I watched part of the video BBC Horizon: The Secret You, where a man tests scientific experiments on himself. The part I watched was about a brain activity test that showed the differences in consciousness verses unconsciousness. He had something on his head that looked like a shower cap that recorded his brain activity. The question was, "What does the difference in consciousness between waking and sleeping tell us about our sense of self?" When we are awake and one part of the brain is activated, that starts many other responses throughout the brain. But when we are asleep, or unconscious, only the part of the brain that was stimulated is activated.
Here is a screen shot of the awake and asleep brain and the amount of brain activity. They show how the activity around a waking state brain is all around, the in a sleep state, just focused around the area.
I thought the findings were interesting. I thought when we were unconscious, more parts of the brain would still be activated from a stimulation. But as they explained it in the video, it is like the channels have shut down for the night.