Differences in the distribution of reaction times of single and double decisions and their relations to working memory

Abstract

Aging is an important factor for decreased performance on single reaction time tasks. However, single decisions in reaction time tasks might not contain the most predictive power of everyday cognitive functioning in people. This thesis aims to achieve a description of behavior, like chained decisions, that better resembles everyday functioning. With this purpose in mind, we investigated the differences in the distribution of reaction time of single and double decisions and their relation to WM. This was done by using a clinical task that measured the span of WM and by using reaction time tasks that consisted of color and contrast judgment tasks. Three levels were used in the reaction time tasks, single decisions, double independent decisions, and double dependent decisions. These tasks were used to get the drift rate, boundary separation, and non-decision time of reaction times of the EZ-diffusion model. There was an effect on all three parameters on single decision tasks compared to the double decision tasks. However, no effect was found between the double independent decisions and the double dependent decisions. Also, the link between the cost of making a double decision and the span of WM was nonsignificant although in the expected direction. Follow-up research is recommended to test these effects with a higher statistical power.