Speaker 1: Can you measure pedophilia in a brain scan? Can you
Speaker 1: measure a lie from somebody's blood pressure? And how should
Speaker 1: a judge in court who's not an expert in science
Speaker 1: decide these things? What does any of this have to
Speaker 1: do with President Ronald Reagan or antisocial personality disorder or
Speaker 1: how the television show CSI has impacted courtrooms. Welcome to
Speaker 1: Inner Cosmos with me David Eagleman. I'm a neuroscientist and
Speaker 1: an author at Stanford and I've spent my career at
Speaker 1: the intersection of our brains and our lives. In today's
Speaker 1: episode is about an aspect of the intersection between brains
Speaker 1: and the legal system, and it's a tricky one. The
Speaker 1: question is when neuroscience techniques are allowed in courts, When
Speaker 1: should they be allowed? What bars need to be passed
Speaker 1: for a technology to be accepted. So let's start on
Speaker 1: March thirtieth, nineteen eighty one, when the President of the
Speaker 1: United States, Ronald Reagan, has been delivering a speech and afterwards,
Speaker 1: he and his team are returning to his limousine and
Speaker 1: he gives a two big arm wave to the crowd
Speaker 1: and suddenly there are gunshots ringing out and everyone's diving,
Speaker 1: and President Reagan is hit with a ricochet off his limousine,
Speaker 1: and Press Secretary James Brady falls and Secret Service agent
Speaker 1: Tim McCarthy falls, and a DC Police officer named Thomas
Speaker 1: del Haunty is also wounded, and the President arrives at
Speaker 1: the emergency room in critical condition and almost dies. And
Speaker 1: for those of you who weren't alive in nineteen eighty one,
Speaker 1: or for whom this has re seated in memory, just
Speaker 1: try to picture the horror that this entailed. Now you
Speaker 1: may remember that the gunman, John Hinckley, had a deep psychosis.
Speaker 1: He was divorced from reality, and he believed that if
Speaker 1: he shot the president, he would win the love of
Speaker 1: the actress Jody Foster. There's a lot to say about
Speaker 1: this case, and in episodes thirty six and thirty seven
Speaker 1: I talked about the insanity defense, but here I want
Speaker 1: to zoom in on a very particular aspect. The thing
Speaker 1: most salient to us today was the fact that this
Speaker 1: was the first high profile case to use a form
Speaker 1: of brain imaging. Hinckley's lawyers pled not guilty by reason
Speaker 1: of insanity, and to support their defense, they introduced brain
Speaker 1: imaging evidence so his defense counsel argued that he was schizophrenic,
Speaker 1: and they argued they could prove this by showing CAT
Speaker 1: scans or CT scans. CT stands for computer aided tomography
Speaker 1: or computerized demography. Now, the lawyers on both sides agreed
Speaker 1: that cat scans had never before been admitted as evidence
Speaker 1: in a courtroom. Neuroimaging was brand new at this time,
Speaker 1: So should the judge allow this new Fengal technology to
Speaker 1: be accepted or not? Well, it's not obvious. Can you
Speaker 1: really tell if someone suffers from schizophrenia just by looking
Speaker 1: at an anatomical picture of the brain. It's not obvious.
Speaker 1: So the judge decided to dismiss the jury so that
Speaker 1: he could hear the arguments about whether or not the
Speaker 1: technology was relevant and should be admitted. And expert witness,
Speaker 1: a physician, pointed out that Hinckley's soul sigh, which are
Speaker 1: the valleys running along the outside of the brain, these
Speaker 1: were wider than average, and this physician cited a paper
Speaker 1: suggesting a connection between schizophrenia and wider sulsie. So the
Speaker 1: assertion was, if you have schizophrenia, you can see that
Speaker 1: just by looking at a cat scan of the brain.
Speaker 1: So this doctor said, quote the fact that one third
Speaker 1: of schizophrenic participants in the study had these widened sulsie
Speaker 1: whereas in normals probably less than one out of fifty
Speaker 1: have them. That is a very powerful fact. But the
Speaker 1: prosecution rebutted this. They said, no way, it has not
Speaker 1: been proven that a cat scan can aid in the
Speaker 1: diagnosis of schizophrenia, and therefore this evidence should not be
Speaker 1: presented to the jury. In other words, they argued the
Speaker 1: technology should be excluded from the courtroom because it was
Speaker 1: not yet ready for prime time. The judge listened to
Speaker 1: the arguments and he finally decided that he would not
Speaker 1: admit the cat scan. Then nine days later he heard
Speaker 1: more expert testimony and he confirmed that he would not
Speaker 1: take the cat scan. And then he changed his mind
Speaker 1: and reported he would take the cat scan. Okay, So
Speaker 1: what is this back and forth illustrate? It illustrates the
Speaker 1: difficulty for a judge to decide what makes meaningful evidence
Speaker 1: and what does not. In the end, Hinckley was found
Speaker 1: not guilty by reason of insanity, although that had little
Speaker 1: or nothing to do with the cat scan. But this
Speaker 1: high profile case is just one of hundreds where this
Speaker 1: question comes up, should neuroimaging be allowed in the courtroom.
