Self-Organization by Optimizing Free-Energy

We present a variational Expectation-Maximization algorithm to learn probabilistic mixture models. The algorithm is similar to Kohonen’s Self-Organizing Map algorithm and not limited to Gaussian mixtures. We maximize the variational free-energy that sums data loglikelihood and Kullback-Leibler divergence between a normalized neighborhood function and the posterior distribution on the components, given data. We illustrate the algorithm with an application on word clustering.