I am a new user of Freesurfer. My questions are related to the head modeling and MEG/EEG source modeling.
1. Can freesurfer generate the 3-shell boundary element model (BEM): 3 triangulated interfaces of air-scalp, scalp-skull, skull-brain? 2. Is it possible to generate a closed and folded cortical surface after the segmentation on MR images? Freesurfer seems to output two splitted hemispheres of cortex. I am particularly concerning this, because I will use the cortical surface to constrain the MEG/EEG source location and direction. 3. Is it possible to evenly (or nearly evenly) down-sample the vertices of a fine cortical surface into around 6,000 points, onto which the elementary dipole will be placed? Freesurfer generates the cortical surface with a huge number of triangles, which makes it impossible for MEG-based source imaging.
Looking forward to your reply.
Best regards,
Zhongming Liu