Time underlies many interesting human behaviors. Thus, the question of how to represent time in connectionist models is very important. One approach is to represent time implicitly by its effects on processing rather than explicitly (as in a spatial representation). The current report develops a proposal along these lines first described by Jordan (1986) which involves the use of recurrent links in order to provide networks with a dynamic memory. In this approach, hidden unit patterns are fed back to themselves: (...) the internal representations which develop thus reflect task demands in the context of prior internal states. A set of simulations is reported which range from relatively simple problems (temporal version of XOR) to discovering syntactic/semantic features for words. The networks are able to learn interesting internal representations which incorporate task demands with memory demands: indeed, in this approach the notion of memory is inextricably bound up with task processing. These representations reveal a rich structure, which allows them to be highly context‐dependent, while also expressing generalizations across classes of items. These representations suggest a method for representing lexical categories and the type/token distinction. (shrink)

A central goal of contemporary cognitive science is the explanation of cognitive abilities or capacities. [Cummins 1983] During the last three decades a wide range of cognitive capacities have been subjected to careful empirical scrutiny. The adult's ability to produce and comprehend natural language sentences and the child's capacity to acquire a natural language were among the first to be explored. [Chomsky 1965, Fodor, Bever & Garrett 1974, Pinker 1989] There is also a rich literature on the ability to solve (...) mathematical problems [Greeno 1983], the ability to recognize objects visually [Rock 1983, Gregory 1970, Marr 1982], the ability to manipulate and predict the behavior of middle sized physical objects [McClosky 1983, Hayes 1985], and a host of others. (shrink)

The essays in this volume make it abundantly clear that there is no shortage of disagreement about the plausibility of the simulation theory. As we see it, there are at least three factors contributing to this disagreement. In some instances the issues in dispute are broadly empirical. Different people have different views on which theory is favored by experiments reported in the literature, and different hunches about how future experiments are likely to turn out. In 3.1 and 3.3 we will (...) consider two cases that fall under this heading. With a bit of luck these disputes will be resolved as more experiments are done and more data become available. Faulty arguments are a second source of disagreement. In 3.2 and 3.4 we will set out two dubious arguments advanced by our critics and try to explain exactly why we think they are mistaken. The third source of disagreement is terminological. Terms like "theory-theory," "simulation theory" and a number of others are often not clearly defined, and they are used in different ways by different authors. (Worse yet, we suspect they are sometimes used in different ways by a single author on different occasions). Thus it is sometimes the case that what appears to be a substantive disagreement turns out to be simply a verbal dispute. Moreover, since the labels "theory-theory" and "simulation theory" are each used to characterize a broad range of theories, it may well turn out that some of the theories falling under both headings are correct. In Sections 1 and 2, we will set out a variety of different views for which the labels "theory-theory" and "simulation theory" might be used. As we proceed we'll point out a number of places where disagreements diminish when distinctions among different versions of the theory-theory and the simulation theory are kept clearly in mind. (shrink)

For the last 25 years discussions and debates about commonsense psychology (or “folk psychology,” as it is often called) have been center stage in the philosophy of mind. There have been heated disagreements both about what folk psychology is and about how it is related to the scientific understanding of the mind/brain that is emerging in psychology and the neurosciences. In this chapter we will begin by explaining why folk psychology plays such an important role in the philosophy of mind. (...) Doing that will require a quick look at a bit of the history of philosophical discussions about the mind. We’ll then turn our attention to the lively contemporary discussions aimed at clarifying the philosophical role that folk psychology is expected to play and at using findings in the cognitive sciences to get a clearer understanding of the exact nature of folk psychology. (shrink)

