Hey! I'm resending this email because I think it got lost on the list.

Hello FreeSurfer Developers,

I'm extracting beta values ​​from some analyzes and I would like to know if I'm extracting and interpreting these values ​​correctly.

To extract the beta values ​​I used this command:

mri_segstats --seg lh.cortisol_CSF.glmdir/cortisol_CSF_slope/perm.th20.neg.sig.ocn.mgh --i lh.cortisol_CSF.glmdir/beta.mgh --excludeid 0 --avgwf lh.cortisol_CSF.beta.clusters.dat

The model consists of 1 group and 1 covariate.

I used the contrasts for intercept and slope.

The fsgd file looks like this:
 
GroupDescriptorFile 1                 
Title cortisol_CSF                    
Class Main                     
Variables      cortisol_CSF           
Input   011_S_0003_S9128       Main    2.397895273
Input   022_S_0004_S9233       Main    2.772588722
Input   011_S_0005_S9137       Main    3.044522438
Input   011_S_0008_S9196       Main    2.397895273
Input   011_S_0010_S8800       Main    2.151762203
... (n=300)

The beta values ​​extraction file contains 2 lines (image below).

 Would the first line be the beta value for the intercept and the second line for the slope?
Thus the glm equation for the 1st cluster would be:    cortical thickness = 2.57 - 0.12X + n

Is this correct?

Thank you very much in advance.

Laura Willers de Souza