Future research is needed to better examine how other span measures can be accounted for by multiple factors and whether these multiple factors account for the relations among the span measures themselves and with higher-order cognition. Based on the multifaceted view of WM, the current results suggest that, at least, three separate factors drive performance in working memory tasks and give rise to individual

differences in working memory. Naturally one question is whether these Pifithrin-�� nmr results suggest that complex span tasks simply have poor construct validity. That is, are complex span tasks bad measures because they reflect multiple factors? We believe the answer is No. Rather than suggesting that complex span measures are poor indicators of WM, the current results suggest that the overall WM system is multifaceted and made up of several important processes. Thus, complex span measures are actually

valid indicators because they pick up variance from each of these important processes. That is, no task is a process pure measure of the construct of interest; rather performance on any measure reflects the joint interaction of several learn more processes. As such WM measures reflect the joint interaction of several processes that are needed for accurate performance. Thus, these results demonstrate that complex span measures reflect these separate factors which accounts for variability

across individuals. This finding is not necessarily unique to the complex span measures. For example, consider the change detection measures used in the current study. These measures likely reflect individual variation in the number of things that can be distinctly maintained (i.e., capacity; Cowan et al., 2005) as well as individual differences in the ability to control attention and filter out irrelevant information and prevent attentional capture (Fukuda and Vogel, 2009, Fukuda and Vogel, 2011 and Vogel et al., 2005). The fact that the capacity and attention control clonidine factors were so highly correlated is evidence that these two factors are strongly linked and provides evidence that change detection measures likely reflect both. Furthermore, recent research has suggested that these change detection measures also partially measure individual differences in secondary memory (Shipstead & Engle, 2013). Thus, like complex span measures, this suggests that change detection tasks measure variation in all three factors, but differ in the extent to which any factor drives performance (with secondary memory playing less of a role than capacity and attention control).