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Hi Zhi Li,
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<div class="">I am unfamiliar with the way in which EEGLAB deals with sensor/electrode positions, and how these are read from the data file. </div>
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<div class="">On the other hand it is unclear to me what your actual problem is. Is it only a matter of visualization (because for ICA the sensor positions are not needed)? Have you checked the EEGLAB documentation?</div>
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<div class="">Since you are asking for another solution: you can also do the ICA in fieldtrip, there’s no need to go to eeglab for that.</div>
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<div class="">Best wishes,</div>
<div class="">Jan-Mathijs</div>
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<div class="">On 30 Jun 2022, at 22:07, Zhi Li via fieldtrip <<a href="mailto:fieldtrip@science.ru.nl" class="">fieldtrip@science.ru.nl</a>> wrote:</div>
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<div dir="ltr" class="">Hi,
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<div class="">I would like to use ICA and IClabel in EEGLAB to detect artefacts in my MEG data. But no matter if I used <i class="">fieldtrip2eeglab</i> or <i class="">pop_fileio</i>, the<i class=""> </i>gradiometer channel positions cannot be correctly extracted from the
ctf275 .ds folder. The channel positions in eeglab format <i class="">EEG</i> are all empty.</div>
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<div class="">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.</div>
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<div class="">May I ask how I could transform the MEG channel position from FieldTrip to EEGLAB appropriately, or is there any other solution? Many thanks.</div>
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<div class="">Best regards,</div>
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<div class="">Zhi Li</div>
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