Think about it; biological neurons most definitely don't use backprop. Physical neurons can't backprop linearly if they forward prop nonlinearly. I think Hinton pointed this out, though almost all ANN researchers agree.

Hebbian learning .... maybe. I never thought too much about contrastive divergence.

It doesn't really matter; brains most certainly don't work like ANNs, except maybe in some weird mean field sense for a few things like liquid state machines. It would be a huge coincidence if LeCun or Hinton or whoever magically wrote down the brain equation....