Dear SPM masters,
I am trying to perform source reconstruction on the grand-averaged
ERPs from an EEG study (BrainAmp, 64 channels) with 20 subjects. Since
the EEG electrode positions were not digitized, I am using the
standard EEG template with standard electrode positions.
My problem is that I see a quite wide variability in the sources by
varying two parameters of the reconstruction:
1) use of coarse or normal cortical mesh
2) use or not of hanning window when inverting
My questions are:
1) Is it normal to see large variability when using normal or coarse
mesh? What would be the best for 64 electrodes?
2) What does the hanning window exactly refers to? I intuitively think
that data in time are weighted by this window, but I could not find
the exact info on the manual.
3) Any other important factor that you think is crucial for source
reconstruction in this case?
Thanks for your feedback,
Best,
Marco
--
Marco Buiatti, PhD
CEA/DSV/I2BM / NeuroSpin
INSERM U992 - Cognitive Neuroimaging Unit
Bāt 145 - Point Courrier 156
Gif sur Yvette F-91191 FRANCE
Ph: +33(0)169.08.65.21
Fax: +33(0)169.08.79.73
E-mail: [log in to unmask]
http://www.unicog.org/pm/pmwiki.php/Main/MarcoBuiatti
***********************************************
|