Virtual source maps MN (unconstrained)

Discussions
1

Hello!
I was just wondering what is plotted when I double-click on the virtual source map obtained through unconstrained source MN estimation (for example for one epoch). How are the 3D values flattened? I guess it's the norm of the 3D components, right? Not the principal component as explained here: https://neuroimage.usc.edu/brainstorm/Tutorials/PCA#Unconstrained_source_flattening_with_PCA
Thanks!

2

This is correct:

Brainstorm displays the norm of the vectorial sum of the three orientations at each vertex.
S = sqrt(Sx^2 + Sy^2 + Sz^2)

https://neuroimage.usc.edu/brainstorm/Tutorials/SourceEstimation#Unconstrained_orientations

3

thanks a lot Raymundo! Sorry I oversaw this line in the tutorial!