Date of Degree

1995

Document Type

Dissertation

Degree Name

Ph.D.

Program

Speech-Language-Hearing Sciences

Advisor(s)

David Swinney

Committee Members

Helen S. Caims

Lynne W. Clark

Subject Categories

Speech and Hearing Science

Abstract

This research investigation explored the cognitive processing operations of 18 healthy elderly (HE) subjects and 12 Alzheimer's Disease (AD) subjects in the mild clinical stage of the disease in their performance on a semantic priming task involving semantic lexical activations of both automatic and controlled processing natures.

Relatively little conclusive evidence has been documented regarding the relative roles of attention and memory processing in the lexical-semantic impairment of Alzheimer's Disease. A lexical decision processing task was implemented to investigate the effects of normal aging and neuropathological damage of Alzheimer's Disease on subjects' semantic priming abilities. The research design was based on the growing body of literature reporting successful procedural use of priming techniques with HE and AD subjects, as well as the fact that temporal boundaries reflecting attention-dependent and non-attention dependent processing have been suggested, particularly with healthy young populations. Findings of this investigation revealed that healthy elderly subjects demonstrate priming of a facilitative nature, at both automatic and controlled temporal processing boundaries, whereas AD subjects demonstrated priming due to inhibition at long controlled temporal processing boundaries. Implications of these findings relative to normal age-related changes in language function and progressive lexical semantic impairment in AD are addressed.

Comments

Digital reproduction from the UMI microform.

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