When is seeing part of an object enough to qualify as seeing the object itself? For instance, is seeing a cat’s tail enough to qualify as seeing the cat itself? I argue that whether a subject qualifies as seeing a given object varies with the context of the ascriber. Having made an initial case for the context-sensitivity of object-seeing, I then address the contention that it is merely a feature of the ordinary notion. I argue that the notions of object-seeing (...) that earn their explanatory keep in both vision science and the philosophy of perception are context-sensitive as well. (shrink)

When we see an object, we also represent those parts of it that are not visible. The question is how we represent them: this is the problem of amodal perception. I will consider three possible accounts: (a) we see them, (b) we have non-perceptual beliefs about them and (c) we have immediate perceptual access to them, and point out that all of these views face both empirical and conceptual objections. I suggest and defend a fourth account, according to which we (...) represent the occluded parts of perceived objects by means of mental imagery. This conclusion could be thought of as a (weak) version of the Strawsonian dictum, according to which “imagination is a necessary ingredient of perception itself”. (shrink)

In "Things and Places," Zenon Pylyshyn argues that the process of incrementally constructing perceptual representations, solving the binding problem (determining which properties go together), and, more generally, grounding perceptual ...

I develop several new arguments against claims about "cognitive phenomenology" and its alleged role in grounding thought content. My arguments concern "absent cognitive qualia cases", "altered cognitive qualia cases", and "disembodied cognitive qualia cases". However, at the end, I sketch a positive theory of the role of phenomenology in grounding content, drawing on David Lewis's work on intentionality. I suggest that within Lewis's theory the subject's total evidence plays the central role in fixing mental content and ruling out deviant interpretations. (...) However I point out a huge unnoticed problem, the problem of evidence: Lewis really has no theory of sensory content and hence no theory of what fixes evidence. I suggest a way of plugging this hole in Lewis's theory. On the resulting theory, which I call " phenomenal functionalism", there is a sense in which sensory phenomenology is the source of all determinate intentionality. Phenomenal functionalism has similarities to the theories of Chalmers and Schwitzgebel. (shrink)

Tyler Burge presents an original study of the most primitive ways in which individuals represent the physical world. By reflecting on the science of perception and related psychological and biological sciences, he gives an account of constitutive conditions for perceiving the physical world, and thus aims to locate origins of representational mind.

Several of these essays have been printed whole in journals; others are in varying degrees new. Two main themes run through them. One is the problem of meaning, particularly as involved in the notion of an analytic statement. The other is the notion of ontological, commitment, particularly as involved in the problem of universals.

Only human beings have a rich conceptual repertoire with concepts like tort, entropy, Abelian group, mannerism, icon and deconstruction. How have humans constructed these concepts? And once they have been constructed by adults, how do children acquire them? While primarily focusing on the second question, in The Origin of Concepts , Susan Carey shows that the answers to both overlap substantially. Carey begins by characterizing the innate starting point for conceptual development, namely systems of core cognition. Representations of core cognition (...) are the output of dedicated input analyzers, as with perceptual representations, but these core representations differ from perceptual representations in having more abstract contents and richer functional roles. Carey argues that the key to understanding cognitive development lies in recognizing conceptual discontinuities in which new representational systems emerge that have more expressive power than core cognition and are also incommensurate with core cognition and other earlier representational systems. Finally, Carey fleshes out Quinian bootstrapping, a learning mechanism that has been repeatedly sketched in the literature on the history and philosophy of science. She demonstrates that Quinian bootstrapping is a major mechanism in the construction of new representational resources over the course of childrens cognitive development. Carey shows how developmental cognitive science resolves aspects of long-standing philosophical debates about the existence, nature, content, and format of innate knowledge. She also shows that understanding the processes of conceptual development in children illuminates the historical process by which concepts are constructed, and transforms the way we think about philosophical problems about the nature of concepts and the relations between language and thought. (shrink)

Reflection on the fine-grained information required for visual guidance of action has suggested that visual content is non-conceptual. I argue that in a common type of visually guided action, namely the use of manipulable artefacts, vision has conceptual content. Specifically, I show that these actions require visual attention and that concepts are involved in directing attention. In acting with artefacts, there is a way of doing it right as determined by the artefact’s conventional use. Attention must reflect our understanding of (...) the function and appropriate ways to use these artefacts, understanding that requires possession of the relevant concept. As a result, we attend to the artefact’s relevant functional properties. In these cases, attention is structured by concepts. This discussion has a bearing on the dual visual stream hypothesis. While it is often held that the two visual streams are functionally independent, the argument of this essay is that the constraints on attention suggest a functional interaction between them. (shrink)

In this lucid portrayal of human behavior, Fred Dretske provides an original account of the way reasons function in the causal explanation of behavior.

We show that early vision can use monocular cues to rapidly complete partially-occluded objects. Visual search for easily detected fragments becomes difficult when the completed shape is similar to others in the display; conversely, search for fragments that are difficult to detect becomes easy when the completed shape is distinctive. Results indicate that completion occurs via the occlusion-triggered removal of occlusion edges and linking of associated regions. We fail to find evidence for a visible filling-in of contours or surfaces, but (...) do find evidence for a "functional" filling-in that prevents the constituent fragments from being rapidly accessed. As such, it is only the completed structures—and not the fragments themselves—that serve as the basis for rapid recognition. (shrink)

Carey's claim that no object representations are perceptual rests on a faulty view of perception. To delineate origins of post-perceptual ( or ) representation, we need a more accurate view of perceptual representation.

