By aligning images from multiple subjects to a common reference brain or coordinate system, statistical maps can be made to show the evidence for group differences in gray matter at each location in the co-registered images. Additional detailed maps can show brain regions where significant changes occur over time, revealing at each location in the brain whether the individual differences are associated with specific genes, medications, symptoms, or clinical outcomes (Cannon et al., 2006; P. M. Thompson et al., 2008).
