What are the relations between preattentive feature-placing and states of perceptual awareness? For the purposes of this paper, states of "perceptual awareness" are confined to the simplest possible exemplars: states in which one is aware of some aspect of the appearance of something one perceives. Subjective contours are used as an example. Early visual processing seems to employ independent, high-bandwidth, preattentive feature "channels", followed by a selective process that directs selective attention. The mechanisms that yield subjective contours are found very (...) early in this processing. An experiment by Greg Davis and Jon Driver is described; it seems to show that multiple subjective figures can be coded in these preattentive, parallel stages of visual processing. I propose that some of these preattentive states might register the very same differences that, were one aware of them, would be phenomenal differences. Some arguments pro and con on this possibility are assessed. (shrink)
Like those famous nations divided by a single tongue, my paper (this volume) and Professor P.M. Churchland's deep and engaging reply offer different spins on a common heritage. The common heritage is, of course, a connectionist vision of the inner neural economy- a vision which depicts that economy in terms of supra-sentential state spaces, vector-to-vector transformations, and the kinds of skillful pattern-recognition routine we share with the bulk of terrestrial intelligent life-forms. That which divides us is, as ever, much harder (...) to isolate and name. Clearly, it has something to do with the role of moral talk and exchange, and something to do with the conception of morality itself (and, correlatively, with the conception of moral progress). Most of this Reply will be devoted to clarifying the nature of the disputed territory. First, though (as a prophylactic against misunderstanding) I shall rehearse some points of agreement concerning moral talk and progress. (shrink)
Computational learning theory explores the limits of learnability. Studying language acquisition from this perspective involves identifying classes of languages that are learnable from the available data, within the limits of time and computational resources available to the learner. Diﬀerent models of learning can yield radically diﬀerent learnability results, where these depend on the assumptions of the model about the nature of the learning process, and the data, time, and resources that learners have access to. To the extent that such assumptions (...) accurately reﬂect human language learning, a model that invokes them can oﬀer important insights into the formal properties of natural languages, and the way in which their representations might be eﬃciently acquired. In this chapter we consider several computational learning models that have been applied to the language learning task. Some of these have yielded results that suggest that the class of natural languages cannot be eﬃciently learned from the primary linguistic data (PLD) available to children, through.. (shrink)
Markets, companies and various forms of business organizations may all (we have argued) be usefully viewed through the lens of CAS -- the theory of complex adaptive systems. In this chapter, I address one fundamental issue that confronts both the theoretician and the business manager: the nature and opportunities for control and intervention in complex adaptive regimes. The problem is obvious enough. A complex adaptive system, as we have defined it, is soft assembled and largely self-organizing. This means that it (...) is the emergent product of multiple, and often very heterogeneous, interacting factors and forces, and that the crucial interactions are not controlled and orchestrated by an overseeing executive, detailed program, or any other source of strict hierarchical control. There is thus a pressing problem -- are such systems strictly out of control and beyond the reach of useful governance? I shall argue that they are not. Such systems, though initially unfamiliar, can nonetheless be led, influenced and enabled in a variety of ways. (shrink)
1. Throughout the paper, and especially in the section called "LISP vs. DST", I worried that there was not enough focus on EXPLANATION. For the real question, it seems to me, is not whether some dynamical system can implement human cognition, but whether the dynamical description of the system is more explanatorily potent than a computational/representational one. Thus we know, for example, that a purely physical specification can fix a system capable of computing any LISP function. But from this it (...) doesn't follow that the physical description is the one we need to understand the power of the system considered as an information processing device. In the same way, I don't think your demonstration that bifurcating attractor sets can yield the same behavior as a LISP program goes any way towards showing that we should not PREFER the LISP description. To reduce symbolic stories to a subset of DST (as hinted in that section) requires MORE than showing this kind of equivalence: it requires showing that there is explanatory gain, or at the very least, no explanatory loss, at that level. I append an extract from a recent paper of mine that touches on these issues, in case it helps clarify what I am after here. (shrink)
Much work in economics, the social sciences, and elsewhere takes as its starting point a somewhat unrealistic conception of rationality Ã¢â¬â a conception that ignores or downplays both the temporal and the situated aspects of human reason. Biological reason, I shall argue, is better conceived as an iterated process of adaptive response made under extreme time pressure and exquisitely keyed to a variety of external structures and circumstances. These external structures and circumstances act as filters and constraints on the spaces (...) of possible real-time responses. Paramount among such structures and circumstances, in the case of human reason, are the cultural artifacts of language and of social and economic institutions. Models of rational decision making need to situate the reasoning agent as just one element in a complex and time-sensitive feedback system in which such external structures play a major role. It is therefore crucial that we understand the complex and mutually modulatory interplay between individual cognition and the extended environmental loops in which it participates. I shall explore a few potential avenues for developing such an understanding including neural network research and multiple time scale.. (shrink)
