And wouldn't that language need to be able to account for different physiological states? Thinking when one is hungry or sleepy is quite different than thinking when one is well-fed or fully rested.
Yes. To validate the claim would require not only a formal instruction set but also the code to account for all sorts of cognitive states and processes. I'm not ruling out that some people are indeed programmable computers but I would like to see some actual evidence presented by the people who make these claims about themselves.