The scientific works of P. V. Simonov are devoted to the physiology of higher nervous activity, that is, the study of the brain foundations of behavior. He created and experimentally substantiated a need-information approach to the analysis of behavior and higher mental functions of humans and animals, which made it possible to provide a natural scientific justification for such key concepts of general psychology as need, emotion, will, and consciousness. The book is interdisciplinary in nature: it examines neurophysiological, neuroanatomical and psychological aspects of the study of emotions.