bci2000.org BBS

Hi, I have qst plz

I read article talk about bci & home appliance ... & I want to realise the same work to controle a domotic home by using a 4x4 matrix that allowed a total of N=8 stimulus classes.
and in the middle of this matrice I want to put a fixation cross.... The fixation cross was static in the middle of
interface and never flashing, also during stimulation. how can do that?????

they said: " An asynchronous operating mode was implemented within the BCI2000 framework"

my qst is : how they do that ... i don't understand anythings

plz help me to found a solution
thank you

and in the middle of this matrice I want to put a fixation cross....

The GazeMonitorFilter can do that for you:
http://www.bci2000.org/wiki/index.php/C ... itorFilter

they said: " An asynchronous operating mode was implemented within the BCI2000 framework"
my qst is : how they do that ... i don't understand anythings

If you don't fully understand the content of a scientific article, you might proceed as follows:
* Ask your supervisor to translate the difficult sentences into your native language.
* Use Google/Wikipedia to learn about the meaning of words that you don't know, or which don't make sense to you in the meaning that you know.
* Use Google Scholar to search for scientific BCI articles that have such a word in their title.
* Then, read the paper again. Actually, the authors should have described how they implemented the "asynchronous operating mode," or they should provide a reference to a description elsewhere.
* If for some reason you think you really need to reproduce the authors' experiment, write to the one who is marked "corresponding author," and ask whether you may obtain a copy of the source code and other files used to implement the experiment.

HTH,
Juergen

Dear Juergen
Hi
thank you for your reply to my question, it's okay I found it how can I put the fixation cross in the middle


But now I need To implement an asynchronous mode, it is implemented for the classifier
The asynchronous mode is implemented within the P300Speller application and it modifies the Classifier pipe, providing the asynchronous feature. Instead of waiting for the end of the trial to look for the winner symbol, the asynchronous classifier looks for the higher score value both for row and column classes and compares these values to the corresponding threshold values. If thresholds are exceed a classification occurs before the end of the trial, adapting the number of stimuli repetitions to the current user's state.

my question is:

How can I implement this ? should be modify the source code of P300Speller for implementing or what? it's alittle bit not obvious for me

because I'm beginning in this field.... I don't have a lot of experience within



thank you another time
Regards

Hiba_AZIZ

Hi,

when thinking about your question how to add the "asynchronous" mode to P3Speller, it turned out that it would be more difficult to explain how to do it than to do it myself.

So the current SVN version of the P3Speller supports asynchronous operation. To use it, first configure P3Speller in the standard way.

Then, change parameter settings as follows:
EpochsToAverage: 1
NumberOfSequences: 1
AccumulateEvidence: 1
MinimumEvidence: 2

You may need to experiment a bit in order to determine the optimum value for the MinimumEvidence parameter. If it is too low, selections will happen even if the subject is not paying attention. If it is too high, a very large number of stimulus repetitions will occur before a selection is made.

For background information about the MinimumEvidence parameter, see
http://www.bci2000.org/wiki/index.php/U ... umEvidence

Regards,
Juergen

Hi Sir
thank you for your reply
but I have some questions related to tortoiseSVN:
you said:" the current SVN version of the P3Speller supports asynchronous operation". I didn't understand until now the relation between the Tortoise SVN & the P300Speller ? and how can I use it with the P300Spller application?

you also said:" change parameter settings as follows:
EpochsToAverage: 1
NumberOfSequences: 1
AccumulateEvidence: 1
MinimumEvidence: 2"

I didn't found this parameter in P300Speller application!! or I will be find it in the source code of P300speller ?!!!

please can you explain that for me, because this my first time when I heard by the existing of TortoiseSVN

thank's another time
regards
Hiba_AZIZ

hi again
plz Mr.Juergen can you give me reply to my question.... I am s late .. and should be do something

regards
tank you again

A SVN server is a convenient way to manage source code.
Tortoise SVN is just a client for exchanging code with a SVN server.
Tortoise SVN has nothing to do with BCI2000 except that it will help you download the source code. There are other SVN clients out there, but Tortoise SVN is probably the best one on Windows.

I think what Juergen meant was that to use the new software that he made, you will have to download the latest source code then compile it. For instructions on how to download the code, see here:
http://www.bci2000.org/wiki/index.php/P ... ource_Code

For instructions on how to compile the new code, see here:
http://www.bci2000.org/wiki/index.php/P ... ild_System

Thank you so much Mr.boulay for your reply

Hi again

please I have question
when can I find this parameters settings exactly because I see in the P3speller application and I didn't found it

AccumulateEvidence
MinimumEvidence

thanks again

Regards

Hiba_AZIZ

You will have to download the most recent source code using TortoiseSVN, and compile it.

Gerv