If you are using default electrodes positions from one of the templates in Brainstorm, do not use the function "Refined registration using head points": this is only for the electrodes positions have been digitized on the head of the subject.
The correct procedure:
- Link your recordings to the database
- Right-click on the channel file > Add EEG positions > ...
- Right-click on the channel file > MRI registration > Edit.
- Adjust the electrodes on the head of the subject: rotations, translations, rescaling, until it looks like the real positions of the EEG cap during acquisition (a photo of the participant with the cap on would help)
- Then finally click on the button "Project electrodes on surface", to make sure the electrodes are in contact with the skin and not inside the head (which causes issues in the forward modeling)