The book presents a set of ten carefully designed experimental studies which aim to investigate the nature of different aspects of linguistic abilities and their relative impairments in Hungarian speaking individuals with Williams Syndrome, a rare genetically-based developmental disorder that has in recent years become the focus of great deal of attention in the cognitive and brain sciences. The central theoretical interest in studying Williams syndrome has to do with the fact that it presents a rare and intriguing profile of apparent dissociation between a surprisingly spared linguistic competence on the one hand, and relatively severe deficits in a range of other cognitive domains (especially in spatial cognition and motor skills) on the other, together with mild to moderate mental retardation. This provides an intriguing testing ground for such central questions of current-day cognitive science as whether the language faculty is modular or not, how language and cognition are interfaced, or how severe deficits in different types of cognitive mechanisms might influence linguistic abilities and/or their acquisition.