)

The mainstream science of consciousness offers a few predominate views of how the brain gives rise to awareness. Chief among these are the Higher-Order Thought Theory, Global Neuronal Workspace Theory, Integrated Information Theory, and hybrids thereof. In parallel, rapid development in predictive processing approaches have begun to outline concrete mechanisms by which interoceptive inference shapes selfhood, affect, and exteroceptive perception. Here, we consider these new approaches in terms of what they might offer our empirical, phenomenological, and philosophical (...) understanding of consciousness and its neurobiological roots. (shrink)

In recent years, there has been a proliferation of neuroscientific theories of consciousness. These include theories which explicitly point to EM fields, notably Operational Architectonics and, more recently, the General Resonance Theory. In phenomenological terms, human consciousness is a unified composition of contents. These contents are specific and meaningful, and they exist from a subjective point of view. Human conscious experience is temporally continuous, limited in content, and coherent. Based upon those phenomenal observations, pre-existing theories of consciousness, and a large (...) body of experimental evidence, I derived the Temporally-Integrated Causality Landscape. In brief, the TICL proposes that the neural correlate of consciousness is a structure of temporally integrated causality occurring over a large portion of the thalamocortical system. This structure is composed of a large, integrated set of neuronal elements, which contains some subsystems, defined as having a higher level of temporally-integrated causality than the System as a whole. Each Subsystem exists from the point of view of the System, in the form of meaningful content. In this article, I review the TICL and consider the importance of EM forces as a mechanism of neural causality. I compare the fundamentals of TICL to those of several other neuroscientific theories. Using five major characteristics of phenomenal consciousness as a standard, I compare the basic tenets of Integrated Information Theory, Global Neuronal Workspace, General Resonance Theory, Operational Architectonics, and the Temporo-spatial Theory of Consciousness with the framework of the TICL. While the literature concerned with these theories tends to focus on different lines of evidence, there are fundamental areas of agreement. This means that, in time, it may be possible for many of them to converge upon the truth. In this analysis, I conclude that a primary distinction which divides these theories is the feature of spatial and temporal nesting. Interestingly, this distinction does not separate along the fault line between theories explicitly concerned with EM fields and those which are not. I believe that reconciliation is possible, at least in principle, among those theories that recognize the following: just as the contents of consciousness are distinctions within consciousness, the neural correlates of conscious content should be distinguishable from but fall within the spatial and temporal boundaries of the full neural correlates of consciousness. (shrink)

We present a theoretical view of the cellular foundations for network-level processes involved in producing our conscious experience. Inputs to apical synapses in layer 1 of a large subset of neocortical cells are summed at an integration zone near the top of their apical trunk. These inputs come from diverse sources and provide a context within which the transmission of information abstracted from sensory input to their basal and perisomatic synapses can be amplified when relevant. We argue that apical amplification (...) enables conscious perceptual experience and makes it more flexible, and thus more adaptive, by being sensitive to context. Apical amplification provides a possible mechanism for recurrent processing theory that avoids strong loops. It makes the broadcasting hypothesized by global neuronal workspace theories feasible while preserving the distinct contributions of the individual cells receiving the broadcast. It also provides mechanisms that contribute to the holistic aspects of integrated information theory. As apical amplification is highly dependent on cholinergic, aminergic, and other neuromodulators, it relates the specific contents of conscious experience to global mental states and to fluctuations in arousal when awake. We conclude that apical dendrites provide a cellular mechanism for the context-sensitive selective amplification that is a cardinal prerequisite of conscious perception. (shrink)

