Who is 'we'? There was a canadian study in the 80s that used MRI machines, which 'showed' that the brain did different things when one is OBE as when one is dreaming, but I don't know how else you can test it with an MRI or an eeg. I do know that eeg is used to test for alpha intrusions in the delta phase, (which happens with lucid dreaming), but other than that, I don't know. In the articles section, Robert talks about experiments used on epileptic patients when they're having an episode of autoscopy (or rather, that it provokes it) but once again, not sure what that proves.