Although cerebral dominance, the specialization of each side of the brain for different functions, was discovered in the 1860s, almost nothing was known for many years about its biological foundations, the study of which has undergone what can only be described as a revolution in the past decade and a half.

Norman Geschwind and Albert Galaburda, two of the leaders of this new field, have assembled a distinguished group of investigators, each a pioneer in some aspect of the biology of dominance. The authors document human brain asymmetry at gross and microscopic levels in both adults and fetuses, its visualization in life by radiological methods, and its manifestation in brain waves. The evolutionary history of brain asymmetry over more than 300,000 years is shown in fossil skulls of humans and apes. In a dramatic reversal of older beliefs, asymmetry of anatomy, function, and chemistry has been demonstrated in many nonhuman species, and experiments have shown the role of hormones and other prenatal influences in the production of asymmetry. The surprising associations of non-right-handedness with twinning and immune disorders are discussed, as well as the asymmetrical malformation of the cortex in childhood dyslexia.

This volume, combining scholarly authority and the excitement of the birth of a new discipline, will be welcomed by those to whom the implications of dominance are becoming evident—neuroscientists, neurologists, linguists, psychologists, experts in learning disorders, speech pathologists—and by specialists in nearly every branch of biology, medicine, and psychology.

Dyslexia and Development presents the latest findings of neurobiological research, which suggest a link between seemingly minor brain abnormalities and epilepsy, learning disorders, and autism. The authors focus on the plasticity of the developing nervous system and the possible role of subtle early brain injury in the emergence of these disorders, particularly dyslexia.

The distinguished contributors to this volume examine epidemiological and clinical issues that may make the developing brain more vulnerable to environmental and genetic influences, which can in turn lead to abnormal brain plasticity and behavior. Although major forms of brain malformation have been clearly associated with functional deficits, mild forms have historically been ignored or trivialized; this book supports the hypothesis that several types of such malformation reflect brain injury during critical stages of development, and also the premise that more and more disturbances of thought and behavior stem from abnormalities of brain organization.

Neurologists and neurobiologists, psychologists, psycholinguists, psychiatrists, and special educators will find here a guide to more enlightened understanding and more effective treatment of dyslexia. In fact, the book emphasizes the positive aspect of the neurobiological deviation that dyslexic brains seem to show, along with the observation that people with such brains are often quite creative and extraordinary, rather than handicapped. In turn, the revised consideration of dyslexia should lead to more serious attention to other disturbances of childhood behavior as problems in developmental neurology, as well as to a deeper analysis of possible neurological bases for individual differences in normal behavior and personality.

The only way we can convey our thoughts in detail to another person is through verbal language. Does this imply that our thoughts ultimately rely on words? Is there only one way in which thoughts can occur? This ambitious book takes the contrary position, arguing that many possible "languages of thought" play different roles in the life of the mind.

"Language" is more than communication. It is also a means of representing information in both working and long-term memory. It provides a set of rules for combining and manipulating those representations.

A stellar lineup of international cognitive scientists, philosophers, and artists make the book's case that the brain is multilingual. Among topics discussed in the section on verbal languages are the learning of second languages, recovering language after brain damage, and sign language, and in the section on nonverbal languages, mental imagery, representations of motor activity, and the perception and representation of space.