My brain made me do it

A man committed a crime. He admitted it. Then something alarming showed up on an image of his brain. The criminal case that followed in 1991 brought neuroscience into the courtroom for good. How does our ever-changing understanding of the brain impact how we approach justice? Guests: Josh May, professor of philosophy, University of Alabama, Birmingham, author of Neuroethics: Agency in the Age of Brain Science, Anthony Wagner, neuroscientist and professor of psychology, Stanford University Memory Lab, and Adina Roskies, professor of philosophy, UC Santa Barbara. For show transcripts, go to ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/unxtranscripts⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ For more, go to ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/unexplainable⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ And please email us! ⁠⁠⁠[email protected]⁠⁠⁠ We read every email. Support Unexplainable (and get ad-free episodes) by becoming a Vox Member today: ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/members⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ Thank you! Learn more about your ad choices. Visit podcastchoices.com/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Noam Hassenfeld?

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• 1:21Speaker 02

  The year was 1991 and Herbert Weinstein was retired ad executive.

• 1:27Speaker 03

  He's 65 years old and he's living in Manhattan in a 12-story apartment.

• 1:32Speaker 02

  I called up Josh May to tell me this story. He's an ethics professor at the University of Alabama at Birmingham.

• 1:39Speaker 03

  Gets into an argument with his wife at the time. And he apparently got into such a fit that he strangled her and then tried to make it look like a suicide by pushing her body out of the 12-story window.

• 1:56Speaker 02

  There was a 911 call. The officers responded to claims that a woman may have jumped. When the police arrived, they saw a woman lying on the sidewalk in broad daylight. And they saw a window open in the building above. Weinstein was in the lobby. One of the officers asked the man if he lived there. "He did," he replied, and gave them his name. He said he lived upstairs with his wife, Barbara. He didn't know where she was. Then Weinstein and the officers went up to the 12th floor. He got agitated once they reached the apartment. Where was she? Why were there officers there? The officer told him that there was a woman dead on the sidewalk.

• 2:40Speaker 02

  And Weinstein's like, is it Barbara?

• 2:43Speaker 03

  He was acting kind of strangely. Apparently, he seemed a bit unconcerned that his wife had just died and that he was being a suspect in this case.

• 2:53Speaker 02

  The officers asked him questions. Why do you have a scratch on your face? And they noticed that one of his hands was black and blue with a spot of blood on it. And so then, he came clean.

• 3:04Speaker 03

  There were witnesses or people who saw that he had pushed the body out. And he pretty readily confessed to it.

• 3:11Speaker 02

  To everything. He confessed to strangulation. He confessed to throwing her out the window in a panic. And he admitted to covering up the crime. And so, the officers arrested him.

• 3:25Speaker 02

  Weinstein's defense attorney was struck by how relaxed his client seemed in the days after the crime. And so, he ordered a psychiatric evaluation. The man's history indicated nothing glaring. He had no criminal record, no history of violence. And there was no known motive. His defense team did a PET scan, basically a snapshot of his brain. What they found was shocking.

• 3:54Speaker 02

  And in the ensuing trial, People versus Weinstein, it was the first time a judge allowed a PET scan as evidence to determine the defendant's guilt or innocence. What I find so fascinating, though, is that this PET scan sort of opened up a Pandora's box in the courts. As one New York Times writer put it, "This case was arguably the moment that neuroscience began to transform the American legal system." Today, what is the role of neuroscience in the law? And what are its limits? I'm Amy Padula, and this is Unexplainable.

• 4:52Speaker 02

  So when Weinstein's PET scan came back, the image revealed something alarming: a big, dark circle.

• 5:00Speaker 03

  He had a orange-sized cyst pressing on his frontal lobe.

• 5:06Speaker 02

  It was an arachoid cyst, which forms in the arachoid tissue of the brain. There are sort of multiple layers of protective tissue that surround the brain. The PET scan showed diminished glucose metabolism near the cyst.

• 5:20Speaker 04

  The arachoid, sort of the middle layer, predominantly has cerebrospinal fluid in it. These tissues essentially provide some protection to the brain.

• 5:30Speaker 02

  Anthony Wagner is a neuroscientist at Stanford University. So the cyst was on the left side of Weinstein's brain.

• 5:38Speaker 04

  Essentially, it's sort of a filling up. It's a little sack within the arachoid space. It's the filling up of that space with cerebrospinal fluid. And so it begins to fill up. It can actually sort of impinge on the underlying brain tissue. In a small percentage of cases, it could impact brain function. Most individuals who have arachoid cysts, there are no consequences for behavior for neural function, but a small percentage, it can. And so it's this sort of impinging on the brain that can perhaps change brain function for some individuals.