We seem, or so it seems to some theorists, to experience a rich stream of highly detailed information concerning an extensive part of our current visual surroundings. But this appearance, it has been suggested, is in some way illusory. Our brains do not command richly detailed internal models of the current scene. Our seeings, it seems, are not all that they seem. This, then, is the Grand Illusion. We think we see much more than we actually do. In this paper (...) I shall (briefly) rehearse the empirical evidence for this rather startling claim, and then critically examine a variety of responses. One especially interesting response is a development of the so-called ‘skill theory’, according to which there is no illusion after all. Instead, so the theory goes, we establish the required visual contact with our world by an ongoing process of active exploration, in which the world acts as a kind of reliable, interrogable, external memory (Noe, Pessoa and Thompson (2000), Noe (2001). The most fully worked-out versions of this response ( Noe and O’Regan (2000), O’Regan and Noe 2001) tend, however, to tie the contents of conscious visual experience rather too tightly to quite low-level features of this ongoing sensorimotor engagement. This (I shall argue) undervalues the crucial links between perceptual experience, reason and intentional action, and opens the door to a problem that I will call ‘sensorimotor chauvinism’: the premature welding of experiential contents to very specific details of our embodiment and sensory apparatus. Drawing on the dual visual systems hypothesis of Milner and Goodale (1995), I sketch an alternative version of the skill theory, in which the relation between conscious visual experience and the low-level details of sensorimotor engagement is indirect and non-constitutive. The hope is thus to embrace the genuine insights of the skill theory response, while depicting conscious visual experience as most tightly geared to knowing and reasoning about our world.. (shrink)
I'm very happy here to be sandwiched between Lycan and Millikan, two of the living philosophers from whom I've probably learned the most, and to whom I am the most grateful. Plus the intermediary position is appropriate for someone commenting on intermediary representations in vision. There's much to like in Bill's account of "layering" in visual representation. For one, it makes explicit and publicizes the notion that there are multiple layers of representation involved even in the seemingly simple achievement (...) of.. (shrink)
We assemble here in this time and place to discuss the thesis that conscious attention can provide knowledge of reference of perceptual demonstratives. I shall focus my commentary on what this claim means, and on the main argument for it found in the first five chapters of Reference and Consciousness. The middle term of that argument is an account of what attention does: what its job or function is. There is much that is admirable in this account, and I am (...) confident that it will be the foundation, the launching-pad, for much future work on the subject. But in the end I will argue that Campbell's picture makes the mechanisms of attention too smart: smarter than they are, smarter than they could be. If we come to a more realistic appraisal of the skills and capacities of our subpersonal minions, the "knowledge of reference" which they yield will have to be taken down a notch or two. But first let us clarify what the argument is. (shrink)
We assemble here in this time and place to discuss the thesis that conscious attention can provide knowledge of reference of perceptual demonstratives. I shall focus my commentary on what this claim means, and on the main argument for it found in the first five chapters of Reference and Consciousness. The middle term of that argument is an account of what attention does: what its job or function is. There is much that is admirable in this account, and I am (...) confident that it will be the foundation, the launching-pad, for much future work on the subject. But in the end I will argue that Campbell's picture makes the mechanisms of attention too smart: smarter than they are, smarter than they could be. If we come to a more realistic appraisal of the skills and capacities of our sub-personal minions, the "knowledge of reference" which they yield will have to be taken down a notch or two. But first let us clarify what the argument is. (shrink)
If, as Ned Block has argued, consciousness is a mongrel concept, then this collection resembles nothing so much as a visit to a dog pound, where one can hear all the varieties baying, at full volume. The experience is one of immersion in a voluminous excited cacophony, with much yipping and barking, some deep-throated growling, and other voices that can only be characterized as howling at the moon. What a time to be conscious! What a time to be conscious of (...) being conscious! (shrink)
The question of whether it is possible to characterise grammatical knowledge in probabilistic terms is central to determining the relationship of linguistic representation to other cognitive domains. We present a statistical model of grammaticality which maps the probabilities of a statistical model for sentences in parts of the British National Corpus (BNC) into grammaticality scores, using various functions of the parameters of the model. We test this approach with a classifier on test sets containing different levels of syntactic infelicity. With (...) appropriate tuning, the classifiers achieve encouraging levels of accuracy. These experiments suggest that it may be possible to characterise grammaticality judgements in probabilistic terms using an enriched language model. (shrink)
