Speaker 1: How do brain's time travel. We all know what a
Speaker 1: prediction is, but why is the important thing to the brain?
Speaker 1: What's called a prediction error? And what does any of
Speaker 1: this have to do with the two thousand and eight
Speaker 1: crash of the economy, or how we keep internal price
Speaker 1: tags on everything, or what we should do with the
Speaker 1: war on drugs. Welcome to Inner Cosmos with me David Eagelman.
Speaker 1: I'm a neuroscientist and an author at Stanford and in
Speaker 1: these episodes we dive deeply into our three pound universe
Speaker 1: to uncover some of the most surprising aspects of our lives.
Speaker 1: Today's episode is part two about decision making, so let's
Speaker 1: quickly summarize last week's episode to get ourselves back up
Speaker 1: to speed. In that episode, we saw how the brain
Speaker 1: is a sophisticated decision making machine. It's constantly engaged in
Speaker 1: choosing among options. Now, this can be something trivial like
Speaker 1: deciding between a taco and a burrito, all the way
Speaker 1: to life altering decisions like whether to take that job
Speaker 1: or whether to propose marriage. Now, while early economists assumed
Speaker 1: that humans make decisions rationally by weighing pros and cons
Speaker 1: to arrive at the optimal choice. Modern day psychology and
Speaker 1: neuroscience reveals a pretty different story and what we saw
Speaker 1: last week, and something I've talked about before here a
Speaker 1: lot is that the brain is composed of multiple networks,
Speaker 1: each with its own goals and desires, and these often
Speaker 1: compete with one another to influence the decisions that we make,
Speaker 1: and this internal conflict is at the heart of how
Speaker 1: we navigate the world. And by the way, the massive
Speaker 1: battles under the hood largely occur below our conscious awarenes
Speaker 1: So for example, when you look at a picture that
Speaker 1: can either be perceived as a duck or a rabbit,
Speaker 1: your brain chooses one interpretation over the other, and we
Speaker 1: can measure what's happening in the activity of neurons to
Speaker 1: see how one network wins over the other one. And
Speaker 1: in the case of a picture like that, your interpretation
Speaker 1: goes back and forth and back and forth. Now that
Speaker 1: might not feel like a decision to you, but it's
Speaker 1: the same neural process of having competing networks that are
Speaker 1: fighting for dominance, and the same neural battle is mirrored
Speaker 1: in everyday choices, like when you choose between different flavors
Speaker 1: of a sports drink or whether to take the right
Speaker 1: trail or the left trail. All your options are represented
Speaker 1: by different coalitions of neurons in the brain, and these
Speaker 1: coalitions compete for dominance and the winner determines the action
Speaker 1: we take. And we saw simple tasks like this stroop
Speaker 1: task where you have conflicting information like the word reed
Speaker 1: printed in blue ink and you're supposed to name the
Speaker 1: color of the ink. This highlights the tension between different
Speaker 1: networks in the brain. And similarly, we are always facing
Speaker 1: moral dilemmas like I mentioned the trolley problem last week,
Speaker 1: and this demonstrates how emotional and rational networks can come
Speaker 1: into conflict and it can lead to different outcomes depending
Speaker 1: on which network prevails. And one of the things we
Speaker 1: saw from that was that emotions play a really crucial
Speaker 1: role in decision making. The importance of emotional input into
Speaker 1: your decision making is seen really clearly when people get
Speaker 1: brain injury like damage to the orbit or frontal cortex,
Speaker 1: because then they can't integrate the emotional signals from the
Speaker 1: body into a decision, and that leaves a person paralyzed
Speaker 1: within decision even in very simple situations. So without the
Speaker 1: ability to read these bodily signals which we're providing summaries
Speaker 1: of different options. People struggle to make choices. So the
Speaker 1: brain's decision making process is not a straightforward calculation of
Speaker 1: pros and cons but a dynamic interplay of competing networks
Speaker 1: and emotional signals. Every decision we make from what to
Speaker 1: where in the morning, or which coffee shop to choose,
Speaker 1: or how we respond in a crisis, the choices are
Speaker 1: all the results of this ongoing conflict within our brains.
