Michael Gazzaniga talks cognitive neuroscience with TMW

Michael Gazzaniga is one of the leaders in the field of cognitive neuroscience, and is currently a professor at the University of California, Santa Barbara. He is perhaps best known for pioneering research in patients who have had their corpus callosum severed to treat severe epilepsy, disconnecting their left and right brain hemisphere. These are known as split-brain patients. Currently, he is the director the Law and Neuroscience Project, and is publishing a book entitled, “Who’s in Charge? Free Will and the Science of the Brain”. The Mac Weekly sat down with Dr. Gazzaniga before his lecture in Kagin on Wednesday to talk about his influences, where neuroscience is headed, and some of the field’s most exciting developments.

TMW: When you were in college, what was going on in the field of neuroscience and what influenced you to think that it was something you wanted to do with your life?

MG: Well my plan was to go to medical school, so I was just taking the normal pre-med curriculum. Then in my junior year, I read an article by Roger Sperry in Scientific American on nerve regeneration. I just thought that was about the coolest stuff I’d ever read. He was at CalTech, which was next door to where I grew up, so I wrote him out of the blue, said I liked his stuff, and asked if he had summer jobs there, if I could carry his water for three months basically. He wrote back and said, “Yeah, we have NSF [National Science Foundation] summer fellowships, why don’t you come out and take one?” So I did.

When I got out there the whole lab was very busy doing animal split-brain work that had been discovered and really got going in 1956. I did a little project of figuring out how to anesthetize half the brain of a rabbit. The idea was you’d have one hemisphere of the brain asleep, train the other one on something, and see what would transfer when you woke up the “sleeping” hemisphere. So I did that, and I got the thing to work, and then it was time to go back to school. By then I was hooked. So I applied and got into CalTech, turned down medical school. That was upsetting for my father, since he was a physician and he loved medicine. He’d say, “Why be a Ph.D. when you can hire one [laughs]?” That was his view.

What was going on in neuroscience back then?

For one it was called something different back then, it was called psychobiology. Neuroscience was coined about ten years later … There was fundamental neuroscience going on in crayfish, studying how synapses and reflexes worked, and there was the animal split-brain work, and then there was the beginning of Hubel & Wiesel’s classic work on the basic physiology of the visual system, that was huge. That was all in the early 60s, which really saw the launching of neuroscience, with people studying it not only in lower animals, simple animals, but also primates and cats. The human part was mostly just lesion correlations [seeing the direct effects of brain damage] … very basic, actually.

In the 40 or 50 years you’ve been involved in neuroscience, what change do you think was most influential?

For me it coincided with what I was interested in. A big change for the field came in the early 1980s when it became clear that neuro-imaging [ways to see activity in functioning brains] was going to lead the way into new insights into human neurobiology—you were going to be able understand processes in normal brains … That was huge, that really gave birth to the field of cognitive neuroscience … If you took people of my age in various sub-fields of neuroscience … each would give their perspective and see it through those eyes [of this neuro-imaging]. As a whole, it was just an explosion of energy.

How do you think the field of neuroscience will change most noticeably by the time undergraduates finish their educations and enter it eight years or so from now?

I think it’ll be highly math-based and quantitative, and a lot of concepts and tools from engineering will be brought in, like control theory and dynamical systems. We’re trying to start a program at UC Santa Barbara about dynamical neuroscience.

Do you mean making diagrams of nervous system processing and having engineers sort of figure out how it might work?

The engineers have figured it out—they have this whole control theory, [which deals with] how systems interact on different time scales. The problem with neuroscience—one of the problems—is that you have the molecular time scale, you have the systems time scale, you have the behavioral time scale, and you have the cognitive time scale. There are laws and rules going on in each of these layers. How do you coordinate all that to get a large, causal picture of how this thing [the brain] works? Control theorists deal with that problem all the time—how to articulate different parts working in different time courses that produce the whole of whatever it is you’re talking about.

Neuroscience research makes its way into general culture a lot these days, and sometimes the implications of the studies are exaggerated. How do people make sense of, and not get carried away by, things like findings which show that scientists are able to model decisions with brain imagery before the person making the decision becomes aware of it?

In some ways that’s a reading of this guy Benjamin Libet’s findings from 25 to 30 years ago now [Libet discovered strong evidence that unconscious neural processes proceed conscious decisions]… that issue has been heatedly debated over the last 30 years. There are books coming out to this day on Libet’s findings and what they mean. The data’s simple enough, the experiments have been repeated and actually extended by others. So there’s no arguing about the phenomena, the question is what the hell does it mean? That’s what people have battled over, because the philosophers are very interested in [the implications of] this and they get into the act, and then neuroscientists try to find the actual physiology behind it, etc. It’s been rigorously examined, and it should be. That’s a good sign that it’s something.

What do you think of Henry Markram’s Human Brain Project in Switzerland, which attempts to model a human brain by using supercomputers to recreate it piece-by-piece, neuron-by-neuron? On its website, it proposes to examine questions like “What does it mean to think?” and “What does it mean to be conscious?” This strikes me as sort of reductionist—it reduces the brain completely to the sum of its parts. Given that you think consciousness is an emergent property, do you think this project will succeed, do you think it has potential, and how do you account for emergence when you have a system that’s basically reconstructed based on the physical properties of neurons only?

Those are all great questions [laughs]. There are Markram enthusiasts and there are Markram doubters, for pretty much the reason you stated. You take emergence out of the equation of something that’s self organized [the brain] and can produce another level of organization [conscious experience], and how is this going to be accomplished in this artifact? Some people say, “It can’t, this is not the way it goes, you can’t go bottom-up, it’s much more complicated than that.” Other people say, “Let him start it, let him try.”

I’ve never been there, or seen it, or done it, so I can’t really comment on that. I’ve heard him talk a few times, and it is a bold, ambitious project, that’s for damn sure. I don’t know. In some sense, it’s a realization of what Sebastian Seung wants in his Connectome [a comprehensive map of connections in the brain]: he wants all the connections realized and known, and only through that route can we figure out the differences between people, mental states, or anything else.

Of all that’s going on in neuroscience right now, what do you think is going to be most relevant in the daily lives of the public?

Well, my guess is that advances in biotechnology, pharmacological agents, and such will be the things that get to the public first. Some memory pills, starting off with t hose that help with normal aging. Then [as the pills become usable to enhance normal individuals] there’ll be all the issues of use and misuse, the ethical side of it … Right now, at least the last time I checked, there’s still no pills that beat caffeine for staying alert and on top of things. Your double latte’s still the best way to go, and all the exotic pharmacological agents that were thought to help still can’t beat caffeine so far—so far. They’ll come up with it, someone will figure something out. I think that kind of thing will dissipate quickly to the public.

For example, there’s a tremendous amount of work going into prosthetics for lost limbs, and it’s impressive what those things can do. [Lost limbs] are not as [widespread] a problem. Everybody loses their memory—by which I mean it gets diminished, you’re not as quick, and so forth. Trust me [laughs], I used to remember everything. Not anymore.