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Abstract
We explore a network architecture introduced by Elman (1990) for predicting successive elements of a sequence. The network uses the pattern of activation over a set of hidden units from time-step t-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 net has a minimal number of hidden units, patterns on the hidden units come to correspond to the nodes of the grammar, however, this correspondence is not necessary for the network to act as a perfect finite-state recognizer. Next, we provide a detailed analysis of how the network acquires its internal representations. We show that the network progressively encodes more and more temporal context by means of a probability analysis. Finally, we explore the conditions under which the network can carry information about distant sequential contingencies across intervening elements to distant elements. Such information is maintained with relative ease if it is relevant at each intermediate step, it tends to be lost when intervening elements do not depend on it. At first glance this may suggest that such networks are not relevant to natural language, in which dependencies may span indefinite distances. However, embed dings in natural language are not completely independent of earlier information. The final simulation shows that long distance sequential contingencies can be encoded by the network even if only subtle statistical properties of embedded strings depend on the early information. The network encodes long-distance dependencies byshading internal representations that are responsible for processing common embeddings in otherwise different sequences. This ability to represent simultaneously similarities and differences between several sequences relies on the graded nature of representations used by the network, which contrast with the finite states of traditional automata. For this reason, the network and other similar architectures may be calledGraded State Machines.
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References
Allen, R.B. (1988). Sequential connectionist networks for answering simple questions about a microworld.Proceedings of the Tenth Annual Conference of the Cognitive Science Society.
Allen R.B., & Riecksen M.E. (1989). Reference in connectionist language users. In R.Pfeifer, Z.Schreter, F.Fogelman-Soulié, & L.Steels (Eds.),Connectionism in perspective. North Holland: Amsterdam.
Allen R.B. (1990).Connectionist language users (TR-AR-90–402). Morristown, NJ: Bell Communications Research.
Cleeremans A., Servan-Schreiber D., & McClelland J.L. (1989). Finite state automata and simple recurrent network.Neural Computation,1, 372–381.
Cottrell G.W. (1985). Connectionist parsing.Proceedings of the Seventh Annual Conference of the Cognitive Science Society. Hillsdale, NJ: Erlbaum.
Elman J.L. (1990). Finding structure in time.Cognitive Science, 14, 179–211.
Elman J.L. (1990). Representation and structure in connectionist models. In Gerry T.M.Altmann (Ed.),Cognitive models of speech processing: Psycholinguistic and computational perspectives Cambridge, MA, MIT Press.
Fanty M. (1985).Context-free parsing in connectionist networks (TR174) Rochester, NY: University of Rochester, Computer Science Department.
Hanson S. & Kegl J. (1987). PARSNIP: A connectionist network that learns natural language from exposure to natural language sentences.Proceedings of the Ninth Annual Conference of the Cognitive Science Society Hillsdale, NJ: Erlbaum.
Hinton G., McClelland J.L., & Rumelhart D.E. (1986). Distributed representations. In D.E.Rumelhart and J.L.McClelland (Eds.),Parallel distributed processing, I: Foundations. Cambridge, MA: MIT Press.
Jordan M.I. (1986). Attractor dynamics and parallelism in a connectionist sequential machine.Proceedings of the Eighth Annual Conference of the Cognitive Science Society. Hillsdale, NJ: Erlbaum.
Luce R.D. (1963). Detection and recognition. In R.D.Luce, R.R.Bush and E.Galanter (Eds.),Handbook of mathematical psychology (Vol. 1). New York: Wiley.
McClelland J.L. & Rumelhart D.E. (1988).Explorations in parallel distributed processing: A handbook of models, programs and exercises. Cambridge, MA: MIT Press.
Pollack, J. (in press). Recursive distributed representations.Artificial Intelligence.
Reber A.S. (1976). Implicit learning of synthetic languages: The role of the instructional set.Journal of Experimental Psychology: Human Learning and Memory,2, 88–94.
Rumelhart D.E. & McClelland J.L. (1986).Parallel distributed processing, I: Foundations. Cambridge, MA: MIT Press.
Rumelhart D.E., Hinton G., & Williams R.J. (1986). Learning internal representations by error propagation In D.E.Rumelhart and J.L.McClelland (Eds.),Parallel distributed processing, I: Foundations. Cambridge, MA: MIT Press.
Sejnowski T.J., & Rosenberg C. (1987). Parallel networks that learn to pronounce english text.Complex Systems1, 145–168.
Servan-Schreiber D., Cleeremans A., & McClelland J.L. (1988).Encoding sequential structure in simple recurrent networks (Technical Report CMU-CS-183). Pittsburgh, PA: Carnegie Mellon University, School of Computer Science.
Servan-Schreiber D., Cleeremans A., & McClelland J.L. (1989). Learning sequential structure in simple recurrent networks. In D.S.Touretzky (Ed.),Advances in neural information processing systems 1. San Mateo, CA: Morgan Kaufmann. [Collected papers of the IEEE Conference on Neural Information Processing Systems Natural and Synthetic, Denver, Nov. 28–Dec. 1, 1988].
St. John, M., & McClelland, J.L. (in press). Learning and applying contextual constraints in sentence comprehension.Artificial Intelligence.
- David Servan-Schreiber
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- Axel Cleeremans
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- James L. Mcclelland
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School of Computer Science and Department of Psychology Carnegie Mellon University
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Servan-Schreiber, D., Cleeremans, A. & Mcclelland, J.L. Graded state machines: The representation of temporal contingencies in simple recurrent networks.Mach Learn7, 161–193 (1991). https://doi.org/10.1007/BF00114843
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