Cross-form priming in normal aging and in mild dementia of the Alzheimer type

Twenty patients at early stages of Alzheimer's disease (AD), 20 elderly control subjects and 20 young subjects completed a cross-form priming task, followed by a free recall task. Results show that patients with mild AD display priming effects, and that these priming effects are strictly comparable to those obtained by elderly and young control subjects. Moreover, while the patients' performances are normal in the implicit part of the task, they are massively impaired in the explicit free recall task. These results don't support the hypothesis of a dissociation of performances between identification tasks and generation tasks in Alzheimer's disease, and show that conceptual priming can be observed at early stages of the disease, despite semantic memory impairments.