Dear LME developer and expert,
I am using LME recently, based on longitudinal brain structural data, but I have two confusions in using it.
1) I followed the tutorial at: https://surfer.nmr.mgh.harvard.edu/fswiki/LinearMixedEffectsModels However, I don't actually understand the Contrast matrix design in this tool. In the example the contrast C matrix is a 3*14, is there any explain about this matrix design? For my study, I want to explore 3 treatment (2 therapy methods and 1 waitlist) effects on the brain structural, If I want to explore the main effect of treatment, how could I write the Contrast matrix, and whether I can explore each treatment effect on the brain structural? And how can explore the time*treatment effect contrast matrix?
2) For the mass-univariate analysis, the example C matrix is 3*17, and it will explore the group differences in the rate of change over time among the four groups, and if I get the four group difference maps, How can I know the difference between each two groups? If I need to do the another qdec file and do the following steps as mris_preproc and mri_surf2surf? Thank you very much! Best,
Gallen