You argue that an "organism" is not a computer (as it does not compute). But why should I believe that a computer is not necessarily an "organism" in your sense of the word? Or would you have us believe that organisms and computers are not made from the same universal stuff?
> For more than half a century now, psychologists, linguists, neuroscientists and other experts on human behaviour have been asserting that the human brain works like a computer.
That is the opposite of what I have read from those groups of people.
It is not true that all computers are digital. A computer made out of Tinkertoys or DNA is no less of a computer although the rules of operation may be different.