In a recent Prospect essay, neuropsychologist Paul Broks reviews Nicholas Humphrey's book, Seeing Red: A Study in Consciousness. He also recounts his own experiences of consciousness and his travels to a recent meeting of philosphers and scientists who debated the matter. As the color in the title portends to those who follow theories of consciousness, this book is largely concerned with qualia, the mysterious phenomenological experiences by which some philosphers believe we are aware of sensations, thus making it a critical part of understanding consciousness. The essay acknowledges that some philosphers, such as Daniel Dennett, are begining to view qualia with a bit of skepticism these days. It's an interesting essay and well worth a read of you're fascinated by these sorts of things.