I went digging through the bst_duneuro.m script, and the problem is now obvious, though I don't have a solution yet.
The script is not fully written for 'mixed' or 'volume' head model support, specifically for shrinking the cortex surface and forcing dipoles within the GM layer. Even though I have "Force source space inside layer "gray"":
There is no code to actually enforce that constraint.
Starting at line 188, there are switch cases that are empty for 'volume' and 'mixed':
switch (cfg.HeadModelType)
case 'volume'
% TODO or keep it as it's now....
case 'surface'
...
case 'mixed'
% TODO : not used ?
Any help in coding the 'mixed' case to enforce the grey matter constraint would be greatly appreciated.
Thanks,
Kyle