Effect of manipulation and irrelevant noise on working memory capacity of patients with Alzheimer's dementia.

The effect of manipulation and distracting noise on immediate serial recall was measured in patients with dementia of the Alzheimer type (DAT), neurologically healthy elderly individuals, and young adults. In Experiment 1, the authors compared serial word recall with word recall in alphabetical order. Alphabetical recall requires the active manipulation of the contents of working memory. Findings indicated that DAT patients were severely impaired in the alphabetical recall task, whereas the performance of neurologically healthy elderly participants was comparable with the performance of young adult participants. In Experiment 2, the authors investigated the effect of different irrelevant auditory backgrounds on immediate digit recall. In this task, both elderly participants and DAT patients performed similarly to the group of young adult participants, indicating comparable efficacy to resist auditory distraction.