I am a microsurgeon of the mind,"" announces the author, in this unusually engaging presentation of her theory about how psychotherapy alters the way the brain operates and thus how the mind works. Vaughan, a psychiatrist and NIMH research fellow at the New York State Psychiatric Institute, is a gifted explicator of scientific concepts. Here she draws on research in cognitive science, neurobiology, and developmental psychology to back up her theory about the effects of psychotherapy on the human brain. Vaughan proposes that a network of neurons in the cerebral cortex functions as a ""story synthesizer"" that shapes our approach to relationships in daily life, and that the connections between these neurons are rewired through intensive, psychoanalytically oriented psychotherapy. Well-crafted descriptions of sessions with patients in her private practice provide the framework within which she develops her theory and describes the research that she believes substantiates it. Data about the neural pathways of sea slugs, anxiety in monkeys, and the neurobiology of infants alternate with passages revealing her thoughts about and interactions with her patients. Clear and precise when it needs to be, Vaughan's writing is informal without being chatty. She has the knack of seeming to converse directly with the reader, and she can turn a memorable phrase: ""For most people . . . medication changes how they feel, but psychotherapy is what changes what their lives are like."" What she is doing here is fusing two positions in psychiatry--the biological approach, which explains mental disorders in terms of the brain and advocates medication to correct the disorder, and the psychological approach, which sees talk therapy as the answer. Whether her theory meets with the approval of her professional colleagues remains to be seen. Meanwhile, she has given the general reader a highly readable explanation of how one psychotherapist views her work. Especially interesting to those who have experienced psychotherapy or are considering it.