I tried that out and for some reason it isn't working, though logically everything seems like the right move. It is performing voxelwise addition right? So voxel x1, y1, z1 from each of my 120 sub-briks should be added together? When I look at the results this does not seem to be the case, as my output files have extremely small values at each voxel (0.0000x), despite the input sub-briks being z-scored, with values ranging from 0 to +-4.