Laterally Interconnected Self-Organizing Maps in Hand-Written Digit Recognition

An application of laterally interconnected self-organizing maps (LISSOM) to handwritten digit recognition is presented. The resulting excitatory connections focus the activity into local patches and the inhibitory connections decorrelate redundant activityon the map. The map thus forms internal representations thatare easy to recognize with e.g. a perceptron network. The recognition rate on a subset of NIST database 3 is 4.0% higher with LISSOM than with a regular Self-Organizing Map (SOM) as the front end, and 15.8% higher than recognition of raw input bitmaps directly. These results form a promising starting point for building pattern recognition systems with a LISSOM map as a front end. 1 Introduction Handwritten digit recognition has become one of the touchstone problems in neural networks recently.