Wang, have a look at: http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/QdecGroupAnalysis
and also: http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/QdecMultipleComparisons which itself has some links explaining the necessity for correcting for multiple comparisons. the newer qdec has the 'simulation' method for correction built-in to it, which is superior to FDR for this kind of analysis. this simulation method calls the freesurfer utility mri_glmfit-sim, described here: http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/GroupAnalysis#ClusterwiseCorrectionforMultipleComparisons in the cluster output data, 'Max' is maximum (log)p-value for that cluster, VtxMax is the vertex where that max was found, NVtxs is the number of vertices in that cluster. n. On Tue, 2011-03-08 at 10:05 +0800, 汪贵宏 wrote: > Hi,all: > > I have several problems about the qdec in freesurfer 5.0. > Firstly,can somebody explain the function of the buttons in the qdec's > third step (display),such as Set using FDR in the False Discovery > Rate ,Monte Carlo Null-Z simulation.If I just let these buttons as the > default ,is it right ? > > Secondly, what does the "MAX" and "VtxMAX" and "NVtxs"mean just as > follows,which is output from the teminal. > > Generating cluster stats using min threshold of 2... > Found 5 clusters > Contrast: 'rh-Diff-Yes-No-Intercept-thickness', 10fwhm, DOF: 21 > ClusterNo Max VtxMax Size(mm2) TalX TalY TalZ NVtxs > Annotation > --------- --- ------ --------- ---- ---- ---- ----- > ---------- > 1 -3.4159 8928 51.50 31.9 -34.9 46.8 146 > postcentral > 2 -2.6111 120796 42.30 30.5 -6.5 -32.9 79 > entorhinal > 3 -2.5302 122287 22.28 35.4 -68.1 43.1 41 > inferiorparietal > 4 2.3762 145773 21.24 40.3 22.6 20.6 46 > parsopercularis > 5 2.1491 24852 19.94 4.8 -40.1 71.5 55 > paracentral > ============================================================ > > Thanks, > Wang > > > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ 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.
