Individual Publication

Here we show that cortical gray matter volume and thickness estimates based on MRI (FreeSurfer 5.3, VBM8 SPM, and FSL Siena 5.0.7) are biased by head motion with an average apparent volume loss of roughly 0.7%/mm/min of subject motion. Effects vary across regions and remain significant after excluding scans that fail a rigorous quality check. In view of these results, the interpretation of reported morphometric effects of movement disorders or other conditions with increased motion tendency may need to be revisited: effects may be overestimated when not controlling for head motion. Furthermore, drug studies with hypnotic, sedative, tranquilizing, or neuromuscular-blocking substances may contain spurious effects of reduced atrophy or brain growth simply because they affect motion distinct from true effects of the disease or therapeutic process. hide