[Freesurfer] help with contrasts

hi Experts,

I'm struggling to conceptualize the appropriate contrasts for my cortical thickness analysis. I have four classes [two groups; two levels (patients,controls; male,female) and two behavioral variables. I want to see if together the two variables account significant proportion of the variance in y (thickness) and if this differs by group whilst regressing out gender. - i.e. if I enter both behavioral variables into the model does it account for more variance than either variable on their own (after controlling for gender)? What I have is this:

.5 .5 -.5 -.5 0 0 0 0 0 0 0 0 .5 .5 -.5 -.5

Does this look right?

Thanks!

Laura.