Science Talk

Neuroscience and the Law

In this episode, neuroscientist Michael Gazzaniga talks about neuroscience's impact on legal practice, and The Law and Neuroscience Project, a new MacArthur Foundation effort, which he directs, to delineate the issues surrounding neuroscience and the law. Plus we'll test your knowledge of some recent science in the news. Websites mentioned on this podcast include:;

Welcome to Science Talk, the weekly podcast of Scientific American for the seven days starting November 28th. I am Steve Mirsky. This week on the podcast, neuroscientist, Michael Gazzaniga talks about the relationship between brain science and the law. Plus, we'll test your knowledge about some recent science in the news. Michael Gazzaniga is professor of Psychology at the University of California, Santa Barbara, and directs that institution's Sage Center for the study of the mind. He is the founder and editor in chief emeritus of the Journal of Cognitive Neuroscience. Gazzaniga is the author of numerous books including The Ethical Brain and he is a member of the president's council on bioethics, which we also talk about toward the end of the interview. In October, the McArthur Foundation initiated what they are calling The Law and Neuroscience Project. It is an effort to try to help integrate new developments in neuroscience into the legal system. Former Supreme Court justice Sandra Day O'Connor is the honorary chair and Gazzaniga is the director and principal investigator. I caught up with him at the official announcement last month. We spoke in the Daniel Patrick Moynihan U.S. Courthouse in New York City.

Steve: Dr. Gazzaniga, great to talk to you today.
Gazzaniga: Hi Steve.

Steve: Tell us about the connection between neuroscience and the law; it's something that we're all a little bit familiar with—with the idea of lie detectors.

Gazzaniga: Exactly! That's one of the problems that we're going to address and examine very carefully, but overall I think people can fairly ask, "Why now? Why has this come up so intently in the last few years?" And I really think it's traceable to 15 to 20 years ago when human neurobiology really came under the microscope. With the development of brain imaging technologies, MRI functional imaging, positron emission tomography and other kinds of imaging, electrical recording kind of imaging, we now have a full-blown human neuroscience and we are beginning to examine questions that were never examined before. So people now have thoughts about what the moral stance of a human should be. How much of that is built and how much of that is a function of cultural learning? And people are beginning to examine them [these] questions that have to do with the real nature of pain. How can you distinguish physical pain from psychological pain? That kind of elucidation of that mechanism is probably going to be very helpful not only in the criminal cases, but also in the civil cases of people judging whether someone who was normal, by accident complaining falsely of pain and so forth. So, there is all kinds of things that just a few years ago simply were not examined in a scientific sense; and to have real scientific methods available for people to try to understand these processes is very powerful and your lie detection is a perfect example.

Steve: Let's talk about, for example, functional MRI.

Gazzaniga: Right.

Steve: Now with functional MRI, we sort of see the brain doing something.

Gazzaniga: Right.

Steve: We see the brain being active in a particular way under a particular set of circumstances.

Gazzaniga: Yes.

Steve: How does that relate to the kinds of mental states that would come up in a courtroom and how do we know that we are actually looking at what we think we are looking at necessarily? You know, can you just do a brain scan and say, "No, this person is guilty." That's obviously not something we can do.

Gazzaniga: Right, exactly! You put your finger on the $64 question, to really use brain imaging in the sense of saying that brain image suggests this kind of mental state is not there yet by a long shot and when that—if that ever—arises, the question will be, will that be a violation of your personal rights? Is that something that one would call the Fifth Amendment? Interestingly, the Fifth Amendment is something that is used for verbal self-incrimination. You might think, well DNA is incredibly incriminating, why is that allowed? Well physical evidences [is] allowed, but not verbal incrimination, so verbal is mental. Are we going to have all these new capacities develop out of the scientific end and then the courts are going to have to decide, should we call these physical evidence—you'd know, it's the substrate of mind? Or is this mental evidence and therefore non-[un]usable in [a] court of law? Those are all uncharted waters because the science of the brain enabling mental life isn't quite there yet.

Steve: So, it's almost inevitable, but we're going to see a Supreme Court case that's going to look at some kind of brain imaging and decide whether it's allowable under the Fifth Amendment.

