mne2grad on fiff file created by kit2fiff

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1

Hi,

I have some Yokogawa data which I have converted into .fif file using
kit2fiff and I want to be able to read the .fif file in FieldTrip.
FieldTrip calls on the function mne2grad from the MNE toolbox to convert
the header into a gradiometer structure that can be understood by field
trip. The gradiometer structure should look like the structure below,
however when I try to do it, the grad field is missing. Does the mne2grad
function not work for fiff files created by kit2fiff?

hdr =

          label: {317x1 cell}
         nChans: 317
             Fs: 1000
           grad: [1x1 struct]
           unit: {1x317 cell}
       nSamples: 396000
    nSamplesPre: 0
        nTrials: 1

           orig: [1x1 struct]

Thanks,
Israr
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2

hi Israr,

I don't know hat Fieldtrip is doing. mne2grad.m is not an MNE function.

Does the converted fif file look good?

Best,
A

3

The fif file seems to be behaving perfectly fine when Im doing the
preprocessing, artefact rejection, frequency transformation etc in
fiedtrip.

when fiieldtrip mentions mne2grad, they refer back to the mne software
http://www.fieldtriptoolbox.org/getting_started/neuromag

I guess the question is whats the difference between a normal .fif file
(from neuromag) and a .fif file created by kit2fiff (from yokogawa)
regarding storage of the coil and sensor location information.

Thanks
Israr

4

hi,

MNE has a dedicated coil type and a coif def file to specify the geometry
of the coil. If the file is working fine I guess it's a fieldtrip
problem to handle
these files properly.

Best,
Alex