Speaker 1: There's no single answer to this question, and in part
Speaker 1: that's because there are many different guyses in which it
Speaker 1: comes up. And so that's what we're going to talk
Speaker 1: about today. We're going to talk about how any technology
Speaker 1: gets into courtrooms. So to motivate this, imagine that we
Speaker 1: start seeing advertisements for a new Silicon Valley company that
Speaker 1: has developed a new mind reading technology. They call this
Speaker 1: the Palo Alto three thousand, and they strap it to
Speaker 1: your head and they measure some brain waves and pass
Speaker 1: that through a large language model, and they print out
Speaker 1: in words to a screen what you are thinking. So
Speaker 1: you might be thinking about wanting a hot dog with pickles.
Speaker 1: In this machine will print to the screen, I want
Speaker 1: a hot dog with pickles. Now this is totally made up,
Speaker 1: but pretend it's true. In a few years that said
Speaker 1: company launches, and let's say the technology looks pretty good.
Speaker 1: It captures the gist of what you are thinking about. Now,
Speaker 1: the question is should this be admissible in a court
Speaker 1: of law. Let's imagine that someone puts it on and
Speaker 1: states under oath that on April twenty fifth, he was
Speaker 1: getting dinner with his family, but suddenly the screen prints
Speaker 1: out I committed the crime. Now, how do you know
Speaker 1: whether to believe that or not? The company is started
Speaker 1: by a handful of young people who dropped out of college,
Speaker 1: and they claim to be experts in neuroscience, But how
Speaker 1: do you know whether it really works? And especially in
Speaker 1: a high stakes situation, should you accept this in a
Speaker 1: court of law or not? Well, some people, in order
Speaker 1: to judge the quality of the technology, they ask, well,
Speaker 1: are they charging for this technology? But that's not a
Speaker 1: meaningful measure. Of course they're charging. They can't develop new
Speaker 1: technologies for free, anymore than you would expect Apple to
Speaker 1: not charge for their laptop. But the fact that they're
Speaker 1: charging certainly doesn't rule in or out anything about its efficacy.
Speaker 1: So how do you know whether the technology is efficacious?
Speaker 1: Can it be used in a court of law? How
Speaker 1: do you know whether it works and provides what the
Speaker 1: legal system calls probative value, which means can it do
Speaker 1: what it's supposed to do? Can it provide sufficiently useful
Speaker 1: evidence to prove something in a trial? So this is
Speaker 1: what we're going to talk about today. Most of the
Speaker 1: time we don't realize that new technologies always have to
Speaker 1: be assessed by courtrooms to know whether they should be
Speaker 1: accepted or rejected. And some get in and then we
Speaker 1: take that as background furniture, and others never make it.
Speaker 1: And what we're going to see today is how and why.
Speaker 1: So fast forward some decades from the Hinckley trial. Where
Speaker 1: are we now? What is allowed in the courtroom? Well,
Speaker 1: we have more sophisticated technologies to image the brain. Now,
Speaker 1: for example, we can get a picture of the brain
Speaker 1: in an MRII scan. Magnetic resonance imaging MRI gives you
Speaker 1: a snapshot of what the brain of a person looks like.
Speaker 1: You're not seeing activity there, You're just seeing the anatomy.
Speaker 1: Think of this an analogy to the way you would
Speaker 1: look at someone's skeleton with an X ray. You can't
Speaker 1: see anything moving around what you see as a snapshot.
Speaker 1: So with MRI you can hope to see abnormalities like
Speaker 1: a tumor or evidence of a stroke, or the consequences
Speaker 1: of a traumatic brain injury. Now, I've been called by
Speaker 1: many defense lawyers over the years who say, I have
Speaker 1: a client who's going up for trial. Can you take
Speaker 1: a brain scan and see if you can find something
Speaker 1: wrong with their brain, so this can serve as a
Speaker 1: mitigating factor. But I always tell them the same thing.
Speaker 1: If you find something wrong with your client's brain, that
Speaker 1: can serve as a double edged sword. The duray might think, Okay,
Speaker 1: I'm convinced there's something different about this man's brain. But
Speaker 1: this presumably means he'll be predisposed to committing this kind
Speaker 1: of crime again, so we should probably lock him up
Speaker 1: for a longer time. So a defense lawyer has to
Speaker 1: utilize this argument with care. In any case, what MRI
Speaker 1: gives you is an anatomical snapshot. And now I want
Speaker 1: to tell you about the next level of technology called fMRI.
