Confusion Ground and Reference function
Troubleshoot007
The Netherlands
Hi there,
I am new to EEG research and for my research I will use OpenBCI. Searching through literature and the internet I got confused about the specific function of the Ground and Reference electrodes and how OpenBCI deals with it. I use a Cyton board +Daisy extension (16 channels). I use OpenVIBE for my Data acquisition. I use PZ as a reference and one of the earlobes as my ground. Does OpenBCI take the reference/ground signals and calculate the data per channel according to these signals? Or does the Cyton+Diasy system acquire the reference/ground data separately and therefore I have to do the processing?
Thanks for your time!
Comments
Rogier, hi again.
Most EEG systems just use Ground (or 'Bias' for Cyton), as means of centering the differential amplifiers and reducing the mains noise somewhat via noise cancelation circuitry. The Ground/Bias lead has no part in the amplitude read by each channel. The channel values are only computed by subtracting the reference electrode from the channel electrode.
William