Speaker 1: Now where we left off last week with seeing how
Speaker 1: each decision involves our past experiences stored in the states
Speaker 1: of our body and the present situation like do I
Speaker 1: have enough money to buy this instead of that? Or
Speaker 1: is this other option available? But there's one more part
Speaker 1: to the story of decisions, and that is predictions about
Speaker 1: the future. So that's what we're going to talk about today. Now,
Speaker 1: across the animal kingdom, every creature is wired to see reward. Now,
Speaker 1: surely this is something you know, but have you ever
Speaker 1: thought about the question what is a reward? At its essence,
Speaker 1: a reward is something that will move the body closer
Speaker 1: to its ideal set points. So water is a reward
Speaker 1: when your body is getting dehydrated. Food is a reward
Speaker 1: when your energy stores are running down. Now, water and
Speaker 1: food are called primary rewards because they directly address biological need.
Speaker 1: But what's super interesting is that human behavior is steered
Speaker 1: by secondary rewards, which are things that predict primary rewards.
Speaker 1: For example, the sight of a metal cylinder wouldn't by
Speaker 1: itself do much for your brain, but because you've learned
Speaker 1: to recognize it as a can of sparkling water, then
Speaker 1: the sight of it comes to be rewarding when you
Speaker 1: are thirsty, and in the case of humans, much more
Speaker 1: than anywhere else in the animal kingdom. We can find
Speaker 1: even very abstract concepts rewarding, such as a political ideology
Speaker 1: or the feeling that we are valued by our local community,
Speaker 1: and unlike other animals, we can often put these rewards
Speaker 1: ahead of biological needs. As my colleague Read Montacu points out,
Speaker 1: sharks don't go on hunger strikes. In other words, the
Speaker 1: rest of the animal kingdom only chases its basic needs,
Speaker 1: while only humans regularly override our basic needs. In deference
Speaker 1: to abstract ideals, concepts that we have decided are rewarding
Speaker 1: to us. So whenever we're faced with different possibilities, we
Speaker 1: integrate internal and external data to try to maximize reward. However,
Speaker 1: reward is defined to you as an individual. Now here's
Speaker 1: the point I want to make. The challenge with any reward,
Speaker 1: whether basic or abstract, is that choices to typically don't
Speaker 1: yield their fruits right away. We almost always have to
Speaker 1: make decisions in which a chosen course of action will
Speaker 1: yield reward at a later time. People go to school
Speaker 1: for years because they value the future concept of having
Speaker 1: a degree, or they slave through decades of work that
Speaker 1: they don't like with the future hope of a promotion.
Speaker 1: Or you push yourself through painful exercise with the goal
Speaker 1: of being fit in the future. Now to understand this,
Speaker 1: let's think about the concept of anticipated reward. To compare
Speaker 1: different options means assigning a value to each one in
Speaker 1: some common currency that of anticipated reward, and then choosing
Speaker 1: the one with the highest value. So let's make this concrete.
Speaker 1: Let's say you have a small window of free time
Speaker 1: and you are trying to decide what to do. You
Speaker 1: know that you need groceries, but you also know that
Speaker 1: you really need to sit down and get that big
Speaker 1: email I'll sent off, and you're also way behind on
Speaker 1: arranging to meet with your friend at the coffee shop. Well,
Speaker 1: these are all very different things groceries, email, friend. So
Speaker 1: how does your brain arbitrate this menu of options. It
Speaker 1: would be easy if you could directly compare these experiences
Speaker 1: by living out each one and then rewinding time and
Speaker 1: finally choosing your path based on which outcome was best.
Speaker 1: But the mummer is that you can't travel in time,
Speaker 1: or can't you? In fact, human's time travel daily time
Speaker 1: travel is what the human brain does relentlessly. When faced
Speaker 1: with the decision. Your brain simulates different outcomes to generate
Speaker 1: a mockup of what your future might be. We call
Speaker 1: this time traveling. Mentally, you can disconnect from the present
Speaker 1: moment and voyage to a world that doesn't yet exist.
