[FieldTrip] Easycap M10 coregistration with head model – no fiducials

Milan Mitka mitka3 at uniba.sk
Sat Mar 21 22:24:16 CET 2015

Dear Jim,

thank you for your reply. I realise that it's not the best setup but it's mostly for learning purposes and should suffice as is. The thing that still confuses me though is that the 10-20 template set does include fiducials whilst the M10 does not.

I've tried manual interactive alignment before but to no avail since the head model doesn't make it very easy to find landmarks. I've also encountered errors when attempting to perform non-linear transformations regardless of the cfg.warp setting.

Anyway, I've solved the issue by utilising a template MRI from SPM which used the MNI coordinate system as a basis for the head model and transformed electrode positions to MNI as well. It appears to be rather tidy so for now all is good.

Yours sincerely,

> On 20.3.2015, at 10:29, Herring, J.D. (Jim) <j.herring at donders.ru.nl> wrote:
> Dear Milan,
> If you have not recorded the electrode positions yourself using, for example, a Polhemus or Localite system you will always end-up with a suboptimal alignment (fiducials, or not). 
> That being said, you can skip the step of automatic realignment in the tutorial and immediately use ft_electroderealign with cfg.method = 'interactive', to manually rotate, translate, and scale the electrode positions to make it fit as well as possible to your headmodel. 
> Best,
> Jim

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