Source Localisation using sLORETA

Discussions
1

Hello,

I am a beginner in Brainstorm. So far I have been following the tutorial videos in accomplishing the pre-processing of my ERP data. I have just measured the weighted averages of my data along with extraction of maximum amplitudes in time between a window of 400 - 800 ms in attempting to mark the Late Positive potentials. Kindly give me guidance as to how to go about with source localization for these maximum amplitudes that have been extracted.

2

Hello,

Welcome to the brainstorm forum ! The videos are nice as a tutorial, but the tutorial section is a bit more extensive, I would suggest following the tutorials from this page: https://neuroimage.usc.edu/brainstorm/Tutorials
And from that page especially :
https://neuroimage.usc.edu/brainstorm/Tutorials/SourceEstimation

Kind regards,
Steven

3

After reading all the introduction tutorials (section "Get started" on the tutorials page), I'd recommend you also read the tutorial "EEG and epilepsy", which explains some more details related with EEG processing.
https://neuroimage.usc.edu/brainstorm/Tutorials/Epilepsy

4

Hi Francois,
Can we try the EEG processing pipeline (mentioned in EEG and epilepsy tutorials) for analysing any ERP wave? If you elaborate a bit, that would be of great help.
Best,
Umesh

6

The standard ERP/ERF pipeline we recommend is the one described in the introduction tutorials (section "Get started", from #1 to #19).

7

Thanks Francois for quick response!
I have followed those steps.
But, my interest is to estimate the cortical sources (preferably sLORETA) of those averaged ERP waves (specific time series); compare group A (clinical population) vs group B (healthy subjects) and correlate the scores (from the source estimates) with the clinical scales. I am not sure how to retrieve the scores (generated from the ROIs or scouts) so that I can use them in a different statistical software.
Lastly, is it ok if I use the source files and do the comparison using SPM 12 or should I go with permutation/parametric test of these source files using brainstorm? I failed to find any reference paper.
Thank you...
Best,
Umesh

8

You can refer to the pipelines described in this tutorial:
https://neuroimage.usc.edu/brainstorm/Tutorials/Workflows#Statistics:_Group_analysis.2C_between_subjects-1

I am not sure how to retrieve the scores (generated from the ROIs or scouts) so that I can use them in a different statistical software.

Please post screen captures of the files you have (database explorer + display of these files), describe the measure you would like to extract from them.
Please create a different thread, as this is not related to the initial question posted here.

Lastly, is it ok if I use the source files and do the comparison using SPM 12 or should I go with permutation/parametric test of these source files using brainstorm?

This is up to you to decide what kind of analysis you want to perform on your data.

The documentation of the Brainstorm statistics:
https://neuroimage.usc.edu/brainstorm/Tutorials/Statistics

The documentation to export data to SPM as surface or volumes:
https://neuroimage.usc.edu/brainstorm/ExportSpm8
https://neuroimage.usc.edu/brainstorm/ExportSpm12

1 Like
9

Thanks so much, Francois.
Best,