Apologies out of the gate here as I'm a CS person with not a huge amount of experience in electronics, so this might be a pretty basic question. I've built basic EEGs before, basically electrodes together with a series of active filters.
My approach in the past has always been to play with my filters until I don't see a peak at 60Hz, and I don't see huge swings when someone moves their eyes. Once that's done there's usually some kind of wave that gets spit out, but I've never really been convinced that I was seeing a
real signal, and not just picking up on some other random noise, which is extremely likely.
I'm now a bit older and more foolish and I wanted to take a more intentional stab at this, but I was wondering if there's any reasonable way of testing this. My naive approach was going to be attempting to generate a signal in the nV realm as input, then trying to re-create it after processing. There are two main reasons why I think this doesn't make sense:
- Electrodes/Skin conduct introduce noise that I can't model this way
- I'm very unclear on exactly why an EEG works. It feels very strange to me that you'd get actual signal by strapping electrodes to your head
So how exactly do I test an EEG, and have confidence that an EEG I create is working?