What anesthesia gone wrong is teaching us about consciousness

For every 1000 people who undergo general anesthesia, there will be one or two who end up aware but frozen. They can hear doctors talking. Sometimes even feel the knife. But they can't move or tell anyone about their experience. Scientists are studying how the brain functions under anesthesia in an attempt to eliminate this problem. As they do, they're learning some amazing things about consciousness, itself — both what it is and how it happens. Turns out, science may vindicate Kant.