Thomas Liu1, Hongjian He2
1UCSD Center for Functional MRI, La Jolla, CA, United States; 2Bio-X Laboratory, Zhejiang University, Hangzhou, China
In resting-state functional connectivity MRI (fcMRI), the presence of global signal confounds lead to variability in connectivity maps. A number of global signal correction methods have been proposed, but have their limitations. Here we demonstrate that a portion of the global signal can be viewed as an additive confound that increases with the mean BOLD amplitude. An approach for minimizing the contribution of this additive confound is presented, and an initial comparison with existing global signal correction methods is provided.
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