It is important to reaffirm the reality of the learning disabilities (LD) phenomenon as a condition that imposes genuine constraints on a student's ability to function, and not as some chimerical entity defined by an ever-changing political situation. Perceptual, memory, attention, linguistic, social, cognitive and neuropsychological factors are an integral part of LD. By mapping out in great detail and with much new data the acquired knowledge on learning disabilities, both empirical and theoretical, this book unravels many mysteries. This book is a landmark in learning disabilities studies, and it lays down solid foundations for future research and practical intervention in the field.