Given the complexity of topics, and importance of the progress of our understanding of how the brain works, has long been a need for introductory texts on complex topics. This book includes an introduction and motivation of a simple model of neurons suitable for exploring information processing in the brain tissue as big. In addition, it introduces several fundamental network architectures and discusses their relevance for information processing in the brain, providing some examples of models of higher-order cognitive functions to demonstrate sophisticated insights to be gained by the study.