Implicit memory and aging: A cognitive neuropsychological perspective

Abstract

Although it is well‐established that there are age deficits on measures of explicit memory, there is conflicting evidence as to whether implicit memory, as measured by performance on various repetition priming tasks, is impaired by age. In order to clarify the relation between aging and implicit memory, priming tasks were organized in the following categories: (a) perceptual‐item priming, (b) perceptual‐associative priming, (c) conceptual‐item priming, (d) conceptual‐associative priming, and (e) perceptual‐motor priming. The taxonomy took into account the type of mental representation that different priming tasks depend on, the neurological structures responsible for these representations, the extent to which priming tasks demand the formation of novel associations, and the various blends of data‐driven and conceptually driven processes that facilitate task performance. A literature review based on this taxonomy revealed two tentative conclusions. First, the processes associated with normal aging are likely to impair performance on tasks of conceptual‐item priming and conceptual‐associative priming, but do not have a negative affect on tasks of perceptual‐item priming, perceptual‐associative priming, and perceptual‐motor priming. Second, this pattern of selective preservation and impairment is also displayed by patients with Alzheimer's disease but not amnesia or Huntington's disease. These findings were interpreted from the perspective of a model of human memory that builds on recent advances within the domain of cognitive neuropsychology.