The extensively re-written and updated edition of this highly acclaimed text provides a synthesis of the latest research on the cognitive defects of dyslexia and reviews evidence concerning its biological bases.

Margaret J. Snowling is Professor of Psychology at the University of York. Widely recognised as an expert in the field of developmental disorders, particularly in children's reading, speech and language difficulties, she is a qualified Clinical Psychologist and was Principal of the National Hospitals College of Speech Sciences until 1992.