The role of detection in mental representation

Abstract

This dissertation critically analyzes current theories of mental representation, with an emphasis on indicator and teleological semantics. Its central claim is that detection-based theories of mental meaning--or more generally, theories which trace the meaning of a cognitive structure S to those environmental conditions which obtain while S executes or acquires its function--cannot explain many of the representational structures invoked in common-sense and computational psychology. The dissertation emphasizes several kinds of representational states (both common-sense and computational) that are not commonly noted in the philosophical literature. By emphasizing the heterogeneity of cognitive contents, the dissertation shows just how robust a notion of content will be needed to naturalize, or even just analyze, mental representation. Chapter one introduces the fundamentals of indicator theories and the notion of a language of thought. Chapter two introduces a class of ordinary beliefs that resist explanation on indicator accounts--viz., mistaken beliefs about the physical appearance of members of a kind. Indicator theories require us to assign propositional contents to these beliefs so as to make them true (counterintuitively), at the additional cost of making false many other beliefs about the kind. Chapter three addresses the implications for content theories of internal instructions in cognitive processing--of structures which specify actions that the cognitive system is to perform. Instructions do not fit naturally within the framework of indicator semantics. Indicator theories take a symbol's meaning to be a function of conditions which regularly precede, and help cause, the symbol's tokening. By contrast, an instruction represents an action which has not yet been performed, an action that will issue from the instruction itself. Indicator theories thus must reconcile the future-directed contents of instructions with the backward-looking mechanism of detection. Chapter four challenges the assumption of both indicator and teleological accounts that meaning is founded on some type of causal interaction between the denoting state and the denoted conditions. It explores the conflict between this foundational assumption and the atomic prototypes invoked in theories of visual object recognition.