Speaker 1: Where the F stands for fancy MRI. Okay, I'm kidding.
Speaker 1: It stands for functional magnetic resonance imaging fMRI. And this
Speaker 1: is because it's telling you about the function of the brain.
Speaker 1: It's measuring blood flow to show you where the activity
Speaker 1: in the brain just was. This works because when brain
Speaker 1: cells are active, they consume energy, and the blood flow
Speaker 1: to that specific region needs to increase so that you
Speaker 1: can bring fresh oxygenated blood to the area to restore
Speaker 1: the used energy. So in fMRI, we see where the
Speaker 1: new oxygenated blood is going and we say, aha, there
Speaker 1: must have just been some activity there a few seconds ago.
Speaker 1: So that's the difference between an anatomical snapshot or a
Speaker 1: functional picture of what's going on. Now. Part of the
Speaker 1: reason that you can use the static snapshot the MRI
Speaker 1: in court is because it's generally seen as hard science.
Speaker 1: This is the guy's brain. But when we're talking about fMRI,
Speaker 1: what we're looking at is the activity in the brain,
Speaker 1: and we're generally asking something about the person's mental state,
Speaker 1: and can that be the same kind of hard science.
Speaker 1: On the one hand, it's a clear question with a
Speaker 1: clear answer if someone has a stroke or a brain tumor.
Speaker 1: But this isn't the case if you want to pose
Speaker 1: a question like did this defendant intend to kill the victim?
Speaker 1: fMRI doesn't and can't give you clear answers like that
Speaker 1: to questions that are useful for the legal system. So
Speaker 1: we're going to dig into this now. So first let's
Speaker 1: start with the question of whether fMRI has been used
Speaker 1: in courts. The answer is yes, But the technology can
Speaker 1: be used in different ways. It doesn't always have to
Speaker 1: involve an individual's brain, but can sometimes be about brains
Speaker 1: in general. So let me give you an example. There
Speaker 1: was a murder case in Missouri where a young man
Speaker 1: named Christopher Simmons broke into the home of a woman
Speaker 1: named Shirley Crook. He covered her eyes and mouth with
Speaker 1: duct tape, he bound her hands together, and then he
Speaker 1: drove her to a state park and threw her off
Speaker 1: a bridge to her death. Now, this was a premeditated crime,
Speaker 1: and the evidence was overwhelming, and he admitted to the murder.
Speaker 1: So the judge and jury handed down a death sentence.
Speaker 1: But there was a complication. Christopher Simmons was only seventeen
Speaker 1: years old at the time he committed the crime. And
Speaker 1: so this case spun all the way up to the
Speaker 1: United States Supreme Court, and the question was can you
Speaker 1: execute someone who was under the age of eighteen when
Speaker 1: they committed the crime? After all, the argument goes, adolescence
Speaker 1: is characterized by poor decision making, and young people should
Speaker 1: have the chance to grow up into a different life. Well,
Speaker 1: one of the things that happened at his trial is
Speaker 1: that the Supreme Court considered fMRI evidence. Now this wasn't
Speaker 1: from Simmons's brain in particular, but from adolescence in general.
Speaker 1: The study compared young people and adults performing the same
Speaker 1: cognitive tasks, and what the researchers found, not surprisingly, is
Speaker 1: that young brains are not doing precisely the same thing
Speaker 1: as older brains. There are measurable differences. A juvenile's brain
Speaker 1: just isn't the same thing as an adult. So the
Speaker 1: Supreme Court justices saw this evidence, considered it, and presumably
Speaker 1: this is part of what led the court to conclude
Speaker 1: that it is unconstitutional to execute someone for a crime
Speaker 1: who is a minor. Now that's an example of fMRI
Speaker 1: making it into the court. It's been used in this
Speaker 1: way to compare groups of people, juveniles versus adults in
Speaker 1: this case. But things get a little trickier when you're
Speaker 1: trying to say something about an individual's brain, the brain
Speaker 1: of the one guy standing in front of the bench.
Speaker 1: So what can we and can we not say with
Speaker 1: the technology? So let's zoom in on a few examples.
Speaker 1: Many researchers and legal minds have been asking whether one
Speaker 1: can use brain imaging to diagnose whether someone has antisocial
Speaker 1: personality disorder, which is a condition in which a person
Speaker 1: has a long term pattern of manipulating, exploiting, and violating
Speaker 1: other people people with antisocial personality disorder or a SPD.
Speaker 1: They'll commit crimes, they'll flaunt rules, they'll act impulsively and aggressively,
Speaker 1: they'll lie and cheat and steal. Now, this is a
Speaker 1: condition that is massively overrepresented in the prison population. But
Speaker 1: biologically it's not obvious what it's about. There's no single
Speaker 1: gene here, and there's not a single environmental factor. It's
Speaker 1: a complicated combination. And the legal system often cares to
Speaker 1: know whether someone has ASPD or not. And so researchers
Speaker 1: started to wonder a long time ago, could you use
Speaker 1: brain imaging to determine in some clear categorical way, does
Speaker 1: this person have ASPD or not. So, in one study,
Speaker 1: researchers highlighted the brain regions that had high probability of
Speaker 1: being anatomically different between people with ASPD and those without.
