Towards a distributed account of conceptual knowledge

How is conceptual knowledge organized and represented? Are domains (such as living things) and categories (such as tools, fruit) represented explicitl y or can domain and category structure emerge out of a distributed system? Taken at face value, evidence from brain-damaged patients and neuroimaging studies suggests that conceptual knowledge is explicitly structured in inde pendent content-based stores. However, recent analyses of the fine-grained details of semantic impairments, combined with research using connectionist modelling, suggest a different picture-one in which concepts are represent ed as patterns of activation over multiple semantic properties within a uni tary distributed system. Within this context, category-specific deficits em erge as a result of differences in the structure and content of concepts ra ther than from explicit divisions of conceptual knowledge in separate store s.