Evidence for scripts in semantic dementia: Implications for theories of semantic memory.

This paper presents evidence that the breakdown of semantic memory in semantic dementia reveals the influence of two properties of script theory (Schank, 1982; Schank & Abelson, 1977). First, the physical and personal context of specific scripts supports meaning for words, objects, and locations that are involved in the script. Second, meaning is updated or transformed by a dynamic memory system that learns continuously from personal experience. In severe cases, semantic dementia exposes the basic level of this learning system from which all knowledge normally develops. It will be argued that the evidence supports a theory of semantic memory that represents meaning in a continuum of levels of meaning from the most specific and context-bound to the most generalisable and context-free. This contrasts with current theories of semantic memory that represent meaning as a collection of abstracted properties entirely removed from the context of events and activities.