Organoids and specifically human cerebral organoids (HCOs) are one of the most relevant novelties in the field of biomedical research. Grown either from embryonic or induced pluripotent stem cells, HCOs can be used as in vitro three-dimensional models, mimicking the developmental process and organization of the developing human brain. Based on that, and despite their current limitations, it cannot be assumed that they will never at any stage of development manifest some rudimentary form of consciousness. In the absence of behavioral (...) indicators of consciousness, the theoretical neurobiology of consciousness being applied to unresponsive brain-injured patients can be considered with respect to HCOs. In clinical neurology, it is difficult to discern a capacity for consciousness in unresponsive brain-injured patients who provide no behavioral indicators of consciousness. In such scenarios, a validated neurobiological theory of consciousness, which tells us what the neural mechanisms of consciousness are, could be used to identify a capacity for consciousness. Like the unresponsive patients that provide a diagnostic difficulty for neurologists, HCOs provide no behavioral indicators of consciousness. Therefore, this article discusses how three prominent neurobiological theories of consciousness apply to human cerebral organoids. From the perspective of the Temporal Circuit Hypothesis, the Global Neuronal Workspace Theory, and the Integrated Information Theory, we discuss what neuronal structures and functions might indicate that cerebral organoids have a neurobiological capacity to be conscious. (shrink)

This paper presents a computer model of cortical broadcast and competition based on spiking neurons and inspired by the hypothesis of a global neuronal workspace underlying conscious information processing in the human brain. In the model, the hypothesised workspace is realised by a collection of recurrently inter-connected regions capable of sustaining and disseminating a reverberating spatial pattern of activation. At the same time, the workspace remains susceptible to new patterns arriving from outlying cortical populations. Competition (...) among these cortical populations for influence on the workspace is effected by a combination of mutual inhibition and top-down amplification. (shrink)

An argument with roots in ancient Greek philosophy claims that only humans are capable of a certain class of thought termed conceptual, as opposed to perceptual thought, which is common to humans, the higher animals, and some machines. We outline the most detailed modern version of this argument due to Mortimer Adler, who in the 1960s argued for the uniqueness of the human power of conceptual thought. He also admitted that if conceptual thought were ever manifested by machines, such an (...) achievement would contradict his conclusion. We revisit Adler’s criterion in the light of the past five decades of artificial-intelligence research, and refine it in view of the classical definitions of perceptual and conceptual thought. We then examine two well-publicized examples of creative works produced by AI systems and show that evidence for conceptual thought appears to be lacking in them. Although clearer evidence for conceptual thought on the part of AI systems may arise in the near future, especially if the global neuronal workspace theory of consciousness prevails over its rival, integrated information theory, the question of whether AI systems can engage in conceptual thought appears to be still open. (shrink)

Local Recurrency Theory (LR) holds that recurrent loops of neural activity localized to the visual cortex are necessary and sufficient for visual consciousness (if certain background conditions obtain). LR’s popularity has recently waned in favor of theories holding that higher-level types of processing are necessary for consciousness (for example, the Global Neuronal Workspace Theory and Higher-order Theory). This has been in part because of empirical evidence thought to disconfirm LR. However, these competing theories now face challenges of (...) their own, often coming in the form of evidence showing that higher-level brain areas (that is, in the prefrontal cortex) are probably not essential for consciousness. Given growing challenges to LR's competitors, it would be timely to re-assess the prospects for LR. This article carries out such an investigation, first laying out the theory precisely, then going on to survey the evidence presented against it. What will be found is that none of the evidence necessarily undermines LR, but instead just fosters its theoretical enrichment. The overall conclusion: LR remains among our most promising neuroscientific theories of visual consciousness. (shrink)

An alternative model of the relation between consciousness and self-consciousness is proposed. The model combines a non-standard version of the higher-order theory of consciousness with the global neuronal workspace theory and argues that implicit higher-order self-awareness is a pervasive feature of the globally integrative states formed in the global workspace.

Evolutionary epistemology (Lorenz, Vollmer) and value-driven decision theory (Pugh) are used to explain the fundamental properties of consciousness. It is shown that this approach is compatible with global workspace theory (Baars) and global neuronal workspace theory (De Haene). The emotions are, however, that what drives consciousness. A hypothetical evolutionary tree of the emotions is given – intended to show that consciousness evolves and is probably qualitatively different in different groups of animals.

