Apply bipolar montage sEEG

Hello,

I followed the tutorial " SEEG epileptogenicity maps" and I have a problem to apply a bipolar montage on my signal.

I am using sEEG data recorded with Neuralynx (.ncs files).

In the process "Standardize", the "Apply montage" option is gray and not available. When I try to click on it, I get an error (see photos).

153730505_2729768233951800_8890983478825992065_n 152795073_898219710930644_4323135247441097156_n 153944079_360893761845853_4225491227770698708_n 154397322_264084711896211_6631501529243454012_n

Could someone help? What am I doing wrong?

Thank you in adavance for helping.

Anaïs

1 Like

The menu "Apply montages" needs to rewrite the data and channel files, it is therefore not available from the original continuous file formats. You need to import epochs to your database before using it, as instructed in the SEEG/Epileptogenicity tutorial:
https://neuroimage.usc.edu/brainstorm/Tutorials/Epileptogenicity#Bipolar_montage

If you are a new Brainstorm user, or if you are not familiar with the different ways Brainstorm handles recordings, I would recommend you start by following the introduction tutorials using the example dataset provided. Then follow the two SEEG tutorials using the example datasets as well. Move on with processing your own recordings only with your are familiar with the software, this might save you a lot of time in trials and errors.

Hello,

Thank you, it's clearer now.

Is it absolutely necessary to import the anatomy and the position of the electrodes contacts when we work on sEEG data?

Because, if I don't do it, after applying the bipolar montage. The software says that there is 0 channel. Is there an alternative if we don't have access to the positions of the contacts?

If you don't have the anatomy available for your subjects and just want to process the signals, select "Default anatomy: YES" when creating your subject.
Then if you import a segment of recordings, apply a bipolar montage and display it, you should not have any problem.

This would work only if the naming of the channels follows the same logic as in the example below, with some letters (the electrode name) followed by the index of the contact on this electrode. A bipolar measure can be taken only if there are two adjacent indices.
If this is not the case: you may either rename your channels from the channel editor, or edit your own custom montage:
https://neuroimage.usc.edu/brainstorm/Tutorials/MontageEditor

image

image

image

image

image

A post was split to a new topic: SEEG bipolar montages with missing contacts