you have the right idea, but it is
cespct = 100*contrast/baseline
The baseline is the mean offset of the fMRI, the contrast is the deviation from baseline
On 2/1/17 4:49 AM, Seung-Goo KIM wrote:
Dear all,
I wish to know how “cespct.nii.gz” is computed in selxavg3-sess. I thought it computes something like a relative change like:
cespct = (contrast-baseline)/baseline*100,
but I cannot figure out what was taken for the baseline. I thought it could be mean beta for constant terms (0-th polynomial) for each run, but my calculation was different from cespct.
I would take average intensity for each voxel I would greatly appreciate a detailed explanation how the program computes it.
Best regards,
Seung-Goo KIM
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer