From a neuropsychological perspective, our understanding about how knowledge is organised in the human brain has emerged largely from the study of so-called 'category-specific' deficits in neurological patients. Category-specificity is, in very broad terms, the relative loss of cognitive performance in one domain of knowledge over another. The most frequently reported and discussed pattern concerns a dissociation between knowledge about nonliving things (e.g. tools) and living things (e.g. animals). Most reports of categorical impairment have emerged from case studies of patients with pathologies such as herpes simplex encephalitis, strokes or head injuries and the dementias (especially Alzheimer's disease). These category specific effects have been fundamental in forming theories and models about the organisation and modular structure of semantic knowledge in the brain. The different chapters of this book illustrate a broad range of interesting and strongly debated issues arising from the category-specific literature, all of them fundamental to cognitive neuropsychology. This book, written by researchers who during the last decade have intensively researched this intriguing field, present an up-to-date exploration of major neuropsychological issues that have general implications beyond the field of category knowledge e.g. issues such as modularity, computational modelling of cognitive processing, gender-related asymmetries and functional imaging.