Hi there,
I'd like to use afni's 3dClustSim to identify the minimum cluster size for our seed ROI resting state analyses. It asks for the FWHM of the data, so I thought computing it from the group analysis smoothness file according to
FWHMav = (resels * pixdim1*pixdim2*pixdim3)^(1/3); which in standard space would be (310.004*2*2*2)^(1/3) = 13.5359
Does this sound correct (we used an 8 mm kernel at the 1st level)?
Would randomise be a better alternative instead of using a cluster extent threshold?
Thanks again for all comments !
Cheers,
Torsten
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