A broad theme that emerges from these studies of functional networks is that at young ages, ROIs tend to have strong rs-fcMRI signal correlations with nearby ROIs, and that over childhood and adolescence, selected local correlations tend to weaken, while correlations with more distant ROIs tend to increase. This trend is evident in the increased seed map bilaterality with gestational age seen in the infants of Smyser et al. (Smyser et al., 2010), in the increased extents of sensorimotor correlation maps of Lin et al. in young children (Lin et al., 2008), and in the increases of edge strengths within the graphs of Supekar et al. (Supekar et al., 2009) and Fair et al. (Fair et al., 2009) over late childhood and adolescence. In the anterior cingulate, Kelly et al. (Kelly et al., 2009) specifically note that this trend is least pronounced in seeds near SMA, and occurs latest and most markedly in ventral seeds typically associated with the DMN. This trend likely stems from several sources. Synaptic pruning takes place throughout the first twenty years of life (Huttenlocher, 1979),
