Why does EOG (eye EEG) first spike and then immediately fall back down when you look to one direction instead of staying spiked and only falling back down when your eyes go back to neutral?
From what I understand the corner (front of eye) is positive while the retina (back of eye) is negative. So if I have electrodes on each temple and I look left I would expect the EOG graph to spike (or dip depending on the electrode placement) and stay up until I move my positive cornea away from the left electrode.
But instead the graph spikes and then dips back to neutral even though my positively charged cornea is still close to the left electrode since I have not returned my eye back to neutral.
To be clear this graph is correct I just don't understand why.
Ex: In the picture below I am holding my eyes left until I look right. But for some reason the graph immediately drops back to neutral even though I'm still looking left.
Ex 2: Here's a video of a live EOG recording and a person moving their eyes showing the same graph behavior.