Hi
I have 2 groups ( Patient and Control ) and 1 psychological score.
(1)
I have already performed individual within group analysis. So...
GLM design 1: EV1=psychological score in patients ( and of course I only run that design in patients )
contrast 1: [1,0] contrast 2:[-1,0]
GLM design 2: EV1=psychological score in controls ( and of course I only run that design in controls )
contrast 1: [1,0] contrast 2:[-1,0]
And then I used randomise "-D".
I got some blobs. And I think I can simply compare the results between patients and controls.
(2)
However, I saw a paper using different approach, so I wonder whether I should also try their method?
In their paper, they tried to find out brain regions where there is a significant difference in the
"correlation of brain and score" in patients and control subjects.
EV1=control ( so all control get 1 , patients get 0 )
EV2=patient.
EV3=age.
EV4=gender.
EV5=total gray matter volume.
EV6=score for control ( so patients get 0)
EV7=score for patients.( so controls get 0)
contrast=[0.0.0.0.0.1.-1] and [0.0.0.0.0.-1.1]
As for the problem of demeaning:
(1) maybe I can not use the additional EV8=1=intercept, because it will be very similar to EV4gender.
(2) maybe I should also not use the "D" function in randomise, because it will demean every EVs, including EV1 and EV2
(3) I should just demean EV3age, EV4gender, EV5total gray matter volume.
And I will keep the original scores of EV1, EV2, EV6, and EV7.
Is that correct?
And do I really need to repeat their method again? Or can I just use my original result?
Thanks so much!!!
