Not to deep nets iirc, which was one of the advancements.
Re:A week-long programming retreat
by pedrosorio on Monday March 05, 2018 @10:41AM
(#16521732)
The GP implies that was not tried before: "There was a revolution, when they started using backpropogation to optimize the gradient search".
"Back-propagation allowed researchers to train supervised deep artificial neural networks from scratch, initially with little success. Hochreiter's diploma thesis of 1991[1][2] formally identified the reason for this failure in the "vanishing gradient problem", which not only affects many-layered feedforward networks,[3] but also recurrent networks."
[Rumelhart, David E.; Hinton, Geoffrey E.; Williams, Ronald J. (8 October 1986). "Learning representations by back-propagating errors". Nature]