bci2000.org BBS

Hello,

Is it possible to display several pictures at the same time with the current GUI? For example, if I wanted to display 6 pictures in a 2x3 matrix, what'd be the best way to do it? Or could you redirect me to an example/manual pages?

Thanks,

Gus

Gus,

There are two possibilities. You do not specify whether you want a 2x3 flashing matrix with pictures. You can configure the P3Speller to do this:

http://www.bci2000.org/wiki/index.php/U ... pellerTask

Alternatively, in case you want to simply present a 2x3 matrix of images as a non-flashing stimulus, you need to use the StimulusPresentation task:

http://www.bci2000.org/wiki/index.php/U ... tationTask

In this case, you will need to create one picture that has the 2x3 images in it (the stim. pres. task can only show one image at a time).

I hope this helps.

Gerv

Gerv,

Thanks for your reply. It looks like I'll have to look at the P3Speller code, because I'd like to specify the pictures composing the matrix in the configuration session, much like the parameters of the StimulusPresentationTask are defined.

However, I do not need the pictures to be flashing, but hopefully it's not that hard to figure out how to make this change in the speller code. I will, at some point, need to change a given picture in the matrix on the fly (i.e for every trial). Maybe I can use something similar to the highlighting code to do that.

Let me know if you can think of anything else that would help.

Thanks,

Gus

Gus,

You can parameterize the P3Speller such that you cannot see the flashing ("flashing" color is same as normal color). If you need help changing it further, let us know.

Gerv

Hello,

I would like to know if is possible to flash, in the matrix of P300Speller, one icon at time. That means that i don´t want to use the flashing first by rows and next by columns, just one icon of the row and column.
Thanks for your attention,

Eliana

Eliana,

flashing of individual P3 speller matrix entries is not available through parameter configuration.

However, you can achieve this by a slight modification to the P3SpellerTask source code in BCI2000/src/core/Application/P3Speller/P3SpellerTask.cpp. There, in P3SpellerTask::Initialize(), matrix elements are grouped into sets ("associations") which are then flashed collectively. By putting each matrix entry into its own set, entries will flash individually rather than grouped into rows/columns.

Feel free to ask for more details if you are interested in performing this modification.

HTH,
Juergen