Contextualist solutions to skeptical puzzles have recently been subjected to various criticisms. In this paper, I will defend contextualism against an objection prominently pressed by Stanley 2000. According to Stanley, contextualism in epistemology advances an empirically implausible hypothesis about the semantics of knowledge ascriptions in natural language. It is empirically implausible because it attributes to knowledge ascriptions a kind of semantic context-sensitivity that is wholly unlike any well- established type of semantic context-sensitivity in natural language.

What is the nature of, and what is the relationship between, external objects and our visual perceptual experience of them? In this book, Frank Jackson defends the answers provided by the traditional Representative theory of perception. He argues, among other things that we are never immediately aware of external objects, that they are the causes of our perceptual experiences and that they have only the primary qualities. In the course of the argument, sense data and the distinction between mediate and (...) immediate perception receive detailed defences and the author criticises attempts to reduce perceiving the believing and to show that the Representative theory makes the external world unknowable. Jackson recognises that his views are unfashionable but argues in detail that they are to be preferred to their currently favoured competitors. It will become an obvious point of reference for all future work on the philosophy of perception. (shrink)

How the various things that are said to have meaning—purpose, natural signs, linguistic signs, perceptions, and thoughts—are related to one another.

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. (shrink)

Research on human infants has begun to shed light on early-developing processes for segmenting perceptual arrays into objects. Infants appear to perceive objects by analyzing three-dimensional surface arrangements and motions. Their perception does not accord with a general tendency to maximize figural goodness or to attend to nonaccidental geometric relations in visual arrays. Object perception does accord with principles governing the motions of material bodies: Infants divide perceptual arrays into units that move as connected wholes, that move separately from one (...) another, that tend to maintain their size and shape over motion, and that tend to act upon each other only on contact. These findings suggest that o general representation of object unity and boundaries is interposed between representations of surfaces and representations of objects of familiar kinds. The processes that construct this representation may be related to processes of physical reasoning. (shrink)

The notion that visual attention can operate over visual objects in addition to spatial locations has recently received much empirical support, but there has been relatively little empirical consideration of what can count as an `object' in the ®rst place. We have investi- gated this question in the context of the multiple object tracking paradigm, in which subjects must track a number of independently and unpredictably moving identical items in a ®eld of identical distractors. What types of feature clusters can (...) be tracked in this manner? In other words, what counts as an `object' in this task? We investigated this question with a technique we call target merging: we alter tracking displays so that distinct target and distractor loca- tions appear perceptually to be parts of the same object by merging pairs of items (one target with one distractor) in various ways ± for example, by connecting item locations with a simple line segment, by drawing the convex hull of the two items, and so forth. The data show that target merging makes the tracking task far more dif®cult to varying degrees depending on exactly how the items are merged. The effect is perceptually salient, involving in some conditions a total destruction of subjects' capacity to track multiple items. These studies provide strong evidence for the object-based nature of tracking, con®rming that in some contexts attention must be allocated to objects rather than arbitrary collections of features. In addition, the results begin to reveal the types of spatially organized scene components that can be independently attended as a function of properties such as connectedness, part struc- ture, and other types of perceptual grouping. q 2001 Elsevier Science B.V. All rights reserved. (shrink)

We present three studies examining whether multiple-object tracking (MOT) benefits from the active inhibition of nontargets, as proposed in (Pylyshyn, 2004). Using a probedot technique, the first study showed poorer probe detection on nontargets than on either the targets being tracked or in the empty space between objects. The second study used a matching nontracking task to control for possible masking of probes, independent of target tracking. The third study examined how localized the inhibition is to individual nontargets. The result (...) of these three studies led to the conclusion that nontargets are subject to a highly localized object-based inhibition. Implications of this finding for the FINST visual index theory are discussed. We suggest that we need to distinguish between the differentiation (or individuation) of enduring token objects and the process of making the objects accessible through indexes, with only the latter being limited to 4 or 5 objects. (shrink)

Although the mechanics of how the eye works are well understood, debate still exists as to how the complex machinery of the brain interprets neural impulses...

In this paper I apply an old problem of Quine's (the inscrutability of reference in translation) to a new style of theory about mental content (causal/nomological/informational accounts of meaning) and conclude that no "naturalization" of content of the sort currently popular can solve Quine's "gavagai" enigma. I show how failure to solve the problem leads to absurd conclusions not about one's own mental life, but about the non-mental world. I discuss various ways of attempting to remedy the accounts so as (...) to avoid the problem and explain why each attempt at solving the problem would take the information theorists further from their self-assigned task of "naturalizing" semantics. (shrink)

This book is largely a reconsideration of the arguments that are supposed to ground this consensus.

How we see and how we visualize: why the scientific account differs from our experience.

In three experiments, subjects attempted to track multiple items as they moved independently and unpredictably about a display. Performance was not impaired when the items were briefly (but completely) occluded at various times during their motion, suggesting that occlusion is taken into account when computing enduring perceptual objecthood. Unimpaired performance required the presence of accretion and deletion cues along fixed contours at the occluding boundaries. Performance was impaired when items were present on the visual field at the same times and (...) to the same degrees as in the occlusion conditions, but disappeared and reappeared in ways which did not implicate the presence of occluding surfaces (e.g. by imploding and exploding into and out of existence, instead of accreting and deleting along a fixed contour). Unimpaired performance did not require visible occluders (i.e. Michotte’s tunnel effect) or globally consistent occluder positions. We discuss implications of these results for theories of objecthood in visual attention. (shrink)

I shall propose five theses on de re states and attitudes. To be a de re state or attitude is to bear a peculiarly direct epistemic and representational relation to a particular referent in perception or thought. I will not dress this bare statement here. The fifth thesis tries to be less coarse. The first four explicate and restrict context- bound, singular, empirical representation, which constitutes a significant and central type of de re state or attitude.