Dear all,
I am trying to import in Brainstorm EEG data originally recorded with the Brain Vision system and the 64 channels easycap. I have imported the data in EEGLAB, while I do not actually have them anymore in the original Brain Vision Analyzer format.
My problem is that when I import the EEG channel locations from the EEGLAB data file I obtain a mismatch with the default anatomy (see figure attached). Does anyone have a correct EEG channel location file that fits with Brainstorm’s default anatomy (as Brainstorm’s default EEG caps)? Attached also the channel location file from EEGLAB. Unfortunately none of the default EEG caps coincide with the locations of my cap.
Thanks for your help,
Marco
Hi Marco,
You can do a bit a manual alignment: right-click on the channel file > MRI registration > Edit.
Then read the tooltips for all the buttons in the toolbar to learn how to do translations/rotations/scaling.
When you’re done, click on the button “Project on scalp”, then Ok.
If would be easier if you have some transparency for the head surface. The head should be transparent by default, if it is not check the Brainstorm preferences and enable the OpenGL renderer.
Cheers,
Francois
Thanks Francois, but since I have standard positions, I wonder whether this has been done previously in a systematic way - I do not trust much my manual alignment.
In fact I see that the standard EEG channel setups for the Colin27 anatomy contain all my channels (though I need to combine 2 or 3 setups) but two: F9 and F10. Does anyone have these locations?
And by the way, is it correct to combine the 3D position of the electrodes having standard names (e.g. Cz, Cpz etc…) from different setups, or each setup was obtained separately?
Thanks,
Marco
[QUOTE=Francois;5575]Hi Marco,
You can do a bit a manual alignment: right-click on the channel file > MRI registration > Edit.
Then read the tooltips for all the buttons in the toolbar to learn how to do translations/rotations/scaling.
When you’re done, click on the button “Project on scalp”, then Ok.
If would be easier if you have some transparency for the head surface. The head should be transparent by default, if it is not check the Brainstorm preferences and enable the OpenGL renderer.
Cheers,
Francois[/QUOTE]
Dear Francois and all,
I have eventually modified the “BrainProducts ActiCaps 65” by:
- adding F9 and F10 by hand
- adding FPz by setting FP1 y coordinates to zero and then projecting the electrode to the scalp
- removing the electrodes not included in my setup
- rearranging the electrode order in the channel*.mat file
It is not perfect, but it might help, you’ll find it attached.
Best,
Marco
Hi Marco,
This looks great! I don’t think there is not any set of electrodes positions that can be considered as perfect for the template anatomy…
The idea is to have something that looks ok and that can be re-adapted to other subjects if need.
You checked that the order of the electrodes in the channel file matches what you have in the recordings, right?
I’ve already added it to the brainstorm distribution.
Thanks
Francois
Great!
And yes I have checked that the order of the electrodes is the same in the data and in the channel file.
Best,
Marco
Dear Marco,
This template is very good, thanks for doing that.
I was wondering if any of you have a easy cap-128 electrodes (56 or 58-size) digitized.
I am experimenting some problems with our zebris system, so it would help me a lot if I could have a more realistic template than my manual positioning version.
Cheers,
Danilo
Hi Danilo,
No, I’m sorry I don’t have electrodes 3D positions for an EasyCap 128…
If you find this somewhere you can send it to me as well, so I can include it in the Brainstorm distribution.
Cheers,
Francois
I do not have either, sorry.
Marco
[QUOTE=Francois;6836]Hi Danilo,
No, I’m sorry I don’t have electrodes 3D positions for an EasyCap 128…
If you find this somewhere you can send it to me as well, so I can include it in the Brainstorm distribution.
Cheers,
Francois[/QUOTE]