Hi Gang,
Thank you again for your help!!

As advised, I ran the command:

3dLME -prefix 3dLME_.nii.gz -jobs 8 \
-model "gender*age" \
-qVars "age" \
-ranEff '~1+age' \
-dataTable
Subj	age	Sexe	InputFile
Oliver	1128.0	M	/Oliver2019_02_02_ztest.nii.gz \
Oliver	1247.0	M	Oliver2019_06_01_ztest.nii.gz \
Oliver	1353.0	M	Oliver2019_09_15_ztest.nii.gz \
Oliver	1437.0	M	Oliver2019_12_08_ztest.nii.gz \
Pickle	1065.0	M	Pickle2019_02_02_ztest.nii.gz \
Pickle	1184.0	M	Pickle2019_06_01_ztest.nii.gz \
Pickle	1289.0	M	Pickle2019_09_14_ztest.nii.gz \
Pickle	1375.0	M	Pickle2019_12_09_ztest.nii.gz \
...

and I obtain for

3dinfo 3dLME_.nii.gz

Number of values stored at each pixel = 4
-- At sub-brick #0 '(Intercept) F' datum type is float
statcode = fift; statpar = 1 22
-- At sub-brick #1 'gender F' datum type is float
statcode = fift; statpar = 1 6
-- At sub-brick #2 'age F' datum type is float
statcode = fift; statpar = 1 22
-- At sub-brick #3 'gender:age F' datum type is float
statcode = fift; statpar = 1 22

Few last basic questions (sorry it is the first time that I use statistical commands with AFNI):

- Intercept is like a one-sample t-test? It is the total group effect? basically do my network exist on a group basis?

- I guess that my contrast of interest is 'gender:age F'??
However, I do not have an equal distribution between male (n=6) and female (n=2) is it a problem? Because it seems that I have way more contrast on 'age F' alone that on 'gender:age F'. Even if the contrast for 'gender F' is weak.

-Finally, if I want to convert the F stat into z values the command would be?

3dcalc -a 3dLME_.nii.gz'[3]' -expr 'fift_t2z(a, 1, 22)'  -prefix 3dLME_z.nii.gz

thanks a lot,
Clément



Edited 3 time(s). Last edit at 03/02/2020 02:46PM by Doughboys.