ABSTRACT This project develops a research program, the Sub-Symbolic Paradigm (SSP), which exploits connectionist computation as a bridge between numerical neural computation and symbolic mental computation, and forges an integration in which the latter is an approximate higher-level description of the former. While much of connectionist research has addressed problems and data from cognitive psychology, SSP has focused on complementary data and problems in higher cognition that are centrally located in linguistics and the foundations of cognitive science. SSP has already made significant progress, including (a) mathematical techniques for representing symbolic structures as lower-level distributed patterns of activity and for (b) performing massively parallel structure-sensitive processing on such representations; (c) the analysis of connectionist computation as maximizing Harmony, a well-formedness measure on representations; (d) contributions to theoretical linguistics in the areas of syntax/semantics and phonology that rely on using Harmony to measure the well-formedness of linguistic structures; and (e) contributions to the foundations of cognitive science deriving from the interpretation of the preceding results. The new research to be supported by the present grant will build on (d), expanding the theory of grammar as a well-formedness optimizing system, and on (e), systematically developing a typology of strategies for connectionist-grounded explanations of the striking productivity of human higher cognition. SSP is contributing to the development of a new methodology for cognitive science which is more than just the sum of those of its sister disciplines, a methodology capable of yielding results which are beyond the reach of all the other disciplines proceeding individually. By integrating linguistic, philosophical, and mathematical analysis, computer simulation, and techniques from both discrete and continuous computation, this new methodology can develop more powerful connectionist systems, innovative symbolic formalisms, and general cognitive principles that constitute real progress towards the unification of connectionist and symbolic theories of brain and mind.
