Hi,
I did a SPM VBM (using dartel) analysis as well as a freesurfer group analysis. After correcting for multiple comparisons. Both maps give me pretty different results. From the literature review both sets of results make sense but the fact that the results don't agree is troubling me. I have checked everything multiple times and still get the same results.
Is it common that the two methods give different results?
I also wanted to know the interpretation of the surface measures that freesurfer reports, especially the curv and sulc measures. What does it mean exactly when two groups have different sulc or curv measures? In my results I get a negative correlation between curv measure and volume measure in the same region. So in that region for curv measure group1 > group 2 while in the same region for the volume measure group1 < group2. How exactly is the curv measure related to volume and area measures? Is there a standard reference where all the details for these measures are mentioned?
Thank you.