Speaker 1: And you can look in the cortex what's called the
Speaker 1: gray matter, or below the core text what's called the
Speaker 1: white matter, and you can measure these small anatomical differences
Speaker 1: between those with and without. So the question arose, can
Speaker 1: you use this technology in court as a diagnostic tool
Speaker 1: to say that this person has ASPD or not? Now
Speaker 1: do you see any problems with this off the top
Speaker 1: of your head about whether this technology can be used.
Speaker 1: The problem is that all the scientific results come about
Speaker 1: from examining groups of people, like fifty people in each group,
Speaker 1: and the question is whether these group differences are strong
Speaker 1: enough to tell you about individual differences. So this is
Speaker 1: known as the group to individual problem. In other words,
Speaker 1: you have data from groups of people that can be
Speaker 1: distinguished on average, but you're trying to say something about
Speaker 1: this individual. It would be like making an accurate statement
Speaker 1: that men on average are taught than women, and then
Speaker 1: asking whether some individual, like a tall woman, could be
Speaker 1: categorized as a man because her height clocks in at
Speaker 1: the average mail. The legal system is well aware of
Speaker 1: this grouped individual problem, and so as technologies are introduced,
Speaker 1: the justice system always needs to ask how specific is
Speaker 1: this technology and how sensitive is it? Is it good
Speaker 1: enough for individual diagnosis. Brain imaging studies generally just give
Speaker 1: us group average results, and the question is whether it
Speaker 1: tells us enough or anything about the person who's standing
Speaker 1: in front of the bench right now. Now. The idea
Speaker 1: of bringing functional brain imaging to bear on questions of
Speaker 1: criminal behavior is an old one, and this grouped individual
Speaker 1: problem is just as old. For example, there was a
Speaker 1: study in nineteen ninety seven where researchers image the brain
Speaker 1: of normal participants and murderers, and they found, on average,
Speaker 1: there was less activity in the frontal lobes in murderers.
Speaker 1: So you look at the activity in the front of
Speaker 1: the brain behind the forehead and you say, hey, on average,
Speaker 1: there's less going on here in the murderer group. But
Speaker 1: you can't use this on an individual. You can't say, oh,
Speaker 1: this person has less activity, so he must have been
Speaker 1: the murderer. In other words, it has no power in
Speaker 1: a court of law. You still face the problem of
Speaker 1: trying to say anything about an individual from a group average.
Speaker 1: And so it's for reasons like this that brain imaging
Speaker 1: on individuals has not gotten very far in courtrooms. Let
Speaker 1: me give one more example. Another research group used brain
Speaker 1: imaging fMRI to see if they could identify pedophiles. They
Speaker 1: found twenty four pedophiles and thirty four controls, and they
Speaker 1: showed them images of naked men and women and boys
Speaker 1: and girls. And what they found is that they could
Speaker 1: on average separate the participants who were pedophiles from the
Speaker 1: participants who were not. In other words, the pedophilic brain
Speaker 1: shows a subtly different signature of brain activity than the
Speaker 1: non pedophilic brain when shown these pictures. It turns out
Speaker 1: that heterosexual versus homosexual seems to be distinguishable as well.
Speaker 1: So you might think that sounds quite useful for the
Speaker 1: legal system, but when scientists and legal scholars take a
Speaker 1: closer look, it's not as clear. The first question is
Speaker 1: what are these brain signals actually measuring. The assumption is
Speaker 1: that it's measuring a state of arousal, like sexual attraction,
Speaker 1: but what else might be going on? Well, the difference
Speaker 1: in brain signals could be driven by a stress response
Speaker 1: or an anxiety response by the pedophilic participants who know
Speaker 1: they're being measured. Or perhaps what you're seeing is a
Speaker 1: measure of disgust by the non pedophilic group who knows
Speaker 1: the purpose of the study and doesn't like gazing at
Speaker 1: pictures of children in this context. Or what if the
Speaker 1: pedophilic participants were just slightly more likely to avert their
Speaker 1: eyes because of shame or not wanting to get measured.