• 6:11Speaker 02

  Weinstein's cyst was also critically pressing up against his frontal lobe.

• 6:18Speaker 04

  At a high level, we know a lot about the frontal lobes, the frontal lobes roles in allowing us to sort of represent our goals, our plans, to represent the context that we're in and to try to bring our behavior in line, act appropriately within a particular context.

• 6:33Speaker 02

  So Anthony says, for instance, if you had a wound in this area of the brain, your behavior might change. Say you're in your doctor's office, maybe the phone rings. Someone with damage in that part of the brain might simply just pick up the phone.

• 6:51Speaker 04

  That's a habitual response. These are things we do with phones. But given the context in which one is in, it's not your home, it's not your office, it's your doctor's office, most of us would not sort of go ahead and pick up the phone. Right? So lateral dorsolateral prefront cortex or lateral prefrontal cortex, interacting with other brain regions, allow us to represent our goals, our context, bring our behavior in line with and to produce contextually appropriate behavior. One might be a bit more impulsive. On average, individuals who have prefrontal lesions or impairment in prefrontal function might be a bit more impulsive. They might struggle to regulate emotion. They might struggle to regulate overlearned or habitual behaviors that are not context relevant.

• 7:36Speaker 02

  So Weinstein's defense team has this scan at their disposal. The prosecution was really anxious about it because even though Weinstein had already admitted to what he had done, was he going to get off easy because of the cyst? Because maybe Weinstein was one of the unlucky ones that did have cognitive impairment. But it's tricky. The pet image was taken after the crime was committed, not the day of the crime. The scan proved he had a cyst in his brain, but that's about all it showed.

• 8:09Speaker 04

  One of the challenges for the courts is to try to figure out what evidence should they allow in. Either the prosecution or the defense, one side wants to bring the evidence forward. And do you just have a free for all? Or is there some process upon which or by which the court should be making these decisions?

• 8:28Speaker 02

  We actually have a special process in the court system to help us figure out what scientific evidence is admitted and not admitted. One is something called the FRI standard. Today, we have another one called DOBERT.

• 8:39Speaker 04

  The FRI standard, at the highest level, is to have experts or have one or both sides of the case weigh in on whether or not this new scientific method is generally accepted as doing the thing that is being proffered to do in that particular case, sort of setting up the judge as essentially the gatekeeper. Should I let this particular scientific evidence enter the courtroom, be presented to the jury? Does it meet this set of criteria? What do we know about that? And so in FRI hearings and DOBERT hearings, these are pretrial hearings where there's presentation from both sides about the state of the science.

• 9:21Speaker 02

  In the Weinstein case, the judge conducted a special hearing for the scan, and the FRI standard was applied. If he found that the PET scan was a generally accepted technological tool, then experts could testify about whether that scan supported a claim of brain dysfunction. They could argue that because of this cyst and its location near the frontal lobe, Weinstein lacked the capacity to behave normally, that he had gone temporarily insane.

• 9:51Speaker 02

  But this hearing would also give the prosecution the opportunity to ask questions and bring in experts to argue like, well, just because Weinstein's frontal lobe was affected, it doesn't mean it could cause violent behavior. And it doesn't follow that it caused him to commit this crime. Biology says one thing. There was a cyst on this man's brain. We know that from the PET scan. But Josh May says, in the law, the law is interested in something else.

• 10:22Speaker 03

  Really, in the law, it's not largely about the science. It's about, can you convince a jury?

• 10:29Speaker 02

  Okay, so the judge poured over the testimonies of physicians and scientists who had defended both arguments, that the scans showed that the cyst could reasonably have impacted how he behaved. Other experts testified that the mere existence of the cyst was not the cause of this man's actions. So Weinstein's lawyer suggests that his client should not be held responsible for his actions because of this, because of the presence of this. That's essentially the argument.

• 10:55Speaker 03

  Yep, that he's not fully in control. At the very least, he should be held less responsible. The question here is about whether he really had control over it, and so that could be a mitigating factor.

• 11:06Speaker 02

  This is really what we call the brain defense. Basically, my brain made me do it. Was Weinstein in control of what he did? Or was his brain impacted by this cyst in this specific area of the brain that we know controls executive function, personality, and some behavior? Because of that, did he make a sudden, awful choice?

• 11:32Speaker 03

  The district attorney got worried that a jury would possibly acquit if they saw this large cyst pressing on his frontal lobe.

• 11:41Speaker 02

  Basically, oh, so there's a cyst on his brain. They might assume his brain made him do it and then let him off.

• 11:48Speaker 03

  The prosecution, I think it's mostly that they're worried that even if it's a bad argument, that a jury might be swayed by it. And especially in Weinstein's case, the brain imaging is very powerful, compelling evidence that there is that brain abnormality. And it is so tempting to go from brain abnormality to absolving of guilt in the minds of some people at least.

