Breaking Rotational Symmetry in a Self-Organizing Map-Model for Orientation Map Development

We analyze the pattern formation behaviour of a high-dimensional SelfOrganizing-Map-model for the competitive projection of ON-center-type and OFF-center-type inputs to a common map layer. We mathematically show, and numerically con rm that even isotropic stimuli can drive the development of oriented receptive elds and an orientation map in this model. This result provides an important missing link in the spectrum of pattern formation behaviours observed in SOM-models. Extending the model by including further layers for binocular inputs, we also investigate the combined development of orientation and ocular dominance maps. A parameter region for combined patterns exists; corresponding maps show a preference for perpendicular intersection angles between iso-orientation lines and ocularity domain boundaries, consistent with experimental observations. 2