Functionalist Theories of Consciousness

To explain the origin of anything, we must be clear about that which we are explaining. There seem to be two main meanings for the term consciousness. One might be called open in that it equates consciousness with awareness and experience and considers rudimentary sensations to have evolved at a specific point in the evolution of increasing complexity. But certainly the foundation for such sensation is a physical body. It is unclear, however, exactly what the physical requirements are for a (...) “central experiencer” to emerge in the course of evolution. Some suggest that it would require a basic brain, others a central nervous system, and others stipulate only a cellular membrane. The open definition is most often assumed by the so-called hard sciences. -/- The closed meaning of consciousness differentiates between a special sort of experience, i.e., conscious experience, and a special sort of awareness (i.e., self-awareness). This is the approach of psychoanalysis and psychology that accepts the existence of an unconscious mind. It is also the view of most phenomenological philosophers and psychologists (Martin Heidegger, Maurice Merleau-Ponty, Jacques Lacan, etc.). This entry discusses several scientific and philosophical views of consciousness and its origins. (shrink)

Dennett and Kinsbourne argue that metacontrast backward visual masking provides a clear illustration that ‘there is really only a verbal difference’ between two versions of the Cartesian Theater model of the mind. This alleged lack of a distinction is both the crucial premise of their main argument against the Cartesian Theater and a motivator for accepting their own Multiple Drafts model. I argue that metacontrast reveals a difference between the two versions of the Cartesian Theater that meets criteria found in (...) for determining such a difference. This difference undermines the soundness of their argument against the Cartesian Theater, and exerts pressure on Dennett and Kinsbourne to offer a more detailed articulation of their model. Introduction Brief Explanation of Metacontrast Backward Visual Masking The Stalinesque and Orwellian Models of Metacontrast 3.1 Criteria for determining a difference A Difference That Makes a Difference 4.1 Skeptical hypothesis objection Other Objections and Replies 5.1 Straw person objection 5.2 Corroborative issues objection Conclusion. (shrink)

Beenfeldt assesses Dennett's approach to the philosophical problem of consciousness.

Paul Churchland's book (hereafter ER)is an entertaining and instructive advertisement for a "neurocomputational" vision of how the brain (and mind) works. While we agree with its general thrust, and commend its lucid pedagogy on a host of difficult topics, we note that such pedagogy often exploits artificially heightened contrast, and sometimes the result is a misleading caricature instead of a helpful simplification. In particular, Churchland is eager to contrast the explanation of consciousness that can be accomplished by his "aspiring new (...) structural and dynamic cognitive prototype: recurrent PDP networks" (p.266) with what strikes him as the retrograde introduction by Dennett of a virtual von Neumannesque machine--a "failed prototype"--as the key element in an explanation of human consciousness (in Consciousness Explained, 1991, hereafter, CE). We will try to show that by oversimplifying Dennett's alternative, he has taken a potential supplement to his own view--a much needed supplement--and transformed it in his imagination into a subversive threat. In part 1, we will expose and correct the mistaken contrasts. In part 2, we will compare the performance of the two views on Churchland's list of seven features of consciousness any theory must account for, showing that Dennett's account provides more than Churchland has recognized, and indeed offers answers to key questions that Churchland's account is powerless to address. At that point, Churchland's project and Dennett's could be seen to collaborate in a useful division of labor instead of being in mortal combat, were it not for what appears to be a fairly major disagreement about consciousness in non-human animals. Part 3 briefly examines this issue. It may be due to a misunderstanding, which when cleared up might restore the happy prospect of unification. (shrink)

Judgments of plausibility involve appearance of the truth or reasonableness, which is always a function of background knowledge. What anyone will countenance is conditioned by what they already know (or think they know). Marc Kirschner (professor of systems biology at Harvard) and John Gerhart (professor of molecular and cell biology at the University of California—Berkeley) aim to show that molecular, cellular, and developmental processes relevant to the generation of phenotypic variation in anatomy, physiology, and behavior demonstrate how evolutionary processes, especially (...) the origins of novelty, are plausible. The outstanding question for Kirschner and Gerhart concerns not the modification of structures but their origination—a question unanswered by the theoretical framework of the modern synthesis. (shrink)

