Gerard O'Brien

One of the principal tasks Dennett sets himself in Consciousness Explained is to demolish the Cartesian theater model of phenomenal consciousness, which in its contemporary garb takes the form of Cartesian materialism: the idea that conscious experience is a process of presentation realized in the physical materials of the brain. The now standard response to Dennett is that, in focusing on Cartesian materialism, he attacks an impossibly naive account of consciousness held by no one currently working in cognitive science or the philosophy of mind. Our response is quite different. We believe that, once properly formulated, Cartesian materialism is no straw man. Rather, it is an attractive hypothesis about the relationship between the computational architecture of the brain and phenomenal consciousness, and hence one that is worthy of further exploration. Consequently, our primary aim in this paper is to defend Cartesian materialism from Dennett’s assault. We do this by showing that Dennett’s argument against this position is founded on an implicit assumption (about the relationship between phenomenalexperience and information coding in the brain), which while valid in the context of classical cognitive science, is not forced on connectionism.

In their target article, Hutto and Satne eloquently articulate the failings of most current attempts to naturalize mental content. Furthermore, we think they are correct in their insistence that the only way forward is by drawing a distinction between two kinds of intentionality, one of which is considerably weaker than—and should be deployed to explain—the propositional variety most philosophers take for granted. The problem is that their own rendering of this weaker form of intentionality—contentless intentionality—is too weak. What’s needed is a species of intentionality distinct from both the industrial-strength version beloved by philosophers and the intentionality lite recommended by Hutto and Satne. We briefly motivate and sketch this alternative, and say a few words about the account of cognition that it spawns.

Stich begins his paper "What is a Theory of Mental Representation?" (1992) by noting that while there is a dizzying range of theories of mental representation in today's philosophical market place, there is very little self-conscious reflection about what a theory of mental representation is supposed to do. This is quite remarkable, he thinks, because if we bother to engage in such reflection, some very surprising conclusions begin to emerge. The most surprising conclusion of all, according to Stich, is that most of the philosophers in this field are undertaking work that is quite futile: It is my contention that most of the players in this very crowded field have no coherent project that could possibly be pursued successfully with the methods they are using. (p.244) Stich readily admits that this is a startling conclusion; so startling, he thinks, that some may even take it as an indication that he has simply "failed to figure out what those who are searching for a theory of mental representation are up to" (p.244). But it is a conclusion that he is willing to stand by, and he sets about it defending it in the body of his paper. Stich, I think, is right about this—I do take his conclusion to indicate that he has failed to figure out what those who are searching for a theory of mental representation are up to. And he has failed to do this largely because he has failed to distinguish between the theory of mind that is implicit in our folk psychology and the mental mechanism that is responsible for our capacity to make folk psychological judgements. When this conflation is undone, so too is the reasoning that takes Stich to his startling conclusion. This is not to say that the conclusion itself is clearly false; it is merely to say that Stich has failed to show that it is true. In what follows I will defend this analysis of Stich's self-conscious reflections on what a theory of mental representation is supposed to do. I will begin with a very brief exposition of Stich's survey of the logical terrain in this part of the philosophical landscape and the line of reasoning that subsequently delivers up the aforementioned conclusion. I will then go on to argue that the latter line of reasoning is fundamentally misdirected because of an error in the former survey.

The connectionist vehicle theory of phenomenal experience in the target article identifies consciousness with the brain’s explicit representation of information in the form of stable patterns of neural activity. Commentators raise concerns about both the conceptual and empirical adequacy of this proposal. On the former front they worry about our reliance on vehicles, on representation, on stable patterns of activity, and on our identity claim. On the latter front their concerns range from the general plausibility of a vehicle theory to our specific attempts to deal with the dissociation studies. We address these concerns, and then finish by considering whether the vehicle theory we have defended has a coherent story to tell about the active, unified subject to whom conscious experiences belong

In recent years, a number of contemporary proponents of psychoanalysis have sought to derive support for their conjectures about the _dynamic_ unconscious from the empirical evidence in favor of the _cognitive_ unconscious. It is our contention, however, that far from supporting the dynamic unconscious, recent work in cognitive science suggests that the time has come to dispense with this concept altogether. In this paper we defend this claim in two ways. First, we argue that any attempt to shore up the dynamic unconscious with the cognitive unconscious is bound to fail, simply because the latter, as it is understood in contemporary cognitive science, is incompatible with the former, as it is traditionally conceived by psychoanalytic theory. Second, we show how psychological phenomena traditionally cited as evidence for the operation of a dynamic unconscious can be accommodated more parsimoniously by other means

