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We are using a paired analysis approach to study cortical thickness in a dataset with 2 timepoints (called pre-protocol and post-protocol). Regarding the mean cluster summary (contrast: [1 0]), we understand positive values to mean pre > post (thinning) and negative values to mean post > pre (thickening). The covariate results are more difficult to interpret. For instance, we’re interested in looking at the effects of age (contrast: [0 1]) on the cortical thickness results. In the age cluster summary, is it fair to interpret positive results as positive correlation (older subjects show more thickening) and negative results as inverse correlation (older subjects show more thinning) or is the interpretation more complex than this? We’re getting mainly negative cluster results for age so this interpretation may make sense, but we’d like more clarity. Thank you for your help.