Converting smr file (Spike2) to edf for EEGLAB

Discussions
1

Good morning from Spain!

I am doing my first EEG analysis for my PhD and am using Spike2 but would like to run ICA on EEGLAB to clear the signal. I would need to convert .smr files from Spike2 into .edf files. I know this is doable through Brainstorm but am unsure how.
Thank you all,

Carlos

2

Hello

You could use Brainstorm to create EDF files from Spike2 .smr files:

  • Link your .smr files to your Brainstorm database
  • Right-click on the “Link to raw file” > File > Export to file, and select “EEG: European Data Format (*.edf)”

You need to be very careful with such conversion, as it might result in important data loss. This procedure is not a clean file conversion, it converts data from integers to floating point values (.smr => Brainstorm) and then back to integers (Brainstorm => EDF). This may result in distortions of the final signals, that could be insignificant in your analysis, or that could cause some visible artifacts in the frequency domain.

You can call EEGLAB’s runica function from Brainstorm direction (https://neuroimage.usc.edu/brainstorm/Tutorials/Epilepsy#Artifact_cleaning_with_ICA), so maybe you don’t have to convert back to EDF at all.

For learning how to use Brainstorm, I recommend you start by following the introduction tutorials (section “Get started”, at least until #19), followed by the tutorial “EEG and epilepsy” available from the same page.
https://neuroimage.usc.edu/brainstorm/Tutorials

Cheers
Francois

3

Cher François,

Merci beaucoup de votre réponse. I am doing my PhD at UQTR-UdM, and have heard a lot about you!

Thank you for your advice. I have read the first 19# so far, and have also been able to export as .EDF. I still have to try to run ICA through Brainstorm, which might save some of the data as you suggested. I would like to ask you, if I export from SPike2 as .mat, does it make it any better?

Thanks again,

Carlos

4

I export from SPike2 as .mat, does it make it any better?

Yes, it is better. If you keep the data in .mat format, you keep in in floating point values, which avoids the possibly damaging conversion floating point=>integer.
Export and process your recordings as .mat if possible.

5

It is possible, thanks again!