Speaker 1: That would cause a statistical difference in the brain signals
Speaker 1: and could, in theory, explain the results. So there are
Speaker 1: lots of things that could yield this brain imaging result
Speaker 1: of a difference between the two groups, beyond the hypothesis
Speaker 1: that it's just measuring arousal, So stress, anxiety, discuss shame,
Speaker 1: all these things might be what's getting measured here. And
Speaker 1: part of why this matters is because there are many
Speaker 1: brain imaging measures where it turns out it's easy to
Speaker 1: manipulate the results. So let's say you are a pedophile
Speaker 1: who doesn't want to be labeled as such. Can you
Speaker 1: purposely move your eyes whenever you see a picture of
Speaker 1: the children, and that messes up the ability of the
Speaker 1: scanner to measure something. If something can be faked or
Speaker 1: messed up, then the technology is useless. But let's say,
Speaker 1: for argument's sake, that you have a technology that can't
Speaker 1: be faked or manipulated, and that allows us to move
Speaker 1: on to the second point. Let's say you don't even
Speaker 1: care what's getting measured, like stress or anxiety or whatever.
Speaker 1: All you care to know is whether there is a
Speaker 1: neural signature that can distinguish the pedophiles from the non pedophiles,
Speaker 1: irrespective of what is causing that signal. Well, there's also
Speaker 1: a legal problem here, which is that it's not illegal
Speaker 1: for a person to be attracted to children. It is
Speaker 1: only illegal if they act on that. All that's illegal
Speaker 1: is whether you have committed a crime or not, not
Speaker 1: whether you are attracted to children. So you can think
Speaker 1: about whatever attracts you ostriches or jello or whatever, as
Speaker 1: long as you don't commit an illegal act. So whether
Speaker 1: you're talking about ASPD or murderers or pedophile while, you'll
Speaker 1: see that measuring something that matters for a court of
Speaker 1: law isn't as straightforward as it might have originally seemed.
Speaker 1: So now let's return to the Palo Alto three thousand.
Speaker 1: The question is just because the company claims that it functions, well,
Speaker 1: how do you know whether or not to admit it
Speaker 1: into the courtroom? After all, remember what I said about
Speaker 1: the John Hinckley case, how cat scans were admitted into
Speaker 1: the court to argue that he had schizophrenia. Well, it's
Speaker 1: now known that wide and salsa in the brain have
Speaker 1: no relationship to schizophrenia. There are other better anatomical signatures
Speaker 1: that we have now, like thinner cortices in the frontal
Speaker 1: and temporal lobes and shrunkened thalamuses. But it turned out
Speaker 1: that the idea of white and salsa I just didn't
Speaker 1: hold up. Now, there was nothing fraudulent going on with
Speaker 1: the claim. It was just a new technology at the
Speaker 1: time and they were doing the best they could with
Speaker 1: small sample sizes. But it turned out the theory of
Speaker 1: white and sul sight was scientifically unsound. Remember how I
Speaker 1: mentioned that the judge went back and forth several times
Speaker 1: about the issue of whether to accept Hinckley's cat scan
Speaker 1: into the courtroom. That's exactly the right thing that should
Speaker 1: have happened. Not all claims are going to be correct
Speaker 1: just because a scientist says so. Despite best efforts, science
Speaker 1: can often be incorrect, and that is the importance of
Speaker 1: the scientific method. It's always knocking down its own walls.
Speaker 1: So what is a court to do about all this? Well,
Speaker 1: let's say that someone wants to introduce the Palo Alto
Speaker 1: three thousand into a court case, and you are the judge.
Speaker 1: You have expertise in the legal system, but you don't
Speaker 1: know the details of what's possible in neuroscience and large
Speaker 1: language models, and you have questions about whether this technology
Speaker 1: should be admitted, questions about whether it can accurately read
Speaker 1: people's thoughts, So how do you decide whether it should
Speaker 1: or should not be admitted. So let's step back to
Speaker 1: nineteen twenty three. There was a man named mister Fry
Speaker 1: who said that he had developed a lie detection technology
Speaker 1: and it relied on a measure of your blood pressure,
Speaker 1: and he wanted to introduce this into a court case
Speaker 1: the way you might want to get the Palo Alto
Speaker 1: three thousand into a case. But it turned out that
Speaker 1: mister Fry's claims were not widely accepted by anyone else
Speaker 1: in the scientific community, and so on those grounds, the
Speaker 1: court decided not to admit it into the courtroom. What
Speaker 1: they said was, look, we'll accept expert testimony that comes
Speaker 1: from well recognized science, but if there's some new technology,
Speaker 1: it has to be sufficiently established so that it's gained
Speaker 1: general acceptance in the field in which it belongs. In
Speaker 1: other words, if other experts in the field don't believe
Speaker 1: that mister Fry's systolic blood measurement is actually good at
Speaker 1: detecting lies, then you can't admit it as evidence in
Speaker 1: the court. And that case set the bar for what
Speaker 1: came to be known as the Fry standard, which is
Speaker 1: that technologies need to be generally accepted by other experts
Speaker 1: in the field before they can be admitted into the courtroom.
