[Eeglablist] electrode locations shifted when using headplot on EGI's GSN-HydroCel-128.sfp

[Ingrid Nieuwenhuis]

Hello everyone,

I am trying to make a beautiful 3D topoplot on the head using headplot. I
have 128 channel EGI data, GSN-HydroCel-128.sfp layout. When I plot the
electrode positions they are not correct, see the picture here:
https://www.dropbox.com/s/g4b1uvwlgof63cm/headplot_GSN-HydroCel-128.jpg. It
looks as if the net is not pulled down enough: the electrodes that should
be on the cheeks way under the eyes are located on the eye balls, and also
the ear in the picture is not in the ear hole of the net. All the
electrodes are too high up.

I've created the spline file with the option 'sfp' for 'filetype' as I read
that sfp data format is supported. I used the standard EGI electrode
location file GSN-HydroCel-128.sfp, after removing the FidNz, FidT9, FidT10
place holders. Does any one know why this happens, and how I can fix it?

I'm new to EEGlab (normally use FieldTrip). I haven't used the GUI but used
code:

% step 1 create spline file
elocs =
readlocs('C:\Users\Ingrid\Documents\MATLAB\FieldTrip\template\electrode\GSN-HydroCel-128.sfp',
'filetype', 'sfp');
splinefile = [cur_path_MLD, 'EEGLAB_splinefiles', filesep, 'EGI_128.spl'];
headplot('setup', elocs, splinefile);

% step 2 test the electrode locations
splinefile = [cur_path_MLD, 'EEGLAB_splinefiles', filesep, 'EGI_128.spl'];
figure;
headplot(rand(128,1), splinefile)

Thanks a lot!
Ingrid
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