Patients with Alzheimer's disease (AD) and healthy control participants per
formed 2 conceptual repetition priming tasks, word-associate production and
category-exemplar production. Both tasks had identical study-phases of rea
ding target words aloud, had the most common responses as target items, and
required production of a single response. Patients with AD showed normal p
riming on word-associate production but impaired priming on category-exempl
ar production. This dissociation in AD suggests that conceptual priming is
not a unitary form of memory but rather is mediated by separable memory sys
tems.