afni.nimh.nih.gov

Hello Kai,

Hard to tell without looking in detail at what you've done. One way to get to the bottom of this is to simplify the problem to an ROI of a single voxel and very few subjects (you can acutally use 1D files as input instead of volumes). With just one voxel in the ROI, it should be easier to get things sorted out.

cheers
Ziad