I want to perform an analysis of the difference between two groups in cortical thickness, having cortisol levels as covariate.
This is my model: cortical thickness ~ pathology (CU/CI) + CSF cortisol + pathology*CSF cortisol
From the GLM DODS analysis I want to know if:
- the regression coefficient is significant only for the difference between groups,
- or only for cortisol,
- or for both,
- or if the coefficient of the intercept between group and cortisol is significant.
Is my FSGD file (attached) correct? What would the contrasts look like?