Hi.
I would like to test the effect of a covariate that interact with a factor.
Eg. I have group (XX and XY) as fixed factors, and a ROI thickness (L Fusiform) as covariate.
Now I would like to calculate the "correlation LFusiform for XX - correlation LFusiform for XY".
Is this possible by using qdec? If so, how should I proceed?
Best regards, Emilia