Increase only one electrode amplitude gain in a multielectrode montage

[aclesage]

Dear all,

Thalamic electrodes generally exhibit seizure-onset amplitudes roughly ten times smaller than cortical electrodes. Is it possible to apply an increased gain to only one electrode in a multielectrode SEEG montage? If native per-electrode gain control is unavailable, please advise how to modify the acquisition/processing source code to scale a single electrode independently.

thank you

Best Regards

Anne-Cecile Lesage, PhD

Research Scientist

Department of neurosurgery

University of Texas Medical Branch

anlesage@utmb.edu

[Raymundo.Cassani]

Hello @aclesage,

Yes, it is possible to have the per-electrode-gain behaviour by using Custom montages.
https://neuroimage.usc.edu/brainstorm/Tutorials/MontageEditor#Custom_montage

The idea is to create a custom montage were you indicate the gain for each of the electrode.

E.g., Here, there are electrodes AH1 to AH14, to change the gain (to 3x) for AH1 electrode, this is how the custom montage looks:

Now these are the plots for original AH electrodes (left), and for AH electrodes using the custom montage (right). Same scale in both plots.

Changes performed with montages are only for visualization, if you want to apply those changes in the data, you need to use the process Standardize > Apply montage to apply the montage on the original data and save the results as a new data file.

[aclesage]

thank you very much, it answers my question