A very surprising shortcut
• Instead of getting the correct probability distribution over
rivals by running a Markov chain until it reaches the
equilibrium distribution, use slight corruptions of the
data-vectors as the rivals (Bartlett’s experiments)
• Learn by modifying the weights so as to lower the
energy of the true data and raise the energy of the
slightly corrupted data.
• The learning stops when the model’s prejudices do not
corrupt the data in any systematic way.
– Its OK if unlikely data-vectors are usually corrupted
into more likely ones.
– This is exactly balanced by corrupting a small
fraction of the likely data-vectors into unlikely ones.