This is not my understanding. It is completely dependent on the threshold used, which can be arbitrary. See Supplemental figure 7, page 16 of this document:
http://www.jneurosci.org/cgi/data/30/6/2268/DC1/1 This was the motivation for Smith & Nichols' TFCE: http://www.ncbi.nlm.nih.gov/pubmed/18501637 On 02/22/2011 05:53 AM, Rafa x wrote: > Dear Freesurfers, > > I have performed a permutation test with the command: > > mri_glmfit-sim --glmdir rh.fsgd_subj_gauss005 --sim mc-z 10000 > THRESHOLD csd --sim-sign pos --seed 1297708255 > > And after that I have obtained the clusters with: > > mri_surfcluster --subject CNTRL_MCI_RAFA_average –mask > rh.fsgd_subj_gauss005/mask.mgh --sum > rh.fsgd_subj_gauss005/contrast/clustsum.txt --in > rh.fsgd_subj_gauss005/contrast/sig.mgh --cwsig > rh.fsgd_subj_gauss005/contrast/cwsig.mgh --vwsig > rh.fsgd_subj_gauss005/contrast/vwsig.mgh --sign pos --csd > rh.fsgd_subj_gauss005/csd/csd.j001-contrast.csd > > > I’ve did it over the same dataset but with two different thresholds, > THRESHOLD: 2.301 (pvalue=0.005) and 1.301 (pvalue=0.05). As far I know > the cwsig.mgh resulting using the 1.3 threshold should be similar than > the cwsig.mgh from the second thr, but with a more restrictive > significative clusters (some coloured areas should disappear, in other > words, clusters returned in the first case should be included in > clusters returned by the 1.3 threshold). My results didn’t show that > behaviour, some of the cwsig clusters can be contained in the other, > but others don’t (see attached Figure). It is my reasoning correct? If > so, why the images mismatching? > > Thank you all in advance. > Rafa. > > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------ > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > The information in this e-mail is intended only for the person to whom it is > addressed. If you believe this e-mail was sent to you in error and the e-mail > contains patient information, please contact the Partners Compliance HelpLine > at > http://www.partners.org/complianceline . If the e-mail was sent to you in > error > but does not contain patient information, please contact the sender and > properly > dispose of the e-mail. > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
