Friday, March 29, 2013

Fishing for answers


OK, we agree that consciousness is a mystery we would most like to see solved. That's been the case since philosophy began. After all, nothing is more interesting than ourself, and self and consciousness are pretty much the same thing.

Is consciousness an emergent property of neuronal activity; that is, is mind inseparable from the physical brain? Or does consciousness partake of something that transcends the flesh? The stakes are huge. The immortality of the soul presumably rides on the answer.

The scientific consensus has settled on the former hypothesis, for the simple reason that it lends itself to experimental investigation. The non-scientific community is generally attached to the latter hypothesis, for the simple reason that most people want to live forever.

And here, precisely, is the crux of the cultural war that pits science versus religion.

How to resolve the issue?

One can sit around and ponder, as philosophers are wont to do. They have been doing it for thousands of years, and have made no substantial progress. Thomas Nagel's Mind and Cosmos might have been written in Plato's time.

Or one can ask nature for the answer, which turns out to be damnably difficult given the staggering complexity of the human brain.

And this is where reduction comes in. Start small. Take on the problem piece by piece. Nibble away at the riddle from the bottom up.

Which is what Harvard University's Florian Engert is doing, as described in the 24 January issue of Nature. Engert works with zebrafish larvae, tiny creatures with just 300,00 or so neurons. They can be genetically modified so that their neurons light up when they fire. And because the fish are transparent, their neuronal activity can be observed as the fish react to various stimuli. I won't say anything more about the experiments; you can watch a video here.

Of course, zebra fish are a pale representation of the human brain, but they are conscious of their environment and react to stimuli. The human brain has about 85 billion neurons, hundreds of thousands times more than zebrafish. Does that difference alone account for our greater degree of self-consciousness and the richness of our cognitive lives. Time will tell. Engert's experiments are just one of many possible ways of approaching the question empirically.

My opinion counts for nothing (to anyone but me), but I'm inclined to think we stand to learn more about the nature of consciousness from a clever scientist with a zebrafish than from a gaggle of philosophers.