A surface scout but the sources are calculated on a volume grid

Dear Brainstorm Team,

I am trying to calculate PSD and Connectivity metrics for EEG data after computing sources. Everything works fine for surface sources but I am facing a problem when I am doing it for Volume sources as it gives me this error although I am using AAL1 atlas for both computations.
I went through similar problems like Error: scouts on volume grid, but surface sources and tried to fix it using the proposed ways although I still face the problem.

Kindly guide me what to do in this regard.
Sincerely,
Abrar

Please verify the selected Atlas in the process GUI.

From the error message, it seems a Surface atlas was selected. Volume atlases start with the word Volume

https://neuroimage.usc.edu/brainstorm/Tutorials/TutVolSource#Volume_atlases

Thank you for your reply.
I am using AAL volume atlas


Yesterday it was identified by brainstorm as a surface atlas and today as a volume atlas so when I tried to compute PSD and connectivity for surface sources it gave me this error.

Sincerely,
Abrar

Can you share the screenshot of the process GUI and the parameters that you are using?

  1. This is the GUI for surface source PSD computation

  2. I have a question regarding connectivity measures, I am using a data epoch of 63 seconds the parameters in the GUI are as the following;


    in the output file in the TF variable I get matrix which contain:
    TF : [Nr x Ntime x Nfreq] = [44675 X 30 X 7] or [4467 X 29 X 7]
    I know that the first one are the connectivity pairs and the second one are the time points and the third are the frequency bands
    My question is why I get 30 or sometimes 29 for the same folder? And how to get only 1 time point for the whole 60 seconds epoch?

Sincerely,
Abrar

@Abrar, please read carefully the error messages, you have reported two different errors, both have the same cause, the spaces for the sources and for the atlas are note the same:

A: In here, the sources were in volume, but the atlas was surface, thus the error:

B: But here, the sources were in surface but the atlas was volume, thus the error:


Could it be that in some computation you are setting the beginning of the Time window to 0s, rather tha -0.003s?

This is the parameter Time resolution, in the shared screenshot, coherence is computed in windows 4s, and 50% overlap. If one time value is required, there is no time resolution, thus select None

P.S. For any question on a new topics, please create a new post.

Got it, much appreciated for your comprehensive answer :slight_smile: