Hi, folks.

I have generated a few ROIs with multiple loci, which were then imported back into CONN as atlas ROIs.  Unfortunately, the individual loci are not labeled by MNI coordinates but rather a numbering system (e.g., cluster001, cluster002, cluster003).  It looks like the clusters are ordered in descending value based upon their spatial extent.  This causes some confusion given that with TFCE analyses the output is not ordered by cluster extent.  Can someone please confirm the default ordering system by which these iteratively numbered clusters are ordered?

Thanks,
Jeff

Hi Jeff,

That is an excellent point. Yes, you are exactly right the default procedure in REX (in the absence of explicit labels) is to label clusters based on decreasing cluster size, which may be confusing when importing back into CONN masks from second-level analysis results which may have used any criteria other than cluster-size for significance testing (e.g. cluster-mass or TFCE analyses).

In any way, in order to avoid this potential confusion when using the "export mask" option in "results explorer" CONN creates an additional file named *.ROIs.img which contains explicit labels (each cluster is labeled by its peak MNI coordinates; this info is saved in the associatd *.ROIs.txt file). So if you want to import back these clusters into CONN as new ROIs, instead of importing into CONN the original mask file (e.g. mymask.img) I would recommend simply to import the associated ROI file (e.g. mymask.ROI.img) which should avoid these issues. Let me know if that would work in your case

Best
Alfonso
Originally posted by Jeff Browndyke: