Can we think of a task in a distinctively practical way? Can there be practical concepts? In recent years, epistemologists, philosophers of mind, as well as philosophers of psychology have appealed to practical concepts in characterizing the content of know-how or in explaining certain features of skilled action. However, reasons for positing practical concepts are rarely discussed in a systematic fashion. This paper advances a novel argument for the psychological reality of practical concepts that relies on evidence for a distinctively (...) productive kind of reasoning. (shrink)

It is commonly assumed that images, whether in the world or in the head, do not have a privileged analysis into constituent parts. They are thought to lack the sort of syntactic structure necessary for representing complex contents and entering into sophisticated patterns of inference. I reject this assumption. “Image grammars” are models in computer vision that articulate systematic principles governing the form and content of images. These models are empirically credible and can be construed as literal grammars for images. (...) Images can have rich syntactic structure, though of a markedly different form than sentences in language. (shrink)

Mental capacities for perceiving, remembering, thinking, and planning involve the processing of structured mental representations. A compositional semantics of such representations would explain how the content of any given representation is determined by the contents of its constituents and their mode of combination. While many have argued that semantic theories of mental representations would have broad value for understanding the mind, there have been few attempts to develop such theories in a systematic and empirically constrained way. This paper contributes to (...) that end by developing a semantics for a ‘fragment’ of our mental representational system: the visual system’s representations of the bounding contours of objects. At least three distinct kinds of composition are involved in such representations: ‘concatenation’, ‘feature composition’, and ‘contour composition’. I sketch the constraints on and semantics of each of these. This account has three principal payoffs. First, it models a working framework for compositionally ascribing structure and content to perceptual representations, while highlighting core kinds of evidence that bear on such ascriptions. Second, it shows how a compositional semantics of perception can be compatible with holistic, or Gestalt, phenomena, which are often taken to show that the whole percept is ‘other than the sum of its parts’. Finally, the account illuminates the format of a key type of perceptual representation, bringing out the ways in which contour representations exhibit domain-specific form of the sort that is typical of structured icons such as diagrams and maps, in contrast to typical discursive representations of logic and language. (shrink)

It is common to distinguish two great families of representation. Symbolic representations include logical and mathematical symbols, words, and complex linguistic expressions. Iconic representations include dials, diagrams, maps, pictures, 3-dimensional models, and depictive gestures. This essay describes and motivates a new way of distinguishing iconic from symbolic representation. It locates the difference not in the signs themselves, nor in the contents they express, but in the semantic rules by which signs are associated with contents. The two kinds of rule have (...) divergent forms, occupying opposite poles on a spectrum of naturalness. Symbolic rules are composed entirely of primitive juxtapositions of sign types with contents, while iconic rules determine contents entirely by uniform natural relations with sign types. This distinction is marked explicitly in the formal semantics of familiar sign systems, both for atomic first-order representations, like words, pixel colors, and dials, and for complex second-order representations, like sentences, diagrams, and pictures. (shrink)

Some argue that emotions represent so-called core relational themes. A core relational theme describes a relation between a particular event and an organism’s well-being. For instance, the core relational theme of anger is ‘a demeaning offense against me and mine’. I argue that a core relational theme is a summary or generalization of a more complex mental content. Defenders of the Simple Core Relational Theme View reject the idea that emotional content is complex. Instead, they argue that the content of (...) emotion simply consists of a core relational theme. I argue that this view commits the linguistic fallacy: it confuses a theory of emotion categorization with a theory of emotional content. (shrink)

In amodal completion the mind in some sense completes the visual perceptual representation of a scene by representing parts of the scene hidden behind other objects. Cognitive science has had a lot to say about how amodal completion occurs but has had little to say about the format of the representations involved and the way in which they represent. Some philosophers hold that amodal completions take the form of sensory imaginings of the occluded portions. This theory poses a puzzle for (...) both philosophy and neuroscience about how the occluded parts are imagined to be located relative to the unoccluded parts. A better theory begins with the observation that for many purposes it is useful to suppose that the mind contains mental models of three-dimensional structure. Visual perceptions and mental images may be conceived as mental models that represent external scenes by virtue of homomorphism and which possess both a deep aspect, representing both visible and occluded three-dimensional structure, and a perspectival aspect, representing only an arrangement of visible surfaces. In these terms we can explain various problem-solving abilities, such as the ability to imagine what a scene will look like from another point of view. Amodal completions can be treated as deep perceptual representations of three-dimensional structure. Thus amodal completions do not consist of mental imagery, but they can be used to generate mental imagery representing how a scene would look from alternative points of view. (shrink)

Cognitive representations are typically analysed in terms of content, vehicle and format. While current work on formats appeals to intuitions about external representations, such as words and maps, in this paper we develop a computational view of formats that does not rely on intuitions. In our view, formats are individuated by the computational profiles of vehicles, i.e., the set of constraints that fix the computational transformations vehicles can undergo. The resulting picture is strongly pluralistic, it makes space for a variety (...) of different formats, and is intimately tied to the computational approach to cognition in cognitive science and artificial intelligence. (shrink)

I argue that analogue mental representations possess a canonical decomposition into privileged constituents from which they compose. I motivate this suggestion, and rebut arguments to the contrary, through reflection on the approximate number system, whose representations are widely expected to have an analogue format. I then argue that arguments for the compositionality and constituent structure of these analogue representations generalize to other analogue mental representations posited in the human mind, such as those in early vision and visual imagery.

In our target article, we argued that the number sense represents natural and rational numbers. Here, we respond to the 26 commentaries we received, highlighting new directions for empirical and theoretical research. We discuss two background assumptions, arguments against the number sense, whether the approximate number system represents numbers or numerosities, and why the ANS represents rational numbers.

Our awareness of the boundedness of the spatial sensory field—a paradigmatic structural feature of visual experience—possesses a distinctive epistemic role. Properly understood, this result undermines a widely assumed picture of how visual experience permits us to learn about the world. This paper defends an alternative picture in which visual experience provides at least two kinds of non-inferential justification for beliefs about the external world. Accommodating this justification in turn requires recognising a new way for visual experience to encode information about (...) the world. Reflection upon the epistemic contribution of sensory experience's structural features thus forces us to revise our understanding of how perception, cognition, and the world fit together. (shrink)

A compositional theory of perceptual representations would explain how the accuracy conditions of a given type of perceptual state depend on the contents of constituent perceptual representations and the way those constituents are structurally related. Such a theory would offer a basic framework for understanding the nature, grounds, and epistemic significance of perception. But an adequate semantics of perceptual representations must accommodate the holistic nature of perception. In particular, perception is replete with context effects, in which the way one perceptually (...) represents one aspect of a scene (including the position, size, orientation, shape, color, motion, or even unity of an object) normally depends on how one represents many other aspects of the scene. The ability of existing accounts of the semantics of perception to analyze context effects is at best unclear. Context effects have even been thought to call into question the very feasibility of a systematic semantics of perception. After outlining a compositional semantics for a rudimentary set of percepts, I draw on empirical models from perceptual psychology to show how such a theory must be modified to analyze context effects. Context effects arise from substantive constraints on how perceptual representations can combine and from the different semantic roles that perceptual representations can have. I suggest that context effects are closely tied to the objectivity of perception. They arise from a perceptual grammar that functions to facilitate the composition of reliably accurate representations in an uncertain but structured world. (shrink)