Word-stem completion priming in healthy aging and Alzheimer's disease: Theeffects of age, cognitive status, and encoding

There are many conflicting results concerning the effects of age and Alzhei mer's disease (AD) on word-stem completion priming. To examine potential so urces of this variability, the authors examined the influences on such prim ing of age, cognitive status, and encoding in a large sample of young, old, and AD individuals. At study, words were processed aloud by reading, readi ng and rating likeability, or generating from definition. Old participants had less priming than young participants and more priming than AD patients. For the healthy old participants, priming decreased with advancing age and with cognitive loss following generation only. For AD patients, priming de creased as dementia severity increased; patients with the mildest dementia did not differ from healthy old participants. Thus, age, cognitive status, and encoding differentially influenced the magnitude of priming in healthy aging and AD.