creators_name: Harnad, Stevan creators_name: Hanson, S.J. creators_name: Lubin, J. editors_name: Powers, D. W. editors_name: Reeker, L. type: bookchapter datestamp: 2001-06-18 lastmod: 2011-03-11 08:54:40 metadata_visibility: show title: Categorical Perception and the Evolution of Supervised Learning in Neural Nets ispublished: pub subjects: comp-sci-neural-nets subjects: percep-cog-psy full_text_status: public keywords: categorical perception, neural nets, learning abstract: Some of the features of animal and human categorical perception (CP) for color, pitch and speech are exhibited by neural net simulations of CP with one-dimensional inputs: When a backprop net is trained to discriminate and then categorize a set of stimuli, the second task is accomplished by "warping" the similarity space (compressing within-category distances and expanding between-category distances). This natural side-effect also occurs in humans and animals. Such CP categories, consisting of named, bounded regions of similarity space, may be the ground level out of which higher-order categories are constructed; nets are one possible candidate for the mechanism that learns the sensorimotor invariants that connect arbitrary names (elementary symbols?) to the nonarbitrary shapes of objects. This paper examines how and why such compression/expansion effects occur in neural nets. date: 1991 date_type: published publication: Working Papers of the AAAI Spring Symposium on Machine Learning of Natural Language and Ontology publisher: Symposium on Symbol Grounding: Problems and Practice, Stanford University pagerange: 65-74 refereed: FALSE referencetext: Cottrell, Munro & Zipser (1987) Image compression by back propagation: an example of extensional programming. ICS Report 8702, Institute for Cognitive Science, UCSD. Hanson & Burr (1990) What connectionist models learn: Learning and Representation in connectionist networks. Behavioral and Brain Sciences 13:471-518. Hanson, S. J. and Kegl, J. (1987) Parsnip: A Connectionist Model that Learns Natural Language Grammar from Exposure to Natural Language Sentences. "Ninth Annual Cognitive Science Conference, Seattle." Harnad, S. (ed.) (1987) "Categorical Perception: The Groundwork of Cognition" . New York: Cambridge University Press. Harnad, S. (1990) The Symbol Grounding Problem. "Physica D" 42: 335-346. McClelland, J.L., Rumelhart, D. E., and the PDP Research Group (1986) "Parallel distributed processing: Explorations in the microstructure of cognition," Volume 1. Cambridge MA: MIT/Bradford. Miller, G. A. (1956) The magical number seven, plus or minus two: Some limits on our capacity for processing information. "Psychological Review" 63: 81 - 97. citation: Harnad, Stevan and Hanson, S.J. and Lubin, J. (1991) Categorical Perception and the Evolution of Supervised Learning in Neural Nets. [Book Chapter] document_url: http://cogprints.org/1579/1/harnad91.cpnets.html