Dear Fabian,

Since your channels have standard 10-20 labels, using the default locations in SPM will be more precise than fitting spherical locations to a non-spherical head.

For information about loading custom locations file see section 37.4.8 (p. 379) of SPM8 manual.  In addition to the steps described there you will need to  do a 'Coregister' step (also via prepare) using some of your electrodes as fiducials and choosing 'yes' for 'use headshape points'. But as I said, I suggest you only do it if you have something better than converted spherical locations.

Best,

Vladimir


On Mon, Jun 30, 2014 at 12:33 PM, Fabian Klein <[log in to unmask]> wrote:
Dear Vladimir,

I have the spherical coordinates in BESA-format, converted to a .spf file, the content looks like this:

     Fp1    -0.30883     0.95048    -0.034899
     AF3    -0.40625      0.8712     0.27564
      F7    -0.80852     0.58743    -0.034899
      F3    -0.54501     0.67303         0.5
     FC1    -0.37471     0.37471     0.84805
     FC5    -0.88789     0.34083     0.30902
      T7    -0.99939           0    -0.034899
      C3    -0.71934           0     0.69466
     CP1    -0.37471    -0.37471     0.84805
     CP5    -0.88789    -0.34083     0.30902
      P7    -0.80852    -0.58743    -0.034899
      P3    -0.54501    -0.67303         0.5
      Pz           0    -0.71934     0.69466
     PO3    -0.40625     -0.8712     0.27564
      O1    -0.30883    -0.95048    -0.034899
      Oz           0    -0.99939    -0.034899
      O2     0.30883    -0.95048    -0.034899
     PO4     0.40625     -0.8712     0.27564
      P4     0.54501    -0.67303         0.5
      P8     0.80852    -0.58743    -0.034899
     CP6     0.88789    -0.34083     0.30902
     CP2     0.37471    -0.37471     0.84805
      C4     0.71934           0     0.69466
      T8     0.99939           0    -0.034899
     FC6     0.88789     0.34083     0.30902
     FC2     0.37471     0.37471     0.84805
      F4     0.54501     0.67303         0.5
      F8     0.80852     0.58743    -0.034899
     AF4     0.40625      0.8712     0.27564
     Fp2     0.30883     0.95048    -0.034899
      Fz           0     0.71934     0.69466
      Cz           0           0           1



Could you please tell me how I can project these locations to 2D for my layout? Is it possible to do this via GUI?

Thank you very much!

Best regards,
Fabian


On Mon, Jun 30, 2014 at 12:30 PM, Vladimir Litvak <[log in to unmask]> wrote:
Dear Fabian,

The most straightforward was to create a 2D layout for your Biosemi cap would be to load a 3D sensor locations file (in .sfp format) and then project the locations to 2D to make a layout. You could either look for a standard file from the manufacturer or make a measurement with a 3D digitiser. 

SPM currently includes standard locations for 64- and 128-channels Biosemi caps. If there is interest from Biosemi users to also add 256- and 32- channel caps and they provide us with good quality 3D locations I'd be happy to add them but, just to SPM12 as SPM8 is no longer being developed. It shouldn't be a problem to load them manually in SPM8 though.

Best,

Vladimir



On Sun, Jun 29, 2014 at 12:02 PM, Fabian Klein <[log in to unmask]> wrote:
Dear Vladimir,

I am a PHD student at the Bielefeld University and we are trying to analyze our EEG data acquired by a BioSemi system with SPM8.

For our most recent data sets, we need a montage for the 32channel headcap. The only layout file I found for this headcap is from FieldTrip - https://code.google.com/p/fieldtrip/source/browse/trunk/template/layout/biosemi32.lay?r=4536 .

Since I am rather a user than a developer, I have difficulties in finding a way to implement this layout file in SPM.

Could you maybe help me with this issue? That would be great!

I would need a script that uses the layout from the fieldtrip .lay-file, channels 1:32 + VEOG (channel 33-34) + HEOG (channel 35-36).

Since the 32, 64, 128 and 256 channel headcaps from BioSemi all have standardized layouts, it would maybe make sense to include them into the "standard" SPM distribution.

Thank you very much for your help!

Best regards,
Fabian


--
Fabian Klein, M.Sc.
------------------------------
--------------------------------------
Universität Bielefeld
Fakultät für Psychologie
AE Klinische Psychologie und Psychotherapie
Raum: T3-262
Tel.: (0521) 106-4489
[log in to unmask]




--
Fabian Klein, M.Sc.
------------------------------
--------------------------------------
Universität Bielefeld
Fakultät für Psychologie
AE Klinische Psychologie und Psychotherapie
Raum: T3-262
Tel.: (0521) 106-4489
[log in to unmask]