John Dilworth

The double content of perception

Clearly we can perceive both objects, and various aspects or appearances of those objects. But how should that complexity of perceptual content be explained or analyzed? I argue that perceptual representations normally have a double or two level nested structure of content, so as to adequately incorporate information both about contextual aspects Y(X) of an object X, and about the object X itself. On this double content (DC) view, perceptual processing starts with aspectual data Y′(X′) as a higher level of content, which data does not itself provide lower level X-related content, but only an aspectually encoded form of such data. Hence the relevant perceptual data Y′(X′) must be ’de-contextualized’ or decoded to arrive at the X-related content X′, resulting in a double content structure for perceptual data, that persists in higher-order conscious perceptual content. Some implications and applications of this DC view are also discussed.

A reflexive dispositional analysis of mechanistic perception

The field of machine perception is based on standard informational and computational approaches to perception. But naturalistic informational theories are widely regarded as being inadequate, while purely syntactic computational approaches give no account of perceptual content. Thus there is a significant need for a novel, purely naturalistic perceptual theory not based on informational or computational concepts, which could provide a new paradigm for mechanistic perception. Now specifically evolutionary naturalistic approaches to perception have been—perhaps surprisingly—almost completely neglected for this purpose. Arguably perceptual mechanisms enhance evolutionary fitness by facilitating sensorily mediated causal interactions between an organism Z and items X in its environment. A ‘reflexive’ theory of perception of this kind is outlined, according to which an organism Z perceives an item X just in case X causes a sensory organ zi of Z to cause Z to acquire a disposition toward the very same item X that caused the perception. The rest of the paper shows how an intuitively plausible account of mechanistic perception can be developed and defended in terms of the reflexive theory. Also, a compatibilist option is provided for those who wish to preserve a distinct informational concept of perception.

The twofold orientational structure of perception

I argue that perceptual content involves representations both of aspects of objects, and of objects themselves, whether at the level of conscious perception, or of low-level perceptual processing—a double content structure. I present an ‘orientational’ theory of the relations of the two kinds of perceptual content, which can accommodate both the general semantic possibility of perceptual misrepresentation, and also species of it involving characteristic perceptual confusions of aspectual and intrinsic content. The resulting theoretical structure is argued to be a broadly methodological or logical one, rather than a substantive theory that is open to empirical refutation.

Realistic virtual reality and perception

Realistic uses of Virtual Reality (VR) technology closely integrate user training on virtual objects with VR-assisted user interactions with real objects. This paper shows how the Interactive Theory of Perception (ITP) may be extended to cover such cases. Virtual objects are explained as concrete models (CMs) that have an inner generation mechanism, and the ITP is used to explain how VR users can both perceive such local CMs, and perceptually represent remote real objects. Also, concepts of modeling and representation are distinguished. The paper concludes with suggestions as to how the ITP methodology developed here could be extended to iconic external representations and models generally.

The Fictionality of Plays

or concrete entities. I could also give a similar story-relative account of the issue as to whether fictional characters are individual versus general entities such as universals; here too I can simply reply that it depends on whether or not the relevant characters are represented as individuals or as universals, in the fictional story. 35. Thomasson, Fiction and Metaphysics, chap. 1. 36. That is, not in the standard or absolute sense of existence, as opposed to the relational sense discussed in the

In support of content theories of art

A content theory of art would identify an artwork with the meaningful or representational content of some concrete artistic vehicle, such as the intentional, expressive, stylistic, and subject matter-related content embodied in, or resulting from, acts of intentional artistic expression by artists. Perhaps surprisingly, the resultant view that an artwork is nothing but content seems to have been without theoretical defenders until very recently, leaving a significant theoretical gap in the literature. I present some basic arguments in defence of such a view, including the following. Content views of linguistic communication are ubiquitous, so why should they not be applicable in artistic cases as well? Also, propositional accounts of language involve two kinds of content (the proposition expressed by a sentence, plus the worldly state of affairs it represents), both of which kinds can be used in explaining artworks. In addition, the differing modal properties of artworks and concrete artefacts can be used to show that artworks could not be, or include, such physical artefacts.

Semantic Naturalization via Interactive Perceptual Causality

A novel semantic naturalization program is proposed. Its three main differences from informational semantics approaches are as follows. First, it makes use of a perceptually based, four-factor interactive causal relation in place of a simple nomic covariance relation. Second, it does not attempt to globally naturalize all semantic concepts, but instead it appeals to a broadly realist interpretation of natural science, in which the concept of propositional truth is off-limits to naturalization attempts. And third, it treats all semantic concepts as being purely abstract, so that concrete cognitive states are only indexed by them rather than instantiating them.

More on the Interactive Indexing Semantic Theory

This article further explains and develops a recent, comprehensive semantic naturalization theory, namely the interactive indexing (II) theory as described in my 2008 Minds and Machines article “Semantic Naturalization via Interactive Perceptual Causality” (Vol. 18, pp. 527–546). Folk views postulate a concrete intentional relation between cognitive states and the worldly states they are about. The II theory eliminates any such concrete intentionality, replacing it with purely causal relations based on the interactive theory of perception. But intentionality is preserved via purely abstract propositions about the world that index, or correlate with, appropriate cognitive states. Further reasons as to why intentionality must be abstract are provided, along with more details of an II-style account of representation, language use and propositional attitudes. All cognitive representation is explained in terms of classification or sorting dispositions indexed by appropriate propositions. The theory is also related to Fodor’s representational theory of mind, with some surprisingly close parallels being found in spite of the purely dispositional basis of the II theory. In particular, Fodor’s insistence that thinking about an item cannot be reduced to sorting dispositions is supported via a novel two-level account of cognition—upper level propositional attitudes involve significant intermediate processing of a broadly normative epistemic kind prior to the formation of sorting dispositions. To conclude, the weak intentional realism of the II theory—which makes intentional descriptions of the world dispensable—is related to Dennett’s ‘intentional stance’ view, and distinguished from strong (indispensable) intentional realist views. II-style dispositions are also defended.