The Handbook of Psychophysiology has been the authoritative resource for more than a quarter of a century. Since the third edition was published a decade ago, the field of psychophysiological science has seen significant advances, both in traditional measures such as electroencephalography, event-related brain potentials, and cardiovascular assessments, and in novel approaches and methods in behavioural epigenetics, neuroimaging, psychoneuroimmunology, psychoneuroendocrinology, neuropsychology, behavioural genetics, connectivity analyses, and non-contact sensors. At the same time, a thoroughgoing interdisciplinary focus has emerged as essential to scientific progress. Emphasizing the need for multiple measures, careful experimental design, and logical inference, the fourth edition of the Handbook provides updated and expanded coverage of approaches, methods, and analyses in the field. With state-of-the-art reviews of research in topical areas such as stress, emotion, development, language, psychopathology, and behavioural medicine, the Handbook remains the essential reference for students and scientists in the behavioural, cognitive, and biological sciences.