The aim of the article is to formulate a universal characterization of consciousness, despite the conceptual vagueness of that term. The fundamental aspects of this phenomenon as studied by science consist of four features: its being accessible from the inside and the outside (subjectively and objectively), its being about something (referential), its being bodily determined, and its possessing a certain function (being useful). Approached in this way and in broad terms, consciousness seems to be a graded rather than all-or-none phenomenon. (...) However, it is argued that the main problem for the gradational approach is to establish reasonable, empirically justified limits on how extended (locally and globally) the range of a graded consciousness could be. Such constraints should then help to avoid the counterintuitive consequences of IIT (Integrated Information Theory), which ascribes consciousness even to such simple artificial systems as photodiodes. The article introduces global limits for conscious systems by pointing to the ability to individuate information as a necessary developmental condition of subjective perspectives. Local limits, meanwhile, are determined on the basis of a hypothesis about the action-oriented nature of the processes that select states of consciousness. Ultimately, the limits put forward imply that consciousness is to be characterized as individuated information in action. (shrink)

Pregnancy, a human phenomenon experienced throughout the world and throughout history, has been largely ignored by the philosophical community. A preference for the abnormal and the extraordinary has left this common yet challenging process on the sidelines of philosophical discussion. Pregnancy stands as a significant challenge to many of our intuitions about the self, particularly those concerning the boundaries, plurality and diachronic identity of the self. Because of this, pregnancy necessitates a theory of the self which does not merely uphold (...) our usual assumptions about the self. Daniel Dennett presents a theory of the self which meets this criterion. He argues that the self is a centre of narrative gravity: an abstract, theoretical entity which is useful for the explanation and prediction of an individual’s behaviour. Dennett’s theory, though provocative, lacks a basis in typical human experience. He relies primarily on thought experiments and extraordinary conditions to support his theory. To demonstrate the applicability and generality of this theory, it must be tested against a common, natural human occurrence like pregnancy. In this paper we explore the application of Daniel Dennett’s theory of the narrative self to the experience of pregnancy. This application yields a double result. Dennett’s theory is bolstered by a demonstration of its generality and applicability, and the experience of pregnancy is placed into a context in which it can be validated and understood. (shrink)

The philosopher Ludwig Wittgenstein chose as his prime exemplar of certainty the fact that the skulls of normal people are filled with neural tissue, not sawdust. In 1980 the British pediatrician John Lorber reported that some normal adults, apparently cured of childhood hydrocephaly, had no more than 5 % of the volume of normal brain tissue. While initially disbelieved, Lorber’s observations have since been independently confirmed by clinicians in France and Brazil. Thus Wittgenstein’s certainty has become uncertain. Furthermore, the paradox (...) that the human brain’s information content appears to exceed the storage capacity of even normal-sized brains, requires resolution. This article is one of a series on disparities between brain size and its assumed information content, as seen in cases of savant syndrome, microcephaly, and hydrocephaly, and with special reference to the Victorian era views of Conan Doyle, Samuel Butler, and Darwin’s research associate, George Romanes. The articles argue that, albeit unlikely, the scope of explanations must not exclude extracorporeal information storage. (shrink)

This volume includes a critical assessment of Dennett's views on behaviorism and the subjectivity of consciousness, the nature of perception and mental representation.

_Content and Consciousness_ is an original and ground-breaking attempt to elucidate a problem integral to the history of Western philosophical thought: the relationship of the mind and body. In this formative work, Dennett sought to develop a theory of the human mind and consciousness based on new and challenging advances in the field that came to be known as cognitive science. This important and illuminating work is widely-regarded as the book from which all of Dennett’s future ideas developed. It is (...) his first explosive rebuttal of Cartesian dualism and one of the founding texts of philosophy of mind. (shrink)

_Content and Consciousness_ is an original and ground-breaking attempt to elucidate a problem integral to the history of Western philosophical thought: the relationship of the mind and body. In this formative work, Dennett sought to develop a theory of the human mind and consciousness based on new and challenging advances in the field that came to be known as cognitive science. This important and illuminating work is widely-regarded as the book from which all of Dennett’s future ideas developed. It is (...) his first explosive rebuttal of Cartesian dualism and one of the founding texts of philosophy of mind. (shrink)

Baars presents a clear and productive approach to consciousness as a scientific issue. My commentary is motivated by this positive assessment in order to underline what I see as important limitations in the sketch we are presented with, and which are close to my own research interests. I will concentrate only on two fundamental questions here: the still misleading nature of the theatre metaphor for consciousness in spite of Baars’ radically new interpretation; the still unexamined naivite in regards to question (...) of methodologies of access to experience, in spite of Baars’ avowed interest in linking to first-person experience. (shrink)

Baars contends that we must ask answerable questions about consciousness, and that to do so will require definitions of consciousness that permit "contrastive analysis". I endorse this general approach, but find several of Baars claims of processing without consciousness, unconvincing. I show that a more cautious definition of "non-conscious" than Baars' need not impede experimentation and is more likely to enjoy universal agreement.