Speaker 1: So under the Fry standard, the court would work to
Speaker 1: determine whether the Palo Alto three thousand has met the
Speaker 1: general acceptance of the scientific community. If science experts around
Speaker 1: the world say, I've never heard of this Palo Alto
Speaker 1: three thousand, I don't think that it can actually work,
Speaker 1: then you, as the judge, can glued it from admissibility.
Speaker 1: So the court solves the problem by deferring to the
Speaker 1: expertise of other people in the field. But this isn't
Speaker 1: the only way to make that decision. The Fry standard
Speaker 1: still is the rule in about half the states in America,
Speaker 1: but the rest use a different rule to decide whether
Speaker 1: evidence should be admitted, and this is called the Dowbert standard.
Speaker 1: So in nineteen ninety three there was a lawsuit from
Speaker 1: a man named Jason Dalbert. He was born with severe
Speaker 1: birth defects and his parents brought suit against Merrill Dow
Speaker 1: the pharmaceutical company, and they said these severe birth defects
Speaker 1: were caused by the medication that the mother was on
Speaker 1: called Bendicton. So the pharmaceutical company said the birth defects
Speaker 1: were not caused by this medication, and it went to
Speaker 1: federal court and Dalbert said, look, here are animal studies
Speaker 1: showing that this drug is related to birth defects. And
Speaker 1: the pharmaceutical companies expert witnesses got up and said, look,
Speaker 1: this is not generally accept in the field because these
Speaker 1: are just animal studies and there's no conclusive evidence that
Speaker 1: shows the link between these and humans. So if you're
Speaker 1: the judge, how do you know how to arbitrate this?
Speaker 1: It's difficult. Right, here's some science from the laboratories and
Speaker 1: here's the pharmaceutical company saying it's not generally accepted in
Speaker 1: the field that this causes birth effects. So what do
Speaker 1: you do? Well, what happened is the case was decided
Speaker 1: in favor of the pharmaceutical company. So Dalbert took it
Speaker 1: on appeal to the Ninth Circuit and the Ninth Circuit
Speaker 1: judges also awarded this to the pharmaceutical company. So Dowbert
Speaker 1: brought this case to the Supreme Court, and the Supreme
Speaker 1: Court analyzed this carefully, and what came out of this
Speaker 1: was a new standard for when evidence should be admissible,
Speaker 1: and that's known as the Dalbert standard, and the Doalbert
Speaker 1: standard says, look, you accept expert testimony about, for example,
Speaker 1: these labrat studies if it will help the jury to
Speaker 1: understand the evidence better or determine the fact in issue.
Speaker 1: In other words, it doesn't demand general acceptance in the community.
Speaker 1: Under the Dalbert standard, the key is just whether some
Speaker 1: piece of evidence is relevant and reliable. Now, the key
Speaker 1: is that the Fry standard made the scientific community the gatekeeper,
Speaker 1: but the Dalbert standard makes the judge the gatekeeper. The
Speaker 1: judge gets to say from the beginning that they'll evaluate
Speaker 1: this and ask is this evidence relevant and reliable? Does
Speaker 1: it pass my bar for that? So, regarding this hypothetical
Speaker 1: palo alto three thousand, the judge might ask has the
Speaker 1: technique been tested in actual field conditions as opposed to
Speaker 1: just in a laboratory. Have there been any papers on
Speaker 1: the palab alter three thousand that were published in peer
Speaker 1: reviewed journals? What does the rate of error? Do standards
Speaker 1: exist for controlling the operation of the machine, and so on?
Speaker 1: These are often difficult questions. It's not always easy for
Speaker 1: a judge to make a decision about whether or not
Speaker 1: to accept a new technology. But this gives a pathway
Speaker 1: where the judge is the gatekeeper. So let's imagine for
Speaker 1: a moment that the Palo Alto three thousand passes the
Speaker 1: standard for admissibility. Is there any reason why the technology
Speaker 1: might still be excluded from the courtroom. There is one reason.
Speaker 1: Let's say that you're the defence lawyer and you say, Gosh,
Speaker 1: this thing is so stunning that it's going to prejudice
Speaker 1: the jury because they're going to look at this fancy technology,
Speaker 1: and even in the absence of really good evidence, they'll say, Wow,
Speaker 1: this guy seems guilty. Let's send him to the electric
Speaker 1: chair without considering the other points. So to prevent that
Speaker 1: from happening, there's a special rule called Federal Rules of
Speaker 1: Evidence four h three, and this just says you you
Speaker 1: should exclude evidence if what you can learn from it
Speaker 1: is substantially outweighed by the risk of undue prejudice. In
Speaker 1: other words, does it sway the jurors more than it should.
