Conceptual and perceptual contributions to the acquisition and retention of text-specific reading skill in Alzheimer's disease.

In the first experiment, patients with Alzheimer's disease (AD) and normal control (NC) participants read each of two passages three times and then again after either a 1-min or 10-min delay interval. Reading time decreased with practice for both groups, and this facilitation was text-specific. Although both groups retained the facilitation in reading speed after 1 min, it was reduced only in the AD group after 10 min. In the second experiment, the same task was repeated with new passages that encouraged the use of either conceptual or perceptual processing during reading. Patients with AD acquired the facilitation in reading speed normally in both conditions, but were impaired in retaining it over a 10-min delay interval only in the conceptually-weighted condition