Current Limitations in Neuroscience

Simon D. Murray, MD: Albert Einstein’s genius might be explained by his extraordinary brain, but it might also be influenced by the fact that maybe there’s more to the brain than just the flesh-and-blood part? Maybe there’s a soul. And we would call that dualism, right?

Frederick E. Lepore, MD: Yeah.

Simon D. Murray, MD: Versus materialism. Materialism is, “We’re going to attribute everything to physical flesh and blood,” and dualism says they’re separate. And it may be that we won’t know exactly about where thoughts come from and all those kinds of things at this point in time.

Frederick E. Lepore, MD: I agree.

Simon D. Murray, MD: Can’t even fathom it, really.

Frederick E. Lepore, MD: We’re not even close. But when you write a book about somebody’s brain and you know a great deal about his mind, you wonder, can one explain the other? I make my living as a materialist in the sense that as a neurologist, I know that if there’s something wrong with the left side of your brain, you’re going to lose dexterity in your right hand. And if it’s near your speech area, you’re going to have aphasia. You’re not going to talk the way you normally would. Well, there it is—brain, mind.

But when you talk about these other kinds of abstractions—how you come up with general relativity, how you perceive the color red—we’re not at that point. We can’t look at brain tissue and tell you… What David Chalmers, a neuro-philosopher at NYU [New York University], talks about—the hard question of how a chunk of brain produces what you and I would call a thought or a sensation of red. We don’t know.

We all get sucked into this functional neuroimaging. If you see something, if you’re reading something, the left side of your brain—the angular gyrus—will light up. Those kinds of things. And you go, “Well, there it is. Do you see?” That’s the easy question. That just says to you that the circuit is lighting up. It’s increasing its metabolism when you perform this particular mental path, but you really don’t know how it does it in that piece of the brain.

If I can’t answer the hard question and show you how several grams of brain produce the color red, you’re entitled to say, “Well, maybe it’s not materialism. Maybe there is dualism. Maybe there is a substance. There are separate substances.” The neuro-philosopher would go, “Well, this is substance dualism. The brain substance and the spirit, consciousness, soul substance are totally different substances. That creates a whole other problem. How do you explain a substance that’s not a physical substance?

Simon D. Murray, MD: Yes.

Frederick E. Lepore, MD: And we’re not at that point. But that’s dualism, and I prefer to remain agnostic on this. If someone answers the hard question for me. OK, now maybe we’re going to talk about materialism, but you know it may be consciousness, soul, thought. Is it something materially different from the human brain?

Simon D. Murray, MD: Yes.

Frederick E. Lepore, MD: Alternatively, we’re just not smart enough to figure out how the brain works. If we could really drill down, maybe we could say, “OK, the circuitry is such that I can see how you perceive consciousness, thought, and things like that.” So it’s up for grabs. And in that book [Finding Einstein’s Brain], as much as I loved writing it, you’re not going to get the answer.

Simon D. Murray, MD: You know, this is a problem we face every day in medicine. Things that are supposed to happen don’t always happen the way they should. How many stories can you tell us, or can I tell you, of things that don’t turn out the way they should. People should die, and then they don’t. Or you do everything right, and it turns out wrong, and you say, “I don’t know. I just know how that happened.” There’s some magic to this. Or, you know, whatever.

Frederick E. Lepore, MD: You take 4.6 billion years since the first single cell. To evolve a biological structure—it evolves, elaborates, retrenches, throws away some things, adds on. And then at the end of it, supposedly we’re the pinnacle: human beings.

Or maybe the whales are smarter? Who knows. But just in my field, we talk about neurons. That’s our building block of the brain. The neuron was established in terms of Santiago Ramón y Cajal and Camillo Golgi, and they were fighting over whether the neuron was discrete or whether it was part of a greater interconnected network. You’re talking about 110 years that we’ve learned about the basic building blocks. We haven’t been slouches for the past century, but we are a long way…

Simon D. Murray, MD: Yes, that’s what I mean. There’s a lot about medicine that we don’t know. We’re not as scientific as we think we always are. Sometimes there’s a lot of intuitiveness, or luck, or whatever it is.

Frederick E. Lepore, MD: Art, as well as science.

Simon D. Murray, MD: Maybe it’s art. Maybe that’s what we’re talking about—art and science.

Frederick E. Lepore, MD: We all welcome the science if it says, “Oh, really? Should I be using 81 mg of aspirin, or would it be better with 30 mg or 125 mg?” You need to do the studies. And then there’s a certain limit on the studies because…you’d be doing the study on aspirin every 10 years to figure out the optimal dose. There’s a certain amount, and you have limited resources, but we all sort of know if there’s a vascular issue, aspirin might help a patient.

Simon D. Murray, MD: Yes.

Transcript edited for clarity.