Modulation of the brain's core-self network by self-appraisal processes

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• The default mode network (DMN) is crucial for self-referential processing.
• Core DMN regions include the medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), and inferior parietal lobules (IPL).
• Understanding dynamic interactions within the DMN during self-appraisal is key.

Purpose of the Study:

• To investigate dynamic interactions among core DMN regions during direct and reflected self-appraisal.
• To elucidate how these interactions differ between two forms of self-referential cognition.
• To explore the causal mechanisms underlying self-processing within the DMN.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan 111 participants.
• General linear models identified neural responses to direct and reflected self-appraisal.
• Dynamic causal modelling (DCM) analyzed causal interactions among core DMN regions.

Main Results:

• Reflected self-appraisal showed greater activation in posterior DMN regions (PCC, IPL) compared to direct self-appraisal.
• A distinct inhibitory influence of the left IPL on the PCC was observed during reflected self-appraisal.
• These findings suggest differential network dynamics for distinct self-referential tasks.

Conclusions:

• Core DMN regions interact uniquely to support distinct self-referential processes.
• Reflected self-appraisal involves higher-order processing supported by the left IPL and posterior DMN.
• Characterizing DMN interactions advances understanding of self-orchestration in the brain.