Hi FSL experts,
I did some group t-test with randomise analysis. I usually
used the “Cluster-based thresholding corrected for multiple comparisons
by using the null distribution of the max (across the image) cluster
size”.
It worked very well. However, recently I did a paired t-test
analysis in my new project. I made the parameter files with “Glm”
wizard. However, the multiple comparison correction made me confused. I found
the t value (i.e., “-c” option) I set is not corrected any more.
The activated clusters I got looks very very small. For example, If we supposed
t=3.5 (DF=48) means p=0.001 in my study and I used “–c 3.5”
during the analysis, the “maxc” files show activated clusters are
much smaller than I found in “vox” files with p=0.001 threshold. I
found similar results in a 2X2 ANOVA analysis, too. Could you please do me a
favor and give me some idea of it
Xiaochu Zhang Ph.D
Visiting Research Fellow
NIH/NIDA-IRP
Tel: 443-740-2619
Fax: 443-740-2734