This book is a comprehensive overview of the main current concepts in brain cognitive activities at the global, collective (or network) level, with a focus on transitions between normal neurophysiology and brain pathological states. It provides a unique approach of linking molecular and cellular aspects of normal and pathological brain functioning with their corresponding network, collective and dynamical manifestations that are subsequently extended to behavioural manifestations of healthy and diseased brains. This book introduces a high-level perspective, searching for simplification amongst the structural and functional complexity of nervous systems by consideration of the distributed interactions that underlie the collective behaviour of the system. The authors hope that this approach could promote a global comprehensive understanding of high-level laws behind the elementary biological processes in the neuroscientific community, while, perhaps, introducing elements of biological complexities to the mathematical/computational readership. The title of the book refers to the main point of the monograph: that there is a smooth continuum between distinct brain activities resulting in different behaviours, and that, due to the plastic nature of the brain, the behaviour can also alter the brain function, thus rendering artificial the boundaries between the brain and its behaviour.