The SN has been proposed to influence moment-to-moment information processing by identifying the most subjectively relevant stimuli (Seeley et al., 2007), whether arising from internal or external loci, and “toggling” activity between the DMN and ECN accordingly (Uddin et al., 2011; Hamilton et al., 2011; Sridharan et al., 2008). In cognitive task paradigms, insula and dorsal ACC activity routinely co-occur (Lawrence et al., 2003; Medford and Critchley, 2010), likely in the service of monitoring ongoing goal-directed behavior for salient stimuli (e.g., errors, response conflict) which precipitate a cascade of neural events resulting in attentional and behavioral adjustments to optimize behavior (Botvinick et al., 1999; Kerns et al., 2004; Egner and Hirsch, 2005). By assessing the temporal dynamics and directional interactions between specific nodes of the SN, DMN and ECN, Sridharan and colleagues (2008) identified the insula as a causal outflow hub mediating dynamic switching between DMN and ECN activity as dictated by task-events and also occurring intrinsically “at rest” 3. They further postulated that such network switching is facilitated by a set of specialized spindle neurons (Allman et al., 2011),
