Vigo, R. (2006). A Note on the Complexity of Boolean Concepts.                             Journal of Mathematical Psychology, Vol. 50, 501-510. PDF Vigo, R. (2009c). Categorical Invariance and Structural Complexity in Human Concept Learning.                             Journal of Mathematical Psychology, Vol. 53, 203-221. PDF Vigo, R., Allen, C., (2009a). How to reason without words: inference as categorization.                             Cognitive Processing 10(1): 51-88. PDF Vigo, R. (2009b). Modal Similarity.                             Journal of Experimental and Theoretical Artificial Intelligence, Vol. 21, No. 3, pp. 181–196. PDF Vigo, R., Allen. C., (2009d). Form over Mind: How Structure Determines Cognition.                            Trends in Cognitive Science, (under review). PDF Vigo, R. (2009e). A Dialogue on Concepts, THINK, Volume 9, Issue 24, March 2010, pp 109-120. Vigo, R. (2009f). Two Ways of Measuring the Complexity of Boolean Sets. PDF                            Complexity Journal, (under review). Vigo, R., Kruschke, J. (2009g). A Generalization of the Categorical Invariance Model                             to Continuous Domains: from {0,1} to [0,1]. PDF Vigo, R. (2009h). Mathematical Principles of Human Conceptual Behavior. CSLI Publications.                            (in preparation). PDF