Is my 2D sensor cap wrong?

Discussions
1

Hello,

comparing my 2D sensor scalp shape with the one from the "EEG & Epilepsy" tutorial, I just realised that mine looks strange, even rotated by 180°.

I am using an "g.GAMMAcap" EEG cap from g.tec, and recording with 62 electrodes.
I imported a custom .xyz channels file and used "MRI Registration > Edit" to fit it to the default anatomy (I don't have individual MRIs). I'm happy with the result but still concerned about the shape of the 2D sensor cap.

Please find attached to this post screenshots of

  • the electrodes positions after "MRI Registration > Edit"
  • the 2D sensor cap shape
  • the channel file

Is it normal that my 2D sensor cap shape is different or did I miss something ?

Thank you in advance for your help.

François

EEG_3D_Subject04_@rawS04_ind_inv1.tif (165.6 KB)

EEG_TP_Subject04_@rawS04_ind_inv1.tif (319.7 KB)

ChannelFile
ChannelFile271×930 16.9 KB

2

Hi François

The 2D sensor cap looks like the convex hull encompassing all the sensor points, so if you cover a different space than the reference EEG cap the 2D cap can look different and that will not be a problem.

The orientation seems to match the 3D orientation that you sent so I think what you see is normal :slight_smile: Though someone else might have a different opinion.

Kind regards,
Steven

3

I agree, it looks completely normal.

4

Okay, thank you very much to both of you for relieving me from this doubt!

1 Like