Dear NBSers,

I have 2 groups of subjects (controls and patients), who were scanned at 2 time-points (baseline, after 4 years).
These 2 groups differ significantly in age and gender.

I would like to see if there is an interaction between group and time, while controlling for age and gender differences.
My hypothesis is that controls remain relatively stable, whereas patients show decreased connectivity over time.

This is an example of what my design matrix looks like:

Subjects                        Group    Time    Age    Gender    Regressor_Subj1   Regressor_Subj2   Regressor_Subj3    Regressor_Subj4
control01_baseline         1           0         50       1                       1                          0                          0                           0
control01_4years           1           1         54       1                       1                          0                          0                           0
control02_baseline         1           0         45       1                       0                          1                          0                           0
control02_4years           1           1         49       1                       0                          1                          0                           0
patient01_baseline         0           0         36       0                       0                          0                          1                           0
patient01_4years           0           1         40       0                       0                          0                          1                           0
patient02_baseline         0           0         34       1                       0                          0                          0                           1
patient02_4years           0           1         38       1                       0                          0                          0                           1

Does the contrast: 1 -1 0 0 0 0 0 0
allow me to test for Group x Time interaction?

Thank you so much!