I guess you are using non-realistic electrode positions from EEGLAB.
What you import here is not something that matches the real head shape of the template (ICBM152), it is a set of spherical points only used for visualization in EEGLAB.
You need to import correct 3D positions for your electrodes. You have three options:
- if you have a real digitized head shape of your subject, import the positions in Brainstorm as show in the EEG tutorial
- otherwise, you can use one of the template EEG cap available in Brainstorm (right-click on the channel file > Add EEG positions > ICBM152 > …)
- last option, not recommended because of its randomness: edit the positions you got from EEGLAB to fit the head of the subject (right-click on the channel file > MRI registration > Edit)
I recommend you start by reading the introduction tutorials (section “Get started”, at least until #23 if you want to do source analysis, using the example dataset provided with the tutorial). The read the tutorial “EEG & Epilepsy” for additional details about EEG.
http://neuroimage.usc.edu/brainstorm/Tutorials
http://neuroimage.usc.edu/brainstorm/Tutorials/Epilepsy
Francois