our error here that we can locally adjust again all the signals propagated here here and here are just neural activations and all the information required to update a layer of neurons is now contained within that layer of neurons right and and this goes back through the network so this is how they achieve how they achieve this this is a bit of a close-up look and here are the computations to do this so basically for the forward updates you want to adjust W into the direction of the H minus the H tilde and the H tilde in