Mirror-image relations in category learning

Martin Jüttner  and Ingo Rentschler

The discrimination of patterns that are mirror-symmetric counterparts of each other is difficult and requires substantial training. We explored whether mirror-image discrimination during expertise acquisition is based on associative learning strategies or involves a representational shift towards configural pattern descriptions that permit to resolve symmetry relations. Subjects were trained to discriminate between sets of unfamiliar grey level patterns in two conditions, which either required the separation of mirror images or not. Both groups were subsequently tested in a 4-class category-learning task employing the same set of stimuli. The results show that subjects who successfully had learned to discriminate between mirror-symmetric counterparts were distinctly faster in the categorization task, indicating a transfer of conceptual knowledge between the two tasks. Additional computer simulations suggest that the development of such symmetry concepts involves the construction of configural, proto-holistic descriptions, in which positions of pattern parts are encoded relative to a spatial frame of reference.

Keywords: categorization, learning, pattern recognition, mirror image, holistic, configural

Rentschler, I. & Jüttner, M. (2007) Mirror-image relations in category learning. Visual Cognition 15, 211-237.