The following interview explores neuroscientist Christof Koch's participation in the adversarial collaboration, testing the integrated information theory (IIT) of consciousness against the global neuronal workspace theory (GNW). The interview offers a current update on the adversarial project and then pivots to Koch's responses to three standing critiques of IIT, which include the inexactness of IIT's measures of the neural correlates of consciousness, the charge that IIT implies an unwieldy panpsychism, and the claim that IIT conflates its measures (...) with consciousness. (shrink)

In recent years increasing attention has been given to systematic comparison of theories of consciousness. Laudable practical projects have emerged in this regard, such as adversarial collaboration and the development of databases lending themselves to comparisons of empirical support for theories. In addition to the practical advances, theoretical advances have been made, such as a list of issues a theory of consciousness must address. We propose adding the issue of the ontogenetic emergence (O-emergence) of consciousness to the list of issues (...) we use to evaluate theories of consciousness. O-emergence concerns how and when consciousness emerges ontogenetically in human beings. The underlying assumption is that there exists a point in the development of a human individual before which that individual is not and cannot be conscious. This assumption, in turn, depends on a widely shared assumption of cognitive neuroscience, which is that consciousness somehow depends on — or derives from — brain activity. In this paper, we lay out the O-emergence criterion and investigate whether it can be accounted for within the Global Neuronal Workspace theory, the Self-Organizing Meta-representational Account, and the Reorganization of Elementary Functions framework. (shrink)

Modelos neurocognitivos têm sido propostos para investigar a consciência. O objetivo é responder à pergunta sobre como o cérebro é capaz de produzir estados conscientes qualitativos. Os modelos são representações teóricas baseadas em algumas pesquisas empíricas. Contudo, a questão central, aparentemente trivial para alguns autores, refere-se à representatividade e confiabilidade dos modelos, i.e., saber se são capazes de explicar como a consciência emerge de processos neurais. Esses modelos são considerados como guia no estudo científico da consciência: os modelos cognitivos de (...) Dennett e Baars, os modelos neurobiológicos de Edelman, Dehaene et al., de Damásio, e o modelo neurodinâmico proposto por Freeman. O presente texto visa a analisar a coerência e a plausibilidade dos modelos, i.e., se realmente explicam a “consciência” e suas propriedades em termos neurais ou se explicam apenas mecanismos neurobiológicos subjacentes no cérebro. O objetivo é avaliar escopo e limites dos modelos além da aplicabilidade na resolução do problema da consciência. Neurocognitive models are proposed in order to study the problem of consciousness. The models are attempts to answer the question of how the brain can generate conscious and qualitative states. Models are theoretical representations based on empirical data. Nonetheless, the central question concerns the reliability and the representativeness of the models, i.e., whether they in fact represent what they are supposed to explain, viz., how consciousness can emerge from neuronal processes. Such models are taken to be a guide for the scientific study of consciousness. Presently, there are six models: the multiple draft, the global workspace, the dynamic core, the global neuronal workspace, the somatic markers hypothesis, and the neurodynamic model. This text is a survey and a philosophical analysis of the models of consciousness, and it considers their plausibility and coherence. I will concentrate on two points: whether the neuroscientific models are able to explain ‘consciousness’ and its properties in neural terms, or whether the models only explain the neural correlates of conscious states, and the scope, limitations and applicability of the models in the attempt to solve the problem of consciousness. (shrink)

The first decade of event-related potential (ERP) research had established that the most consistent correlates of the onset of visual consciousness are the early visual awareness negativity (VAN), a posterior negative component in the N2 time range, and the late positivity (LP), an anterior positive component in the P3 time range. Two earlier extensive reviews ten years ago had concluded that VAN is the earliest and most reliable correlate of visual phenomenal consciousness, whereas LP probably reflects later processes associated with (...) reflective/access consciousness. This article provides an update to those earlier reviews. ERP and MEG studies that have appeared since 2010 and directly compared ERPs between aware and unaware conditions are reviewed, and important new developments in the field are discussed. The result corroborates VAN as the earliest and most consistent signature of visual phenomenal consciousness, and casts further doubt on LP as an ERP correlate of phenomenal consciousness. (shrink)

