Resting-State fMRI Signal Anti-Correlation Exists in Absence of Global Signal Regression

Xiao Liu¹, Jeff H. Duyn¹

To understand the negative correlation between resting-state fMRI signals and how it could be affected by global signal regression (GSR) procedure, a novel technique was applied to temporally decompose the default mode network (DMN) into multiple co-activation patterns (CAPs). This decomposition of activity patterns during rest suggests that anti-correlation between brain regions is not an artifact of global signal regression but may be caused by brief periods of negatively correlated neuronal activity.