Dear SPM users,
I try to do a multiple regression analysis with covariates.
I have a group of scans (for example patients) and 9 covariates
(ammonia, GMP ciclique, nitrats, IL-6, IL-8, 3 Nitrotirosine,
8-Hidroxideoxiguanine, carbonile proteins and malonaldehide).
I would see the main effect or the interest effect the each covariate
over the respective group (scans) at the second level.
Which are the right F-contrast?
For example:
Column 1: Images group patients
Column 2: Ammonia
Column 3: GMP
Column 4: Nitrate
Column 5: IL-6
Column 6: IL-18
Column 7: 3-Nitrotirosine
Column 8: 8-Hidroxideoxiguanine
Column 9: carbonile proteins
Column 10: malonaldehide
For example if a would like to see the effect of the ammonia covariate
over the patient group the F-contrast would
[1 -1 0 0 0 0 0 0 0 0 0 0 0]
or
[1 0 0 0 0 0 0 0 0 0 0 0 0 0; 0 -1 0 0 0 0 0 0 0 0 0 0 0]
or
[1 0 0 0 0 0 0 0 0 0 0 0 0; 0 -1 0 0 0 0 0 0 0 0 0 0 0; 0 0 0 0 0 0 0 0
0 0 0 0 0; 0 0 0 0 0 0 0 0 0 0 0 0 0; 0 0 0 0 0 0 0 0 0 0 0 0 0; 0 0 0 0
0 0 0 0 0 0 0 0 0; 0 0 0 0 0 0 0 0 0 0 0 0 0; 0 0 0 0 0 0 0 0 0 0 0 0 0;
0 0 0 0 0 0 0 0 0 0 0 0 0; 0 0 0 0 0 0 0 0 0 0 0 0 0]
Please, any help? What is the difference between them?
Thanks in advance!!!!!!
Hector Espinos
INCLIVA Health Research Centre
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