Global Signal and Its Impact on Dynamic Functional Connectivity

COEX 

Global signal regression (GSR) is often considered as a preprocessing step for resting-state fMRI data. The many different analysis pipelines for dynamic functional connectivity (dFC) treat the global signal implicitly through centering, normalization, clustering, and other operations. Therefore, in some cases, the global signal can be separated by the analysis method without the need for GSR as a preprocessing step. In addition, dFC allows to extract properties of the spatiotemporal organization of the global signal that can provide insights into its role and function.