I might start with this paper from Bengio et al. and then read more recent papers which cite it. The problem hasn't been solved though so don't be surprised if

I might start with this paper from Bengio et al. and then read more recent papers which cite it. The problem hasn't been solved though so don't be surprised if you're not fully convinced by the arguments :) https://arxiv.org/pdf/1502.04156.pdf https://arxiv.org/pdf/1502.04156.pdf