Mapping the self in the brain's default mode network
Christopher G. Davey, Jesús Pujol, Ben J. Harrison
NeuroImage February 15, 2016 DOI: 10.1016/j.neuroimage.2016.02.022
Summary
Our sense of self is dynamically orchestrated by specific brain regions. In a study of 88 participants, neuroscience revealed that the posterior cingulate cortex (PCC) drives self-related processes, while the prefrontal cortex (MPFC) provides crucial moderation. This work, rooted in cognitive psychology and functional brain connectivity studies, clarified the default mode network's (DMN) role in the self-reference effect. Examining neural dynamics during resting state fMRI, alongside the inferior parietal lobule, illuminated how these cortical areas exhibit specialized functional connectivity. This advances mental health research topics by detailing the intricate brain function underlying our identity.
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.