In this chapter we consider unsupervised learning from two perspectives. First, we briefly look at its advantages and disadvantages as an engineering technique applied to large corpora in natural language processing. While supervised learning generally achieves greater accuracy with less data, unsupervised learning offers significant savings in the intensive labour required for annotating text. Second, we discuss the possible relevance of unsupervised learning to debates on the cognitive basis of human language acquisition. In this context we explore the implications of (...) recent work on grammar induction for poverty of stimulus arguments that purport to motivate a strong bias model of language learning, commonly formulated as a theory of Universal Grammar (UG). We examine the second issue both as a problem in computational learning theory, and with reference to empirical work on unsupervised Machine Learning (ML) of syntactic structure. We compare two models of learning theory and the place of unsupervised learning within each of them. Looking at recent work on part of speech tagging and the recognition of syntactic structure, we see how far unsupervised ML methods have come in acquiring different kinds of grammatical knowledge from raw text. (shrink)
Indirect negative evidence is clearly an important way for learners to constrain overgeneralisation, and yet a good learning theoretic analysis has yet to be provided for this, whether in a PAC or a probabilistic identification in the limit framework. In this paper we suggest a theoretical analysis of indirect negative evidence that allows the presence of ungrammatical strings in the input and also accounts for the relationship between grammaticality/acceptability and probability. Given independently justified assumptions about lower bounds on the probabilities (...) of grammatical strings, we establish that a limited number of membership queries of some strings can be probabilistically simulated. (shrink)
The last ten years have seen an increasing interest, within cognitive science, in issues concerning the physical body, the local environment, and the complex interplay between neural systems and the wider world in which they function. “Physically embodied, environmentally embedded” approaches thus loom large on the contemporary cognitive scientific scene. Yet many unanswered questions remain, and the shape of a genuinely embodied, embedded science of the mind is still unclear. I begin by sketching a few examples of the approach, and (...) then raise a variety of critical questions concerning its nature and scope. A distinction is drawn between two kinds of appeal to embodiment: ‘simple’ cases, in which bodily and environmental properties merely constrain accounts that retain the focus on inner organization and processing, and more radical appeals, in which attention to bodily and environmental features is meant to transform both the subject matter and the theoretical framework of cognitive science. (shrink)
The first question concerns a fundamental assumption of most researchers who theorize about the brain. Do neural systems exploit classical compositional and systematic representations, distributed representations, or no representations at all? The question is not easily answered. Connectionism, for example, has been criticised for both holding and challenging representational views. The second quesútion concerns the crucial methodological issue of how results emerging from the various brain sciences can help to constrain cognitive scientific models. Finally, the third question focuses attention on (...) a major challenge to contemporary cognitive science: the challenge of understanding the mind as a controller of embodied and environmentally embedded action. (shrink)
Beer’s (2003) paper is a tour de force of detailed comments on the more general notion of “situated- dynamical modeling, and provides a concrete sample ness”, Beer suggests that “on this view, situated action of the kinds of understanding dynamicists may realis- is the fundamental concern and cognition is … one tically hope to achieve. The analysis is thus, as Beer resource among many that can be brought to bear as an states, a “tool for building intuition”, and in this (...) it suc- agent encounters its world”. In the worked example of ceeds brilliantly. But it is also an attempt to show that an agent that approaches circles and avoids diamonds, dynamical approaches can get a foothold in the expla- we see direct evidence of this in the claim that a certain nation of “minimally cognitive behaviors”; that is to three-dimensional projection provides a potent analytic say, behaviors that seem, on the surface at least, good tool. For this projection happens to be one that involves contenders for more traditional forms of problem de- one environmental state variable (vertical object posi- composition and analysis. In these brief comments, I tion), one body state variable (horizontal position rela- want to focus on one important question that I think tive to the object) and one neuronal state variable remains unanswered, and that bears rather directly on (output of interneuron 9). By dispensing with talk of this enterprise of “scaling up”. representations and their contents, and restricting the The question concerns the notion of an integrated depiction of the inner realm to a depiction of inner state dynamical explanation itself. The point about such alone (section 9.3), the dynamicist makes it easy to.. (shrink)
Presented at the University of Glasgow Conference on "Individuating the Senses", organized by Professor Fiona MacPherson, Department of Philosophy and Centre for the Study of Perceptual Experience, 4 and 5 December 2004. This is the final draft of May 2005, under review for publication as part of the volume of conference proceedings.
