Hello experts,

I've completed rs-fMRI analysis of my high and low IQ subjects in Melodic, all run together.  I have set them up as one group in the GLM setup tool, with a contrast set between the high and low IQ groups.

Now, too add age as a regressor, then I assume I can just add an EV and for each individual fill in their demeaned age, which for my group is between -7.4 and  12.9 years.  Just to be sure, this is the correct way of handling this, right?

Also, to test for any existing group-age interaction then is it correct to add 2 contrasts, such that there is a positive and a negative group-age interaction test, as shown below?

/ContrasName1                high IQ>lowIQ /ContrastName2                hight IQ<low IQ
/ContrastName3              age-group-pos
/ContrastName4              age-group-neg
/NumWaves      3
/NumContrasts 4
/PPheights                          1.615499e+00    1.615499e+00    2.347599e+01    2.347599e+01
/RequiredEffect                               1.823     1.823     2.385     2.385

/Matrix                                EV1                           EV2                               EV3
High>low IQ              1.000000e+00     -1.000000e+00         0.000000e+00
High<low IQ            -1.000000e+00      1.000000e+00         0.000000e+00
Age-group pos          0.000000e+00      0.000000e+00        1.000000e+00
Age-group neg          0.000000e+00       0.000000e+00      -1.000000e+00

Thank you for you help,
Varina Wolf, M.D.
Baylor College of Medicine