How to calculate the global correlation between two contrasts

Submitted by yaosir on

Dear Chao-Gan,

Recently I have done a study which includes two datasets (30 patients and 30 controls, and 20 patients and 21 controls, respectively), and the second is the subset of the first. The reviewer required me to report the globle correlation between these two contrasts. However, I have never done such analysis before. Can I use dpabi or any other software to achieve it?

Best,

Vincent 

Dear Chao-Gan,

Thank you for your reply. It is really helpful, but I am not sure whether the "global correlation" that the reviewer mentioned is the spatial correlation of two images either. Actually, the reviewer had explained it: "the global correlation, i.e., the one that once applied minimizes the square error between t[(contrast1 + contrast2) / 2] and (t[contrast1] + t[contrast2]) / 2". Is it the same as the spatial correlation?

Best,

Vincent