This book addresses a previously neglected area in speech therapy research: the conceptualization of non-aphasic central language disorders. The starting point is the consideration that cognitive functions such as attention, memory, and language are based on complex interactions within neural networks that have a highly distributed and parallel architecture. When parts of these networks fail, secondary (system-related) disturbances occur in functionally closely linked systems. Cognitive dysphasias refer to such system-related language disorders resulting from primarily disturbed networks for attention and memory processes. The book provides a detailed description of language disorders following right hemisphere and frontal lesions, after hypoxia, in the context of vascular and degenerative dementias, as well as in endogenous and exogenous psychoses.