Three different ways to understand the representational content of the feature maps employed in early vision are compared. First is Stephen Kosslyn's claim, entered as part of the debate over mental imagery, that such areas support "depictive" representation, and that visual perception uses them as depictive representations. Reasons are given to doubt this view. Second, an improved version of what I call "feature-placing" is described and advanced. Third, feature-placing is contrasted with the notion that the representational content of those feature (...) maps could be conveyed in a list of sentences about visual objects. Some problems with this last alternative are described. (shrink)
Spectrum inversion is a thought experiment, and I would wager that there is no better diagnostic test to the disciplinary affiliation of a randomly selected member of the audience than your reaction to a thought experiment. It is a litmus test. If you find that you are paying close attention, subvocalizing objections, and that your heart-rate and metabolism go up, you have turned pink: you are a philosopher. If on the other hand the thought experiment leaves you cold, and you (...) wonder why otherwise sensible people would worry about such things, you have turned blue and you are a psychologist. (shrink)
Recent work in experimental psychology and neuroscience has revealed a rather surprising architecture for early (or preattentive) perceptual processes. This paper will describe some of the surprising features of that architecture, and how they bear on recent philosophical debates about the notion of phenomenal consciousness. I will argue that the common sense idea that states of phenomenal consciousness are states of a unitary kind cannot survive confrontation with the details of how our early perceptual processing works. In particular, that architecture (...) forces us to contemplate the prospect of phenomenal consciousness being sundered in two, with states that have phenomenal character making an appearance far before the arrival of anything one could call consciousness or awareness. (shrink)
Common sense says that visual agnosia is impossible. It ought not exist. If an object like a safety pin or a bar of white soap is in full view, you see it, and you know what a "safety pin" or a "bar of soap" is, then you cannot fail to recognize what you see. If you identify the safety pin as "something silver and shiny like a watch or a nail clipper," or you identify the bar of white soap as (...) "a piece of paper," then common sense would dictate that either you fail to see the object, or your knowledge is somehow deficient. But visual agnosics, who make such responses, clearly do--in some sense--"see" the objects in question. Often they can, for example, make accurate and recognizable drawings of what they see. Some lack measurable visual field defects; they have a full visual field. And they clearly know what a "safety pin" or a "bar of soap" is: if allowed to touch the object, or its use is pantomimed, correct identification is immediate. "I see it now," they may say. We get a failure specifically in visual recognition, even though sufficient sensory functions and cognitive functions are demonstrably intact. Such is the mystery of visual agnosia. (shrink)
As a reductionist and a subjectivist I find little to dispute, and much to cheer, in the use of the comparative argument against objectivism. The best available form of objectivism is anthropocentric realism, and at the very least the comparative argument dispels much of the..
