bci2000.org BBS

Hi,

As of present, I'm hoping to use BCI2000 to conduct a successful P3 Speller Session. In our system, the acquisition and offline analysis are being run on two different machine (both have BCI2000 installed). Also, I've been using the P300 BCI tutorial for direction and have conducted a speller calibration session. I now want to proceed with the offline analysis but this is where I run into some trouble.
Using the directions described in the tutorial: Obtaining P300 Parameters in a Calibration Session, I run Matlab through tools/OfflineAnalysis/OfflineAnalysis.bat. and change the analysis settings. I add the four data files in which I conducted the speller sessions: "THE" QUICK" "BROWN" "FOX" (separately). I then click "Generate Plots" but after some time, a warning message appears saying that I do not have enough memory to complete the analysis. This is surprising because our system has a separate drive for data files. It could be that the computer we are using is not powerful enough to conduct this analysis. However, this machine uses Pentium 4 (hyper-threaded) with 2GB of memory for analysis. However, it never gave such as error before even when analyzing big MRI images.

Do you have any suggestions as to what the problem may be and how we are to fix it?

Thank you,
Roxane

I'm getting the same error. Following the P300 tutorial to the letter, and when I try to generate plots in the offline analysis I get an out of memory error. This is on a clean computer with plenty of ram, so i don't see how lack of memory could be the actual problem. Running the most recent release of BCI2000 on a clean install of WinXP Sp3 with Matlab R2009b.

I'd appreciate any insight as to why this could happen.

After some more testing, I have found that "generate plots" wont run out of memory as long as I only use data files for "The Quick Brown". As soon as I add any more data, it will fail. It seems like the p300 offline analysis isn't handled in a way that is friendly towards those of us who are using lots of channels.

Cort,

Thanks for the report. This is useful.

Gerv

You might want to try using the P300 GUI tool, found at http://www.bci2000.org/wiki/index.php/U ... s_Tutorial. This does not generate plots, but it will generate a classification matrix using a linear stepwise regression, and tends to work better than the Matlab-based tool.