Changes in mean Hurst exponent (H) between pretreatment cancer groups. A: H maps for control (CNTRL), pre‐radiotherapy (PRE‐RADIO), and pre‐chemotherapy (PRE‐CHEMO) groups. Maps are averaged across four runs for each subject, and then averaged across all subjects. B: Bootstrap significance plot, indicating areas of significant change in mean H, for False‐Discovery Rate FDR = 0.05 threshold and minimum cluster‐size threshold of three voxels. Arrows point toward highly sparse regions of significant change for: PRE‐CHEMO > PRE‐RADIO and PRE‐RADIO > CNTRL. C: Boxplots showing distribution of subjects' average gray matter H values. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]