Functional inhomogeneity of the anatomy-based parcellation and its effects on functional connectivity.

<p>(A) Four subregions within a precentral gyrus showed different fMRI time activities. (B) Mean time series of the precentral gyrus and calcarine sulcus have low correlation (Z=0.3), but there exist several significant correlations among subregions of them. (C) Mean time series of the precentral gyrus and visual cortex had high correlation (Z=3.49), but in reality there exist only low correlations among smaller subregions when each anatomically defined brain region were broken into smaller subregions by modularity optimization.