Chunk #22 — Mature Network Architecture Develops Via Segregation and Integration — Network Relationships Defined Using Region Matrix and Community Detection Methods
The community structure of default mode and control regions develops from a local, anatomical organization into a distributed, functional organization. Fair et al. (2009) used community detection algorithms on matrices derived from default and task control regions, and found that communities were organized largely into lobar communities (e.g., frontal or parietal, see gray and light blue nodes in Fig. 3a) in children, whereas familiar functional systems were recovered in adult modules (e.g., the red default regions of Fig. 3b). This change occurred through segregation of the anatomically adjacent regions and integration of these regions in the distributed adult networks (Fig. 3). For example, while the left angular gyrus and lateral inferior parietal sulcus regions are located in the same module in children, they are separated into the default and fronto-parietal modules in adults (Fig. 3) (Fair et al. 2009). Likewise, the left lateral inferior parietal sulcus and dorsolateral prefrontal cortex regions are in separate modules in children (parietal and frontal, respectively), but integrate into the fronto-parietal module in adults (Fig. 3) (Fair et al. 2007, 2009).