Speaker 1: Now simulating a scenario in your mind. That's just the
Speaker 1: first step. To decide between the imagined scenarios. You try
Speaker 1: to estimate what the reward will be in each of
Speaker 1: those potential futures. So when you simulate filling your pantry
Speaker 1: with the groceries, you feel a sense of relief at
Speaker 1: being organized and avoiding uncertainty. Finishing that email carries different
Speaker 1: sorts of rewards, not only the primary reward of maybe
Speaker 1: securing some money as a result, but more generally, the
Speaker 1: kudos from your boss and a rewarding sense of accomplishment
Speaker 1: in your career. Now you can also imagine yourself at
Speaker 1: the coffee shop with your friend, and that inspires joy
Speaker 1: and a sense of reward in terms of relationships and
Speaker 1: closeness with other people. So your final decision between these
Speaker 1: three options will be navigated by how each future stacks
Speaker 1: up against the other others in the common currency of
Speaker 1: your reward system. Now, this choice isn't easy, because all
Speaker 1: these valuations are nuanced. The simulation of the grocery shopping
Speaker 1: is accompanied by feelings of tedium, and your simulation of
Speaker 1: writing the long email is attended by a sense of frustration,
Speaker 1: and your simulation of your friend at the coffee shop
Speaker 1: is accompanied with guilt about not getting work done. But
Speaker 1: in all these cases, under the radar of awareness, your
Speaker 1: brain simulates all these options one at a time and
Speaker 1: does a gut check on each and that's how you decide.
Speaker 1: But here's a question, how do you simulate these futures accurately?
Speaker 1: How can you possibly predict what it will really be
Speaker 1: like to go down these paths. The answer is that
Speaker 1: you can't. There's no way to know that your predictions
Speaker 1: will be perfectly accurate. Your simulations are only based on
Speaker 1: your past experiences and your current model of how the
Speaker 1: world works. The key business of brains is to predict,
Speaker 1: and to do this well, we need to continually learn
Speaker 1: about the world from our every experience so that we
Speaker 1: can make the best guesses that we can. So in
Speaker 1: this case, you place a value on each of these
Speaker 1: options groceries or email or coffee shop, based on your
Speaker 1: past experiences and using the Hollywood studios in your mind,
Speaker 1: you travel in time to your imagined futures to see
Speaker 1: how much value they'll have, and that's how you make
Speaker 1: your choices. You compare possible futures against one another. That's
Speaker 1: how you convert competing options into a common currency of
Speaker 1: future reward. So think about your predicted reward value for
Speaker 1: each of these options like an internal price tag that
Speaker 1: stores how good something will be. Because grocery shopping is
Speaker 1: going to supply you with food, say it's worth ten
Speaker 1: reward units, and writing that stupid email is difficult but
Speaker 1: necessary to your career, so it weighs in at twenty
Speaker 1: five reward units, and you love spending time with your friend.
Speaker 1: So going to the coffee shop is worth fifty reward units.
Speaker 1: But there's an interesting twist here. The world is complicated,
Speaker 1: and so your internal price tags are never written in
Speaker 1: permanent ink. Your valuation of everything around you is changeable
Speaker 1: because quite often our predictions don't match what actually happens.
Speaker 1: The key to effective learning lies in tracking this prediction error.
Speaker 1: The prediction error means the difference between what you thought
Speaker 1: was going to happen and what actually happened. In the
Speaker 1: case of this decision about groceries or email or coffee shop,
Speaker 1: your brain has a prediction about how rewarding the coffee
Speaker 1: shop is going to be. Now, let's say it turns
Speaker 1: out that they have some new snack there, and also
Speaker 1: you run into other friends there and the whole experience
Speaker 1: is even better than you thought. That raises the price
Speaker 1: tag the next time you're thinking about the coffee shop.
Speaker 1: On the other hand, if the coffee is cold and
Speaker 1: your friend is late and distracted, that might lower your
Speaker 1: price tag for the next time around. Now, how does
Speaker 1: this work in the brain? How do you have these
Speaker 1: dynamic internal price tags. There's a tiny, ancient system in
Speaker 1: the brain whose mission is to keep updating your assessments
Speaker 1: of the world. The system is made of tiny groups
Speaker 1: of cells in your midbrain that speak in the language
Speaker 1: of a neurotransmitter called dopamine. When there's a mismatch between
Speaker 1: your expectation and your reality, this midbrain dopamine system broadcasts
Speaker 1: a signal that reevaluates the price point. The signal tells
Speaker 1: the rest of the system whether things turn out to
Speaker 1: be better than expected, in which case you get an
Speaker 1: increased burst of dopamine, or worse than expected, in which
Speaker 1: case you get a decrease in dopamine. And that prediction
Speaker 1: error signal, meaning there was an error in the prediction
Speaker 1: that I had made, allows the rest of the brain
Speaker 1: to adjust its expectations to try to be closer to
Speaker 1: reality next time. So the dopamine acts as an error corrector.
Speaker 1: It's a chemical appraiser that always works to make your
Speaker 1: price tags as updated as they can be. That way,
Speaker 1: you can rank your decisions based on your optimized guesses
Speaker 1: about the future. Fundamentally, what the brain pays attention to
Speaker 1: are the unexpected outcomes, something being better than expected or
Speaker 1: worse than expected, and this sensitivity is at the heart
Speaker 1: of animal's abilities to adapt and learn. It's no surprise then,
Speaker 1: that the brain architecture involved in learning from experience is
Speaker 1: consistent across species. You see this from honeybees to humans.
Speaker 1: In other words, brains discovered the basic principles of getting
Speaker 1: feedback from reward a long time ago. So we've seen
Speaker 1: how values get attached to different options. But there's a
Speaker 1: twist that often gets in the way of good decision making,
Speaker 1: which is that options that are right in front of
Speaker 1: you tend to be valued higher than those that you
Speaker 1: merely simulate. The thing that trips up good decision making
Speaker 1: about the future is the present. I'll give you a
Speaker 1: really interesting example of this. In two thousand and eight,
Speaker 1: the US economy took a sharp downturn. Many of you
Speaker 1: may remember that at the heart of all the trouble
Speaker 1: was a simple fact, which is that many homeowners had overborrowed.
Speaker 1: They had taken out these mortgage loans that had really
Speaker 1: low interest rates for a period of a few years,
Speaker 1: and the problem occurred at the end of that period
Speaker 1: when the interest rate suddenly shot up to something quite high,
Speaker 1: and a lot of homeowners suddenly found themselves facing down
Speaker 1: the barrel of these higher interest rates. And they realized
Speaker 1: they weren't going to be able to make the payments.
Speaker 1: So close to a million American homes went into foreclosure,
Speaker 1: and that sent shockwaves through the economy of the planet. Now,
Speaker 1: what in the world does this have to do with
Speaker 1: competing networks in the brain. Here's what these loans called
Speaker 1: subprime loans. They allowed people to obtain a nice house
Speaker 1: right now, with the high interest rates defferred until later.
Speaker 1: As such, the offer perfectly appealed to the neural networks
Speaker 1: that care about instant gratification. In other words, those networks
Speaker 1: that want things right now. The idea was here, take
Speaker 1: these keys, this house is yours. The mortgage payments are
Speaker 1: pretty easy to make. Oh yeah, the rates will go up,
Speaker 1: but that's a long way away. That's obscured in the
Speaker 1: midst of the future. You don't have to worry about
Speaker 1: that right now. That's a long way off. And because
Speaker 1: of the seduction of the immediate satisfaction, as in, wow,
Speaker 1: I can move into this house right now, I can
Speaker 1: impress my parents and my friends and whatever. Because the
Speaker 1: now pulls so strongly on our decision making, the two
Speaker 1: thousand and eight housing bubble can be understood not simply
Speaker 1: as an economic phenomenon, but as a neural one. And
Speaker 1: by the way, the pull of the now wasn't just
Speaker 1: about the people borrowing, of course, but it's also about
Speaker 1: the lenders who are getting rich right now by offering
Speaker 1: loans that they suspec might not ever get paid. They
Speaker 1: rebundled these loans and sold them off. Practices like this
Speaker 1: are unethical and illegal, but it proved too enticing to
Speaker 1: many decision makers when they were faced with that temptation. Now,
Speaker 1: this now versus the future battle. This doesn't just apply
Speaker 1: to housing bubbles. It cuts across every aspect of our lives.
