original way biocells and view in 1986 they're much route there there are different ways now I think young mother talked about encoded decode architectures I'll talk a bit more about that later today but I think this intuition of learning sparse features has been kind of key for is one of the ideas I guess that allows us to learn very useful features even from unlabeled data come back to this later as well there are there other ways to do it if any of you are familiar with ICA actually how many of you have heard of