Hi-

Thanks, I thiiiink I see the issue, and I noticed this looking at the top text rows of your cluster report. And thanks for including the 3dClusterize commands.

The F-stat here should be equal to t-squared---fine. There will be a bit of rounding difference, which might affect some thresholding, but that should be minimal. In each case, AFNI should be able to translate a given p-value to an equivalent stat---more fine.

But squaring t also loses valuable sign information, which is actually used in the clustering. Note that, as is likely correct, you are using 'bi-sided' clustering for the t-stat data: that is, adjacent positive and negative voxels do *not* cluster with each other. However, your F-stat clustering cannot use that sign information, because it is positive definite (F>=0, always)---also note that the F-stat clustering should not be "bi-sided", but instead be "1-sided". That should account for some of the difference here, as well, I think. Therefore, there will have to be the possibility of some inherent differences between 1-sided F-stat clustering and bi-sided t-stat clustering, I think.

I'm also a little surprised that the [1]st subvolume is where the F-stat info is. What is the output of:

3dinfo -verb /Users/adjury/MVM_emx_baseline_splitBLOCK_L_Cov_AgenSex_batchomit.nii

?

--pt