Hi Ru-Kai,

I assume the 4th column is age (not gender). The design matrix looks fine. 

The main effect of group would be tested with the contrast of [0 1 0 0] or [0 -1 0 0]. Select two-sample t-test. 

If you really want to model both sex and gender separately, this may be difficult because sex and gender would probably be highly correlated, leading to rank issues in the design matrix. 

Andrew

Originally posted by Ru-Kai Chen:

Dear NBS' users
I am running an analysis were I want to control for age and sex.
My study design has two groups (patients and controls) and I would like to use age and gender as covariates to analyse the brain network connections that differ between the two groups
What about setting up that part of the design matrix which models the covariate in NBS like this (in the example I put 3 subjects per group)
1 1 0 34
1 1 1 53
1 1 1 23
1 0 0 60
1 0 1 35
1 0 1 23
The first column represents the constant, the second column is the group (1 for patient, 0 for control), the third column is the sex (1 for male, 0 for female), and the fourth column is the gender, which seems to be possible to design in this way as I looked through the forum discussions, but I don't know if it is correct or not
Finally how should I look at the main effect of the group and the choice of the test（two-sample t-test？？？）。
Thank you in advance for any kind of advice.
Kind regards
Chenrukai