Speaker 1: So what you'll see in courtrooms all the time is
Speaker 1: that if a lawyer tries to exclude a piece of
Speaker 1: evidence from being admitted based on let's say a Doubert objection,
Speaker 1: but the evidence gets past that, then the lawyer is
Speaker 1: going to take a second bite at the apple by
Speaker 1: calling on federal rules of Evidence four three, saying, look,
Speaker 1: even if this is relevant and reliable, it's going to
Speaker 1: have too much sway on the jury. So why is
Speaker 1: this an issue? Are there technologies that have undue sway
Speaker 1: on jurors? Is that a concern? It is? And this
Speaker 1: brings us back to fMRI. In a court of law
Speaker 1: where jurors are your neighbors and your community and probably
Speaker 1: not experts in neuroscience, a lot of people will be
Speaker 1: swayed by a colorful brain image. They're going to put
Speaker 1: a higher weight on this than maybe they should, and
Speaker 1: possibly at the cost of not weighing this evidence appropriately
Speaker 1: in the context of the whole case. And this is
Speaker 1: part of the concern that some legal scholars have, and
Speaker 1: this has come to be known as the CSI effect.
Speaker 1: So you remember the television show CSI. This stood for
Speaker 1: Crime Scene Investigation, and it's a television drama about a
Speaker 1: team of forensic scientists and detectives in Las Vegas who
Speaker 1: use cutting edge scientific techniques to solve murders. So they
Speaker 1: go around each week and meticulously gather and analyze evidence
Speaker 1: from crime scenes and each episode features a complex case
Speaker 1: with an intricate puzzle and the CSI team has to
Speaker 1: solve this to bring the criminals to justice. Well, the
Speaker 1: idea with the real life CSI effect is that jurors
Speaker 1: come to expect what they've seen on TV in terms
Speaker 1: of magical machinery that does something like you hit a
Speaker 1: button to enhance the picture and then the computer enhances it,
Speaker 1: and they see everything with clarity, where the plot twist
Speaker 1: requires that the investigator pull out some magical technology that
Speaker 1: suddenly solves the crime, or looking at the pedophile's brain
Speaker 1: with neuroimaging and knowing whether he did the crime or not.
Speaker 1: So jurors have come to expect this sort of thing
Speaker 1: because you don't spend all your time in a courtroom
Speaker 1: if you're not a lawyer, and something like the television
Speaker 1: show CSI is their only window into that world. The
Speaker 1: problem is that it often turns out to be a
Speaker 1: false window, and when researchers do studies on this, they
Speaker 1: generally find that jurors see neuroimaging as the truth of
Speaker 1: the matter asserted. So we just spent a minute on
Speaker 1: looking at the claim that you can measure pedophilia and
Speaker 1: we noted that the brain signals might represent that you're
Speaker 1: a pedophile, or it might represent stress or anxiety, or
Speaker 1: disgust or shame or averting the eyes or all kinds
Speaker 1: of things. But that kind of nuanced analysis doesn't usually
Speaker 1: get done, and so neuroimaging often comes to be interpreted
Speaker 1: by the jury as the truth of the matter asserted.
Speaker 1: This is what scholars sometimes call the fallacy of neurorealism,
Speaker 1: and the fallacy is just that what you see in
Speaker 1: these pretty false color images is the truth. In other words,
Speaker 1: somebody thinks, oh, you're capturing the moment of pedophilia in
Speaker 1: its raw form there whereas, of course, the truth is
Speaker 1: that fMRI signals are not direct proof of the experience itself.
Speaker 1: As a side note, these questions of bringing visual evidence
Speaker 1: into the courtroom, they're not unique to brain imaging. They've
Speaker 1: been around for a long time. It goes back at
Speaker 1: least to X rays. So when X rays got introduced
Speaker 1: in the eighteen nineties, they immediately started showing up in
Speaker 1: court and everybody was absolutely blown away by the idea
Speaker 1: of being able to see inside of a body. It's
Speaker 1: like magic. So what happened over a century ago is
Speaker 1: people asked this question of can we use this as
Speaker 1: evidence in court? And the judge said at the time,
Speaker 1: as long as it was scientifically reliable, it could be introduced.
Speaker 1: But the same questions about influence on the jury came up,
Speaker 1: because there's a real power to seeing something. And of
Speaker 1: course what we have currently with brain imaging is even
Speaker 1: a deeper issue because it touches on all our notions
Speaker 1: of being human. For example, I saw a cover of
Speaker 1: a Time magazine a while ago and the title read
Speaker 1: what makes us Good or Evil? And the cover image
Speaker 1: was a huge picture of a brain scan, and there
Speaker 1: was a little picture of Mahatma Gandhi with a pointer
Speaker 1: to a part of the brain. And there was a
Speaker 1: little picture of Adolph Hitler with a pointer to a
Speaker 1: different part of the brain. And in case you haven't
Speaker 1: heard my other episodes on this, I want to make
Speaker 1: it clear there is no such thing. You can't measure
Speaker 1: some spot in the brain to determine whether someone is
Speaker 1: good or evil. And by the way, Friedrich Nietzsche wrote
Speaker 1: about this over a century ago, the words good and
Speaker 1: evil don't even represent something fundamental, but instead these words
Speaker 1: end up getting defined by your moment in time. What
Speaker 1: is good right now may be seen as evil in
Speaker 1: a century. These terms are defined by your culture. What
Speaker 1: you think is good might be seen as sacrilege by
Speaker 1: another group. So the idea that you could just measure
Speaker 1: something in the brain and say whether the person is
Speaker 1: good or evil really makes no sense. However, millions of
Speaker 1: people see this kind of Time magazine cover, and this
Speaker 1: is why legal scholars worry that brain images could be
Speaker 1: persue of past the point that they should be in
Speaker 1: the legal argot. This is known as something having undue influence.
