I don't think that a human brain, isolated and somehow kept alive, would be able to pass the Turing test. Especially not if it was grown in a tank or something. I might be wrong, of course. The story of Helen Keller seem to imply that very little stimuli is needed to become self-aware and be able to communicate in a meaningful way -- but who can say how important it is to be able to relate, on some fundamental level -- in order to share enough to pass a Turing test?

I completely agree with you.

However, Kurzweil's argument focuses on the fact that he believes we will someday be able to simulate the human brain, and that's something I disagree with strongly.