Hello, I was wondering if I could get some clarification regarding the longitudinal measure of rate of change in sulci depth. In our study we have a patient population that participated in an intervention and a similar group of wait list controls. We have scans for pre and post intervention timepoints. I have ran the longitudinal analysis in QDEC looking at the thickness change measures, however I was also interested in the sulc measures. I was able to get the analysis to run with the new measures long.sulc-rate etc. However I am having a hard time conceptualizing the meaning of the results. Does a negative rate change indicate either a deepening or a shallowing of the sulci? Is the opposite the case for gyral regions? Any advice would be greatly appreciated. -Andrew