I understand that in the single-electron-at-a-time double slit experiment, if a detector is placed before the slit, the interference pattern vanishes.
Suppose I left the detector on, but put a bag over its screen (I can't tell what state the electron is before it passes the slits), does the interference pattern come back?
If so, does that mean the electron "knows" I'm not "looking" and proceeds to interfere with itself?
Edit: I had photons passing through the slit initially. I've updated it to electrons to reflect a more common setup.