Hi,
I tried to read all (I hope) posts on this topic, but some questions still
remain:
1. My design matrix and contrasts are as below and I run standard
randomisation for tbss data, does it mean it did 2-tailed test or two
1-tailed tests?
2. I try to determine appropriate c threshold by looking on tstat maps (I
guess max_tsts and not vox_stats). Do I need my DOF to estimate it correct
for p-value I choose? If so, is my DOF 33? (controls 18, patients 17)?
3. Function -c is recommended for tbss, but isn`t -C more suitable? Is there
any difference in estimating the c threshold for both -c and -C options?
4. What are the situations other than analyzing paired data to use -D
function (demeaning)?
5. I am thinking of the meaning of -c funtion: for very small group, the
cluster forming t-threshold can help to find significant differences. Is it
simply by restricting the area of search? However, high threshold like 3 or
more will again restrict the number of "significant" voxels. Am I correct?
Thank you for all help!
Aga
(design.con)
/ContrastName1 controls>patients
/ContrastName2 patients>controls
/NumWaves 2
/NumContrasts 2
/PPheights 1.000000e+00 1.000000e+00
/RequiredEffect 1.501 1.501
/Matrix
1.000000e+00 -1.000000e+00
-1.000000e+00 1.000000e+00
design.mat
/NumWaves 2
/NumPoints 35
/PPheights 1.000000e+00 1.000000e+00
/Matrix
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
1.000000e+00 0.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
0.000000e+00 1.000000e+00
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