Dear FSL experts,

i want to do a simple correlation analyse with TBSS. I have one group, a psychological variable of interest (RT) and 3 variables of no interest (Age, Education, Gender).  
My design Matrix is as follows:

Group   EV1 (RT)   EV2(Age)   EV3(Education)   EV4(Gender)

My contrasts are: -1 0 0 0 and 1 0 0 0 for positive and negative correlation.

Is this correct, if i am interested in a correlation between FA-values and a psychological variable corrected for Age, Gender and Education?

I also demeaned all my variables (EV1 - EV4) and used the -D option in randomise. I am not sure, if I have to demean all covariates and my variable of interest (EV1) ?

my kind regards,
Dominik