What might a theory of mental imagery look like, and how might one begin formulating such a theory? These are the central questions addressed in the present paper. The first section outlines the general research direction taken here and provides an overview of the empirical foundations of our theory of image representation and processing. Four issues are considered in succession, and the relevant results of experiments are presented and discussed. The second section begins with a discussion of the proper form (...) for a cognitive theory, and the distinction between a theory and a model is developed. Following this, the present theory and computer simulation model are introduced. This theory specifies the nature of the internal representations (data structures) and the processes that operate on them when one generates, inspects, or transforms mental images. In the third, concluding, section we consider three very different kinds of objections to the present research program, one hinging on the possibility of experimental artifacts in the data, and the others turning on metatheoretical commitments about the form of a cognitive theory. Finally, we discuss how one ought best to evaluate theories and models of the sort developed here. (shrink)

Various reflections on the nature of consciousness, partly inspired by Alastair Hannay's views on the subject, are presented. In particular, its reality as a distinct non-physical existence is defended against such alternatives as have dominated philosophy for many years. The main difficulty in such a defense concerns the contingency it seems to imply as to the relations between consciousness and its expression in behaviour. But it only implies such contingency if some version of the Humean principle that there cannot be (...) necessary connections between distinct existences is assumed. It is more promising to see this relation as the falsification of this Humean principle and thus avoid what seems the main recommendation of behaviourism, functionalism etc. Some final reflections on the nature of the physical suggest that something like consciousness may be the noumenal essence of the physical in general. (shrink)