Figure 2. .

TBI-induced alterations to brain dynamics within individual modules revealed by resting-state fMRI. For each of the M = 20 modules in the hierarchical atlas, we extracted the time series of the first principal component and calculated four different descriptors: the variance, skewness, kurtosis, and number of points after the point process analysis (PPA; Materials and Methods). (a) Only Module 11 showed differences between the TBI and control groups with respect to the variance of the time series of the first principal component. The dashed lines represent the mean value of the time series, and the solid lines represent the threshold used for the PPA, here equal to the mean + 1 SD. (b) For Module 11, the variance of the first component (plotted here as its square root—i.e., the standard deviation) differed between TBI and control subjects. In particular, the fact that the variance was higher in TBI (red) than in controls (blue) showed compensation rather than a deficit. The color of Module 11 (magenta) is just indicative and coincides with the color used in Diez, Bonifazi, et al. (2015), where we first published the hierarchical brain atlas.