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Your steps are correct, in that specifically you can regard the peak voxel as having survived small volume correction. My complaint was with the SVC procedure in general because of the problem that you can't say anything about the rest of the voxels in the cluster because you only know that they survived the initial threshold. You can also do clusterwise inference in the small volume from the cluster p-value columns, though as it has been shown a lenient initial threshold there is inappropriate. I wasn't suggesting an explicit mask before the analysis, but rather at the time of viewing results you can specify a mask to restrict your search volume. I believe it's the first or second prompt after selecting a contrast to view if you're using the SPM GUI. -Mike > -----Original Message----- > From: Mike [mailto:[log in to unmask]] > Sent: Wednesday, August 31, 2016 11:42 PM > To: [log in to unmask]; Angstadt, Mike > Subject: Re: initial threshold for small volume correction > > Hi Mike, > > May I ask what does "to use a mask (your ROI(s)) on your results and then > specify a corrected voxelwise threshold" mean? Do you mean I use the ROI > as an explicit mask in my 2nd level model, i.e., before model estimation? > However, this approach seems not the exact svc. > > But please someone could confirm that steps 1-4 below are correct for a svc > procedure. My question is for (1), can I use a lenient initial threshold? > > (1). an intial uncorrected threshold, e.g. 0.001 (2). select "small volume" in > SPM8 (3). define the small volume, either a sphere centered at predefined > coordinates (e.g. from previous literature) or a mask (e.g. from an anatomical > mask in an atlas) (4). check the peak-level threshold. If a voxel survives FWE > 0.05, it is regard as significant. > > Mike ********************************************************** Electronic Mail is not secure, may not be read every day, and should not be used for urgent or sensitive issues