Artificial neural networks are everywhere in research and technology, as well as in everyday technologies such as speech recognition. Despite this, it is still unclear to researchers what is exactly going on deep down in these networks. To find out, researchers at the Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN) at Göttingen University, and the Max Planck Institute for Dynamics and Self-Organisation (MPI-DS) have carried out an information-theoretic analysis of Deep Learning, a special form of machine learning.