On the Bookshelf: Ethics, science, and the brain
When Dr. Michael Gazzaniga calls in for an interview, while vacationing in California, he apologizes for having "12 things going on at once." The repairman is coming, dogs are barking in the background, and the hustle-bustle is evident even on the other end of the line. This environment is not new to Gazzaniga. A founder of the field of cognitive neuroscience, he still runs a busy lab at Dartmouth College and sits on the president's Council on Bioethics. In addition to several textbooks, he has written four books for popular audiences, including his latest, The Ethical Brain, one of the first to examine what the field of neuroscience has to say about modern ethical dilemmas.
Where can neuroscience help us to work through current ethical dilemmas?
Well, there's the whole stem-cell debate. The life scientists want to be able to use these blastocysts, up to 14-day-old fertilized eggs, and then harvest the stem cells from them. Well, at 14 days there is no nervous system in the clump of eggs; there's nothing there. So you realize that and then you say, "Well what about at the other end of life, where people are willing to harvest hearts and livers from brain-dead people?" There's no major ethical issue with that; it's well accepted in all western cultures. And so if we're willing to do that on a brain-dead person, what about on a person that doesn't have a brain at all?
How does that go over with president's council?
I don't know. Every person had their view and a vote came in, and what went into that vote was a product of lots of these kinds of discussions.
That's very diplomatic of you. Where is neuroscience being used to too much?
In the courtroom. People are always looking for reasons why someone is exculpable for a crime, and they overstate the neuroscience. They say that someone should not be held responsible because of this condition, or that lesion, or whatever. With the knowledge that we're getting about brains now, we're showing the mechanisms for different processes, and therefore by showing the mechanism, we can argue we're not responsible for stuff, our brains are. That's a bad kind of thinking.
Do you believe in an insanity defense?
I never have. You know one of the reasons is if you look at schizophrenics for example. Their rate of violent behavior is not above that of the normal population, especially when they're on their medication. So, if that's true, how can you use that as a defense, that they're doing something because they're insane. But the notion of personal responsibility has to do with the fact that people follow rules because they're in a social group and people with these various kinds of disorders can still follow those rules.
What about the idea that certain people, like sociopaths, have particular brain abnormalities that make them impervious to society's rules?
You can always quote an extreme case and there certainly are some pretty extreme cases out there. But the vast majority of it is really dealing with people who know how to follow rules, can follow rules, and they choose not to follow rules. And there should be a consequence for that. I think we've just gone way over in the other direction in the thinking that we understand mechanisms that would excuse somebody from following those rules.
So you're saying that people have free will above and beyond their brains. But if it's our brains that govern what we think and what we do, what is the separation between a person's brain and the person?
The concept of a person is generated by the brain in some mechanism that we're all trying to figure out. We certainly know the parts of the brain where there are devices that build a narrative and a story about who we are. It's the left-brain interpreter, I've called it, and it's somewhere in the left hemisphere.
So the left hemisphere of the brain tries to seek an explanation for the pattern of behavior in ourselves or others, and you build up theories around this. It is through those theory-building mechanisms that we come to have a belief about who we are and what we're like, and who other people are and what their intentions are.
Now, when I'm talking to you, I'm not thinking that I'm talking to your brain; that's just not how we go around thinking about the world. The phenomenon that we immediately confer on each other personhood?that sense of awareness that we're doing that, that's the deep, core hard problem in the field.
Is it a problem for neuroscience or philosophy?
Neuroscientists want to solve it, but the quip has been through the years that for humans to understand consciousness is kind of like a nematode trying to understand a dog. It's just not going to happen. It's just too much, too complex. But I don't think that way necessarily. I think you just keep chiseling away at the problem, one issue at a time, and something will arise from that that makes sense.