With new discussions by Theodore Jacobs and Regina Pally Adult psychoanalysis has approached the study of intersubjectivity by concentrating primarily on the verbal dialogue, an explicit mode of communication. Infant research, on the other hand, focuses on nonverbal communication and implicit modes of action sequences, operating largely out of awareness, such as interactions of gaze, facial expression, and body rhythms. This book proposes that an integration of these two approaches is essential to a deeper understanding of the therapeutic action. The authors use a dyadic systems model of self- and interactive regulation as a lens for comparing diverse theories of intersubjectivity, both in adults and infants. Building on the definition of intersubjectivity in infancy as correspondence and matching of expressions, the authors offer an expanded view of the presymbolic origins of intersubjectivity. They address the place of interactive regulation, problems with the concept of matching, the roles of self-regulation and of difference, and the balance of self- and interactive regulation. An adult treatment of early trauma is described through detailed clinical case material illustrating both the verbal narrative and the implicit "action dialogue" operating largely outside of awareness. This book includes new discussions by Theodore Jacobs, arguing that nonverbal communication is vitally important to psychoanalysis, and by Regina Pally, arguing that aspects of this book have parallels in neuroscience.