Cognitive neuropsychology seeks to understand impairments of specific cognitive functions in relation to a model of normal cognitive processing. The conclusions drawn from the study of abnormal processes are in turn used in the development and testing of theories of normal cognition. This book represents an attempt to synthesize and systematize progress so far. In addition to reviewing different forms of impairment and discussing their implications for theories of normal function, this book also examines the empirical and theoretical foundations of the subject including the use of single-case studies and the assumptions that must be made about the mind and brain.