Proceedings of the Annual Meeting of the Cognitive Science Society

In a now famous paper, Fodor and Pylyshyn (1988) argue that connectionist networks, as they are commonly constructed and trained, are incapable of displaying certain crucial characteristics of human thought and language. These include the capacity to employ compositionally structured representations and to exhibit systematicity in thought and language production. Since the appearance of Fodor and Pylyshyn's paper, an number of connectionists have produced what seem to be counter-examples to the Fodor-Pylyshyn thesis. The present work examines two of these apparent counter-examples; one is due to Elman and the other to St. John and McClelland. It is argued that although Elman's and St. John & McClelland's networks discover a degree of compositionality, and display a degree of systematic behaviour, the degrees involved are substantially less than that found in humans, and (consequently) are less than what Fodor ic Pylyshyn require (or presumably would require if the question were put to them).