Hi Daniel,

Sure, why not. Group differences would be shifts/offsets of the lines for each group, while group time interaction would be different slopes.

Best, Martin

On 1. Apr 2025, at 01:23, Bondi, Daniel daniel.bondi@ubc.ca wrote:

Hi FreeSurfer experts,

I am using the univariate LME pipeline (lme_fit_FS & lme_F) to conduct cortical thickness analysis on a subset of D-K atlas ROIs between two groups. Although I am testing longitudinal group*time differences with this pipeline, I am wondering if it is valid to test group-level differences (irrespective of time) with this model as well. I have been doing so by specifying only the group covariate in the contrast matrix before running the model.

Thank you, Daniel Bondi _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edumailto:Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer