An Overview of EEG and MEG

Abstract This brief chapter begins by describing the relatively different historical trajectories of the development of EEG and MEG methods, starting for EEG already in 1875 and for MEG in the 1960s. The main prominent brain rhythms (e.g., alpha and mu), well visible in both MEG and EEG, are briefly introduced. The principle of evoked MEG and EEG responses is described, explaining how they are triggered by incoming sensory stimuli or other events. The chapter ends by summarizing the various advantages and disadvantages of MEG and EEG methods, which are essential for understanding the side-by-side comparisons of electric and magnetic recordings presented in later chapters of the book.