[Eeglablist] CTF sensor coordinates and dipfit approach

[Arnaud Delorme]

Dear Baris,


> 1) The sensor coordinates are already corrected/oriented to the
> fiducials recorded at the beginning of the run, is this correct?


No you have to do that yourself.


> 2) The 2D scalp views of the ICs correctly represent the head
> orientation, right? Nose is pointing to the +X direction -> up? Do I
> have to rotate it?


I am not sure about that. You should use the channel labels to see if the head montage has to be rotated.


> 3) Is there a document / web source comparing the way the EEG versus
> MEG eye and ekg artifacts look alike/different on the scalp
> topography? Is there a toolbox using ICA to reject the MEG artifacts
> automatically (I think ADJUST and others only correct  EEG artifacts,
> not MEG artifacts, is this right?).


EEG and MEG artifact time courses are very similar. However scalp topographies may differ.


> 4) When I followed the dipfit stages defined in the web tutorial
> (coarse fit etc.) it asks for subject mri co-registered with the CTF
> file, this has to be in .mri format. Actually I have AFNI formatted
> anatomical file where I marked the fiducials. Can I convert it back to
> .mri data format, or is there a way that I can use this AFNI file
> instead in DIPFIT? Any suggestions?


The function might load the AFNI file. Try it. It is a generic function that loads many formats.

Note that usually MEG users prefer Fieldtrip or Brainstorm to EEGLAB especially when it comes to source localization.
Fieldtrip and Brainstorm were developed for MEG first and EEGLAB was developed for EEG first (this is a caricature of course). 
In any case, let us know what problem you encounter so we can make EEGLAB more MEG friendly.
Thanks,

Arno