p300 online: Epoch average after Stimulation based epoching

Working with OpenViBE signal processing scenarios and doing scenario/BCI design
Post Reply
etc
Posts: 31
Joined: Sat Mar 07, 2020 4:33 pm

p300 online: Epoch average after Stimulation based epoching

Post by etc »

In the P300 I think that the averaging is very very important: it is possible to extract the ERP (p300), whereas the activity that is not related
to the stimulus onset is expected to be averaged out.
Now, this is a good possibility in the scenarios Openvibe "training": we have the target epochs separated from the notarget epochs, and so it is possible to have good average to try to don't see the activity non related to the stimulus.
But in the scenario online Openvibe, we don't know if an epoch is target or notarget! And the Epoch average after the Stimulation based epoch will make the average of all the epochs (target and notarget together); in this manner the epochs target (P300) with the potenzial peak after 300 ms. will be averaged with the notarget epochs without potential pick after 300 ms.: the average will cut the potenzial and the P300 peak will be reduced.
Is there in Openvibe a method to get a correct average in Online scenario? A solution, but I think that now it is not possible, would be to average in a trial the same rows and the same columns (in a trial, in all the ripetions of this trial, a row and a column will be target or notarget.)
Thank you!
Ettore

Post Reply