Computational neuroscience for machine learning - the study of the brain and its computation to improve the currently naive simplification of ANNs. Deep learning is miles behind the human brain in aspects such as learning and actual deep understanding.

Genetic programming for deep learning- fun methodology of guided randomization to learn neural networks.

Predictive coding - Rao & Ballard. A more advanced form of the MLP which forward propagates errors between predictions and observations rather than input. Spratling 2017 is a good review, but the Rao and Ballard 1999 is fundamental.