Hi, freesurfer expert, I performed the statistical analysis between two groups first in left hemisphere, and got some regions which showed different. 1) so if I then do multiple correction, i don't need to run the mri_glmfit-sim command, and just press the button of the monte carlo null-z simulation in the qdec interface, am i right?
2) Whether mri_glmfit-sim --cache command line and the mc-z in qdec get the same results, or not? and as to the option --cwpvalthresh, should i choose 0.05 or 0.025? 3) And what is the difference between fdr and mc-z correction? Thanks, Meng
On 07/06/2012 10:00 PM, Meng Li wrote:
Hi, freesurfer expert, I performed the statistical analysis between two groups first in left hemisphere, and got some regions which showed different.
- so if I then do multiple correction, i don't need to run the
mri_glmfit-sim command, and just press the button of the monte carlo null-z simulation in the qdec interface, am i right?
correct
- Whether mri_glmfit-sim --cache command line and the mc-z in qdec
get the same results, or not? and as to the option --cwpvalthresh, should i choose 0.05 or 0.025?
If you are drawing conclusions from both hemispheres then you need to use .025
- And what is the difference between fdr and mc-z correction?
mc-z uses a cluster-wise correction and controls the rate of false positive clusters. FDR is voxel-wise and controls the false discovery rate, which is the number of false positives relative to the total number of positives (as compared to the number of false positives relative to the total number of tests).
doug
Thanks, Meng
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Douglas N Greve -
Meng Li