Hi all,
I want to test linear and quadratic effects of age on FA with general linear models (GLMs) while regressing out the
effects of sex.
I finished TBSS and got my "mean_FA","mean_FA_skeleton" and "all_FA_skeletonized" file.
Fist I tried to test linear,I set design box with GUI and put "age" in EV1 dummy variable "gender" in EV2,
And I set contrast ev1 [1] and ev1 [-1] to test positive and negative effect.
Am I right?
How to setting design box if I want to test guadratic effects?
Just put age square in EV3 and contrast [age gender agesquare]=[1 0 1] ?
Best wishes,
M. H.
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