bci2000.org BBS

Hi,

I'm going to run a set of experiments using BCI2000, and i have 2 questions about the configuration that I don't found how to resolve:

1.- ¿How I can query a socket in BCI2000 to get the P300 command signal, using another program from another computer?
It means, I need to know which symbol the system detect and send it over a port

2.- I'm going to record galvanic skin response(GSR) and p300 at the same moment. I already have the P300 experiment ready, and i want to know how to add another channel to record the GSR.

It will be great if somebody can throw some light over this questions. Thanks a lot for your time and knowledge.

Best,

Arnau Espinosa

1.- ¿How I can query a socket in BCI2000 to get the P300 command signal, using another program from another computer?
It means, I need to know which symbol the system detect and send it over a port

When you set the Application->DestinationAddress parameter to an IP address/UDP port combination such as 134.2.200.1:3582, the P3Speller module will send the detected symbol to that UDP port, as described here:
http://www.bci2000.org/wiki/index.php/U ... ionAddress
To read it from a second computer, just specify the second computer's IP address. Then, run a program on the second computer that opens a UDP socket on that port for reading. You might want to experiment with the example programs provided at
src/contrib/AppConnectorApplications/readudp.m
and
src/contrib/AppConnectorApplications/SimpleExample.

2.- I'm going to record galvanic skin response(GSR) and p300 at the same moment. I already have the P300 experiment ready, and i want to know how to add another channel to record the GSR.

In case your GSR meter has an analog output, you may connect that to an EEG input using a simple voltage divider to reduce the output voltage such that the EEG amplifier tolerates it without saturating. E.g., when GSR meter output is in the range of 0 ... 5 Volts, you might use a voltage divider ratio of 1:1e5 to adapt to an EEG input range of 0 .. 50 Microvolts. A logarithmic potentiometer of 1MOhm should work fine for that purpose.

When the GSR meter has a digital output to be read from a computer, then you should consider writing a BCI2000 logger component that connects to it, and records GSR values as BCI2000 events. For information about how to write a logger component, see
http://www.bci2000.org/wiki/index.php/P ... put_Logger

Regards,
Juergen