Hi Lars, I would use the 2nd one. See
https://surfer.nmr.mgh.harvard.edu/fswiki/PairedAnalysis
Lars Tjelta Westlye wrote:
Hi,
we have structural data at two time points (t1/t2) for two different groups (intervention vs control). After processing the data using the long stream, we want to model the group X time interactions to detect intervention specific changes in cortical thickness over time.
Q1) How would you suggest modeling such an interaction?
Q2) Related to the first question, instead of two inputs (t1 and t2) per subject, would you recommend submitting one difference map (t2-t1) for each subject to the GLM, and do something like 1 -1 0? (interv_diff, cont_diff, age)
Thanks for your time, Lars
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