title: Categorical Perception Effects Induced by Category Learning creator: Livingston, Kenneth creator: Andrews, Janet creator: Harnad, Stevan subject: Perceptual Cognitive Psychology description: We test whether effects similar to those observed in the innate categorical perception (CP) of color and phonemes are induced during the learning of both simple unidimensional categories and more complex multidimensional ones. In Experiment 1 no evidence is found for such effects when stimuli vary unidimensionally. Experiments 2 and 3 demonstrate a within-category compression effect but no between-category expansion effect for stimuli varying in two dimensions. Compression only is also shown in Experiment 4, which uses pictures of actual objects. MDS analyses of these data illustrate how within-category compression effects without expansion effects are sufficient to produce categorical clustering of items in the similarity space. These analyses also show that learning changes the dimensional structure of similarity space. Results are compared with those from other studies exploring similar phenomena, and with neural network simulations. The paper closes with suggestions for the direction of future research on these phenomena. date: 1998 type: Journal (Paginated) type: PeerReviewed format: application/pdf identifier: http://cogprints.org/2574/1/harnad98.cp.pdf identifier: Livingston, Kenneth and Andrews, Janet and Harnad, Stevan (1998) Categorical Perception Effects Induced by Category Learning. [Journal (Paginated)] relation: http://cogprints.org/2574/