To answer your question you can watch this presentation by Prof Hinton: http://www.youtube.com/watch?v=AyzOUbkUf3M http://www.youtube.com/watch?v=AyzOUbkUf3M H

To answer your question you can watch this presentation by Prof Hinton: http://www.youtube.com/watch?v=AyzOUbkUf3M http://www.youtube.com/watch?v=AyzOUbkUf3M He shows how he trained a restricted bolzmann machine to recognize handwritten numbers and how he can run it in reverse as a generative model, in effect the machine 'dreams' about all kinds of numbers that it's not been trained on but nonetheless makes up properly formed legible digits.