Coherence widget in development

bmarkusbmarkus
in OpenBCI_GUI
Anyone else interested in alpha coherence? 



I've had a few friends work on a widget for coherence, and it is partially done. 
Still needs a bit of work though.

At the moment the coherence is on the raw EEG, needs a BP filter for alpha.

This widget is intended for full screen usage, displaying 15 or 20 seconds of data. Right now there is a bug where after 7 seconds the graph stops. 

Ideally the graph would run like a heart monitor, refreshing from left to right while the actual graph remains still. In that case 7 seconds on screen would be perfect. 

As is it though, with data refreshing on the right and the whole graph running to the left, the data moves too fast to easily see the distinction between alpha waves and artifacts. Hence the desire for heart monitor style graph. 


The original coherence code was taken from Lagidigu https://github.com/lagidigu/FFT_Coherence/blob/master/Coherence.pde


Comments

  • SkalbeSkalbe Latvia
    Neat! Will try this out.
  • BillhBillh
    You want a heart monitor type interface, where the Y coordinate is updated with the X coordinate (time) done modulus the time window, so the screen does not scroll, the screen is updated one point at a time instead.  An example of this is I believe here:




  • bmarkusbmarkus
    Thanks Bill! 
    Seems like they got that going well in processing, time for some copy paste. I will hopefully update soon. 
  • retiututretiutut Louisiana, USA
    edited May 2019
    Feel free to make an issue on Github https://github.com/OpenBCI/OpenBCI_GUI/issues asking for this new widget. Then you can upload screenshots of the progress.

    Once it's done, we can have the OpenBCI team review the widget and possibly distribute with the GUI for everyone!

    Even if this is an advanced feature for experienced users, we can hide it using the new "Expert Mode" toggle in the Settings.
  • alexjalexj

    I'm curious, has there been any progress on a coherence visualization/neurofeedback software? I feel coherence could be a more efficacious tool for neurofeedback than localized power.

  • wjcroftwjcroft Mount Shasta, CA

    Alex, hi.

    For neurofeedback, alpha multichannel 'synchrony' training has a long history. Going back to Les Fehmi's Open Focus trainings and devices.

    The basic idea is just to sum the relevant channels. Fehmi used 5 channels at: Fz Cz Pz T3 T4. Then feedback on amplitude of the summation. Out of phase channels will tend to cancel. In phase channels will sum.

    The more formal 'coherence' metric is used in QEEG maps. Which is generally shown by a 19 channel 10-20 map, with all possible interconnected lines. Only pairs with strong coherence are illuminated.

    William

Sign In or Register to comment.

© Vanilla Keystone Theme 2026