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
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#Clusterwis...
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 146postcentral 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
����� 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 ?
FDR is a way to set the voxel-wise threshold to control the False Discovery Rate. See the Genovese 2002 NI paper. Monte-Carol Null-Z how we implement cluster-based correction for multiple comparisons.
Secondly, what does the "MAX" and "VtxMAX" and "NVtxs"mean just as follows,which is output from the teminal.
VtxMax is the vertex where the maximum significance occurred in that cluster. Max is the significance (-log10(p)) at the max.
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@nmr.mgh.harvard.edu
-
Douglas N Greve -
Nick Schmansky -
汪贵宏