Speaker 1: It's why car dealers want you to get in and
Speaker 1: test drive the cars, because the seduction of the now
Speaker 1: is probably going to override your thinking about the distant
Speaker 1: future when you have to pay that monthly loan. It's
Speaker 1: why clothing stores want you to try on the clothes,
Speaker 1: because once you see yourself in front of the mirror there,
Speaker 1: you'll think, wow, I can't pass that up. It's why
Speaker 1: merchants want you to touch the merchandise. It's because your
Speaker 1: mental simulations of the future can't compete well against the
Speaker 1: experience of something right here, right now. In your hands.
Speaker 1: In other words, to the brain, the future can only
Speaker 1: ever be a pale shadow of the now. The power
Speaker 1: of now explains why people make decisions that feel good
Speaker 1: in the moment but have lousy consequences for their future.
Speaker 1: So people who take a drink or a drug hit
Speaker 1: even though they know they shouldn't, or married partners who
Speaker 1: give in to an available affair, or athletes who take
Speaker 1: anabolic steroids even though they know it's going to shave
Speaker 1: years off their life. So can we do anything about
Speaker 1: the seduction of the now? Well, with a little bit
Speaker 1: of knowledge about the brain, we can. So consider this.
Speaker 1: We all know that it's really difficult to do certain thing.
Speaker 1: It's like go regularly to the gym. Most people want
Speaker 1: to be in good shape, but when it comes down
Speaker 1: to it, there are usually things right in front of
Speaker 1: us that seem more enjoyable. The pull of what we're
Speaker 1: doing is stronger than the abstract notion of future fitness.
Speaker 1: So here's the solution to make sure you get there.
Speaker 1: You can take in spiration from a man who lived
Speaker 1: three thousand years ago. Now, I talked about this in
Speaker 1: a recent episode, so I'll give the short version here.
Speaker 1: But it's massively important. The man we're going to talk
Speaker 1: about was in a more extreme version of the Jim scenario.
Speaker 1: He had something he wanted to do, but knew that
Speaker 1: he wouldn't be able to resist temptation when the time
Speaker 1: came for him. It wasn't about getting a better physique.
Speaker 1: It was about saving his life from a group of
Speaker 1: mesmerizing maidens. So this was the legendary hero Ulysses, on
Speaker 1: his way back from triumph in the Trojan War. At
Speaker 1: some point on his long journey home, he realized that
Speaker 1: his ship was going to be passing an island where
Speaker 1: the beautiful sirens lived, and the sirens were famous for
Speaker 1: singing songs so melodious that sailors were enchanted. And the
Speaker 1: problem was that the sailors found this irresistible and they
Speaker 1: would crash their ships into the rocks trying to get
Speaker 1: to the sirens, and they would now Ulysses desperately wanted
Speaker 1: to hear these legendary songs, but he didn't want to
Speaker 1: kill himself and his crew, so he hatched a plan.
Speaker 1: He knew that when he heard the music, he would
Speaker 1: be unable to resist steering towards the island's rocks and
Speaker 1: so he recognized that the problem wasn't his present rational self,
Speaker 1: but instead the future illogical Ulysses, the person that he
Speaker 1: would become. When the sirens came with an earshot, so
Speaker 1: Ulysses ordered his men to lash him securely to the
Speaker 1: mast of his ship, and they filled their ears with
Speaker 1: beeswax so it's not to hear the sirens, and they
Speaker 1: rode under strict orders to ignore any of his pleas
Speaker 1: or cries or writhing around. So what was going on here?
