Hi Stan,

you cannot put discrete variables in the nuisance screen. I don't think you can do this analysis from qdec since it contains discrete variables with more than 2 levels. You'll need to use the "command line stream", ie, create an FSDG file, run mris_preproc, and mri_glmfit. See the tutorial http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/GroupAnalysis

doug

On 11/29/2012 06:56 AM, Berg, S.F. van den wrote:

Hi Freesurfer Experts,

In my design i want to use a general linear model tot relate cognitive performance and cortical thickness. I want to control for age, total gray matter, gender and education. I have two discrete variables, including gender (0,1) and Education (1-7). The problem is that the discrete variables do not appear in the nuisance screen in qdec. How can i control for this discrete variables? Can i put these variables in the nuisance screen? Or should i remove the gender.levels and education.levels file? Just highlighting the two variables gender and age result in an error in analyze: command failed: mri_glmfit --y

In the qdec screen. When i just highlight gender and education in the discrete screen, highlight cogitive_performance in the continous screen, and Age and Total_gray in the nuisance screen. Analysing gives a error.

But when i highlight only cognitive_performance in the continuous screen and nuisance factors age and total_gray in the nuisance screet. It work very well. And a vertex-wise cluster analyses can be done.

Thanks,

Stan

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