Daily Archives: October 29, 2004

Amazing Exponentials, The Speech

By popular demand (well, Stephen asked for it, and he’s a popular guy)
here’s the text of my recent speech, which expands on the ideas presented
in the original exponentials post.

Mr. Toastmaster, my fellow Toastmasters and guests, our story begins with the
invention of a game called Chaturanga in India some 1400 years ago. Chaturanga
is the precursor to the game we call chess; it’s played on a board similar to
the one used today for chess, checkers, and backgammon. The ruling prince of
the region where the game was developed was so taken with Chaturanga that he
summoned the game’s inventor and offered to reward him for his genius.


Now the man who invented Chaturanga was, indeed, a genius. He asked the prince
that he be given only a very modest reward. Just one grain of rice placed in
the first square of the Chaturanga board. That’s all. Oh, and then two grains
of rice in the second square and four in the third and eight in the fifth and
so on, doubling until all 64 squares were filled.


Well,
the prince was pretty shocked that his subject should ask for such a paltry
reward, but he felt he had to comply. So he dispatched one of his stewards to
fulfill the order. It took the steward a while to report back, and when
he did the news was not good. Although harvest was just completed, the gift
was going to completely exhaust the royal granaries. And they were only on the
40th square!


In fact, it turns out that if you were to keep doubling until you reached the
64th square, you would have an amount of rice greater than the total
yield of every rice crop in the history of the planet earth. The inventor of
Chaturanga had trapped the prince with what mathematicians call a geometric
progression. As we follow the progress of the rice as it doubles with each step,
we’re witnessing what’s called an exponential increase.


As the example with the rice grains shows, any time we witness an exponential increase, we’re in for quite a show. Things start out small and get
crazy really quickly. Let’s look at a few exponential trends that are unfolding in our world today. (My first three examples come from an article
by Rodney Brooks that appeared recently in MIT Technology Review.)

Brain Prosthesis: Self-Serving or Self-Sacrificing?

brain.jpeg

Phil has linked to and commented on several stories in the last couple of days that have a common theme:

Even though most of these treatments would only be used on diseased or injured brains, some ethical issues must be considered.

If a patient has a stroke that damages a portion of her brain, will she remain the same person if she is treated with a brain prosthesis or brain tissue transplant?

Objectively there is little to argue about. If my family member has suffered a stroke and can’t speak or take care of herself, and if a brain tissue transplant could reverse that, then the post-op person is more like the person I knew before the stroke.

But what is the subjective experience of the patient? Is her personhood violated by the treatment? Certainly the stoke or neurodegenerative disease violated the patient first. But there are many instances in medicine where doctors choose not to treat rather than risk additional harm.

This problem is akin to issues science fiction fans have discussed for years. If my memories and personality are copied into a computer or into another body, have I, personally, been moved? Am I live or Memorex?

Or if the “transporter” from Star Trek can take apart my atoms, transport them through space, and reassemble me perfectly on some alien world, is that still me? Maybe. But, what if – as Star Trek suggests – only the digital information of my pattern is transported. My actual atoms are left behind to replicate Hot Earl Grey tea or something. Is that still me?

I don’t know, but I certainly understand Dr. McCoy’s aversion to the transporter.

The ethical problem with brain prosthesis and tissue replacement is different from these fictional dilemmas only in degree. A brain prosthesis or tissue transplant might simply be thought of as an aid for the remaining brain, but it just as logically could be said to be “new brain.” Where exactly does “self” reside? Does “self” remain in the damaged brain that the prosthesis or new tissue is aiding, or is it within the “new brain?” Could it be a both?

There is no easy answer to that. But I know that if I had a stroke and was told that the only way I could walk again or speak would be to undergo a such a procedure, I’m sure I’d agree to the treatment.

This seems to be the best solution to the problem. Our decisions have an impact on who we are anyway, so there seems little reason to question a patient’s decision regarding such care – provided they are capable of making the decision.

Obviously someone will have to judge whether the patient is capable of understanding the treatment and making the decision. Should that be the doctor or the family? Its time to update my living will forms.