Baars affirms Crick and Koch's position that the timidity most cognitive scientists show in the face of consciousness is ridiculous. Unfortunately, all three succumb to a variation on the timidity they deprecate. Furthermore, Baars' own method, ``contrastic analysis,'' is at odds with the computational conception of mind that dominates contemporary cognitive science.

Baars' contrastive analysis approach offers an essential framework for differentiating conscious processing from the myriad unconscious functions carried out by the mind/brain. In applying this approach it is important to understand that consciousness is not something other than, but something in addition to the unconscious processes that precede and follow the momentary focus of awareness. We have argued elsewhere that neurologically this something is activation via a global attentional matrix which both: 1) controls access to consciousness by competing unconscious processors; (...) and 2) integrates the multimodal representations of those processors which gain momentary access into unified, conscious percepts. (shrink)

This paper considers the Cartesian theatre as a metaphor for the virtual reality models that the brain uses to make inferences about the world. This treatment derives from our attempts to understand dreaming and waking consciousness in terms of free energy minimization. The idea here is that the Cartesian theatre is not observed by an internal audience but furnishes a theatre in which fictive narratives and fantasies can be rehearsed and tested against sensory evidence. We suppose the brain is driven (...) by the imperative to infer the causes of its sensory samples; in much the same way as scientists are compelled to test hypotheses about experimental data. This recapitulates Helmholtz's notion of unconscious inference and Gregory's treatment of perception as hypothesis testing. However, we take this further and consider the active sampling of the world as the gathering of confirmatory evidence for hypotheses based on our virtual reality. The ensuing picture of consciousness resolves a number of seemingly hard problems in consciousness research and is internally consistent with current thinking in systems neuroscience and theoretical neurobiology. In this formalism, there is a dualism that distinguishes between the process of inference and the process that entails inference. This separation is reflected by the distinction between beliefs and the physical brain states that encode them. This formal approach allows us to appeal to simple but fundamental theorems in information theory and statistical thermodynamics that dissolve some of the mysterious aspects of consciousness. (shrink)

The question of how a physical system gives rise to the phenomenal or experiential , is considered the most intractable of scientific and philosophical puzzles. Though this question has dominated the philosophy of mind over the last quarter century, it articulates a version of the age-old mind–body problem. The most famous response, Cartesian dualism, is on Daniel Dennett’s view still a corrosively residual and redundant feature of popular thinking on these matters. Fifteen years on from his anti-Cartesian theory of consciousness (...) , Dennett’s frustration with this tradition is still palpable. This frustration is primarily aimed at philosophers. The “Sweet Dreams” of Dennett’s title are the rationalist thought experiments of wishful thinking philosophers who, neglectful or unaware of empirical evidence, generate premature conclusions “of unexamined presuppositions and circularly defined elaborations” . The nature of such presuppositions renders these thought experiments no more than “intuition pumps,” ostensibly succeeding in stale-mating or in some cases check-mating any moves in the direction of a unified science of consciousness. The extent to which Dennett believes these “pumps” have skewed theorising about consciousness is captured in his remark: “I had no idea philosophers still put so much faith in the authority of their homegrown intuitions. It is almost as if one thought one could prove that the Copernican theory was false by noting that it ‘seems just obvious’ that the Earth doesn’t move and the Sun does”. (shrink)

