Abstract: Here's an old question in the philosophy of perception: here I am, looking at this pen [I hold up a pen in my hand]. Presumably I really am seeing this pen. Even so, I could be having an experience just like the one I am having without anything being there. So how can the experience I am having really involve direct awareness of the pen? It seems as though the presence of the pen is inessential to the way the experience is

Abstract: There is general agreement that from the first few months of life, our apprehension of physical objects accords, in some sense, with certain principles. In one philosopher's locution, we are 'perceptually sensitive' to physical principles describing the behavior of objects. But in what does this accordance or sensitivity consist? Are these principles explicitly represented or merely 'implemented'? And what sort of explanation do we accomplish in claiming that our object perception accords with these principles? My main goal here is to suggest answers to these questions. I argue that the object principles are not explicitly represented, first addressing some confusion in the debate about what that means. On the positive side, I conclude that the principles supply a competence account, at Marr's computational level, and that they function like natural constraints in vision. These are among their considerable explanatory benefits - benefits endowed by rules and principles in other cognitive domains as well. Characterizing the explanatory role of the object principles is my main project here, but in pursuing certain sub-goals I am led to other conclusions of interest in their own right. I address an argument that the object principles are explicitly represented which assumes that object perception is substantially thought-like. This provokes a jaunt off the main path which leads to interesting territory: the boundary between thought and perception. I argue that object apprehension is much closer to perception than to thought on the spectrum between the two

Abstract: This paper contrasts three different schemes of reference relevant to understanding systems of perceptual representation: a location-based system dubbed "feature-placing", a system of "visual indices" referring to things called "proto-objects", and the full sortal-based individuation allowed by a natural language. The first three sections summarize some of the key arguments (in Clark, 2000) to the effect that the early, parallel, and pre-attentive registration of sensory features itself constitutes a simple system of nonconceptual mental representation. In particular, feature integration--perceiving something as being both F and G, where F and G are sensible properties registered in distinct parallel streams--requires a referential apparatus. Section V. reviews some grounds for thinking that at these earliest levels this apparatus is location-based: that it has a direct and nonconceptual means of picking out places. Feature-placing is contrasted with a somewhat more sophisticated system that can identify and track four or five "perceptual objects" or "proto-objects", independently of their location, for as long as they remain perceptible. Such a system is found in Zenon Pylyshyn's fascinating work on "visual indices", in Dana Ballard's notion of deictic codes, and in Kahneman, Treisman, and Wolfe's accounts of systems of evanescent representations they call "object files". Perceptual representation is a layered affair, and I argue that it probably includes both feature-placing and proto-objects. Finally, both nonconceptual systems are contrasted with the full-blooded individuation allowed in a natural language

Abstract: In Clark (2000), Austen Clark argues convincingly that a widespread view of perception as a complicated kind of feature-extraction is incomplete. He argues that perception has another crucial representational ingredient: it must also involve the representation of "sensory individuals" that exemplify sensorily extracted features. Moreover, he contends, the best way of understanding sensory individuals takes them to be places in space surrounding the perceiver. In this paper, I'll agree with Clark's case for sensory individuals (§1). However, I shall argue against his view of sensory individuals as places (§2). Instead, I'll propose and defend an alternative account of sensory individuals that construes the latter as (visual) objects (§§3-5)

Abstract: You might reasonably surmise from the title of this paper that I will be discussing a theory of vision. After all, what is a theory of vision but a theory of how the world is connected to our visual representations? Theories of visual perception universally attempt to give an account of how a proximal stimulus (presumably a pattern impinging on the retina) can lead to a rich representation of a three dimensional world and thence to either the recognition of known objects or to the coordination of actions with visual information. Such theories typically provide an effective (i.e., computable) mapping from a 2D pattern to a representation of a 3D scene, usually in the form of a symbol structure. But such a mapping, though undoubtedly the essential purpose of a theory of vision, leaves at least one serious problem that I intend to discuss here. It is this problem, rather than a theory of vision itself, that is the subject of this talk