Gazzaniga: That would be (laughs) my interpretation. I have to go to my co-directors on this new project and they could straight[en] me out on that, but then that is where I see it going.

Steve: Let's talk about the new project, The McArthur Foundation got involved in this because it is seeing that these kinds of pieces of evidence are going to wind up in courtroom, so we are trying to establish parameters before that happens too much; it's happened already.

Gazzaniga: Right. It's already happened and that's a good way of putting it. What this project is all about is looking both for the abuses and the future uses of neuroscience, because it can be abusefully used. The claims can be too great. I'll give you a concrete example. There's going to be the problem that Jones killed somebody and it turns out Jones has a brain lesion in the frontal lobe—does that make him exculpable, is that a way of getting him off? And that kind of defense is widely used and sometimes admitted into court. Now the underlying problem with that defense is that there are lots of people with that kind of brain lesion and they don't kill people, so the specificity of the observation is not great at this point, even though it seems right. You can say that, that kind of lesion does tend to lead people to certain kinds of bizarre behaviors, but there is a lot of things controlling [the] ultimate action of a human being and there is lots of ways, a tendency can be blocked by other rule learning that has gone on in the person and so forth. So, that's why just having a brain lesion isn't a switch that turns you on to being violent or abusive or whatever. That's why it's a very complex question and that's one of the things that this project is going to examine carefully.

Steve: And the brain lesion would be one of the grosser examples. Ultimately we hope that we will be able with brain scans to look at very kind of fine-tuned levels of brain function.

Gazzaniga: That's right.
Steve: Within the normal range.

Gazzaniga: Exactly! Examination of psychopathy—[does]is this person seem to be immune to knowing right from wrong? Can we tell that through brain imaging? And then this other distinction: well maybe they know right from wrong cognitively, but do they appreciate right or wrong and those kinds of distinctions? Maybe, those were all, are things down the pipe here that are going to be really nailed down and being able to be assessed and claimed and the like.

Steve: So, now proponents of using brain scanning techniques, [will] say we can get a more accurate justice with less bias about guilt and lies and they also think we might even be able to predict criminal behavior. Now that's a hole—I mean, now you are in the Spielberg movie Minority Report.

Gazzaniga: Right, right.

Steve: So, what are some of the concrete dangers that you see with people going too far with the thinking about potential applications of this kind of technology?

Gazzaniga: So much of neuroscience and cognition, neuroscience and behavior, is correlative in nature. This sort of thing correlates with that sort of thing and it is not, in a reflexive sort of way, causal; and so when you have a particular biologic state that you have identified with new brain imaging, does that necessarily mean that person is holding a particular thought or has a certain intention or not? And that's to say that is another central question that has to be examined and one of the things that this project will do. Because there's going to be increasing pressure from people fascinated with brain imaging to use this kind of information in a court. And when its appropriate, its going to be terrific; when its inappropriate, as that said, it just shouldn't be there and there should be someone trying to sort this out and making assessments about it.

Steve: And that's the purpose of this—is to figure out when it's appropriate, when it's not appropriate.

Gazzaniga: Exactly!

Steve: Talk about the three groups that are the first things that are going to be involved in this launch. There is addiction, brain abnormalities and decision making. What does all that mean?

Gazzaniga: Right. So, there are three different networks. The addiction network is going to tackle this whole question of what addiction really is, what is the brain science of addiction? And, if addiction draws you compulsively towards behaviors that wind up in criminal action, how should we think about those people who commit crimes and so forth? Sorting all that out is a very complex and delicate issue for obvious reasons. The second network is looking at normal decision-making gone wrong. So the prisons are full of people who aren't pathological groups, they are not psychopaths, they are not brain damaged, they are not having this problem or that, they've just made some really bum decisions. What are the things that influence that? Why was this poor judgment manifested in particular instances? And the[y]re are also going to be looking at bias and how through the judicial process bias occurs; so whether it's in the courtroom, whether it is in the selection of a jury. There is a host of things, and that is now studied. Of course, it has been studied for years by cognitive psychologists, but now there is a brain imaging component to it that's very interesting. And then finally the third network is looking at this issue of diminished brains, we've called it, leading to criminal behavior and how exculpable should that fact be. And we're going to be examining that very carefully and trying to be specific about how and when that kind of defense should be used and when it should be disallowed.

