Category-specific deficits: Insights from semantic dementia and Alzheimer's disease

Recent investigations and theorising about category-specific deficits have begun to focus upon patients with progressive brain disease such as semanti c dementia and Alzheimer's disease. In this commentary,xe briefly review wh at insights have been gained from studying patients of this type. We concen trate on four specific issues: the sunsory/functional distinction, correlat ion between features, neuroanatomical considerations, and confounding facto rs.