Dear FSL Experts,

 

I have a question regarding my design matrix. I have two groups (G1, G2), one covariate of interest (CI), and three covariates of no interest (CNI). I am interested in within group correlations with my single covariate of interest and was wondering if the following contrasts were correct for the design matrix I have listed below.  

G1	G2	CIG1	CIG2	1st CNI(sex)G1	1st CNI(sex)G2	2nd CNIG1	2nd CNIG2	3rd CNIG1	3rd CNIG2
0	1	0	11	0	1	0	147	0	26.25
0	1	0	11	0	2	0	123	0	31.08
0	1	0	36	0	1	0	119	0	35.83
1	0	33	0	1	0	118	0	62.92	0
1	0	25	0	1	0	162	0	69.83	0
1	0	22	0	2	0	124	0	61.08	0

 

 

 

Contrast1: 0 0 1 0 0 0 0 0 0 0 (give me voxels that show a positive correlation with my covariate of interest in group 1)

Contrast2: 0 0 -1 0 0 0 0 0 0 0 (give me voxels that show a negative correlation with my covariate of interest in group 1)

Contrast3: 0 0 0 1 0 0 0 0 0 0 (give me voxels that show a positive correlation with my covariate of interest in group 2)

Contrast4: 0 0 0 -1 0 0 0 0 0 0 (give me voxels that show a negative correlation with my covariate of interest in group 2)

 

Cheers!