Electrodes positioning for P300 detection

[rafaelduarte]

Hi there,

Has anyone tried to detect P300 potentials using the EEG-SMT? I am currently trying to do it but I am not getting good results. I am not sure if it is due to electrodes misplacing or if the experiment design is wrong.

I tried to use electrodes Pz (Ch1 +) and Cz (Ch1 -) for P300 detection, along with C3 (Ch2 +) and C4 (Ch2 -) for mu-waves detection. To evoke the P300, I am beeping two different tones (standard and target) randomly, at 2 seconds intervals.

Any thoughts?

Thanks,
Rafael

[NicolasP]

Electrode placement is complicated... Yours are also pretty close to each other on top of the head if I'm not mistaken.
I'm also not entirely sure how the 2-channel thing works. With electrodes placed at C3 C4 O1 and O2, I get only one channel registering (Brainbay). In the manual they give examples of placements with fp1 and fp2 on one channel and other symmetrical placements for the other channel. So I'm not sure whether fp placements are a reference of sorts and there's only one channel for active measures...