Proceedings of the Annual Meeting of the Cognitive Science Society

According to prototype theories of categorization, the cognitive system makes the default assumption that a category, C, is a roughly convex region in an internal space. This suggests that the default assumption for the "negative" category, not-C, should be the complement of this region—i.e., the internal space, minus a convex "hole." These different prior assumptions suggest potentially radically different patterns of generalization in category learning. We show experimentally that such effects do occur. These results are compatible with prototype accounts of categorization, but seem incompatible with exemplar accounts. We consider potential empirical extensions of this research, and its wider theoretical implications.