Mental attention capacity (M-capacity) refers to an individuals limited cognitive capacity to hold and manipulate a set of task-relevant information, a function related to working memory. This study analyzes the within- and cross-network resting-state functional connectivity (RSFC) of the default mode network (DMN), the dorsal attention network (DAN), and the frontoparietal control network (FPC) in order to determine if they are related to high versus low performance on varying difficulty levels of mental attention tasks. I hypothesized that, relative to the Low Performance Group, the High Performance Group would have stronger RSFC within-networks, higher anticorrelation or RSFC between the DMN and DAN, and weaker RSFC between the FPC and the DMN. There were no significant differences between the groups to support the hypotheses, however marginally significant trends do support the hypothesis that the High Performance Group has weaker RSFC between the FPC and DAN than the Low Performance Group.