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Dear Kenneth, I would not recommend to use the WM template for spatial normalization. Even for WM analysis the GM template is always a better choice. I guess John's idea of using a GM template rather than a T1 template was to improve normalization quality of the whole image and there might be some (positive) bias for GM areas. Best regards, Christian ____________________________________________________________________________ Christian Gaser, Ph.D. Department of Psychiatry Friedrich-Schiller-University of Jena Philosophenweg 3, D-07743 Jena, Germany Tel: ++49-3641-935805 Fax: ++49-3641-935280 e-mail: [log in to unmask] http://dbm.neuro.uni-jena.de On Fri, 24 Jun 2005 17:04:51 +0100, Kenneth Rando <[log in to unmask]> wrote: >My interest is a white-matter analysis using cg_vbm_optimized. I have >created a study-specific template and my own set of gray, white, and csf >priors using cg_create_template, and I can comfortably run a gray matter >analysis. Now I have modifed cg_vbm_optimized to perform a white-matter >analysis, but don't have a way to verify that I am correctly making the >necessary changes to that program. My spatial normalization using the WM >template appears to be correct when I make the following modifications to >cg_vbm_optimized: > >at line 104 (in my editor): > factor = abs(det(VT(1).mat(1:3,1:3)))/1000; I changed VT(1) to VT(2) >at line 112 > VT = VT(1); I changed VT(1) to VT(2) > >When I execute the script I select my own prior white image for >normalization (rather than gray as in the original script). > >Are these changes correct? Are there other necesary modifications I have >overlooked? > >Thanks. > >Regards > >Kenneth Rando