The brain is an organ that develops neurodynamically through childhood and into adolescence, much as the mental apparatus develops psychodynamically. This allows experience to modify both brain structure and brain function. Thus, one may speak of a brain-mind-self complex. Studies of split-brain patients, those in whom neural connections between the hemispheres are severed or attenuated, elucidate the functional asymmetry of this organ. Each hemisphere has its autonomous streams of consciousness and modes of thought that are unavailable to the other. Recent investigations suggest that the brain may be split not only anatomically but also physiologically. Absence or inhibition of callosal activity provides a model for repression and dissociation. It follows that psychotherapy will cure if it allows integration of right and left hemisphere activities. Similarly, studies of hierarchical brain organization yield a triune brain model that proves useful for understanding anxiety states and psychosomatic disorders. There is a comprehensive list of references that are readily accessible to a clinical psychoanalyst.