COHERENCE PATTERNS IN ALZHEIMERS DISCOURSE

This article reports on linguistic features and patterns of coherence in two levels (mild and advanced) of discourse produced by Alzheimer's patients. It argues and demonstrates that as the disease progresses, the discourse of Alzheimer's patients becomes pregrammatical in that i t is vocabulary driven and reliant on meaning-based features of discou rse rather than grammatically based features. Theories of pregrammatic al and grammatical modes of processing and comprehension are discussed and used as an explanatory framework for understanding 4 fundamental coherence requirements. These are grounding, temporal coherence, spati al coherence, and thematic coherence. Data collected from Alzheimer's patients are used to illustrate how these types of coherence vary from earlier to later stages of the disease.