Hi Gang,

I will try to explain my question more precisely.

1. I measured/calculated the Power-Law Exponent and the Mean Frequency of fMRI runs.
2. Then, I calculated their correlation via 3dTcorrelate. As you know and already stated, the output of 3dTcorrelate is the correlation for every voxel in the brain, i.e., on a voxel-wise level.
3. I used different ROIs to calculate the average correlation of the two variables above (per ROI). What I consequently get is one correlation value per ROI.

Now I would like to check if the correlation value between two ROIs (e.g. ROI1: r=0.74334; ROI2: r=0,79322323) significantly differs or not. I think that this basically sums up my question. I was wondering if there is an appropriate way to calculate this in AFNI, or if that approach might already be ill-posed statistically speaking, leaving AFNI aside.

Philipp