A major driving force behind the attention that cognitive neuroscience has received in recent decades is the deep mystery of how consciousness is related to brain activity. Many scientists have been fascinated by the wealth of empirical data for individual neurons, neural assemblies, brain areas, and related psychological and behavioral features, and by progressively powerful computational tools to simulate corresponding cortical networks. At the same time, the interested public has been attracted by fancy illustrations of brain activity (e.g., from imaging (...) techniques) and by pretentious claims of neural solutions to basic philosophical problems (e.g., free will versus determinism) in popular magazines and newspapers. However, heaps of data, extensive simulations, pretty pictures and bold statements cannot replace the insight that is inevitable to relate the available facts to one another in an intelligible manner. I am talking about the old-fashioned stance that understanding is the ultimate goal of scientific effort. In this respect, the need for new conceptual and theoretical ideas in cognitive neuroscience begins to be recognized by prominent representatives of the field. Theory in this sense must not be confused with models fitting data, e.g. by regression algorithms, cluster analyses, etc. It is uncontroversial that experimental and numerical work is and will remain mandatory for scientific progress. But it can only unfold its full value if it is embedded within a profound theoretical framework. To formulate a serious, clear-cut and transparent formal framework for cognitive neuroscience is a challenge comparable to the early stage of physics four centuries ago. Only very few approaches worth mentioning are visible in contemporary literature. I think that Wallace’s book presents an appreciable step in the right direction. However, it is not the ultimate breakthrough yet. Much is left for future work before a full-fledged theory of consciousness will be established. In two central conceptual respects, Wallace builds on earlier work: Dretske’s (1981) usage of informational terms in consciousness research and Baars’ (1988) global neuronal workspace model.. (shrink)

Peter Carruthers has recently argued for a surprising conditional: if a global workspace theory of phenomenal consciousness is both correct and fully reductive, then there are no substantive facts to discover about phenomenal consciousness in nonhuman animals. I present two problems for this conditional. First, it rests on an odd double-standard about the ordinary concept of phenomenal consciousness: its intuitive non-gradability is taken to be unchallengeable by future scientific developments, whereas its intuitive determinacy is predicted to fall by (...) the wayside. Second, it relies on dismissing, prematurely, the live empirical possibility that phenomenal consciousness may be linked to a core global broadcast mechanism that is shared by a wide range of animals. Future developments in the science of consciousness may lead us to reconsider the non-gradability of phenomenal consciousness, but they are unlikely to lead us to accept that there are no facts to discover outside the paradigm case of a healthy adult human. (shrink)

Global Workspace Theory (GWT) can be compared to a theater of mind, in which conscious contents resemble a bright spot on the stage of immediate memory, selected by a spotlight of attention under executive guidance. Only the bright spot is conscious; the rest of the theater is dark and unconscious. GWT has been implemented in a number of explicit and testable global workspace models (GWM's). These specific GW models suggest that conscious experiences recruit widely distributed brain (...) functions that are mostly unconscious (unreportable). A large body of new findings support that view. For example, brain experiments show that while unconscious visual stimuli evoke high activity in visual cortex, identical conscious stimuli reveal an additional spread of high brain activity to frontal and parietal lobes (Dehaene, 2001). Similar results have been found for hearing, touch, pain, and sensorimotor skills (Baars, 2002). The conscious waking state supports such fast, flexible, and widespread brain interactions, while unconscious states do not (Baars et al, 2004). These findings illustrate the ability of the GW framework to suggest novel and falsifiable hypotheses. (shrink)

Both the global workspace theory and Block’s distinction between phenomenal and access consciousness, are central in the current debates about consciousness and the neural correlates of consciousness. In this article, a unifying global workspace model for phenomenal and access consciousness is proposed. In the model, recurrent neural interactions take place in distinct yet interacting access and phenomenal brain loops. The effectiveness of feedback signaling onto sensory cortical maps is emphasized for the neural correlates of phenomenal consciousness. (...) Two forms of top-down attention, attention for perception and attention for access, play differential roles for phenomenal and access consciousness. The model is implemented in a neural network form, with the simulation of single and multiple visual object processing, and of the attentional blink. (shrink)

