[FieldTrip] How to understand the channel location of ctf275 MEG data

[Zhi Li]

Hi,

I am new to MEG data and have no experience in collecting them. When I
processed the ctf275 MEG data, I found that the channel location in
hdr.grad.chanpos were not the same across subjects. For example, the
Cartesian coordinates of MLC11 from the data of 3 subjects were [7.96,
1.67, 13.94], [8.9, 1.1, 13.68] and [20.04, -0.03, 14.33] respectively.
Hence both the 3D channel location and their 2D projections are different
across subjects. May I ask how these Cartesian coordinates were calculated
and should we standardize them before data processing, i.e., make the
channel location the same across subjects? Any suggestions would be much
appreciated.

Best,

Li Zhi
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20220714/7bae94fd/attachment.htm>