Speaker 1: Ulysses knew that his future self would be in no
Speaker 1: position to make good decisions, so the Ulysses of sound
Speaker 1: mind arranged things so that the future Ulysses could do
Speaker 1: no wrong. This sort of deal between your self and
Speaker 1: your future self is known as the Ulysses contract. In
Speaker 1: the case of getting to the gym, my simple Ulysses
Speaker 1: contract is to arrange in advance for a friend to
Speaker 1: meet me at the gym. So then I feel it's
Speaker 1: pressure to uphold the social contract, and that lashes me
Speaker 1: to the mast, even though when the morning rolls around,
Speaker 1: all I really want to do is just sleep in
Speaker 1: or do something else. I've pre arranged a contract and
Speaker 1: now I have to show up when you start looking
Speaker 1: around for these ulysses contracts, you'll see that they're actually
Speaker 1: all around you. Just as an example, I was recently
Speaker 1: giving a talk on a college campus and learned that
Speaker 1: during the week of final exams, some students will swap
Speaker 1: their TikTok passwords with each other, and then each student
Speaker 1: changes the other's passwords so that they can't log on,
Speaker 1: and then when finals are over, they switch the passwords back.
Speaker 1: So this way, during the week that they're supposed to
Speaker 1: be studying, even though they know that they're going to
Speaker 1: be tempted by the sirens song, they can't do anything
Speaker 1: about it. Similarly, the first step for alcoholics in rehabilitation
Speaker 1: programs is to clear all the alcohol out of their
Speaker 1: house so that the temptation is not in front of
Speaker 1: them when they're feeling weak. People with weight problems sometimes
Speaker 1: get surgery to reduce their stomach volume so they physically
Speaker 1: can't overeat. These are all things that you do right
Speaker 1: now so that your future self won't do something that
Speaker 1: you don't want to. It's a way to structure things
Speaker 1: in the presence so that your future self cannot misbehave.
Speaker 1: And that's the trick for getting around the seduction of
Speaker 1: the now you strap yourself to the mast, and that
Speaker 1: allows you to behave in better alignment with the kind
Speaker 1: of person you would like to be. The key to
Speaker 1: a Ulysses contract is just recognizing that we are different
Speaker 1: people in different contexts. The ancient Greeks had a saying
Speaker 1: they liked, which was know thyself. But I've always felt
Speaker 1: from a neuroscience point of view that the the updated
Speaker 1: version is know thyselves now. What's strange is that knowing
Speaker 1: yourselves is not easy because how you act at different
Speaker 1: times is not always something you can predict. Even though
Speaker 1: you can make good guesses, things can drift around. So
Speaker 1: sometimes you're really jazzed about going to the gym, and
Speaker 1: sometimes not so much. Sometimes you'll stick with the diet
Speaker 1: and sometimes you won't. Sometimes you're more capable of good
Speaker 1: decision making, and other times your neural parliament won't come
Speaker 1: out with the vote that you expected. Why it's because
Speaker 1: the outcome depends on a lot of changing factors about
Speaker 1: the state of your body. For example, states, which can
Speaker 1: change hour to hour. So here's a good way for
Speaker 1: us to appreciate this. There was a study done some
Speaker 1: years ago looking at prisoners who are going in front
Speaker 1: of a parole judge to see if the prisoner could
Speaker 1: get his sentence shortened to go home early. So imagine
Speaker 1: two prisoners both scheduled to appear in front of this
Speaker 1: parole judge. One prisoner goes before the judge at eleven
Speaker 1: twenty seven am. His crime is fraud and he's serving
Speaker 1: thirty months. Another prisoner appears at one fifteen pm. He
Speaker 1: has committed the same crime for which he's been given
Speaker 1: the same sentence. Now, the first prisoner is denied parole,
Speaker 1: the second is granted parole. Why what influenced the decision?
