I have specifically avoided discussion of the F A C A D E theory. In my view the most interesting and significant aspects of Grossberg's vision model are those which have been adopted here in the MLRF model, i.e. the clear and simple principles of boundary completion and surface brightness filling-in. The F A C A D E theory is very much more complex, and has so many different interacting mechanisms and modules that it is difficult to grasp intuitively exactly what is going on in there. So whether or not Grossberg still believes in the simpler (and more elegant) principles of his original BCS / FCS model, it is that model which I have chosen as a jumping-off point for my own theoretical modeling.