Paper Info
Title
The Effects of Global Signal Regression on Estimates of Resting-State Blood Oxygen-Level-Dependent Functional Magnetic Resonance Imaging and Electroencephalogram Vigilance Correlations
Abstract
Global signal regression (GSR) is a commonly used although controversial preprocessing approach in the analysis of resting-state blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) data. Although the effects of GSR on resting-state functional connectivity measures have received much attention, there has been relatively little attention devoted to its effects on studies looking at the relationship between resting-state BOLD measures and independent measures of brain activity. In this study, we used simultaneously acquired electroencephalogram (EEG)-fMRI data in humans to examine the effects of GSR on the correlation between resting-state BOLD fluctuations and EEG vigilance measures. We show that GSR leads to a positive shift in the correlation between the BOLD and vigilance measures. This shift leads to a reduction in the spatial extent of negative correlations in widespread brain areas, including the visual cortex, but leads to the appearance of positive correlations in other areas, such as the cingulate gyrus. The results obtained using GSR are consistent with those of a temporal censoring process in which the correlation is computed using a temporal subset of the data. Since the data from these retained time points are unaffected by the censoring process, this finding suggests that the positive correlations in cingulate gyrus are not simply an artifact of GSR.
Year
DOI
Venue
2018
10.1089/brain.2018.0645
BRAIN CONNECTIVITY
Keywords
Field
DocType
global signal regression,resting-state fMRI,simultaneous EEG-fMRI,vigilance
Neuroscience,Functional magnetic resonance imaging,Regression,Blood-oxygen-level dependent,Resting state fMRI,Vigilance (psychology),Oxygenation,Medicine,Nuclear magnetic resonance
Journal
Volume
Issue
ISSN
8
10
2158-0014
Citations 
PageRank 
References 
0
0.34
0
Authors
3
Name
Order
Citations
PageRank
maryam falahpour1442.22
Alican Nalci2483.23
Thomas T Liu3102276.03