I'll know more after a bit of research. Unfortunately, though, I don't think I'm going to be able to get much in the way of hard data. Firsthand accounts from those affected are bound to be very subjective and variable, and comparing case studies will only get you so far from a scientific standpoint. What I'd really like are brainwave data, but I seriously doubt I'll have the serendipity to stumble upon someone who happens to have been hooked up to an electroencephalogram the entire time.