the pre-motor region, so we can sense the ticks before they happen when they get premonitory urges, but also in the motor region. >> when you think about tourette's, you're thinking about something that is almost half motor movements and almost half emotion. so you take a look at what they're trying to do, they're actually going right in the middle. you've got motor on one side. emotion on the other. and look at that line. that goes right down the middle of both. to make sure they found the right location, they stimulate the leads on amber's motor cortex. that involuntary twitch, that's a good sign. >> is this going to change? >> next, the deep brain electrodes are lowered into place to capture neuronal activity. >> what we're listening to now is three channels. it's like an orchestra. it's an ensemble.