There is a wiki page on https://en.wikipedia.org/wiki/Neural_backpropagation which claims that this effect exists. Also maybe what we experience as night dreams is backproagation through our visual cortex, which becomes at this moment something like generative neural net.
Yes, there is a poorly understood phenomenon whereby action potentials sometimes travel back through the dendrites preceding them. This is insufficient for ML-style backprop because it rarely happens across more than one layer.
There is a wiki page on https://en.wikipedia.org/wiki/Neural_backpropagation which claims that this effect exists. Also maybe what we experience as night dreams is backproagation through our visual cortex, which becomes at this moment something like generative neural net.
Yes, there is a poorly understood phenomenon whereby action potentials sometimes travel back through the dendrites preceding them. This is insufficient for ML-style backprop because it rarely happens across more than one layer.