"Computed" means that only the input and output are important: as long as you can get from "2+2" to "4", it doesn't matter how you do it. "Computation" means that it's the algorithm you use that is important.

If a computer can give the response a human would have to a given situation, despite that computer using an AI which operates on different principles from the human brain (simulating a universe containing a human brain is sufficient), is that computer thinking/conscious? If yes, then thought/consciousness can be computed. If no, then thought/consciousness is the computation.

This is related to the Turing Test, in which a computer is deemed conscious if it can produce responses indistinguishable from those of a human, regardless of the algorithm used.