For nearly six decades, the conscious observer has played a central and essential rôle in quantum measurement theory. I outline some difficulties which the traditional account of measurement presents for material theories of mind before introducing a new development which promises to exorcise the ghost of consciousness from physics and relieve the cognitive scientist of the burden of explaining why certain material structures reduce wavefunctions by virtue of being conscious while others do not. The interactive decoherence of complex quantum systems (...) reveals that the oddities and complexities of linear superposition and state vector reduction are irrelevant to computational aspects of the philosophy of mind and that many conclusions in related fields are ill founded. (shrink)

Comparatively recent advances in quantum measurement theory suggest that the decades-old flirtation between quantum mechanics and the philosophy of mind is about to end. Various approaches to what I have elsewhere dubbed 'interactive decoherence' promise to remove the conscious observer from the phenomenon of state vector reduction. The mechanisms whereby decoherence occurs suggest, on the one hand, that consciousness per se has no role in explaining the outcomes of quantum events and, on the other, that perhaps apart from questions about (...) the very lowest level properties of minds' instantiating hardware or wetware, the unique features of quantum mechanics are utterly irrelevant to the philosophy of mind. Here we explore a better account of interactive decoherence than I have offered elsewhere, make explicit the argument for irrelevance, and address some unanswered questions and an interesting objection against the formulation of decoherence on which our discussion is based. (shrink)

Technical hitches mar van Gelder's proposed map of the conceptual landscape, particularly with respect to descriptive levels and the trio of instantiation, realisation, and implementation. However, for all the formal quibbles, van Gelder is onto something important; the tension he notes between computationalism and a dynamical alternative threatens to transform the way we conduct cognitive science research.