When one is at rest and not engaged in a task and absorbed in a ruminating self-narrative about the past and future then it is during these reflective moments that the default mode network (DMN) is activated and the attention network is anti-correlated or reciprocally deactivated (Raichle et al., 2001; Raichle, 2010). The insula appears to function as a switch that is correlated with phase shifting of the attention and default networks activation vs. suppression (Bressler and Menon, 2010). Petersen and Posner (2012) review the functional MRI (fMRI) studies of the attention network and the DMN in attention deficit disorders that are characterized by the intrusion of the self-narrative in academic situations resulting in poor grades. The reciprocal relationship between the DMN related to an ongoing internal self-narrative and the attention network focused on the external world is an important dynamic, however, fMRI has a limited temporal resolution and is unable to resolve millisecond periods of phase lock and phase shift of neurons located in network nodes and functional connections that comprise the DMN.