Steve: Do you think it's possible that eventually in addition to courtroom testimony, you're going to see brain scans that are put forth as evidence to show the state of maybe the defendant or maybe even the members of the jury.

Gazzaniga: It's scary and I wouldn't want to forecast because I think this is the time to look at all this stuff and to see what we know, and to see what we might know and to see how it should influence law in the judicial process.

Steve: You think there is a parallel to DNA?

Gazzaniga: I mean the reason DNA is so powerful is because it is virtually the raw truth, it's just the deal; and brain science studies are a long way from that kind of certainty, and so I think it'll be a lot more critical need for research to really try to nail some of this stuff down. I can see most claims now being rather easily taken care of in [by] good lawyering.

Steve: Right. It's still better to have a good lawyer than a good neuroscientist. (laughs) Is this a two-way street or is the neuroscience at all being informed by things that are going on in the courtroom?

Gazzaniga: Well, that is the very important goal of this project. This project, to paint the picture—has four types of people on it: the neuroscientists, the lawyers, the judges, and philosophers who have looked at these questions of law in society and where law comes from for years; and one of the goals over the course of this first year is for the lawyers and neuroscientists to come and meet together and to ascertain and sharpen up questions for [the] experimental program, actual empirical work which starts in years two and three. So, yes, there will be a very active exchange: A neuroscientist can think of an interesting experiment and the lawyer might say, "Well that's very interesting, but that'll never have an impact on legal reasoning. So if you make this adjustment and you get this result versus that result that would have an impact conceivably." So, it's going to be a whole new sort of interaction.

Steve: It's really interesting stuff. You know, you made me think of—there is an old axiom that "A good lawyer knows the law, but a great lawyer knows the judge," and maybe in the future a really great lawyer knows the judge—and the fMRI technician.

Gazzaniga: That's right. Well, there are many number of law schools now in the country that are beginning, in their third year of the legal training have neuroscience-in-law courses. They already see that this is an important issue, and I have several friends who are involved in these processes including one of our co-directors setting up a whole program at Vanderbilt University Law School.

Steve: Which makes sense because in our legal system intent is such an important part of the jurist prudence that we sort of have to go in this direction.

Gazzaniga: Right.
Steve: To figure out what people's intent was?

Gazzaniga: Right, exactly! And there are new studies of fMRI, there are studies in the animal literature that prior to the activity of the actual behavior of a person or in the animal experiment of the monkey, the neuroscientist can tell what the person is going to do, choice situation—it's a laboratory sort of situation of course; whether these things move into more realistic, naturalistic kinds of decisions, if someone can actually judge what you're going to do before you actually do it and they know and you don't, but that sort of thing—that's going to be powerful information contributing to the notion that when someone does something, they are going to take the defense, "My brain did it, not me."

Steve: Right. "It was my brain and not me." It's really interesting. Well, anybody listening who is working on their doctorate in neuroscience, you go get yourself a law degree after that and you will be safe for the rest of your life. Since I have you here, lets switch gears, and I'd like to just take a couple of minutes to talk about the president's bioethics commission, of which you are a member; and it was in the news quite a lot about three years ago. Some of the members were resigning and there was a lot of Sturm und Drang within the commission about the direction of the commission in large part due to stem cell research, right?

Gazzaniga: Right.

Steve: So, what's the current attitude within the commission about the work that's being done—you know, is everybody playing nice and getting along right now?

Gazzaniga: Well, there's been quite a change in the membership of the committee. The original committee really was divided—and I must hasten to stay, the majority came out with the view that they did not have a moral problem with stem cell research; they had varying degrees of willingness to enact it, but they did not have a moral problem with it—but [a] lot of those people have gone on [and] resigned and then [been] replaced and the complexion of the committee now is quite different. And they have taken on different topics and we've taken on the issues of organ transplantation, the issues surrounding death and dying and neurologic deaths and how should it be defined, and there are more questions on the horizon so …

Steve: Is that a result of the Schiavo case; did that really bring that to the forefront?

