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PostPosted: Sat Apr 08, 2017 9:24 pm 
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Joined: Tue Jan 19, 2016 12:11 pm
Posts: 4
hello,
I need to use openVibe for the following purposes:
1. harvesting EEG data with Mitsar-202 before neurofeedback training.
2. calculating [b]individual upper alpha (IAF).
3. Neurofeedback for IAF.

I built a simple scenario for acquiring the EEG signal (without calculating IAF) but I am not completely sure its a good one neither training blocks.
May you please help ? :shock: :?

thank you in advance!
Nehai


Last edited by nehaif on Wed Aug 23, 2017 7:38 pm, edited 1 time in total.

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PostPosted: Mon Apr 10, 2017 7:43 am 
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Joined: Tue Dec 04, 2012 3:53 pm
Posts: 572
Location: INRIA Rennes, FRANCE
Hello Nehai,

that would need some work as we don't have classic neurofeedback training example. From what I can see, you need

- a component/technique to clean the data. There's eyeblink removal box ('EOG Denoising') and some filtering boxes provided with openvibe, but we don't have pre-made examples of how they can be used for data cleaning.
- to catch the upper alpha. this you can perhaps do with band pass filter, simple dsp, epoch, average (take band + square + aggregate)
- something to pull the max from the alpha. This can be done with 'percentile' in the 'univariate statistics' box. It computes one value per input buffer (epoch).
- a timeline to control the neurofeedback. in openvibe, this is usually done with lua scripts (e.g. motor imagery and ssvep scenarios)
- a gauge display to show the neurofeedback result. The closest box to that is the Graz Visualization which could be pruned to become a simple gauge. Needs coding.


Good luck,
Jussi


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PostPosted: Tue Apr 11, 2017 12:31 pm 
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Joined: Tue Jan 19, 2016 12:11 pm
Posts: 4
Dear Jussi,
I thank you deeply for your answer. since I am a new user I have lots of question:) besides my neurofeedback protocol is complicated therefore I need to be sure I am using openVibe the right way...

I think I understand how my Neurofeedback design should be...

1. measuring the alpha baseline values above the six Neurofeedback channels - using the aquisition client box; identitity, reference channel, channel selector.
Do I need multible signal display boxes for each electrode I choose?

2. cleaning data - EOG, EOG diagnoses boxes


thanks again for your help,


Last edited by nehaif on Wed Aug 23, 2017 7:36 pm, edited 1 time in total.

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PostPosted: Wed Apr 12, 2017 8:11 am 
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Joined: Tue Dec 04, 2012 3:53 pm
Posts: 572
Location: INRIA Rennes, FRANCE
Here's some thoughts,

1. Signal Display by default shows all channels that are given to it. You can limit this by channel selector. If it makes a reasonable neurofeedback display is another question entirely (thats why I was speaking of a gauge). In principle you can insert signal displays anywhere in the signal processing chain to see how the data gets transformed.

4-5. I think the univariate statistics return the value of the computation, for example the percetile. This value would need to be inserted to simple dsp to scale the signal, but I think there's no neat way to do this automatically. One option is to EBML stream spy or CSV Writer to get the value out and then insert it to the simple dsp formula by hand. Maybe there's a more neat way to achieve the same, but not sure.

6. Basically in openvibe experiments and such are controlled by timelines of stimulations (event markers): a stimulation at some point in time is interpreted by the boxes in the scenarios to do different things. See the mentioned bci example scenarios to see how such timelines can be constructed with .lua. Then you need these stimulations to change what your scenario does, e.g. by using them to route the signal or have boxes in general react to them, for example start or stop audio playback.

Usually cooking something bigger in openvibe is achieved by trying to do it, and eventually you manage to find out how it can be done. In the end it is possible that some features are simply missing and need to be implemented or hacked, some way or another.


Happy hacking,
Jussi


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PostPosted: Tue Jun 06, 2017 10:19 pm 
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Joined: Wed Dec 17, 2014 2:52 pm
Posts: 21
this sounds nice, I am very interested in your scenario, would you mind posting your progress?
isn't individual Alpha Peak Frequency training (iAPF) developed in the netherlands https://www.brainclinics.com/ ?
By Arns et al.? (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3419351/ , ...)

What electrodes are you using for this scenario?


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