Mapping the self in the brain's default mode network

Abstract

The brain's default mode network (DMN) has become closely associated with self-referential mental activity, particularly in the resting-state. While the DMN is important for such processes, it has functions other than self-reference, and self-referential processes are supported by regions outside of the DMN. In our study of 88 participants, we examined self-referential and resting-state processes to clarify the extent to which DMN activity was common and distinct between the conditions. Within areas commonly activated by self-reference and rest we sought to identify those that showed additional functional specialization for self-referential processes: these being not only activated by self-reference and rest but also showing increased activity in self-reference versus rest. We examined the neural network properties of the identified 'core-self' DMN regions-in medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), and inferior parietal lobule-using dynamic causal modeling. The optimal model identified was one in which self-related processes were driven via PCC activity and moderated by the regulatory influences of MPFC. We thus confirm the significance of these regions for self-related processes and extend our understanding of their functionally specialized roles.

A longitudinal study of the effect of short-term meditation training on functional network organization of the aging brain

“…Our findings are also in line with several studies which have found reduced connectivity within certain regions of the DMN in meditation experts compared to novices 19–21 . Given the DMN’s established role in self-referential thinking 22 , these findings are thought to reflect a movement towards an increasingly self-detached viewpoint associated with meditation 13, 23 . The DMN also plays a role in determining the affective relevance of a specific stimulus.…”

Episodic memory and executive functions in cognitively healthy individuals display distinct neuroanatomical correlates which are differentially modulated by aging

“…Moreover, when examining the cerebral GMv correlates of EM in younger individuals of our sample, this set of regions included the bilateral angular gyrus, which is also a prominent structure within the DMN. The DMN mediates internal cognitive processes such as self‐referenced thoughts (Davey, Pujol, & Harrison, 2016) and introspective accuracy (Fleming, Weil, Nagy, Dolan, & Rees, 2010). Importantly, it has been shown that deactivation during encoding in the DMN regions, including posterior middle temporal cortices, predicted successful retrieval for the studied items (Chai, Ofen, Gabrieli, & Whitfield‐Gabrieli, 2014; Daselaar, Prince, & Cabeza, 2004; Kim, Daselaar, & Cabeza, 2010), that is, the ability to suppress their response during active memory tasks constitutes a prerequisite for efficient recall.…”

Neural activations are related to body-shape, anxiety, and outcomes in adolescent anorexia nervosa

“…During neurotypical development, the connectivity between these two regions increases for social and emotional stimuli (Kelly et al, 2009). Recently, two different studies using dynamic causal modeling identified a relationship between left parietal regions and medial prefrontal cortex important for self-specific processing in healthy adults (Davey et al, 2016; Sui et al, 2013); disruption of this neurocircuitry may be important in the pathology of AN. In a systematic review, Jewell (Jewell et al, 2016) reported that a consistent relationship between eating pathology and mentalization difficulties has been observed in adolescents with eating disorders; here we propose neural regions that may mediate these problems.…”