Re-referencing to a different reference electrode

Discussions
,
1

Hi Francois,

I am using brainstorm to analyze connectivity in Ecog data.
Before calculating the connectivity, I want to re-reference the ecog data from different hemisphere separately. In other words, contacts in the left hemisphere to one of the contacts in the left hemisphere or the average in the left and contacts in the right to one of the contacts in the right or the average of the contacts in the right hemisphere.
Is this possible in brainstorm?
I want the re-referencing to be permanent, not only for display.

Thank you.

Best regards,
Hui Ming

2

Hello,

You can probably create a custom montage for this. Not very convenient, because you would have for each contact to add the weight with respect with all the other channels, but at lease you can do it in the interface.
https://neuroimage.usc.edu/brainstorm/Tutorials/MontageEditor#Custom_montage

The other would require some coding and manipulating the internal structures of Brainstorm.
Execute "global GlobalData", then manipulate the structures in "GlobalData.ChannelMontages.Montages".
If this is not obvious to you how this work still want to work with this, let me know and I can give more information (would require good Matlab programming skills).

To apply a montage permanently: use the process "Standardize > Apply montage".

Francois

3

Hi Francois,

Thank you for your help. I have successfully did it through the interface as suggested.

Best regards,
Hui Ming