Two Opposing Views Have Been Advanced on the Relationship Between Brain and Behavior
The Brain Has Distinct Functional Regions
The First Strong Evidence for Localization of Cognitive Abilities Came from Studies of Language Disorders
Affective States Are Also Mediated by Local, Specialized Systems in the Brain
Mental Processes Are the End Product of the Interactions Between Elementary Processing Units in the Brain
The last frontier of the biological sciences—the ultimate challenge—is to understand the biological basis of consciousness and the brain processes by which we feel, act, learn, and remember. During the past few decades, a remarkable unification within the biological sciences has set the stage for addressing this great challenge. The ability to sequence genes and infer the amino acid sequences of the proteins they encode has revealed unanticipated similarities between proteins in the nervous system and those encountered elsewhere in the body. As a result, it has become possible to establish a general plan for the function of cells, a plan that provides a common conceptual framework for all of cell biology, including cellular neural science. The current challenge in the unification within biology, which we outline in this book, is the unification of the study of behavior—the science of the mind—and neural science—the science of the brain.
Such a unified approach, in which mind and body are not viewed as separate entities, rests on the view that all behavior is the result of brain function. What we commonly call the mind is a set of operations carried out by the brain. Brain processes underlie not only simple motor behaviors such as walking and eating but also all the complex cognitive acts and behavior that we regard as quintessentially human—thinking, speaking, and creating works of art. As a corollary, all the behavioral disorders that characterize psychiatric illness—disorders of affect (feeling) and cognition (thought)—result from disturbances of brain function.
How do the billions of individual nerve cells in the brain produce behavior and cognitive states, and how are those cells influenced by the environment, which includes social experience? Explaining behavior in terms of the brain's activities is the task of neural science, and the progress of neural science in explaining human behavior is a major theme of this book.
Neural science must continually confront certain fundamental questions. Is a particular mental process carried out in specific regions of the brain, or does it involve the brain as a whole? If a mental process can be localized to discrete brain regions, what is the relationship between the functions of those regions in perception, movement, or thought and the anatomy and physiology of those regions? Are these relationships more likely to be understood by examining each region as a whole or by studying individual nerve cells?
To answer these questions we shall examine how modern neural science describes language, one of the most human of ...