• 12:13Speaker 02

  It's a hard argument for the prosecution. They want to argue that this man was not insane and that he committed this crime, that he admitted to it. Sister not, he did this.

• 12:23Speaker 03

  So I think that the prosecution is hedging their bets there, and they're worried that some people might make that inference, even if it's not a very good one.

• 12:34Speaker 03

  I think that's exactly what the district attorney was worried about, is that this could be convincing or compelling to a jury. And it is, right? If you can have some, what feels like very solid, hard evidence through some actual, physical object pressing on his brain, that can be pretty compelling to some juries.

• 12:55Speaker 02

  In October of 1992, the judge decided that Weinstein's scan could be admitted as evidence. But they couldn't explicitly say that the cyst caused him to be violent. Tensions rose. The prosecution worried that this was the end of their case. The PET scan was so promising, it could sway the jury. And then, on the morning of jury selection, the prosecution team made a deal. They would let Weinstein plead guilty for a less significant sentence.

• 13:28Speaker 03

  Arguably, brain imaging really reduced someone's sentence. Where you had a charge of second-degree murder down to manslaughter.

• 13:41Speaker 02

  Weinstein was sentenced to seven to 21 years in prison. He also never got the cyst removed. It was too risky. But the thing that strikes me the most, the entire time he was there, more than 12 years, he showed no signs of violence. After the break, how neuroimaging changed and entered the courts after Weinstein. And what's next?

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• 17:47Speaker 02

  The decision to admit the PET scan in Weinstein's trial in 1992 had enormous implications. It arguably pushed neuroimaging into the courtroom for good. In 2005, a super-high-profile Supreme Court case called Roper versus Simmons overturned the juvenile death penalty, an argument that was made citing neuroimaging research showing differences between teenage and adult brains. Neuroimaging has this much of an impact on the court system, a system that operates completely differently than science. And yet, both fields are sort of bound up in each other, knotted like cats' cradle.

• 18:32Speaker 04

  You know, scientists, we have high thresholds for wanting to draw an inference and believe that we've discovered something and are comfortable sort of reporting it out to the broader scientific community. We want there to be fairly convincing evidence that it's more likely than not, due to chance, that we see something. We still have the luxury that when we do our experiments, we should have, and we typically set our standards exceptionally high, and we want to have compelling evidence before we're going to draw an inference. So we can wait out, we can do additional experiments, we can gather more evidence before we actually make a decision, make a determination, write a paper and say, hey, I think I've discovered X. The courts have a different challenge.

• 19:16Speaker 04

  They have a singular case. It's sitting in front of them. They have a particular defendant and they have to make a determination. Look, we have to make a decision. That jury or that judge has to make a determination. You can't punt it down the road. You can't do another trial five years from now and get more evidence. The jury has to make some determination. The basis upon their decision about guilty, not guilty, the ability to sort of form intent, the ability to engage in more reasoned, goal-directed, sort of thoughtful sort of behavior. That seems like it's often a key question in these trials.

• 20:01Speaker 02

  I keep thinking about something Adina Roskies told me. She's a philosopher of neuroscience who specializes in cognitive neuroimaging and neuroethics. She says, "Scientists are interested in understanding how things work and what we know and don't know at a moment in time." But that is a very different project than holding someone responsible for their actions.

• 20:23Speaker 06

  We often have to average across multiple trials, often across multiple people, in order to get any kind of general statement about how brains do the kinds of things that they do. And what we reach is some kind of biological mechanistic understanding. Actually, the level of neuroimaging, we rarely get to the level of mechanism. What the kinds of results of the science give you tend to be general statements about populations when you're talking about neuroimaging.

• 21:02Speaker 06

  The law is typically concerned with social structure and individual acts. And it's really hard to take the kind of science that's predicated on populations and generalities and apply it to these individual acts. And the law works with a very different framework than the sciences work with. I mean, it's very unclear how to apply knowledge in one domain to another domain. I don't think there are any clear deductions.

• 21:40Speaker 02

  If the evidence isn't perfect, if an image of a brain only suggests something about that brain without being definitive about it, should this kind of evidence have been admitted in a case like Weinstein's, after all?

• 21:55Speaker 03

  Do you think that we have to compare it to other kinds of evidence that we already allow into courts? And really, science has revealed that a lot of the evidence we admit is not very reliable. Things like eyewitness testimony is not very reliable, we know. And yet, we don't banish it from courts. And I think part of that reason is that we often don't have a lot of evidence when it comes to these very high-stakes decisions. And we're trying to figure out whether somebody has committed murder or at least a certain degree of murder. And it would be helpful if we had more evidence rather than less. So I'm a bit concerned about pulling evidence off of the table and presuming that juries aren't capable of trying to assess that evidence.

