Topographic visualization

1

Hello Francois!
Is there any specific way to import a channel file in BIDS format. Because when I'm trying using the steps as EEGLAB channels> Add EEG positions>Import from file>.tsv electrodes file from the subject specific folder from BIDS dataset, it displays a distorted topo plot for all channels and infact there is no change in the topo plots across the channels. I'm attaching the figures for reference.

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And the format of channels and electrodes file are .tsv. Please suggest how to correct this as it is importing the correct channel file, but it doesn't show the correct topo plots. Though this is observed only when I imported the data using IMPORT BIDS Dataset option. And is fine when I'm reviewing as raw eeg/meg option.

Thanks in advance!

2

If the list of coordinates do not include the fiducial points NAS/LPA/RPA, there is very little chance that Brainstorm interprets the coordinate system correctly.
Right-click on the channel file > MRI registration > Edit. You can try fitting automatically the EEG cap on the head surface, or doing a manual registration.

If you are using a template head (ICBM152), check if the cap you are using does not already have template positions available in Brainstorm (right-click on channel file > Add EEG positions > ICBM152...)

3

Thank you so much.