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 Post subject: feedback sound play
PostPosted: Thu Apr 23, 2015 9:01 am 
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Joined: Mon Feb 02, 2015 2:46 pm
Posts: 16
Hello everyone,

Firstly thank you for this software and the people who are helping.

I am working on the Cognitive BCI and have a task to see how much the subject is focusing to measure their attention.
For this I have already created a scenario and good some output. Moving future, I would like to add some feedback intimation
i,e when a subject is taking a task and if he/she loses his/her attention, then a sound play to intimation or alert them to focus.

Since I have no idea how to do it Iam requesting people to help me.
Thank you for your time.

Regards,
GR


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 Post subject: Re: feedback sound play
PostPosted: Thu Apr 23, 2015 10:02 am 
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Joined: Sun Mar 14, 2010 12:58 pm
Posts: 108
Hello,

To play a sound following an event, you can use the "sound player" box, which plays a sound when it receives a given stimulation.
So typically, you can use the "sign change detector" box, to send this stimulation when the output of your attention detector (whatever it is) changes from attentive to inattentive for instance.

I hope this helps,

Best regards,
Fabien


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 Post subject: Re: feedback sound play
PostPosted: Thu Apr 23, 2015 11:28 am 
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Joined: Mon Feb 02, 2015 2:46 pm
Posts: 16
Thank you for your response. I will try.

GR


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 Post subject: Re: feedback sound play
PostPosted: Wed Apr 29, 2015 9:39 am 
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Joined: Mon Feb 02, 2015 2:46 pm
Posts: 16
Hello,

I tried to follow the way you suggested but its not working may be i am not doing it correctly.

My scenario is extracting signal from generic file reader and doing all signal processing steps (filtering, epoching )
and feature aggregator ---> classification processor output as matrix display. I don't understand how to differentiate the difference between attentive or inattentive :(
Since, I am not clear to differentiate i can't use sign change detector to produce a sound. could you please guide me. Thank you in advance.

PS: I have attached the scenario for reference.

Regards,
GR


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 Post subject: Re: feedback sound play
PostPosted: Wed May 06, 2015 3:06 pm 
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Joined: Sun Mar 14, 2010 12:58 pm
Posts: 108
Hello,

from just the picture of the scenario, it is very difficult to understand what you really did. For instance, which classifier did you use? how did you train your classifier? on which data? How do you induced attention/inattention, in order to obtain a ground truth to train your classifier? If you don't know how to do all that, I would suggest you to read some research papers on attention-based BCI design as this is not something easy.

Once you have a trained and working classifier (which, again, is not easy), you can use the sign change detector on its output. For instance, the LDA classifier output is positive for one class (e.g., inattention) and negative for the other one (e.g., attention), so a sign change can trigger a different sound play for each attention category.

I hope this helps,

Best regards,
Fabien


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 Post subject: Re: feedback sound play
PostPosted: Wed May 13, 2015 1:55 pm 
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Joined: Mon Feb 02, 2015 2:46 pm
Posts: 16
hi,


I did exactly what you explained, but since I had little problem with classification trainer I directly extracted the LDA classification coefficent value using matlab and I used those values as a configuration file. I extracted this data from matlab since we can't upload matlab in openvibe I have to convert thos data into csv and then i tried but there was again problem with it. I also posted in the forum regarding this. Well any way thank you for your effort and I try to take some more lecture review.

Thank you


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