Neural Computation, Vol 10, 717-730, Copyright © 1998 by The MIT Press
Breaking Rotational Symmetry in a Self-Organizing Map-Model for Orientation Map Development
M. Riesenhuber, H. U. Bauer, D. Brockmann and T. Geisel
We analyze the pattern formation behavior of a high-dimensional
self-organizing map (SOM) model for the competitive projection of
ON-center-type and OFF-center-type inputs to a common map layer. We
mathematically show, and numerically confirm, that even isotropic stimuli
can drive the development of oriented receptive fields and an orientation
map in this model. This result provides an important missing link in the
spectrum of pattern formation behaviors 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.
