[Help] P300 Speller

[Equis]

Hello everyone.
First of all, have mercy since I'm really new here.
For the last 4/5 days I have been researching about this software, watching video tutorials, reading box documentation..
I'm currently carrying out my dregree project based on EEG measurements and its processing.
I want to do a simple P300 Speller so I considered using three boxew: keyboard stimulator, P300 Speller Stimulator and P300 Speller Visualization.
The problem is that I'm not able to know beforehand the order the columns/row will be highlighted. I've tryed to record that order, but it changes every time I run the program, so it looks like so random to me.
I there any way to know beforehand the order of the simulation?
By the way, sorry for my english.
Thank you.

[fabien.lotte]

Dear Equis,

Indeed, the order of the flashes changes everytime your run the program: it has to! Indeed, for the P300 to appear it is better that the user does not know when the target flash will appear and as such the flashes order has to be random, and therefore is random. If I am not wrong, you cannot change that without modifying the code of the corresponding openvibe box. However, you know when the different columns are flashed based on the openvibe stimulations you receive from the "P300 Speller Stimulator" box.

I hope this helps,
Best regards,

Fabien

[gserrier]

Hi,

One simple way to avoid the randomness and have a fix sequence is to generate one sequence and to record it in a file (CSV or .ov) and to read this file instead of using the speller stimulator.

Guillaume

[Equis]

Hi.
Thank you fabiet.lotte for your answer.
gserrier, how do I do that?
I've tryed to use these boxes:
Keyboard stimulation>P300 Stimulation>CSV writer
and
Keyboard stimulation>P300 Stimulation>P300 Visualitation>CSV writer
Both of them gave me an invalidad connection error.
Thank you.

[gserrier]

Hi,

You need to adapt the type of the input of the CSV writer. Double-click on the input and modify the type to Stimulation, and then connect.

Guillaume

[Equis]

Thank you so much Guillaume.
Solved.

[Equis]

Well, not at all. I thought I got it, but actually I didn't. Please, correct me if I'm wrong. I have to:
1. Keyboard stimulation > P300 Speller stimulation > CSV Writer in order to get a csv with the stimulations
2. Keyboard stimulation > P300 Speller stimulation which is loaded with the csv in its config. > P300 Visualisation

Right?

Regards.

[gserrier]

You are right with the first point, but not with the second.
You don't need the stimulator in the second as you already have the sequence of stimulations stored in the CSV file. SO it's just
CSV reader (with output configured) -> p300 visualization

Guillaume

[Equis]

Man, you're awesome, thank you so much.