Articulatory rehearsal in Alzheimer type dementia.

This study investigated the relationship between articulation rate and memory span in a sample of 21 patients with early Alzheimer type dementia (AD), comparing their performance with 21 matched controls. Memory span was measured using auditorily and visually presented digits. The AD patients were moderately impaired in both conditions. Articulation rate was measured either by requiring subjects to read lists of random digits or repeatedly count from 1 to 10. The AD patients were able to read the digits as fast as the controls but were slower in the counting task. The measures of memory span and articulation rate correlated significantly for the controls but not for the AD patients, indicating that the normal association between articulation and memory span is disrupted. These results are discussed in relation to previous results and suggest that articulatory rehearsal processes in primary memory are unimpaired at the early stages of AD.