Speaker 1: Was it? Race? Was at looks was at age? So
Speaker 1: a study by Jonathan levav In colleagues analyzed one thousand
Speaker 1: rulings from judges and found it wasn't about that. Whether
Speaker 1: the prisoner is granted parole or not isn't just about
Speaker 1: the prisoner. It's about the judge's biology. Specifically, it's about
Speaker 1: the judge's hunger. So just after the judge had enjoyed
Speaker 1: a food break, a prisoner's chance of parole rose to
Speaker 1: its highest point of sixty five percent. But a prisoner
Speaker 1: seen towards the end of the session had the lowest
Speaker 1: chances just a twenty percent likelihood of a favorable outcome.
Speaker 1: In other words, decisions get reprioritized as other needs rise
Speaker 1: in importance. Your choices change as circumstances change. A prisoner's
Speaker 1: fate is irrevocably intertwined with the judge's neural networks, which
Speaker 1: operate according to biological needs. Some psychologists describe this effect
Speaker 1: as ego depletion, meaning that higher level cognitive areas involved
Speaker 1: in executive function and planning they get fatigued. So in
Speaker 1: this view, willpower is a limited resources. We can run
Speaker 1: low on it, just like a tank of fuel. In
Speaker 1: the case of the judges, the more cases they had
Speaker 1: to make decisions about, which was up to thirty five
Speaker 1: in one sitting, the more energy depleted their brains became.
Speaker 1: But after they ate something like a sandwich and a
Speaker 1: piece of free their energy stores were refueled and different
Speaker 1: drives had more power now in steering their decisions. Traditionally,
Speaker 1: we assume that humans are rational decision makers. We absorb information,
Speaker 1: we process it, we come up with an optimal answer
Speaker 1: or solution. But real humans don't work this way. Even
Speaker 1: judges striving for freedom from bias are imprisoned by their biology.
Speaker 1: Our decisions are equally influenced when it comes to how
Speaker 1: we act with our romantic partners. So consider the choice
Speaker 1: of monogamy, bonding and staying with a single partner. So
Speaker 1: this would seem like a decision that involves your culture
Speaker 1: and your values and your morals and all. That's true,
Speaker 1: But there's a deeper force acting on your decision making
Speaker 1: as well, which is your hormones, and one in particular
Speaker 1: called oxytocin, which is a key ingredient in the magic
Speaker 1: of bonding. So in one recent study, men who are
Speaker 1: in love with their female partners were given a small
Speaker 1: dose of extra oxytocin. Then they were asked to rate
Speaker 1: the attractiveness of different women. So with the extra oxytocin,
Speaker 1: the men found their partners more attractive, but not the
Speaker 1: other women. In fact, the men kept a bit more
Speaker 1: physical distance from an attractive female research associate in the study,
Speaker 1: So oxytocin only increased bonding to their partner. Why do
Speaker 1: we have chemicals like oxytocin steering our decision making towards bonding?
Speaker 1: After all, from an evolutionary perspective, we might expect that
Speaker 1: a male shouldn't want monogamy if his biological mandate is
Speaker 1: to spread genes as widely as possible. But for the
Speaker 1: survival of the children, having two parents around is better
Speaker 1: than one. And this simple fact is so important that
Speaker 1: the brain has hidden ways to influence you or decision
Speaker 1: making on it. Our decisions are often steered by invisibly
Speaker 1: small molecules that we don't even necessarily know about. Now
Speaker 1: we've been talking all about decision making and how it
Speaker 1: arises from battling networks in the brain. Why does it
Speaker 1: matter to understand this stuff? While a better understanding of
Speaker 1: decision making allows us to better steer our own lives,
Speaker 1: and also it opens the door to craft better social policy.
Speaker 1: For example, all of us, in our own ways, we
Speaker 1: always have to battle impulse control. At the extreme, we
Speaker 1: can end up as slaves to the immediate cravings of
Speaker 1: our impulses. And I think from this perspective we can
Speaker 1: gain a more nuanced understanding of the efficacy of social
Speaker 1: programs like the War on drugs. So take drug addiction.
