Models and concepts of brain function have always been guided and limited by the available techniques and data. This book brings together a multitude of data from different backgrounds. It addresses questions such as: how do different brain areas interact in the process of channelling information? How do neuronal populations encode the information? How are networks formed and separated or associated with other networks? The authors present data at the single cell level both in vitro and in vivo, at the neuronal population level in vivo comparing field potentials (EEGs) in different brain areas, and also present data from spike recordings from identified neuronal populations during the performance of different tasks. Written for academic researchers and graduate students, the book strives to cover the range of single cell activity analysis to the observation of network activity, and finally to brain area activity and cognitive processes of the brain.