I appreciate the question. It seems to come down to definitions (once again!). Perhaps rationality isn't the right term to use,especially if you consider it rational for a life form to respond to stimuli. Tim Anderson uses logic instead and explains it very well in a new post on why science may depend on God. He says:

I suspect that many who subscribe to an atheist materialist philosophy do not even realize that they are signing up to deny the existence of logic itself. But, if you accept logic, rationality, and truth exist, you cannot subscribe to a purely materialist philosophy.

One could argue I guess that a computer gate with an either-or option could represent logic, but obviously, as Anderson suggests, there is much more to it than that.