Hang Joon Jo1, Richard C. Reynolds1, Stephen J. Gotts2, Alex Martin2, Robert W. Cox1, Ziad S. Saad1
1Scientific and Statistical Computing Core, National Institutes of Mental Health, Bethesda, MD, United States; 2Section on Cognitive Neuropsychology, Laboratory of Brain and Cognition, National Institutes of Mental Health, Bethesda, MD, United States
Brain function in the resting state has been extensively studied with MRI since its discovery of correlated temporal signals in distant parts of the cortex. Recent studies have reported major corrupting effects of subject head motion on the results of resting state FMRI analyses. The first study suggested that motion effects induce bias between short- and long-range correlations, casting suspicion on inferences about brain networks (Power et al., 2012). The second study showed how differences in average subject movement between two subjects groups could produce significant differences in apparent brain connectivity (Van Dijk et al., 2012). Herein, we replicate these results, and qualify as follows the conclusions that ascribed them solely to the presence of motion difference between groups.