Dealing with the result file of P300

[smlee]

Hi, I'm using BCI2000 and g.MobiLab+ for measuring P300.

After I did a P300 experiment, I can easily find an output file in the designated folder. But if I input this file(testS001R03.dat) into Matlab, I cannot find the raw signal and even the matrix like data.

The parameter file is the same with the P300 tutorial. Is there any option to save the raw signal into a file or a way for analyzing a data file using Matlab?

[mellinger]

Hi,

BCI2000 supports data analysis in Matlab by providing functions to read and save data, and to do offline processing from Matlab using BCI2000 filters.

For information about read/save functions, see
http://www.bci2000.org/wiki/index.php/U ... _functions
For offline processing of BCI2000 data from Matlab, see
http://www.bci2000.org/svn/trunk/tools/ ... 000chain.m

Juergen

[smlee]

I'm sorry. My reply was too late.

Anyway, thanks mellinger. It was very helpful.

However, can I ask you one more question?

After I input the data using 'load_bcidat.m' file, I can save the raw signal. But, its value is a little bit strange. Though EEG signal has very small amplitude, like 'uV', its value is integer, like 1813 or -155. Is there any way to check its degree?

[mellinger]

By default, load_bcidat reads data in raw A/D units, as digitized in the amplifier or A/D board. In order to get the data calibrated into muV, specify '-calibrated' as an additional argument when calling load_bcidat. This is also described in the load_bcidat documentation.

Juergen