Dear Avi,

Sorry for the late reply.

I agree with Anton in suggesting a specific cortical gray matter mask, please contact us by email as this is still not published.

We have not a specific correlation template for the gyrification index... You could use the VBM gray-matter template as an approximation (i.e., assuming that the correlation in gyrification index between two given adjacent voxels is similar to the correlation in gray matter volume between these two voxels). Alternatively, you could set the anisotropy to 0, i.e., assuming that the correlation in gyrification index between any pair of adjacent voxels is the same in all the mask.

Regarding the ROI study, I understand that even if it uses ROIs, it covers all the cortex. However, I would at least report the results of an analysis without this study.

With the best wishes,

Joaquim