Running head: WM TRAINING IN OLDER ADULTS

Recent studies suggest that executive control and working memory training can benefit older adults, however, findings regarding the amounts of training and transfer effects are mixed. The current study aimed to investigate the effects of a process-based training intervention in a diverse sample of older adults and explore possible moderators of the amount of training and transfer effects. For that purpose, 80 older adults (65-95 years) were enrolled in the study, half of them were trained for three weeks on visuospatial, verbal, as well as executive working memory tasks; the other half did not receive training. Performance on trained and transfer tasks was assessed before and after training, as well as at a nine-month follow-up. Analyses revealed significant training effects in all three tasks, as well as near transfer to a verbal working memory and far transfer to a fluid intelligence task. Remarkably, all training effects and the transfer effect to verbal working memory were stable at the nine-month follow-up. Further analyses revealed that training gains were predicted by baseline performance in training tasks and (to a lesser degree) by age. Transfer gains on the other hand, were predicted by age and by the amount of improvement in the trained tasks. These findings suggest that cognitive plasticity is preserved over a large range of old age and that even a rather short training regimen can lead to (partly specific) training and transfer effects. However, there are a range of factors that may moderate the amount of plasticity.