Blindsight

"Say you’ve got a device designed to monitor—oh, cosmic rays, say. What happens when you turn its sensor around so it’s not pointing at the sky anymore, but at its own guts? ... It does what it’s built to. It measures cosmic rays, even though it’s not looking at them any more. It parses its own circuitry in terms of cosmic-ray metaphors, because those feel right, because they feel natural, because it can’t look at things any other way. But it’s the wrong metaphor. So the system misunderstands everything about itself."

The consciousness stuff was interesting - it assumes that consciousness is something that affects behaviour, and that losing consciousness is something that would make you act differently (more efficiently even, the book argues). This is not how I really think of consciousness, but even if all it did was consume neural energy resources, it would need to be useful for something or it would be removed by natural selection. Assuming that it were possible to remove and isn't, say, a by-product of something else it needs without itself having any effect.

The actual story that it's packaged in was not quite as interesting.