Strange Noise/Charge buildup on the Cyton

I have this issue that only happens when i am connected to a person. i get a strange noise signature that varies between just a general increase in noise or spikes that are like 5 times a second. i dont have an image to share at this moment but i saw a similar noise signature in another post that looks similar in the forum post (Strange Data from Headset - All 16 Channels, Same Pattern [resolved]).
In that forum post it seemed that the battery was the issue, but in my case i have used both 2500mAh batteries, 500mAh, and 4 fresh double A's. No matter my battery or current charge condition i see this issue eventually. it seems like the system is building up charge because it only happens after a few minutes of recording.
To further explain my setup i have injected a stimulation/synchronization signal onto channel 2 that is 100uV. if i duplicate that signal onto my other channels and run it for an hour or 2 i will never see this weird noise. but if i replace my other channels with a real signal eventually i will begin to see strange noise. the noise goes away momentarily if i disconnect close out and reconnect but the time is much reduced to seconds or a couple minutes before the noise comes back if i have already seen the noise.

Is it possible that because i have injected this stimulation/synchronization signal into the cyton that when i connect a real person there is a grounding/charge issue that builds up? i do not see this issue at all if i dont connect a person. and i seem to have made it go away by connecting something i call global ground to my bias. the global ground is the ground from my computer that my stimulation/synchronization device is connected/powered by.

Any thoughts/help would be greatly appreciated.