This paper explores the difference between Connectionist proposals for cognitive a r c h i t e c t u r e a n d t h e s o r t s o f m o d e l s t hat have traditionally been assum e d i n c o g n i t i v e s c i e n c e . W e c l a i m t h a t t h (...) e m a j o r d i s t i n c t i o n i s t h a t , w h i l e b o t h Connectionist and Classical architectures postulate representational mental states, the latter but not the former are committed to a symbol-level of representation, or to a ‘language of thought’: i.e., to representational states that have combinatorial syntactic and semantic structure. Several arguments for combinatorial structure in mental representations are then reviewed. These include arguments based on the ‘systematicity’ of mental representation: i.e., on the fact that cognitive capacities always exhibit certain symmetries, so that the ability to entertain a given thought implies the ability to entertain thoughts with semantically related contents. We claim that such arguments make a powerful case that mind/brain architecture is not Connectionist at the cognitive level. We then consider the possibility that Connectionism may provide an account of the neural (or ‘abstract neurological’) structures in which Classical cognitive architecture is implemented. We survey a n u m b e r o f t h e s t a n d a r d a r g u m e n t s t h a t h a v e b e e n o f f e r e d i n f a v o r o f Connectionism, and conclude that they are coherent only on this interpretation. (shrink)

Preface 1 Introduction: The Persistence of the Attitudes 2 Individualism and Supervenience 3 Meaning Holism 4 Meaning and the World Order Epilogue Creation Myth Appendix Why There Still Has to be a Language of Thought Notes References Author Index.

Are there really beliefs? Or are we learning (from neuroscience and psychology, presumably) that, strictly speaking, beliefs are figments of our imagination, items in a superceded ontology? Philosophers generally regard such ontological questions as admitting just two possible answers: either beliefs exist or they don't. There is no such state as quasi-existence; there are no stable doctrines of semi-realism. Beliefs must either be vindicated along with the viruses or banished along with the banshees. A bracing conviction prevails, then, to the (...) effect that when it comes to beliefs (and other mental items) one must be either a realist or an eliminative materialist. (shrink)

Eliminative materialism is the thesis that our common-sense conception of psychological phenomena constitutes a radically false theory, a theory so fundamentally defective that both the principles and the ontology of that theory will eventually be displaced, rather than smoothly reduced, by completed neuroscience. Our mutual understanding and even our introspection may then be reconstituted within the conceptual framework of completed neuroscience, a theory we may expect to be more powerful by far than the common-sense psychology it displaces, and more substantially (...) integrated within physical science generally. My purpose in this paper is to explore these projections, especially as they bear on (1) the principal elements of common-sense psychology: the propositional attitudes (beliefs, desires, etc.), and (2) the conception of rationality in which these elements figure. (shrink)

Jerry Fodor argues against the widely held view that mental processes are largely computations, that the architecture of cognition is massively modular, and...

This collection was prepared in the belief that the most useful and revealing of anyone's writings are often those shorter essays penned in conflict with...

Over the last two decades, debates over the viability of commonsense psychology have been center stage in both cognitive science and the philosophy of mind. Eliminativists have argued that advances in cognitive science and neuroscience will ultimately justify a rejection of our "folk" theory of the mind, and of its ontology. In the first half of this book Stich, who was at one time a leading advocate of eliminativism, maintains that even if the sciences develop in the ways that eliminativists (...) foresee, none of the arguments for ontological elimination are tenable. Rather than being resolved by science, he contends, these ontological disputes will be settled by a pragmatic process in which social and political considerations have a major role to play. In later chapters, Stich argues that the widespread worry about "naturalizing" psychological properties is deeply confused, since there is no plausible account of what naturalizing requires on which the failure of the naturalization project would lead to eliminativism. He also offers a detailed analysis of the many different notions of folk psychology to be found in philosophy and psychology, and argues that simulation theory, which purports to be an alternative to folk psychology, is not supported by recent experimental findings. (shrink)

We explore a network architecture introduced by Elman (1988) for predicting successive elements of a sequence. The network uses the pattern of activation over a set of hidden units from time-step 25-1, together with element t, to predict element t + 1. When the network is trained with strings from a particular finite-state grammar, it can learn to be a perfect finite-state recognizer for the grammar. When the network has a minimal number of hidden units, patterns on the hidden units (...) come to correspond to the nodes of the grammar, although this correspondence is not necessary for the network to act as a perfect finite-state recognizer. We explore the conditions under which the network can carry information about distant sequential contingencies across intervening elements. Such information is maintained with relative ease if it is.. (shrink)