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Making P300 Speller Faster by reducing flashes

Posted: Sat May 19, 2018 1:12 pm
by usama1
Hi OpenVIBE community,

I have modified the P300 speller from 6 X 6 to 3 X 3. I only need a total of 9 values for my speller. For this, I modified the P300-speller.ui and the p300-speller-target.lua. I am also saving the output characters in a text file.

My problem now is that the P300 speller is incredibly slow. Infact it has gotten more slow after modifying the User Interface. Can anyone guide me as to what should I do to make it faster. I need to reduce the number of success stimulations required to make it faster.

Thank you.

Update: I realised that the target selection is still trying to select a target beyond the Matrix it has. Even though I had updated the matrix and also the loop underneath it. I am definitely missing something.

SOS guys. Please can anyone tell me exactly what configurations and variables was I supposed to edit to shorten the 6 X 6 speller to 3 X 3?

Re: Making P300 Speller Faster by reducing flashes

Posted: Tue Feb 28, 2023 11:24 am
by zhangxuyf
hello, Have you resolved this problem? If yes,would you please share your solution? I am facing the same problem.

Re: Making P300 Speller Faster by reducing flashes

Posted: Tue Mar 14, 2023 1:51 pm
by Thomas
Hi zhangxuyf,

I quickly tested modifying the p300 speller into a 3x3.

I modified the .ui by removing all the letters beyond the 3x3, but not rearranging them, which means that I had a table with the following lines ABC, GHI and MNO. I used Glade in order to do this.
Then I modified the p300-speller-target.lua file to have the grid array match the new UI, and the function get_location double for-loop to loop from 1 to 3 instead of 1 to 6.

I just tested the acquisition scenario with generatored data from the acquisition server, and I didn't have any speed issue.

Did you perform the same changes as I did, or did you do something slightly differently, or something more ?

Cheers,
Thomas