The design matrix file designated which participants were seropositive for CMV and which were negative in order of the 4D file. The contrast file delineated which contrasts were to be run, in this case, we conducted four separate contrasts: one where cortical thickness is greater for CMV seropositivity, one for greater cortical thickness in the CMV seronegative group, and then one contrast each for the mean cortical thickness of each group. Each image was then viewed using fslview on a local Macintosh computer using the population template with overlays for each contrasts indicated previously. The statistical overlays were thresholded so that p<0.05, corrected for familywise error. The code used to create these images was: