Hello
I had posted this design before, but I just heard different opinion from a professor, so I'd like to bring this up again, thanks.
Structural MRI analysis of a psychological scale.
So each subject had a score and a MRI image, they are assigned into 2 groups.
The research question is: Concerning the relationship between the psychological score and the gray matter, can we find any difference between these 2 groups ???
GLM design
EV1 = age ( demeaned )
EV2 = gender ( demeaned )
EV3 = total gray matter volume ( demeaned )
EV4 = control ( so all subjects in control group get 1, others get 0 )
EV5 = patient ( so all subjects in patient group get 1, others get 0 )
EV6 = psychological score of the control group ( I DO NOT demean this value, and patients get 0 )
EV7= psychological score of the patient group ( I DO NOT demean this value, and controls get 0 )
So the problem is:
I think Jeanette told me to combine scores from All subjects together and demean them, then separate them into EV6 and EV7.... But the professor told me not to demean EV6 or EV7 ?????????
THANKS a lot!!!
|