Hello,
I have a repeated measures design, 19 subjects x 4 timepoints (1 covariate and 1 connectivity matrix for each timepoint). I believe I understand how to model the within-subjects effects at this stage; however, I'm unclear, given the 4 timepoints, how to model the between-subjects effects other than simply averaging the connectivity matrices + covariates to now have 19 datapoints each instead of 76. Is there a way to set up the design matrix so that between-subjects effects can be modeled?

Thank you,
Danie