Effect of presentation rate on word list learning in patients with dementia of the Alzheimer type

The efficacy of simple interventions for the improvement of memory performance in patients with dementia of Alzheimer type (DAT) has rarely been evaluated. Therefore, we examined the effects of presentation duration and task practice on word list learning in this sample: 19 patients with DAT and 21 control subjects (with remitted major depression) repeatedly performed modifications of a word list learning task using five different presentation durations (i.e. 1, 2, 5, 10 or 20 s/word). In agreement with previous observations, prolonged visual presentation of words significantly improved recall and recognition in demented subjects, whereas task practice did not improve memory performance. The performance in the demented sample after long presentation times (20 s/item) does not reach the level of performance of the comparison group after short presentation limes (1 s/item). Consequently, it seems unlikely that memory dysfunction is caused by increased item processing times in patients with dementia. To reach comparable performance of demented and controls for intervention or activation studies, presentation times must be shortened below 1 s/item in the control sample.