Ganglion 1 electrode in use, same baseline on 2,3,4

bbny

Hi. I plan on only using 1 electrode to measure activity from different things. So I only connect channel 1(plus the ref and dg). But on the OpenBCI_GUI, the other channels (2/3/4) are showing the same baseline signals as one (I can mute them, but can't help to notice it's the same baseline waves).. When I interact with the channel-1 source, then channel 1 fluctuates, while the others don't.

But why are the baseline waves the same for channel 1 and the other channels, when the channels aren't even connected to anything?

Impedence for the ref is <10... and for channel 1 is 38... while the other channels aren't connected,

Thanks,

BB

wjcroft

BB, hi.

Are you doing ECG, EMG, or EEG? There can be some cross coupling between channels, especially if the other channels are in high impedance because of no connection. Higher level voltage signals such as EMG or ECG (millivolts vs microvolts with EEG) can show more of this. Unused channels should be muted because they will be showing garbage values without full connection to the skin.

William

bbny

Thank you.