  Deep reinforcement learning approaches have shown impressive results in a
variety of different domains, however, more complex heterogeneous architectures
such as world models require the different neural components to be trained
separately instead of end-to-end. While a simple genetic algorithm recently
showed end-to-end training is possible, it failed to solve a more complex 3D
task. This paper presents a method called Deep Innovation Protection (DIP) that
addresses the credit assignment problem in training complex heterogenous neural
network models end-to-end for such environments. The main idea behind the
approach is to employ multiobjective optimization to temporally reduce the
selection pressure on specific components in multi-component network, allowing
other components to adapt. We investigate the emergent representations of these
evolved networks, which learn to predict properties important for the survival
of the agent, without the need for a specific forward-prediction loss.
