Hi,
I didn’t understand the different estimation of the sphere based on the inner skull, scalp, EEG and cortex.
I have tried all of them and performed MNE and sLORETA and all four head models show sources almost in the same location but the intensity of the sources varies from max. to min. in the following order for cortex, EEG, skull and scalp respectively.
Can anyone explain the differences?
Looking forward for the response.
Best regards,
Kidist
As explained in the head modeling tutorial (neuroimage.usc.edu/brainstorm/Tutorials/TutHeadModel), these spherical models approximate the head with one unique sphere.
But the head is not a sphere, there is no way around it. Those different options are just different suggestions for the sphere, there is not necessarily one better than the other. In the end they are all bad, in different ways.
Use instead the head models suggested in the same tutorial: Overlapping spheres (MEG) and OpenMEEG BEM (EEG).
Cheers,
Francois
Hi,
When using the 3-shell spherical head model, am not able to see all the 3 spheres on the image rather just a single sphere.
Is there a possibility to see all the 3-spheres?
Best regards,
Kidist
Hi Kidist,
In previous versions the three spheres were displayed, but it was making the figure difficult to read. It was not very informative because it was difficult to see where the two inner spheres were.
You can edit the function brainstorm3/toolbox/gui/view_spheres.m: at line 161, change “Radii(end)” to “Radii(1)” or “Radii(2)” to see the two other spheres.
Cheers,
Francois