Speaker 1: Brain images are influential because they take some abstract issue
Speaker 1: like evil intent and seem to nail it down to
Speaker 1: the physical. So this is why something like Federal Rules
Speaker 1: of Evidence four h three plays an important role in
Speaker 1: asking whether something has undo influence, whether it sways people
Speaker 1: more than it should now. At the extreme, some people
Speaker 1: say functional brain images should never be allowed in the
Speaker 1: courtroom because of their influence. One solution that a colleague
Speaker 1: of mind suggested is that you ban the visual aspects
Speaker 1: of brain images from the courtroom, so you just have
Speaker 1: expert witnesses come on to the stand and tell you
Speaker 1: what they think is going on as best they can.
Speaker 1: But they're verbally presenting the results, not showing them. But
Speaker 1: these are tough issues, right because you can show a
Speaker 1: gory photograph from a crime scene, which can also prejudice
Speaker 1: an entire courtroom. Or you can show a reenactment of
Speaker 1: a murder, but if you can't show a brain scan,
Speaker 1: that seems like maybe a double standard. So should you
Speaker 1: rule out all visual images or allow everything? And if
Speaker 1: you heard episode nineteen, I talked about eyewitness testimony and
Speaker 1: how massively swaying that is to jurors. You can have
Speaker 1: all sorts of expert scientific testimony, but then you have
Speaker 1: the person get up on the stand with tears and
Speaker 1: a cracking voice and say, I don't care what they say.
Speaker 1: I know that's the guy. And we're all moved and
Speaker 1: influenced by that, even though eyewitness testimony is so deeply fallible.
Speaker 1: So this is all just to say that the question
Speaker 1: of undue influence always has to be asked. Compared to
Speaker 1: what compared to other technologies, compared to gory photographs of
Speaker 1: the crime scene, compared to acting out a rape scene
Speaker 1: or a murder scene, do those unduly sway a jury?
Speaker 1: So I hope what you see is that These are
Speaker 1: tough issues, perhaps tougher than you had intuited at the
Speaker 1: beginning of the episode, So let's wrap up. We often
Speaker 1: think that when a new technology comes along, like a
Speaker 1: new brain technology, it always gives useful information, and we
Speaker 1: might assume that courts start leveraging it right away. But
Speaker 1: there are complexities around this. For example, in an earlier episode,
Speaker 1: I talked about lie detection. How do you know when
Speaker 1: somebody is actually lying? There are lots of technologies that
Speaker 1: try to measure some version of this, but nothing can
Speaker 1: simply tell you the answer because the whole concept of
Speaker 1: a lie is complex. Sometimes you might be telling the
Speaker 1: truth but you're factually incorrect, for example, because you're honestly
Speaker 1: misremembering how something went, but you believe your memory. Or
Speaker 1: for someone else, they might have no associated stress response
Speaker 1: because they just don't care that they're lying. So when
Speaker 1: somebody comes to the courts and says, hey, I have
Speaker 1: a new lie detection technology, the judge can't just say great,
Speaker 1: bring it to the case, because the judge first has
Speaker 1: to decide whether it should be admitted or instead, whether
Speaker 1: its promise will sway the jurors more than its value.
Speaker 1: We're all enthusiastic about the next stages of technology and
Speaker 1: being able to make important measures about what's happening in
Speaker 1: the brain. But the legal system has to be very
Speaker 1: careful about this, whether by standards of general acceptance in
Speaker 1: the scientific community or by the choice of the judge's gatekeeper.
Speaker 1: Each new technology has to be weighed carefully for admissibility
Speaker 1: every time before it can enter the esteemed halls of justice.
Speaker 1: Eagleman dot com slash podcast. For more information and to
Speaker 1: find further reading, send me an email at podcast at
Speaker 1: eagleman dot com with questions or discussion, and check out
Speaker 1: and subscribe to Inner Cosmos on YouTube for videos of
Speaker 1: each episode and to leave comments Until next time. I'm
Speaker 1: David Eagleman, and this is Inner Cosmos.