Mark Bishop is one of the few defenders of the thesis that computationalism is false. "Computationalism" is the idea that if you created a computer that accurately reproduced the calculations performed in your brain as you experience color, the computer would actually see color-- that is, have a subjective experience of color. The computer would be a conscious observer.
He points out how this leads to panpsychism: the idea that everything is conscious, including rocks. If you want to avoid panpsychism, you have to also give up the idea that mere computation is responsible for conscious experience.
Why Computers Can't Feel Pain