Thanks for the tip. I just checked the dimensions of all of the input files and all of the output files (shown below), they seem to match. vbm_stats.nii.gz here is the output of the 3dttest++. Oddly if I put the stats file as the underlay and the aveBrain (3dMean of all datasets going into 3dttest++), the datasets look to be roughly the same size.
aveBrain.nii.gz 1.500000 -1.500000 1.500000
vbm_stats.nii.gz 1.500000 -1.500000 1.500000
I also tried stripping out the extensions of both the underlay (aveBrain.nii.gz) and the overlay (vbm_stats.nii.gz) and still get the overlay/underlay distortion problem shown in the screenshot.
Edited 2 time(s). Last edit at 10/15/2012 04:55PM by Peter Molfese.