Potentially one of the more heuristically useful perspectives to emerge from the nascent functional connectivity literature relates this antagonistic TPN and DMN dynamic to consequences during goal-directed behavior (e.g., Fig 3AB). Specifically, intermittent failures to adequately suppress DMN activity during goal-directed behavior have been identified as one source of interference limiting optimal performance (Songua-Barke et al., 2007). Task-induced DMN suppression is parametrically altered as a function of cognitive load (Fransson 2006, McKiernan et al., 2003), suggesting reallocation of processing resources as dictated by task demands along a continuum rather than an “all-or-none” phenomenon. Fluctuations along this continuum manifest during monotonous task performance, where decreases in DMN suppression and concomitant reductions in regional TPN activity increase the probability of error commission (Fig 3C; Eichele et al., 2008) and protracted response times (Weissman et al., 2006). Maladaptive interactions between DMN and TPN regions partly underlie suboptimal performance (Prado and Weissman, 2011), such that decreased negative coupling between these networks predicts increased variability in trial-to-trial response times across individuals (Kelly et al., 2008). As such, altered network dynamics and/or a compromised ability to
