While at the Game Developers' Conference, I checked out Emotiv Systems and their EEG-based input ('mind-reading') technology in the form of the $300 EPOC to be released later this year. I spoke to the Emotiv guys at their booth, they seemed a bit secretive about their technology. They described it as telepathy. The EEG input device concept is interesting to me, but seems a little gimmicky. In fairness, though, I didn't try it. Like a resurrected computer-enhanced biofeedback machine? Not sure how well it would work in real life. The devices don't use conductive gel like real EEGs use. The input device also tracks eye and facial muscular movement, so it's more than just an EEG, but an EMG as well. Also, EEGs require the user to be still. That's a tall order for a videogame player. Anyhow, assuming that sophisticated signal processing could overcome the lack of conductive gel and motion, it seems that the response time in changing gross brain state (for example, to punch a bad guy) would be glacial and using it would be exhausting. What is really interesting to me, though, is how they're doing their signal processing. My initial guess is principle components analysis with a prototype database. I wonder if I'm way off base there.