Question about epoch-specific bad channels

1

Hi, I had a question concerning bad channels. I currently work on another software where I've already visually inspected my EEG data and labelled some channels as bad but only for specific segments.

I take these labels/events, and import them on brainstorm to run further analyses on the EEG.
Currently, this looks like this:
image

I have a label called "Eveil", which is the EEG i want to further analyze, and amongst the events labelled as "Eveil", I also have concurrent labels of channels with artefacts. In the screenshot above, I have segments for which the channel C3-M2 is bad. These "bad" segments are of varying lengths and are specific to the C3-M2 channel.

I know I can reject all of the segments where C3-M2 is artefacted, by rejecting the trials (or naming it as bad__ as I've done here). However doing it this way reduces my data by a lot because it also rejects the good channels in that segment.

My question is, if for my label "Art C3-M2" I specify the bad channels, are these also excluded from my "Eveil" segments? Although these are two different labels, they overlap in time.

Thank you,

Edit: I've previously read on the forum that, when averaging the trials, the bad channels are indeed excluded. But I wondered if this would still apply in my case, where the "trials" have different labels-- yet overlap in time.

Soraya

2

The bad channels are defined file by file.
If you mark some channels as bad in trials of the group bad_"Art C3-M2", there is no reason for which they would be tagged as bad in any other files (e.g. the files from the "Eveil" group).
To get the list of bad channels for all the files in a folder or in a trial group: right-click on the folder > Good bad channels > View all bad channels.
https://neuroimage.usc.edu/brainstorm/Tutorials/BadChannels

Another advice: I'd recommend you don't use special characters (eg. like double quotes ", French accents, spaces) in your even names, file names or folder names... File comments or event names with double quotes may cause weird behaviors in some processes.

3

Okay I see. Just to clarify the wording; the trials in the group bad_art C3-M2 are from the same EEG file as the trials in the Éveil group. So effectively, they are the same file— are you talking about the folder grouping specifically?

And okay thanks for tip about special character !

4

I'm sorry, I don't think I understand what you are expecting from us.
Can you please include more descriptions and screen captures to explain better your request/problem/question?