But perhaps the most important research topics in cognitive science are those that are truly interdisciplinary, i.e., in which researchers from the several cognitive sciences apply their differing methodologies to a common problem and, conversely, inform their own studies with results of investigations from the complementary disciplines. Prime examples of these would be research in visual perception, which has been investigated in psychology, in artificial intelligence (in particular, the work of David Waltz (1975) and, especially, David Marr (1982)), and in robotics, not to mention in physiology and biophysics (cf. Leibovic 1990); research into mental imagery, which, in addition to the work in psychology mentioned above, has received critical philosophical attention from Zenon Pylyshyn and Dennett (cf. Block 1981); research on categorization, where results from psychology (notably the work of Eleanor Rosch (1978))--influenced by philosophical studies of family resemblance (Wittgenstein 1953)) and natural kinds (cf. Wolterstorff 1970)--have largely overturned the ``classical'' philosophical view going back to Aristotle of there being necessary and sufficient conditions for membership in a category; and research on the logic of belief and knowledge, in which people from artificial intelligence have not only adapted, for use in artificial intelligence programs, systems of epistemic and doxastic logics developed by philosophers, but have also offered solutions to many open problems in these logics that philosophers have largely ignored.