The Global Workspace Theory (GWT) proposed by Bernard Baars (1988) along with Daniel Dennett’s (1991) Multiple Drafts Model (MDM) of consciousness are renowned cognitive theories of consciousness bearing similarities and differences. Although Dennett displays sympathy for GWT, his own MDM does not seem to be fully compatible with it. This work discusses this compatibility, by asking if GWT suffers from Daniel Dennett’s criticism of what he calls a “Cartesian Theater”. We identified in Dennett 10 requirements for avoiding the (...) Cartesian Theater. We believe that some of these requirements are violated by GWT, but not all, hence there is partial incompatibility with MDM, and it is nonsense to answer if GWT is or is not a Cartesian Theater. However, by asking such question we conclude that the issues around this discussion involve fuzzy claims about degrees of consciousness and we show how the Neuro-Astroglial Interaction Model (NAIM) is fit for solving such conceptual issues. (shrink)

Peter Carruthers argues that the global workspace theory implies there are no facts of the matter about animal consciousness. The argument is easily extended to other cognitive theories of consciousness, posing a general problem for consciousness studies. But the argument proves too much, for it also implies that there are no facts of the matter about human consciousness. A key assumption of the argument is that scientific theories of consciousness must explain away the explanatory gap. I criticize this (...) assumption and point to an alternative strategy for defending scientific theories of consciousness, one that better reflects the ongoing scientific practice. I argue there are introspectable inferential connections from phenomenal concepts to functional concepts that scientists can use to individuate the global workspace in terms of capacities that animals and humans share. (shrink)

Our aim in this reply is to defend Global Workspace theory (GWT) from the challenge of Block's article. We argue that Block's article relies on an outdated and imprecise concept of access, and perpetuates a common misunderstanding of GWT that conflates the global workspace with working memory. In the light of the relevant clarifications, Block's conclusion turns out to be unwarranted, and the basic tenets of GWT emerge unscathed.

The subject of consciousness, long shunned by mainstream psychology and the scientific community, has over the last two decades become a legitimate topic of scientific research. One of the most thorough attempts to formulate a theory of consciousness has come from Bernard Baars, a psychologist working at the Wright Institute. Baars proposes that consciousness is the result of a Global Workspace in the brain that distributes information to the huge number of parallel unconscious processors that form the rest (...) of the brain. This paper critiques the central hypothesis of Baars' theory of consciousness. (shrink)

The two leading cognitive accounts of consciousness currently available concern global workspace (a form of working memory) and metacognition. There is relatively little interaction between these two approaches and it has even been suggested that the two accounts are rival and separable alternatives. Here, we argue that the successful function of a global workspace critically requires that the broadcast representations include a metacognitive component.

In the target article, Baars has offered both a theory of consciousness and a strategy for scientifically testing the theory. This commentary is intended as an addendum. I'd like to suggest implementing global workspace agents as both an additional strategy toward scientific testing, and as a means of fleshing out the theory.

Surprisingly, Dennett and Baars have no real quarrel with each other, despite the fact that Dennett wants to escape from the Theatre of Consciousness and Baars is happy to stay there. Both believe that consciousness has structures that can be analysed, and is not just ‘the mysterious glow that no one but me can see’ described by Chalmers and Searle. Both acknowledge that their theories of consciousness are only metaphors, and there is no conflict in saying that Consciousness is both (...) like a theatre and like a series of multiple drafts. And both Dennett and Baars would agree that Consciousness seems to be like a theatre. Their main disagreement is how deep the similarity goes, and whether the similarity is more misleading than useful. There are other scientific controversies that could probably be dissolved by such an ecumenical attitude: there is no paradox in saying that an electron is both like a wave and like a particle, or that thought is both like a language in the head and like a connectionist network. But a non-aggression pact of this sort does not absolve us from enumerating the ways in which each of these metaphors does and does not map onto its object. And as this enumeration continues, it is likely to make one of these metaphors seem more plausible than the other. (shrink)