To Cognize is to Categorize: Cognition is Categorization To categorize is to do the right thing with the right kind of thing

Innate Categories Evolved categories

Color Categorical Perception

Most of our categories are learned. Open a dictionary. Learned Categories

Trial-and-Error Learning with corrective feedback

Learned Categorical Perception (CP) Pevtzow, R. & Harnad, S. (1997)

ERP activity changes during the course of learning Upper: learners Lower: non-learners Post-learning minus pre-learning msec msec Upper: learners Lower: non-learners Fath-el Bab (2001)

St, Louis & Harnad 2007 Texture category learning Late ERP positivity in learners (only) All learning explicit Late positivity can be induced by telling rule

Sensorimotor Invariants Tijsseling & Harnad 1997

Implicit and Explicit Learning of Artificial Grammars Martina Johnson (2006) Classical Artificial Grammars are too hard to learn with corrective feedback Grammars easy enough to learn are learned explicitly EASY MEDIUM HARD 100% 80% 60% 40% 20% % Correct

The Libet Effect: Implicit premotor potential precedes conscious willing of movement

The Chinese-Chinese Dictionary and the Symbol Grounding Problem

Symbolic Theft and Language Evolution A New Way To Acquire Categories Cangelosi & Harnad 2002

Acquiring Categories Through Definition and Description ZEBRA = HORSE + STRIPES

Mapping definitional structure in the dictionary

Our Category Commons Open Access to Scholarly and Scientific Research on the Web