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Dear Donald, I presume you are using the non-isotropic cluster correction in VBM5 toolbox. The reason as to why the adjusted cluster size is different from the unadjusted cluster size is explained in Christian Gaser's email at https://www.jiscmail.ac.uk/cgi-bin/wa.exe?A2=ind0802&L=SPM&D=0&P=45184 While VBM5 actually adjusts the number of voxels in clusters in the output, our NS-toolbox (another non-stationary cluster toolbox) doesn't. We have had some discussions on the subject before on the SPM list, but my answer to your question would be to report the cluster size as 5,000 voxels. That is because 5,000 voxels correspond to the volume this particular cluster occupies in a 3D space. Hope this helps, -Satoru From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of MCLAREN, Donald Sent: Friday, March 27, 2009 3:58 PM To: [log in to unmask] Subject: [SPM] Non-istropic voxel size correction I just performed an analysis with and without nonisotropic correction; however, I am confused as to how to interpret the corrected cluster sizes. I am using SPM5.Update1782. For example, uncorrected size of a cluster is 5000 voxels and the corrected cluster size is 8000 voxels (as displayed whole-brain statistics table under Ke). If I click the eigenvariate button and specify VOI as the cluster, it reports 5000 voxels in the cluster in the image. (1) What should 8000 voxels be interpreted as? (2) How should it be reported in a paper? -- Best Regards, Donald McLaren ===================== D.G. McLaren University of Wisconsin - Madison Neuroscience Training Program Office: (608) 265-9672 Lab: (608) 256-1901 ext 12914 ===================== This e-mail contains CONFIDENTIAL INFORMATION which may contain PROTECTED HEALTHCARE INFORMATION and may also be LEGALLY PRIVILEGED and which is intended only for the use of the individual or entity named above. If the reader of the e-mail is not the intended recipient or the employee or agent responsible for delivering it to the intended recipient, you are hereby notified that you are in possession of confidential and privileged information. Any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this e-mail unintentionally, please immediately notify the sender via telephone at (608) 265-9672 or email.