Dear SPM users,
I'm currently trying to do some source reconstruction analyses using SPM12.
I am using individual T1s and individual electrode locations(3 fiducials (nasion, lpa and rpa)+128 electrode positions). I extracted the coordinates of the MRI fiducials by clicking on nasion, lpa and rpa using the display->images buttons and used these coordinates for the co-registration. I further aligned electrode positions manually using fieldtrip (ft_electroderealign; using the standard headmodel as scalp reference), since they were rotated 90 degrees clockwise and had a vertical offset of ~5-10cm.
As a first check, I wanted to localize a visual ERP and realized that the blob I got sits too low in the brain and is lateralized, even though stimuli were presented centrally.
I think that something went wrong in the co-registration step. When I try to plot the different meshes, fiducials and electrode locations using the SPM gui (3D Source Reconstruction -> load (.mat file) -> display (below Co-register)), it doesn't show the electrode locations. It only shows the different meshes and the fiducials but no electrode locations (i.e. green discs are missing).
However, if I plot the forward model (clicking on display below Forward Model button), the electrode locations appear as turquoise asterisks and seem to be at the right locations (projected to the skin).
But if the co-registration went well, shouldn't I then also see the electrode locations in the co-registration figure?
Thanks a lot for your help!
Rodika
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