Speaking is not only the basic mode of communication, but also the most complex motor skill humans can perform. Disorders of speech and language are the most common sequelae of brain disease or injury, a condition faced by millions of people each year. Health care practitioners need to interact with basic scientists in order to develop and evaluate new methods of clinical diagnosis and therapy to help their patients overcome or compensate their communication difficulties. In recent years, collaboration between those in the the disciplines of neurophysiology, cognitive psychology, mathematical...