The perception of the lightness of surfaces has been shown to be affected by information about the spatial configuration of those surfaces and their illuminants. For example, two surfaces of equal luminance can appear to be of very different lightness if one of the two appears to lie in a shadow. How are we to understand the character of the processes that integrate such spatial configuration information so as to yield the eventual appearance of lightness? This paper makes some simple (...) observations about the vocabulary of appearance used in these contexts, and proposes that the end results can be called "phenomenal" in a traditional sense of that word. Processes whose products are phenomenal are next distinguished from processes characterized in other terms: (a) processes of perceptual grouping; (b) processes of perceptual organization; and (c) attentional (as opposed to preattentive) processes. These four categories are conceptually and empirically distinct. In particular, the paper reviews some evidence that appearances as of contours, occlusion, and amodally completed shapes can occur preattentively. Some implications for understanding gestalt grouping processes are briefly discussed. (shrink)
Sensory substitution devices are a type of sensory prosthesis that (typically) convert visual stimuli transduced by a camera into tactile or auditory stimulation. They are designed to be used by people with impaired vision so that they can recover some of the functions normally subserved by vision. In this chapter we will consider what philosophers might learn about the nature of the senses from the neuroscience of sensory substitution. We will show how sensory substitution devices work by exploiting the cross-modal (...) plasticity of sensory cortex: the ability of sensory cortex to pick up some types of information about the external environment irrespective of the nature of the sensory inputs it is processing. We explore the implications of cross-modal plasticity for theories of the senses that attempt to make distinctions between the senses on the basis of neurobiology. (shrink)
Learning theory has frequently been applied to language acquisition, but discussion has largely focused on information theoretic problems—in particular on the absence of direct negative evidence. Such arguments typically neglect the probabilistic nature of cognition and learning in general. We argue first that these arguments, and analyses based on them, suffer from a major flaw: they systematically conflate the hypothesis class and the learnable concept class. As a result, they do not allow one to draw significant conclusions about the learner. (...) Second, we claim that the real problem for language learning is the computational complexity of constructing a hypothesis from input data. Studying this problem allows for a more direct approach to the object of study—the language acquisition device—rather than the learnable class of languages, which is epiphenomenal and possibly hard to characterize. The learnability results informed by complexity studies are much more insightful. They strongly suggest that target grammars need to be objective, in the sense that the primitive elements of these grammars are based on objectively definable properties of the language itself. These considerations support the view that language acquisition proceeds primarily through data-driven learning of some form. (shrink)
An appreciation of the many roles of ‘precision-weighting’ (upping the gain on select populations of prediction error units) opens the door to better accounts of planning and ‘offline simulation’, makes suggestive contact with large bodies of work on embodied and situated cognition, and offers new perspectives on the ‘active brain’. Combined with the complex affordances of language and culture, and operating against the essential backdrop of a variety of more biologically basic ploys and stratagems, the result is a maximally context-sensitive, (...) restless, constantly self-reconfiguring architecture. (shrink)
Does the material basis of conscious experience extend beyond the boundaries of the brain and central nervous system? In Clark 2009 I reviewed a number of ‘enactivist’ arguments for such a view and found none of them compelling. Ward (2012) rejects my analysis on the grounds that the enactivist deploys an essentially world-involving concept of experience that transforms the argumentative landscape in a way that makes the enactivist conclusion inescapable. I present an alternative (prediction-and-generative-model-based) account that neatly accommodates all the (...) positive evidence that Ward cites on behalf of this enactivist conception, and that (I argue) makes richer and more satisfying contact with the full sweep of human experience. (shrink)
Finding the Mind Content Type Journal Article DOI 10.1007/s11098-010-9598-9 Authors Andy Clark, Philosophy, University of Edinburgh, Dugald Stewart Building, 3 Charles Street, Edinburgh, EH8 9AD Scotland, UK Journal Philosophical Studies Online ISSN 1573-0883 Print ISSN 0031-8116.
Précis of Supersizing the mind: embodiment, action, and cognitive extension (Oxford University Press, NY, 2008) Content Type Journal Article DOI 10.1007/s11098-010-9597-x Authors Andy Clark, Philosophy, University of Edinburgh, Dugald Stewart Building, 3 Charles Street, Edinburgh, EH8 9AD Scotland (UK) Journal Philosophical Studies Online ISSN 1573-0883 Print ISSN 0031-8116.
The papers by Macpherson, O'Callaghan, and Batty reveal some startling differences in the objects and properties represented by different modalities. They also reveal some tensions between different ways of understanding what it is for any one modality to represent objects and properties.
