FreeSurfer's LME wiki site states:
"For computational efficiency reasons, these tools require the data ordered according to time for each individual (that is, your design matrix needs to have all the repeated assessments for the first subject, then all for the second and so on)."
The dataset I need to process includes pairs (and trios) of brothers, and although they're definitely clustered statistical units, there is no pre-defined sorting of individuals within a family (at least in this study). Please note that mine is not a longitudinal study, and the need for a cluster-correction arises from brotherhood...
Is FreeSurfer's LME still the appropriate choice? How should this dataset be processed in FreeSurfer for cortical thickness analysis? Would you recommend another option?
Regards, Ricardo