Gazzaniga: It might've been. I don't know how it actually came up, but it has come up in lots of circles, last year exactly, just a year or little over a year ago, the Pontifical Academy of Science held an international meeting in the Vatican wanting to reexamine the question of brain death and definition of it for organ transplantation. [A] lot of people don't know actually that when organ transplantation was started, it was actually Pope Pius XII that gave it the green light. He said it was fine if someone is basically declared brain death [dead] then [and] use[d] the reasoning that no greater love can a person give than a life to another, so that he gave the green light and organ transplantation started. The Catholic moral philosophy was very important in pushing this forward. So Pope Benedict, the new pope had one of this[these] re-examined and they just came out with the report, which is quite fascinating to read; and I think it was pretty much determined that the current way of judging brain death as death—[at] this point—is acceptable, and I don't think that there are going to be any changes in the issue. And I know the president's commission is just finishing a report where they pretty much come to the same conclusion.

Steve: So, stem cells are pretty much quiescent right now, that's not a topic that the …

Gazzaniga: It is not a topic that the bioethics council is examining. It has gone forward in so many other venues, from California State and other countries; and in the upcoming election I see that some of the leading candidates are already staking at their position that they will reverse the current ban on embryonic stem cell research from government funding, because it's legal from private funding.

Steve: Right.

Gazzaniga: So, I think it is a kind of past the committee's jurisdiction now—they just are not tackling the question; it is out in the public, they leave that out, say, "it's now time for others to say."

Steve: All right, so you have brain death and organ transplantation; what else is actively under consideration right now?

Gazzaniga: At the last counsel meeting, which I had to miss, there was quite an impatient plea to put on the agenda the national health care issue: Is it moral not to provide health care for every American?

Steve: Very interesting. That is a very different kind of question from what the ethics commission usually considers.

Gazzaniga: And it reflects who is the new chair; the new chair comes out of traditional medical ethics at Pellegrino, and the previous chair of course, Leon Kass, came at it from a more of a philosophical background and the likes. So that is being discussed as being one of the things that will be examined in the remaining two years of the commission.

Steve: Well, this has been a lot of fun. I appreciate your time and hope we get to talk about some of these things as they develop over the coming years.

Gazzaniga: Good to see you, Steve.

Steve: For more on the law and neuroscience project just go to and you can find a podcast of the entire panel discussion that accompanied the official announcement as well as brief video highlights at


Story number 1: Even six-month-old babies can tell helpers from hinderers.

Story number 2: Up to half of all nanotechnology companies don't actually do any nanotechnology.

Story number 3: Brown bears from 20,000 years ago had a different genetic makeup from today's brown bears and the ice sheets of the last ice age probably drove off the genetic changes.

And story number 4: A sea scorpion that lived at least 255 million years ago was bigger than a grown man.

Time is up.

Story number 1 is true. Tests on six-month-olds found that they could tell who was trying to help a third party and who was getting in the way of that third party and they preferred to play with the helper. For more check out the November 26th episode of the daily Scientific American podcast, 60-Second Science.

Story number 2 is true. A recent Ph.D. thesis finds that half of all companies labeling themselves as nanotech are engaged in activities that are not truly nanotech. Many are doing what they always did but are now calling themselves nanotech to appeal [appear] state of the art, and only a small part of the revenues for companies that actually do nanotech are coming from their nanotech ventures. The doctoral thesis was presented at the Helsinki School of Economics.

Story number 4 is true. The recently discovered fossil remains of the sea scorpion showed that it was bigger than a grown man—and I am not talking about Peter Dinklage. According to research published online in the Royal Society's journal, Biology Letters, the scorpion would have been close to eight feet long.

All of which means that story number 3, about the ice age driving the genetic changes in brown bears over the last 20,000 years is TOTALL……. Y BOGUS. Because research published in the journal Molecular Ecology shows that the gene changes are much more likely the result of hunting and other human activities in the bear's environment. Time will tell if humans are indeed smarter than the average bear.

Well that's it for this edition of the weekly Scientific American podcast. You can write to us at and check out numerous features at our brand-new, redesigned Web site, including new[s] stories, theblog and the SciAm Community. For Science Talk, the weekly podcast of Scientific American, I'm Steve Mirsky. Thanks for clicking on us.

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