The structural and functional brain networks that support human social networks

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Social Neuroscience

Background:

• Social skills are underpinned by complex cognitive processes.
• Individual variations in social network size (SNS) may correlate with differences in brain structure and function.
• Understanding the neural basis of social network size is crucial for comprehending social behavior.

Purpose of the Study:

• To investigate the relationship between an individual's social network size and their brain's structural and functional networks.
• To identify specific white matter (WM) tracts and gray matter (GM) regions associated with SNS.
• To explore the functional connectivity patterns related to SNS.

Main Methods:

• Multimodality neuroimaging, including diffusion MRI (dMRI) and voxel-based morphometry.
• Analysis of white matter tract integrity (e.g., cingulum bundle, extreme capsule, arcuate fasciculus).
• Assessment of gray matter volume in limbic and temporal regions and resting-state functional connectivity (rsFC) in prefrontal cortex and default mode network (DMN).

Main Results:

• dMRI revealed associations between WM tract integrity and SNS.
• Voxel-based morphometry showed correlations between GM volume in limbic and temporal regions and SNS.
• Altered rsFC between prefrontal cortex and DMN was observed as a function of SNS, with significant overlap between social GM clusters and the DMN.

Conclusions:

• Specific brain structural and functional networks are associated with individual differences in social network size.
• Integrative neuroimaging analyses provide convergent evidence for neural circuits supporting social network size.
• These findings highlight the neural underpinnings of social behavior and adaptation in social environments.