Book Review

Of Two Minds: The revolutionary science of dual-brain psychology

N Engl J Med 1999; 340:1218-1219April 15, 1999

Article

Of Two Minds: The revolutionary science of dual-brain psychology
By Fredric Schiffer. 243 pp. New York, Free Press, 1998. $25. ISBN: 0-684-85424-4

Of Two Minds breaks new ground. The book's premise is that each hemisphere of the brain contains its own mind and its own distinct personality. In the normal person, the two hemispheres and their respective minds are in balance and interact harmoniously. However, when they are out of balance, mental illness may result, according to the book's author.

Schiffer's theory stems from his work with patients. He has observed that patients appear to be dominated by different personalities at different times — sometimes by mature, reasonable, patient, self-confident personalities, and sometimes by insecure, anxious, self-denigrating, primitive personalities. The notion of more than one personality in one person is not new. Clinicians have written about the “inner child” and the “unconscious mind” for a long time. However, Schiffer's approach is new — he links the dual minds with the hemispheres of the brain.

Schiffer decided to try to communicate directly with a single hemisphere after learning of an experiment conducted in Germany. In this experiment, different emotional responses were elicited in normal persons when movies were directed to one hemisphere or the other. This experiment prompted Schiffer to construct two sets of eyeglasses: one with lenses that were opaque except at the extreme left side and one with lenses that were opaque except at the extreme right side. The glasses directed all visual input to a single hemisphere of the brain. Schiffer asked patients to put on one set of glasses and tell him what they experienced. He then asked them to put on the other set of glasses and tell him what they experienced. He observed that for a substantial number of patients, one set of glasses tended to have a calming effect, whereas the other set caused patients to feel depressed, edgy, anxious, or agitated. With the use of the glasses, Schiffer developed a psychotherapeutic approach that involved speaking directly to the troubled mind (hemisphere). Over time, he observed clinical improvement. Schiffer states, “The aim of `dual-brain' therapy is to mend the archaic, destructive ideas and emotions of the mind on the troubled side, to teach it that it is safer and more valuable than it learned during some traumatic experiences. . . . I teach patients how to recognize and listen for the mind in their troubled hemisphere, and then how to speak to it — out loud!” On the basis of these experiences, he reasons that there are two minds, each with a distinct personality associated with one hemisphere, and that an imbalance between them is responsible for mental illness.

Schiffer postulates that major psychiatric illnesses can result from problems with brain laterality. For example, depression may stem from an experience in early childhood, a time of extreme vulnerability, defenselessness, and dependency. Trauma during this period, according to Schiffer, is retained in the mind of one hemisphere. Depression comes from the defensiveness and the despondency associated with the memory of this experience in the one hemisphere. Treatment involves communicating directly with the troubled hemisphere by using the eyeglasses in a healing manner. When both sides of the brain are healthy, the depression subsides.

Schiffer describes other major psychiatric conditions from the standpoint of the laterality of the brain. His psychoanalytic background leads him to emphasize early trauma in the pathogenesis of psychiatric illnesses, trauma that is visited on one hemisphere.

The science on which brain laterality is based is extensive. Several decades ago, Roger Sperry demonstrated the existence of distinct “minds” in humans and in animals in which communication between the hemispheres was disrupted. He received a Nobel prize for this work. As an example of the “split brain,” Schiffer describes a patient of Sperry's who was awakened from a sound sleep by her left hand slapping her across the face. “The patient had overslept, and the right mind must have awakened, realized the time, and tried to rouse her.”

This book is bold, interesting, and ambitious. At times, it makes scientific leaps whose logic is hard to follow. The descriptions of the neurobiology of depression, schizophrenia, drug addiction, panic disorder, and bipolar illness are somewhat superficial. The key biologic link between laterality and mental illness needs substantially more elucidation to be convincing. Thus, in the end, the book is more provocative than scientific, but it is well worth reading.

Robert M.A. Hirschfeld, M.D.
University of Texas Medical Branch, Galveston, TX 77555-0429