> I ran 3dMVM on the coefficients obtained with 3dREMLfit, and defined my desired GLTs. Is this legit?

Yes, that's fine.

> any tips on the advatages of 3dMEMA over 3dttest++ would be appreciated

Ideally the analysis for a dataset should be performed with one integrative model. In real practice this is not always feasible in neuroimaging due to a couple of limitations: model complexity, computational cost and the need for data quality control. Therefore, the analysis pipeline is usually split into two steps: one for each individual subject, and another one for group analysis. Such a two-step approach may result in information loss since the group analysis only uses the effect estimates (betas) as input most of the time. One way to make up for the information loss is to take the uncertainty of the effect estimates (embedded in the t-statistic) into consideration during group analysis. This pretty much explains what you experienced in your analysis ("I chose 3dMEMA just because the results looked a little better compared to what I got with 3dttest++").

Gang



Edited 1 time(s). Last edit at 10/31/2019 09:38PM by Gang.