Visuo-perceptive priming in Alzheimer's disease: evidence for a multi-componential implicit memory system.

In the past two decades research has highlighted how implicit memory processes are spared in degenerative disorders, such as Alzheimer's disease (AD), which are characterized by the early onset of explicit memory deficits. However, according to recent studies, there may be dissociations among different types of implicit memory. Although several studies have shown selective sparing of lexical priming in AD, it is not completely clear what happens to other types of implicit memory processes, such as visuo-perceptual priming. The present study examines the possibility that the visuo-perceptual priming effect is spared in AD. We tested two groups of participants, i.e., a group of AD patients and a group of healthy age-matched controls, using a visuo-perceptual priming task. The task required the identification of fragmented pictures. Results showed a deficient priming effect in AD patients when it was measured by an Identification of Fragmented Pictures task. We discuss our results in light of the current hypothesis of a functional segregation in priming processes.