Abstract: This paper argues that a theory of situated vision, suited for the dual purposes of object recognition and the control of action, will have to provide something more than a system that constructs a conceptual representation from visual stimuli: it will also need to provide a special kind of direct (preconceptual, unmediated) connection between elements of a visual representation and certain elements in the world. Like natural language demonstratives (such as `this' or `that') this direct connection allows entities to be referred to without being categorized or conceptualized. Several reasons are given for why we need such a preconcep- tual mechanism which individuates and keeps track of several individual objects in the world. One is that early vision must pick out and compute the relation among several individual objects while ignoring their properties. Another is that incrementally computing and updating representations of a dynamic scene requires keeping track of token individuals despite changes in their properties or locations. It is then noted that a mechanism meeting these requirements has already been proposed in order to account for a number of disparate empiri- cal phenomena, including subitizing, search-subset selection and multiple object tracking (Pylyshyn et al., Canadian Journal of Experimental Psychology 48(2) (1994) 260). This mechanism, called a visual index or FINST, is brie¯y discussed and it is argued that viewing it as performing a demonstrative or preconceptual reference function has far-reaching impli- cations not only for a theory of situated vision, but also for suggesting a new way to look at why the primitive individuation of visual objects, or proto-objects, is so central in computing visual representations. Indexing visual objects is also, according to this view, the primary means for grounding visual concepts and is a potentially fruitful way to look at the problem of visual integration across time and across saccades, as well as to explain

Abstract: We discuss in some length evidence from the cognitive science suggesting that the representations of objects based on spatiotemporal information and featural information retrieved bottomup from a visual scene precede representations of objects that include conceptual information. We argue that a distinction can be drawn between representations with conceptual and nonconceptual content. The distinction is based on perceptual mechanisms that retrieve information in conceptually unmediated ways. The representational contents of the states induced by these mechanisms that are available to a type of awareness called phenomenal awareness constitute the phenomenal content of experience. The phenomenal content of perception contains the existence of objects as separate things that persist in time and time, spatiotemporal information, and information regarding relative spatial relations, motion, surface properties, shape, size, orientation, color, and their functional properties

Abstract: What is the difference between perception and mere sensation? Take a typical perceptual experience, such as an experience of seeing a fish or a table, and a merely sensory experience, such as the experience of ‘seeing stars’ or of enjoying a red phosphene (a phosphene is a kind of afterimage). One difference between these experiences is that in the first case, there is an external object that one sees. But this difference is not the only difference. On the face of it, typical perceptual experiences and mere sensations also differ in their phenomenal character. How can this difference be understood?

Abstract: First, what it is for a sentient being to sense is for it to employ two distinct capacities: one for representing places-at-times; the other for representing "features" (60, cf. 70). Exercised together, the result is akin to feature-placing, which brings us to the second thesis: what sensory systems represent is that features are instantiated at place-times. Accordingly, sensory systems do not, for instance, attribute properties to objects, such as trees, tables, bodies, or persons (163)

Abstract: What is the difference between perception and mere sensation? Take a typical perceptual experience, such as an experience of seeing a fish or a table, and a merely sensory experience, such as the experience of ‘seeing stars’ or of enjoying a red phosphene (a phosphene is a kind of afterimage). One difference between these experiences is that in the first case, there is an external object that one sees. But this difference is not the only difference. On the face of it, typical perceptual experiences and mere sensations also differ in their phenomenal character. How can this difference be understood?

Abstract: The focus of this paper will be on the problem of perceptual presence and on a solution to this problem pioneered by Kant [1781; 1783] and refined by Sellars [Sellars, 1978] and Strawson [Strawson, 1971]. The problem of perceptual presence is that of explaining how our perceptual experience of the world gives us a robust sense of the presence of objects in perception over and above those sensory aspects of the object given in perception. Objects possess other properties which are, one might say, phenomenologically present even though they are admittedly sensorily absent. The general form of the solution to this problem that Kant developed seems to me to be a neglected resource in contemporary work on perceptual consciousness. Kant solves the problem of perceptual presence by appealing to that which he called the productive use of the imagination. This faculty of mind supplies schematic representations of the object of perception that explains a phenomenological sense of perceptual presence even of those features that are not, in a sense to be further clarified, “present” in one’s perception of an object. This argument will, I will demonstrate, prove important to an assessment of a recent debate as to whether or not an appeal to the phenomenology of imagination can help one to choose between two putatively “directly realist” views in recent philosophy of perception. [Martin, 2002; Noordhoff, 2002] It has been argued that the choice between strong representationalism and a disjunctive theory of perception cannot be determined by an appeal solely to the argument from phenomenal transparency deployed by Gilbert Harman, Michael Tye and Fred Dreske [Harman 1990; Dretske 1995; Tye