Odelia Schwartz Terrence J. Sejnowski Peter Dayan Soft Mixer Assignment in a Hierarchical Generative Model of Natural Scene Statistics. 2680-2718 2006 18 Neural Computation 11 http://dx.doi.org/10.1162/neco.2006.18.11.2680 db/journals/neco/neco18.html#SchwartzSD06