Unsupervised Coding with LOCOCODE

Traditional approaches to sensory coding use code component-oriented objective functions (COCOFs) to evaluate code quality. Previous COCOFs do not take into account the information-theoretic complexity of the code-generating mapping itself. We do: \Low-complexity coding and decoding" (Lococode) generates so-called lococodes that (1) convey information about the input data, (2) can be computed from the data by a low-complexity mapping (LCM), and (3) can be decoded by a LCM. We implement Lococode by training autoassociators with Flat Minimum Search (FMS), a general method for nding low-complexity neural nets. Lococode extracts optimal codes for diicult versions of the \bars" benchmark problem. As a preprocessor for a vowel recognition benchmark problem it sets the stage for excellent classiication performance.