sLORETA dipole orientation file

Discussions
1

Hello,

My question is : Where can I find the dipole orientation file after computing sources with the sLORETA method?

Process:
The dataset used is the sample_introduction.

  1. Import MEG files.
  2. Notch filter the MEG files.
  3. Classifying as deviant and the standard raw files.
    4.Averaging both.
  4. Computing Head Model
  5. Computing the Sources using sLORETA method for both deviant and standard files
    7.Extracting the values (process selection/extract/extract values)

Chatbot of brainstorm has recommended going to brainstorm_db\Introduction\data\NewSubject\S01_AEF_20131218_01_600Hz_notch and the file results_sLORETA_MEG_KERNEL_230712_2043.mat shall contain a column labelled 'ORIENTATION'.

Unfortunately, I can't find any column named orientation containing the locations of dipoles(x,y,z) and their orientation (θ,φ).

Goal:

The goal is to compare the results of sLORETA algorithm (dipole amplitude and orientation) with a home-brew source localization software.

image

2

Hi @GiannisNanis,

From the screenshots, sources were computed with sLORETA using constrained dipole orientations, i.e., the orientations are normal to the cortex (Surface), that was used to create the Head Model.

These orientations are stored in the field GridOrient in the HeadModel file (with path in the HeadModelFile field in the Sources file). In addition, these orientations are the same as the ones stored in the field the VertNormals in the Surface file (with path SurfaceFile field in the HeadModel file)

More details: https://neuroimage.usc.edu/brainstorm/Tutorials/HeadModel#On_the_hard_drive

3

Dear Raymundo,

Thank you a lot for your fast reply. Your answer covered me!