Dear SPMers,I'm faced with a bit of a strange problem. I'm attempting to select voxels in my beta-maps with on a mask that I've created on the basis of a contrast. However, upon selecting said voxels, I discovered that they all contain NaN values.Intrigued, I loaded up the beta maps using spm_check_registration and found, much to my chagrin, that SPM's segmentation function has apparently removed brain matter around the cerebellar tentorium (please see attached).What could be responsible for this problem?To reiterate, the masks that led to the discovery of this problem are based on first-level contrasts, which worked beautifully. Strange, considering there's a gaping hole in the beta-map ... no?Many thanks in advance,Louis--Louis ThibaultLaboratoire de Psychologie de laPerceptionRoom H418B
45, rue des Saints-Pères
75006 Paris