Dear Sir/Madam,

Could you please tell me what measure of correlation the 'h' column in the ROI.mat file contains exactly (second-level ROI-to-ROi analyses, GLM correlation option)?

Also, does anyone have any advice on the following:
I have 4 conditions: 1) A_0, 2) A_200, 3) B_0, 4) B_200 and I want to create a contrast of two contrasts: (A > B) > (200 > 0). I have run the contrasts A > B and 200 > 0 in conn. However, it seems not possible to create a contrast of these two contrasts within conn. Therefore, I plan to subtract the values saved in the ROI.mat file for each of the two conducted contrasts to achieve this. I see two options there: 1) directly subtracting t-values (F column) or 2) subtracting correlation coefficients (? h column) and run the resulting values through an external NBS.

Do you see any problems with simply subtracting the t-values (the less labour intensive option)? Logically, would you expect any difference in result between the two options?  

Thanks very much for your help.
Best wishes,
Joyce Vromen