I sometimes have these weird artifact appearing after importing a freesurfer folder.
There is some artifact in your MRI scan: right-click on one of the slices in the MRI Viewer and move your mouse up, you will see that the intensity is much higher around the chin.
Unfortunately, I can't help you with this. You need to ask the FreeSurfer or CAT12 developers how to pre-process the MRI to get rid of this bias before processing it.
Or if it works with BrainSuite, then maybe use BrainSuite instead.
@CGaser @Anand_Joshi ?
you mentioned to "right-click on the MRI > Compute head surface", but I don't see this option in brainstorm now
It is named "Generate head surface" now.