Dear FSL experts,

I have a question regarding GLM usage. There is an example of usage of additional covariate when running single-group average analysis on FSL wiki: https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/GLM#Single-Group_Average_with_Additional_Covariate

But can this model be used for multiple addiotional covariates? E.g. I would like to know if there is effect of age, gender or behavioural score on brain volume. Can I enter those in such matrix at once, or should I use different model for each covariate I am looking at?

I have looked through the maillist and have not found an answer.

Also will entering +1 / -1 in the contrast show me the positive/negative relationship? Such as in https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/GLM#Two-Group_Difference_Adjusted_for_Covariate

Any help is appreciated.

Best regards,

Adam