questions on using MindAffect with Cyton
Hi there!
I'm trying to make this system to allow my mom, who has ALS, to talk to us, at least with a simple YES/NO.
I have purchased all the components and assembled the hardware, but I can't get MindAffect to work.
Do the electrodes have to be connected in a specific order to the pins on the Cyton board?
If not, what else could I be doing wrong?
I start a Windows > CMD, use the code
python -m mindaffectBCI.online_bci
and select the file \pymindaffectBCI\mindaffectBCI\online_bci.py, but it doesn't seem to work.
Can you help me?
Thank you very much in advance for any help!
Nicola
Comments
Nicola, hi.
There are many steps required in setting up the MindAffect system. I assume you are reading their pages,
https://mindaffect-bci.readthedocs.io/en/latest/
https://mindaffect-bci.readthedocs.io/en/latest/quickstart.html
https://mindaffect-bci.readthedocs.io/en/latest/quickstart.html#2.-Signal-Quality
https://mindaffect-bci.readthedocs.io/en/latest/quickstart.html#3.-Calibration
https://mindaffect-bci.readthedocs.io/en/latest/fitting_guide.html [general location of occipital electrodes]
One factor that is extremely important with the cVEP / VEP display screen stimulation used by MindAffect, is the frequency fidelity of the entire graphics chain timing. MindAffect has written extensively on this.
https://github.com/mindaffect/pymindaffectBCI ['FrameRate check' section, and read about VSync feature]
https://mindaffect-bci.readthedocs.io/en/latest/build_your_own_optical_sensor.html
https://mindaffect-bci.readthedocs.io/en/latest/stimulus_time-lock_test_tutorial.html
Regards, William
Hi William,
thank you so much for your response!
I did some more testing and was only able to get debug mode to work.
Specifically:
Double click on "online_bci.py" and opening the "debug.json" file.
What is the correct file that should ultimately be used?
I tried "noisetag_bci.json" and it starts, but it doesn't work. It doesn't detect activity on the electrodes.
Thank you very much for your help!
See you soon!
Nicola
I'll also take the opportunity to ask you another question already.
For my mother (sick with ALS) I would need to make a very simple screen with only two keys YES and NO and not the whole QWERTY keyboard, how can I do?
Thank you very much!
Hi,
Nicola
Nicola, see this section in the tutorial document (previously linked),
https://mindaffect-bci.readthedocs.io/en/latest/goingfurther.html
It shows how to setup your own matrix of choice buttons, using phrasing of your choice of words.
William
Thanks William!
About the other question that I repost here, can you help me?
I did some more testing and was only able to get debug mode to work (debug.json).
Specifically:
Double click on "online_bci.py" and opening the "debug.json" file.
What is the correct file that should ultimately be used?
I tried "noisetag_bci.json" and it starts, but it doesn't work. It doesn't detect activity on the electrodes.
Thank you very much for your help!
See you soon!
Nicola
Are you going through ALL the Quickstart steps in the order outlined?
https://mindaffect-bci.readthedocs.io/en/latest/quickstart.html#1.-EEG-headset-Setup
Hi William,
I had the wrong connection! I had indicated the wrong COM port!
Now it sees correctly all the channels of the Cyton, but I still have a problem: the noise level is very high, practically always at 100, when it should be less than 5.
It seems that there are a lot of factors that affect it: the power batteries of the Cyton board (which are necessarily close to the board itself) the bundle of electrode cables (which are currently all connected together), etc..
Do you have any suggestions for bringing the noise level down to the acceptable threshold?
If it helps, I can send a picture of my current setup.
Thanks a lot for your help!!!
Generally, EEG noise level is highly correlated with the quality of your scalp electrode connections. You should use 'wet' electrodes with MindAffect. 'Dry' electrodes have less signal amplitude and quality. Wet electrode types include: cups and paste, gel, saline. Mindaffect's headband uses silver chloride pins wrapped in a sponge soaked in water.
You can use the OpenBCI GUI to check the impedance of your electrode connections. Lower is better.
There are multiple sections in the Mindaffect docs, regarding noise reduction, calibration, etc. Previously mentioned the importance of the accuracy of the flash frequencies produced by your monitor. Mindaffect provides calibration procedures using a photodiode.