It is commonplace for both philosophers and cognitive scientists to express their allegiance to the "unity of consciousness". This is the claim that a subject’s phenomenal consciousness, at any one moment in time, is a single thing. This view has had a major influence on computational theories of consciousness. In particular, what we call single-track theories dominate the literature, theories which contend that our conscious experience is the result of a single consciousness-making process or mechanism in the brain. We argue that the orthodox view is quite wrong: phenomenal experience is not a unity, in the sense of being a single thing at each instant. It is a multiplicity, an aggregate of phenomenal elements, each of which is the product of a distinct consciousness-making mechanism in the brain. Consequently, cognitive science is in need of a multi-track theory of consciousness; a computational model that acknowledges both the manifold nature of experience, and its distributed neural basis

Carruthers presents evidence concerning the cross-modular integration of information in human subjects which appears to support the “cognitive conception of language.” According to this conception, language is not just a means of communication, but also a representational medium of thought. However, Carruthers overlooks the possibility that language, in both its communicative and cognitive roles, is a nonrepresentational system of conventional signals – that words are not a medium we think in, but a tool we think with. The evidence he cites is equivocal when it comes to choosing between the cognitive conception and this radical communicative conception of language.

We think the best prospect for a naturalistic explanation of phenomenal consciousness is to be found at the confluence of two influential ideas about the mind. The first is the _computational _ _theory of mind_: the theory that treats human cognitive processes as disciplined operations over neurally realised representing vehicles.1 The second is the _representationalist theory of _ _consciousness_: the theory that takes the phenomenal character of conscious experiences (the “what-it-is-likeness”) to be constituted by their representational content.2 Together these two theories suggest that phenomenal consciousness might be explicable in terms of the representational content of the neurally realised representing vehicles that are generated and manipulated in the course of cognition. The simplest and most elegant hypothesis that one might entertain in this regard is that conscious experiences are identical to (i.e., are one and the same as) the brain’s representing vehicles

Although connectionism is advocated by its proponents as an alternative to the classical computational theory of mind, doubts persist about its _computational_ credentials. Our aim is to dispel these doubts by explaining how connectionist networks compute. We first develop a generic account of computation—no easy task, because computation, like almost every other foundational concept in cognitive science, has resisted canonical definition. We opt for a characterisation that does justice to the explanatory role of computation in cognitive science. Next we examine what might be regarded as the “conventional” account of connectionist computation. We show why this account is inadequate and hence fosters the suspicion that connectionist networks aren’t genuinely computational. Lastly, we turn to the principal task of the paper: the development of a more robust portrait of connectionist computation. The basis of this portrait is an explanation of the representational capacities of connection weights, supported by an analysis of the weight configurations of a series of simulated neural networks

In this paper we defend a position we call radical connectionism. Radical connectionism claims that cognition _never_ implicates an internal symbolic medium, not even when natural language plays a part in our thought processes. On the face of it, such a position renders the human capacity for abstract thought quite mysterious. However, we argue that connectionism is committed to an analog conception of neural computation, and that representation of the abstract is no more problematic for a system of analog vehicles than for a symbol system. Natural language is therefore not required as a representational medium for abstract thought. Since natural language is arguably not a representational medium _at all_, but a conventionally governed scheme of communicative signals, we suggest that the role of internalised (i.e., self- directed) language is best conceived in terms of the coordination and control of cognitive activities within the brain

Stich begins his paper "What is a Theory of Mental Representation?" by noting that while there is a dizzying range of theories of mental representation in today's philosophical market place, there is very little self-conscious reflection about what a theory of mental representation is supposed to do. This is quite remarkable, he thinks, because if we bother to engage in such reflection, some very surprising conclusions begin to emerge. The most surprising conclusion of all, according to Stich, is that most of the philosophers in this field are undertaking work that is quite futile: " It is my contention that most of the players in this very crowded field have _no_ coherent project that could possibly be pursued successfully with the methods they are using. " Stich readily admits that this is a startling conclusion; so startling, he thinks, that some may even take it as an indication that he has simply "failed to figure out what those who are searching for a theory of mental representation are up to". But it is a conclusion that he is willing to stand by, and he sets about it defending it in the body of his paper

Any creature that must move around in its environment to find nutrients and mates, in order to survive and reproduce, faces the problem of sensorimotor control. A solution to this problem requires an on-board control mechanism that can shape the creature’s behaviour so as to render it “appropriate” to the conditions that obtain. There are at least three ways in which such a control mechanism can work, and Nature has exploited them all. The first and most basic way is for a creature to bump into the things in its environment, and then, depending on what has been encountered, seek to modify its behaviour accordingly. Such an approach is risky, however, since some things in the environment are distinctly unfriendly. A second and better way, therefore, is for a creature to exploit ambient forms of energy that carry information about the distal structure of the environment. This is an improvement on the first method since it enables the creature to respond to the surroundings without actually bumping into anything. Nonetheless, this second method also has its limitations, one of which is that the information conveyed by such ambient energy is often impoverished, ambiguous and intermittent