bci2000.org BBS

Dear all,
I have a doubt concerning the CAR filter use during a 1D cursor task..assuming that I would like to use this kind of filter both in the calibration session and in the cursor task session, I should:

- fill the "CAR output channels list" box with ALL the used channels, in both sessions;
- fill the "CAR output channels list" box with only the channel whose signal will drive the cursor (let's say, C3), in both sessions;
- fill the "CAR output channels list" box with ALL the used channels for the calibration session, and only with C3 for the cursor task one?
I wonder about the third choice, because it's impossible to know, a priori, which channel(s) will drive the cursor, but I would like to have your confirmation.

Thank you,
kind regards

Anything that happens to the signal in the SignalProcessing module or the Application module is irrelevant if you aren't providing feedback. The raw data are stored by the SignalSource module before any filters are applied. Thus, you can use whatever you like for the spatial filter during the calibration session as it won't affect the application or the stored data.

Then, you would analyze the stored data offline to see which signal features are useful for controlling the cursor.
http://www.bci2000.org/wiki/index.php/U ... hm_Session

Then, you would configure BCI2000 to provide feedback based on the identified features.
http://www.bci2000.org/wiki/index.php/U ... e_Feedback
When configuring BCI2000, the spatial filter only needs to output as many channels as will be used by the ClassifierMatrix.

The only reason I can think of why you might want to properly configure the filters during the calibration session is that you want to use the parameters stored in the file itself for subsequent analysis. For example, the bci2000chain can simulate online processing of a data file using only the built-in parameters. However, you can also pass bci2000chain additional parameters to overwrite the stored parameters, such as the spatial filter and the classifier matrix; I expect you will overwrite these parameters when doing an analysis of a calibration session. You can read more about the bci2000chain here:
http://www.bci2000.org/wiki/index.php/U ... i2000chain

[Edited a few typos]

Thank you so much, your explanation was very helpful!