Cerebral plasticity is perhaps the most fundamental principle of neuropsychology that is invoked, measured, analyzed, and targeted for treatment and experimental intervention each day by clinicians and scientists. Whether the focus is central nervous system development, recovery from brain damage, or age-associated changes and diseases, understanding cerebral plasticity is vital to scientific and clinical advances in human brain function and treatment of neurologic disorders in millions of people. Some of these advances have been succinctly summarized in two recent volumes. The first (McGaugh et al.) is a handsomely bound summary of basic research investigating brain mechanisms underlying learning and memory. The text resulted from a symposium featuring largely American and Mexican investigators who addressed cellular aspects of memory and how brain systems may mediate different types of memory. As John Garcia emphasizes in the opening chapter, such investigation is driven by the need to interrelate behavior and brain processes, bridging the barranca or chasm between behavioral and brain research. The fundamental role of learning and memory to behavior of all varieties, and the widespread involvement of cortical, limbic, basal ganglia, diencephalic, brain stem, and cerebellar structures in memory provides the massive playing field on which the ensuing behavioral, electrophysiologic, neurochemical, and molecular studies are described.