Unsupervised learning for the visual cortex (layer IV): model and simulations

The authors present a statistical model to study the evolution of orientation columns in layer IV of the visual cortex after birth by simulating, on the retina, the first visual experiences of an animal (darkness, biased, and normal visual environments). The results are consistent with biological experiments. The authors show the necessity of introducing a new nonlinear model in which both vertical and intracortical connections evolve simultaneously as soon as the visual experience begins. The model sets up intracortical connections and achieves the maturation of orientation columns. It takes into account recent neurobiological observations for the development of intracortical connections. Simulations reproduce the results of experiments which observe excitative intracortical connections between cells of similar orientation in different hypercolumns