This project compares the operational methods of three of Cole Swensen's books of poetry with ways in which the human mind and consciousness function. I use Daniel Dennett's Multiple Drafts Model of consciousness, as described in Consciousness Explained, alongside concepts presented in several other philosophical works , to demonstrate that significant similarities exist between the operations of poetry and consciousness in general, and that these operational similarities are especially noticeable in Swensen's work. This thesis examines several operational modes that are (...) present within the human mind , as they are contingent upon the Multiple Drafts Model, and constructs a theory of how these same concepts and principles function within Swensen's poetic texts. (shrink)

ernard Baars’ metaphor of the theatre of consciousness has the ability to powerfully evoke and illustrate in a single image many of the functions of the mind and the brain, both conscious and unconscious. The simplicity and sheer appeal of the image of the stage, with conscious events acted out upon it by players moving under the spotlight of attention, makes it easy to visualize, to remember, and to think about. Thus, it is richly evocative, inviting further speculation as to (...) how the elements in front, behind, and on the stage, interact to yield the conscious experiences of daily life. I suspect that the ease and power of this metaphor will go a long way toward making the study of consciousness in psychology not only academically legitimate -- a battle we have just about won -- but something other than mush in the minds of most academic psychologists. I believe that this metaphor will play the role for the cognitive psychology of consciousness that the Atkinson-Shiffrin stage model of memory played for the cognitive psychology of memory some decades back . Like that model, it summarizes most current findings and organizes them in a fashion easily understood by a wide readership. My guess is that it will stimulate a broad range of research and scholarship during the coming years. (shrink)

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)

Can we understand conscious experience? It can seem that the answer is ‘no’. Even when we have well-supported cognitive accounts of consciousness, such as global workspace theory, experience itself seems to elude our grasp. It is easy to see how a global workspace might be a useful adaptation, much harder to see what role is played by conscious experience. For instance, if I'm looking for a blue notebook, why do I need to experience colours? Why wouldn't it suffice to have (...) an unconscious mechanism that recognized colours, and could make such information available to other systems? Why couldn't the mechanisms of the workspace operate without experience at all? (shrink)

One of the central puzzles for Baars is the contrast between the small window of consciousness of which we all have direct experience and the massive collection of specialized neural nets, all working in parallel in the depths of our brain. Why is this window so small? Can we use the metaphor of a theatre, in which we regard consciousness as merely acting like a spotlight moving over an already existing structure of thoughts, memories and experiences, or does it involve (...) something more active with thoughts being created anew from moment to moment? (shrink)

The target article by Bernard Baars presents a quick way of grasping the gist of his book In the Theater of Consciousness: The Workspace of the Mind, published recently . The metaphor of consciousness as a theatre has a long history. A prototype of the theatre model may be traced back to Plato's Allegory of the Cave, in which we are like prisoners living in a cave just observing the shadows of reality. The modern theatre model insists on consciousness being (...) under the control of attention by introducing a searchlight metaphor . The target article explores some evidence from the viewpoint of Global Workspace theory by using a method of ‘contrastive analysis’. According to this theory, GW works as the publicity organ of the brain and has a facility for accessing, disseminating, and exchanging information, and for exercizing global coordination and control . Baars describes his GW as a theatre. ‘As the house lights begin to dim and the audience falls silent, a single spotlight pierces the descending darkness, until only one bright spot, shining on stage, remains visible. You know that the audience, actors, stagehands, and spotlight operators are there, working together under invisible direction and guided by an unknown script, to present the flow of visible events on stage. As the house lights dim, only the focal contents of consciousness remain. Everything else is in darkness’ . According to GW theory, a theatre stage with a bright spot is just a working memory. So I would like to comment on some general characteristics of the working memory and related spotlight problem. (shrink)

David Chalmers has proposed several principles in his attack on the ‘hard problem’ of consciousness. One of these is the principle of organizational invariance , which he asserts is significantly supported by two thought experiments involving human brains and their functional silicon-based isomorphs. I claim that while the principle is an intelligible hypothesis and could possibly be true, his thought experiments fail to provide support for it.

Much of neuroscience is currently dominated by an information processing metaphor which is largely conceptualized in discrete terms. An alternative metaphor conceptualizes information flow as continuous. A qualitative set of hypotheses based on this metaphor, the energy model, is described here. This model considers information transfer in terms of the flow of an abstract variable, energy, between points in a field comprising the extent of the nervous system. Although extremely simple, it generates some intriguing consequences. In particular, it provides a (...) useful way in which to look at consciousness. Traditional problems of consciousness, such as qualia and the unity of consciousness, are briefly addressed, and outlines are sketched of the answers given by the energy model. (shrink)