Dear Freesurfer support,

we met some probelm when we investigate difference between two groups. We have two sets of data, one is the TLE group, the other is the extraTLE. We also has the variables: age,gender and neuropsychological test scores. We want to analyze the relationship between cortical thickness and neuropsychological test, controlling for age, gender and group.

The contrast in the full DODS model in the mri_glmfit is 0 0 0 0 0.5 0.5 0 0, with the fsgd file being:

GroupDescriptorFile 1 Title MyTitle MeasurementName thickness Class Class1_TLE Class Class3_extra_TLE Variables Age factor4 gender Input PT1_01 Class1_TLE 23 12 1 Input PT1_03 Class1_TLE 38 10.26 0 Input PT1_04 Class1_TLE 26 13 0 Input PT1_06 Class1_TLE 45 13 1 Input PT1_11 Class1_TLE 20 15 1 Input PT1_12 Class1_TLE 23 10.26 0 Input PT1_14 Class1_TLE 39 9 1 Input PT1_27 Class1_TLE 51 14 1 Input PT1_32 Class1_TLE 33 11 0 Input PT1_33 Class1_TLE 27 8 1 Input PT1_34 Class1_TLE 19 8 0

Preproc was done with:

mris_preproc --fsgd patients_age_gender_Arithmetic.fsgd \
	     --cache-in thickness.fwhm15.fsaverage \
	     --target fsaverage \
	     --hemi rh \
	     --out rh_thickness_Arithmetic/rh.thickness.fwhm15_arithmetic.mgh


 GLM was done with:

  mri_glmfit --y rh_thickness_Arithmetic/rh.thickness.fwhm15_arithmetic.mgh \

	   --fsgd patients_age_gender_Arithmetic.fsgd dods \
	   --C difference_Arithmetic_all.mtx \
	   --surf fsaverage rh \
	   --glmdir rh_thickness_Arithmetic

My questions are：

 (1)Are the command lines, fsgd file and the contrast matrix correct?

 (2)We have used  qdec (DODS) to visualize the results, but I can't open the sig.mgh file. I dont know why? The terminal shows that :

Reading /usr/local/freesurfer/tktools/tkUtils.tcl

Using /usr/local/freesurfer/lib/tcl/fsgdfPlot.tcl
ERROR: MRISread: file '/usr/local/freesurfer/subjects/Neuropsychology/rh_thickness_Arithmetic/difference_Arithmetic_all/F.mgh' has 0 vertices!
Probably trying to use a scalar data file as a surface!

Invalid argument

I dont know how to solve it. I very appreciate your help.

Kind regards,
Kan