mrostami:
So just to make sure if I have understood your answer clearly:
tmedani:
If you want to use the Gain matrix outside of Brainstorm, you can either use the average re-referencing or re-reference the Gain matrix to your reference electrode, just be subtracting the value of your reference from all the electrodes (moving the zeros line to the new reference).
Do you mean I can simply get the mean of each column of the Gain matrix to make a new Gain matrix suitable for average-reference data? I am asking since the method of computations is not linear and is dependent on the channels' settings. So is applying the average function on this level (final Gain matrix) safe in terms of keeping the real contributions of every source to every channel? Theoretically I couldn't verify, so if you have any experience with it, it would be valuable to have it here.
I'm not sure if I understand what you mean by "nonlinear", the gain matrix map the contribution of each source to each channel and it's linear. The average referencing is also a linear operation,
Hello Rasheeda, and Others interested in the algorithm used for EEG source modeling,
Thanks to questions by Rasheeda, and in timely parallel, my own modeling efforts, we snaked out a workflow problem in Brainstorm that was sometimes plaguing our new ability to source model EEG data, while also allowing users to make their own custom EEG montages.
For those whom this post is TL;DR, then the IMPORTANT NOTE IS: All EEG source modelers should update to the latest Brainstorm, to correct a problem w…
https://neuroimage.usc.edu/brainstorm/Tutorials/MontageEditor#Custom_montage
A+
1 Like