Modelling cognitive control in task switching and ageing

In an attempt to better understand the reasons for old-age effects on task switching performance, we fitted a quantitative model (Meiran, 2000a) to re sults from an experiment comparing young and elderly participants. Modellin g results indicate that the most pronounced effect of old age was in what c an be broadly defined as the duration of the response selection. In additio n, compared to young participants, the elderly tended to rely on learning f rom the preceding trial, which improved their performance in single-task co nditions but impaired it when the tasks switched frequently. Relatively mod est effects of old age were found in the ability to selectively attend to t he task relevant stimulus dimension and on the duration of processing stage s preceding or following response selection.