Electrode Mapping in Brainstorm without Converting to FreeSurfer

[Raymundo.Cassani]

Hi @HOno,

@HOno

What steps are involved in converting the electrode locations from Brainstorm into the FSaverage space of FreeSurfer? Are there any specific considerations or requirements that I should be aware of during this process?

The requirement would be that Subject's individual anatomy has been MNI-normalized.

@HOno

Can Brainstorm directly support the summation of electrode mapping in several patients without converting the electrode locations to the FreeSurfer space? If so, could you provide an overview of the steps or tools available within Brainstorm for achieving this electrode mapping?

The aggregation of electrodes is not done automatically, but all the data that is needed is there.

The steps to follow are:

1. Create a Subject to aggregate all the electrodes (CoReg Subject)

   • Create a new Subject: Default anatomy NO, Default channel file NO
   • In the Anatomy view, right-click on the Subject > Use Template > FsAverage > FsAverage_2020

2. For each of the Subjects

   • Right click their Channel file > File > Export to File
   • Export the channel file as the type EEG: BIDS electrodes.tsv, MNI space mm (*.tsv)

3. Aggregate electrodes from all Subjects

   • Create a empty text file with any name and extension .tsv, e.g.: electrodes_coreg.tsv
   • For each Subject copy their electrodes to the coreg file. You will need to edit the electrode names, so they are unique, you could add the Subject name to each electrode
   • In the Functional data view, right-click on the coreg Subject > Import channel file select type EEG: BIDS electrodes.tsv, MNI space mm (*.tsv) and select the merge .tsv file

A Forum post relevant to this: Visualizing electrodes on default anatomy

Best,
Raymundo