How do questions concerning consciousness and phenomenal experience relate to, or interface with, questions concerning plans, knowledge and intentions? At least in the case of visual experience the relation, we shall argue, is tight. Visual perceptual experience, we shall argue, is fixed by an agent’s direct unmediated knowledge concerning her poise (or apparent poise) over a currently enabled action space. An action space, in this specific sense, is to be understood not as a fine-grained matrix of possibilities for bodily movement, (...) but as a matrix of possibilities for pursuing and accomplishing one’s intentional actions, goals and projects. If this is correct, the links between planning, intention and perceptual experience are tight, while (contrary to some recent accounts invoking the notion of ‘sensorimotor expectations’) the links between embodied activity and perceptual experience, though real, are indirect. What matters is not bodily activity itself, but our practical knowledge (which need not be verbalized or in any way explicit) of our own possibilities for action. Such knowledge, selected, shaped and filtered by the grid of plans, goals, and intentions, plays, we argue, a constitutive role in explaining the content and character of visual perceptual experience. (shrink)
It is common to think that clarity is an essential ingredient of good teaching, meaning, in part, that good teachers always make it as easy as possible to follow what they say. We disagree. What we argue is that there are cases in which a philosophy teacher needs to forego clarity, making strategic use of obscurity in the undergraduate classroom.
Adams and Aizawa, in a series of recent and forthcoming papers ((2001), (In Press), (This Volume)) seek to refute, or perhaps merely to terminally embarrass, the friends of the extended mind. One such paper begins with the following illustration: "Question: Why did the pencil think that 2+2=4? Clark's Answer: Because it was coupled to the mathematician" Adams and Aizawa (this volume) ms p.1 "That" the authors continue "about sums up what is wrong with Clark's extended mind hypothesis". The example of (...) the pencil, they suggest, is just an especially egregious version of a fallacy said to pervade the literature on the extended mind. This fallacy, which they usefully dub the "coupling-constitution fallacy", is attributed , in varying degrees and manners, to Van Gelder and Port (1995), Clark and Chalmers (1998), Haugeland (1998), Dennett (2000), Clark (2001), Gibbs (2001), and Wilson (2004). The fallacy, of course, is to move from the causal coupling of some object or process to some cognitive agent, to the conclusion that the object or process is part of the cognitive agent , or part of the agent's cognitive processing (see e.g. Adams and Aizawa (This volume) ms p.2). Proponents of the extended mind and related theses, Adams and Aizawa repeatedly assert, are prone to this fallacy in part because they either ignore or fail to properly appreciate the importance of " the mark of the cognitive" viz the importance of an account of "what makes something a cognitive agent" (op cit ms p.3). The positive part of Adams and Aizawa's critique then emerges as a combination of the assertion that this "mark of the cognitive" involves the idea that "cognition is constituted by certain sorts of causal process that involve non-derived contents" (e.g. op cit ms p.3) and that these processes look to be characterized by psychological laws that turn out to apply to many internal goings-on but not currently (as a matter of contingent empirical fact) to any processes that take place in non-biological tools and artifacts. In what follows, I shall try to show why these arguments display nothing so much as mutual failures of communication: crossed wires concealing a couple of real, important, but much more subterranean, disagreements. In particular, I try to show why the negative considerations advanced by Adams and Aizawa fail to successfully undermine the argument for the extended mind, and why their more radical positive story, unless supplemented by implausible additional claims, fails to cast doubt on the claim that minds like ours can (without the need for any radically new techniques, technologies or interventions) extend into the world. (shrink)
In the movie, Memento, the hero, Leonard, suffers from a form of anterograde amnesia that results in an inability to lay down new memories. Nonetheless, he sets out on a quest to find his wife’s killer, aided by the use of notes, annotated polaroids, and (for the most important pieces of information obtained) body tattoos. Using these resources he attempts to build up a stock of new beliefs and to thus piece together the puzzle of his wife’s death. At one (...) point in the movie, a character exasperated by Leonard’s lack of biological recall, shouts. (shrink)
A standard view in philosophy of mind is that qualia and phenomenal character require consciousness. This paper argues that various experimental and clinical phenomena can be better explained if we reject this assumption. States found in early visual processing can possess qualitative character even though they are not in any sense conscious mental states. This non-standard interpretation bears the burden of explaining what must be added to states that have qualitative character in order to yield states of sensory awareness or (...) sensory experience. I argue that the study of selective attention reveals resources that can be useful in that project. Two traditional objects are briefly considered. (shrink)