• 22:38Speaker 03

  It's a hard issue to resolve, but I think it's better in general to give them more evidence rather than less.

• 22:48Speaker 02

  A more fine-tuned technology emerged after PET, called FMRI, Functional Magnetic Resonance Imaging.

• 22:55Speaker 04

  FMRI is really the workhorse now of modern, sort of, human systems neuroscience. It's transformed our field in so many different ways. FMRI today is the dominant technique used to try to understand brain function.

• 23:09Speaker 02

  FMRI looks at changes in oxygenated blood flow in the brain that show changes in brain activity. Anthony Wagner says, "After FMRI broke through in the 90s, there have been these bursts of development with the technology." And another phase has been underway for a while.

• 23:29Speaker 04

  The combining of current, modern-day AI tools and systems with behavioral phenotypes of people, behavioral, rich behavioral assaying of people, but also underlying neural signals. And I think that that's going to give rise to an explosion in the field of neuroscience, as well as, obviously, in many other fields. So we have these moments of, sort of, what seem like bursts of discovery, often tied to changes in what we can do as scientists, the techniques we have. But, on the whole, science is slow. It's incremental. It's accumulating evidence over years.

• 24:07Speaker 02

  He says, "We can now get closer and closer to understanding the brain at increasing levels of specificity." Right now, fMRI has been used in combination with machine learning tools.

• 24:19Speaker 04

  Classifiers that can be trained over brain patterns to detect mental states like, is the person remembering the face that they're being presented at this moment versus perceiving the face as novel? Are they perhaps lying versus not lying?

• 24:36Speaker 02

  Lying. There's been a tremendous push from the mid 2000s onward to develop a reliable brain-based lie detector. Anthony was actually part of a huge effort through the MacArthur Foundation to assess the literature on the validity of brain-based lie detection.

• 24:53Speaker 04

  The details of what's in somebody's mind are still fairly limited. I think it's not clear how far we'll get, but I'm pretty confident that leveraging brain patterns as inputs to AI models will allow us to do, we're already beginning to see this on the visual perceptual reconstruction, we will do even better in terms of being able to, it's a little scary, this notion of mind reading, trying to understand and reconstruct. And I think that those discoveries will continue to come and there'll be many others. It's pretty clear to me that there's not consensus within the neuroscience community that fMRI can be used to differentiate with unknown precision, differentiate between truth and lie.

• 25:37Speaker 04

  It's really hard science to do. I think of myself as a memory scientist. Some of the problems we work on, they're easier problems because in a lab setting, you really cannot create lies of real-world experiences with real stakes that are going to elicit the kind of potential threat.

• 25:59Speaker 02

  It's very hard to concoct a lie in a lab.

• 26:03Speaker 04

  When you're lying, if you're caught lying, you cannot create experimental settings that are, you know, analogues of what might be happening in the real world. The short answer to the question, is it too early? The answer is yes, it's too early from my perspective, which is we just don't know.

• 26:20Speaker 02

  So, brain-based lie detection is unlikely to get anywhere near something like the Frye standard any day soon. But it could. I keep thinking about something Josh May asked. Are we really just these physical things controlled by our brains? And do we actually have any agency over our actions?

• 26:42Speaker 03

  That's still heavily debated. You might think that we have made some progress, but even neuroscientists will tell you, especially when it comes to consciousness, our experiences, we really just have no idea how that arises in the brain. And there are these deep questions about whether that is a fundamentally different thing, our private experiences versus this brain activity. Could they just be one and the same thing? Or are they just fundamentally different? And that's still a hotly debated issue in philosophy, but also in neuroscience. There are these longstanding philosophical questions about, does that mean that we are just our brains?

• 27:17Speaker 02

  The answer to that big question is best left to neuroscience. And as science evolves, our understanding of justice could too.

• 27:35Speaker 02

  If you want to read more about the Weinstein case, you can read a great book by journalist Kevin Davis called The Brain Defense.

• 27:46Speaker 02

  This episode was produced by me, Amy Padula. It was edited by Joanna Solotaroff. Mixing and sound design from Joe Plord, and music from Noam Hassanfeld. Melissa Hirsch checked the facts. Julia Longoria and Jorge Just are our editorial directors. Sally Helm is the fact that brain information travels at speeds up to 268 miles per hour. And Bird Pinkerton headed for the subway. And as soon as she walked down the stairs, she looked at the walls, white tiles in a station. She must be close. So she got on the first A train and headed towards Manhattan. As always, thank you to Brian Resnick for co-creating the show with Noam and Bird.

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