[Eeglablist] CTF275 MEG channel position from FieldTrip to EEGLAB

[Delorme, Arnaud]

Hi Zhi Li, 

You cannot use IClabel to detect ICA artifactual components because MEG components will be different than EEG components, and IClabel has been trained with EEG components. You would need a version of ICLabel that is trained with MEG components (there is no such version to my knowledge). This page describes how to go back and forth between Fieldtrip and EEGLAB https://urldefense.com/v3/__https://eeglab.org/others/EEGLAB_and_Fieldtrip.html__;!!Mih3wA!GdqMukf4QIghAjPElKn7P002MH0bglbmmz2o_rGLB4yz2rDBoG4pz5A0bvDvKyrl8kzwWduwI27V0gtjuVBSS8Ap$ 

Cheers,

Arno

> On Jul 8, 2022, at 4:13 PM, Makoto Miyakoshi via eeglablist <eeglablist at sccn.ucsd.edu> wrote:
> 
> Good to hear that Zhi. And thank you for sharing your solution with others!
> 
> Makoto
> 
> On Fri, Jul 8, 2022 at 3:50 PM Zhi Li <lizhi.psych at gmail.com> wrote:
> 
>> Hi Makoto,
>> 
>> Many thanks for your kind reply. I have solved this problem by adding the
>> channel type to *pop_fileio. *
>> 
>> Best wishes,
>> 
>> Zhi
>> 
>> On Fri, 8 Jul 2022 at 17:09, Makoto Miyakoshi <mmiyakoshi at ucsd.edu> wrote:
>> 
>>> Dear Zhi,
>>> 
>>> I don't have the same experience but I remember I also had some
>>> inconvenience with fieldtrip2eeglab for which I needed to modify it a bit.
>>> Anyway, it sounds like a low-level technical problem, which I recommend you
>>> post to eeglab github issues to let the developers know.
>>> 
>>> https://urldefense.com/v3/__https://github.com/sccn/eeglab/issues__;!!Mih3wA!AShbXpOalytJYyNBenicz3U1qA3DxCYBnVQ8O5jtXMD3GX6wJmHSL8EVomTT7hl7bg4nLYnwC8aRMEF4xG-V2dkZx8c$ 
>>> <https://urldefense.com/v3/__https://github.com/sccn/eeglab/issues__;!!Mih3wA!ExFgptOGjSywLmKWBZm34Y3nUDeCVnEamNcPt-4nV17d-Lr_lGmxxIPChGT1wl-4L2zIZ6MguzDiZOnMyCG9LpE$>
>>> 
>>> It may take some time for the developers to take a look at it. Sorry for
>>> the inconvenience.
>>> 
>>> Makoto
>>> 
>>> On Fri, Jul 1, 2022 at 2:01 PM Zhi Li <lizhi.psych at gmail.com> wrote:
>>> 
>>>> Hi,
>>>> 
>>>> I would like to use ICA and IClabel in EEGLAB to detect artefacts in my
>>>> MEG
>>>> data. But no matter if I used *fieldtrip2eeglab* or *pop_fileio*, the
>>>> gradiometer
>>>> channel positions cannot be correctly extracted from the ctf275 .ds
>>>> folder.
>>>> The channel positions in eeglab format *EEG* are all empty.
>>>> 
>>>> I tried to copy the channel information directly from the header of the
>>>> ctf275 data folder but the MEG channels cannot be projected on the 2-D
>>>> map
>>>> appropriately. It seems like the channel position in the MEG data
>>>> imported
>>>> by FieldTrip are the real locations of the MEG helmet and their unit is
>>>> cm.
>>>> whereas the channel position in EEGLAB is based on the 10-10 system which
>>>> is already on the scalp. Hence the projected channels on the scalp are
>>>> all
>>>> misplaced if I use the raw XYZ from the header of ctf275 data.
>>>> 
>>>> May I ask how I could transform the MEG channel position from FieldTrip
>>>> to
>>>> EEGLAB appropriately, or is there any other solution? Many thanks.
>>>> 
>>>> Best regards,
>>>> 
>>>> Zhi Li
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>>> 
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