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Dear SPM experts, I have a question regarding the regression analysis in SPM5... My data consists of - 1 patient group, - each suject underwent 2 scans (e.g. pre & post scans), - for each of the scan and subject I have a covariate (e.g. pre & post error rate). I first calculated the regression (scans & error rate) SEPARATELY for each scan (pre & post), which is quite simple... Now I want to know, if the regression for one (e.g. pre) scan is stronger than for the other (e.g. post) scan. Jonathan Peelle recently offered me a great explanation how to do this if the two scans are independent using an ANOVA setting (two groups, two covariates, contrast manager setting to 0 0 1 -1). However, now I want to account for the dependency of the two scans (like within a paired T-test). I first thought simply to change the "Factors -> Independence" setting to "No" but then the covariate within my design matrix changes and I do not understand why! Any suggestions would be greatly appreciated :) Thanks a lot, Andreas.