Figure 8. Global signals after denoising continue to reflect unwanted influences.

The standard deviation of the global signal is correlated, across subjects, with motion, heart rate variability, and respiratory variability. The thin red line fits all the data, the thicker dark line fits only subjects with mean FD < 0.2 mm. The top row reflect undenoised data, the bottom row reflects data after the denoising procedure shown in the 4th row of Figure 7.