Speaker 1: It's a big problem for societies. It's about seven out
Speaker 1: of ten prisoners meet the criteria for substance abuse or
Speaker 1: dependence and one study found that over a third of
Speaker 1: convicted inmates were under the influence of drugs at the
Speaker 1: time of their crime. So drug abuse translates into tens
Speaker 1: of billions of dollars, mostly in terms of drug related crime,
Speaker 1: and what this has led to is a burgeoning prison population. Now,
Speaker 1: what most countries do is they deal with the problem
Speaker 1: of drug addiction by criminalizing it. The problem is that
Speaker 1: the number of Americans in prison for drug crimes has
Speaker 1: gone up eightfold since the War on Drugs was declared
Speaker 1: in nineteen seventy one, and every year the US spends
Speaker 1: twenty billion dollars on the War on drugs. But the
Speaker 1: investment hasn't actually worked because since the War on drugs began,
Speaker 1: drug use has actually expanded. So why hasn't it worked well?
Speaker 1: As any economist will tell you, the difficulty with the
Speaker 1: drug supply is that it's like a water balloon, So
Speaker 1: if you push it down in one place, it comes
Speaker 1: up somewhere else. So instead of attacking supply, the better
Speaker 1: strategy is to address demand, and drug demand is in
Speaker 1: the brain of the addict. And by the way, if
Speaker 1: you look at who's incarcerated, the people behind the bars
Speaker 1: aren't the cartel bosses or the big time dealers. Instead,
Speaker 1: they are people locked up for possession of a small
Speaker 1: amount of drugs, usually less than two grams. They're the users,
Speaker 1: the addicts. Now, unfortunately, going to prison doesn't solve their problems.
Speaker 1: It generally worsens it. The problem is that when you
Speaker 1: lock someone up and break their social circles and their
Speaker 1: employment opportunities, where you're doing is you're giving them new
Speaker 1: social circles and new employment opportunities, and those usually don't
Speaker 1: help them break their addiction. Some people argue that drug
Speaker 1: addiction is about poverty and peer pressure, and those do
Speaker 1: play a role, But at the core of the issue
Speaker 1: is the biology of the brain. So just look at
Speaker 1: laboratory experiments where you see rats self administering drugs. What
Speaker 1: they'll do is they'll continually hit this lever over and
Speaker 1: over to get drugs, and they'll do that at the
Speaker 1: expense of food and drink. The rats aren't doing that
Speaker 1: because of finances or social coercion. They're doing it because
Speaker 1: the drugs tapp into fundamental reward circuitry in the brain.
Speaker 1: The drugs effectively tell the brain that this decision is
Speaker 1: better than all the other things it could be doing.
Speaker 1: Other brain networks might be involved in the battle, and
Speaker 1: they're representing all the reasons to resist the drug, but
Speaker 1: in an addict, the craving network wins. In fact, if
Speaker 1: you spend a lot of time talking to people who
Speaker 1: are addicted to drugs, you'll find that the majority of them
Speaker 1: want to quit, and they're perfectly able to list all
Speaker 1: the reasons why they should quit, but they just can't
Speaker 1: do it. Why. It's because they've become slaves to these
Speaker 1: short term gratifies caation circuits. Now, because the problem with
Speaker 1: drug addiction lies in the brain, it's plausible that the
Speaker 1: solutions lie there. Also, one approach is to tip the
Speaker 1: balance of impulse control. So, as an example, one successful
Speaker 1: tactic is to ramp up the certainty and swiftness of punishment,
Speaker 1: for example, by requiring drug offenders to undergo twice weekly
Speaker 1: drug testing with automatic immediate jail time for failure, and
Speaker 1: that way they don't have to rely on a distant
Speaker 1: abstraction alone. Or here's something related. Some economists propose that
Speaker 1: the drop in American crime since the early nineteen nineties
Speaker 1: has been due in part to the increased presence of
Speaker 1: police on the streets. So in the language of the brain,
Speaker 1: the police visibility stimulates the networks of the brain that
Speaker 1: way long term consequences. Now those are social approaches, but
Speaker 1: because this is a neuroscience podcast, I'm going to tell
Speaker 1: you about a brain based approach which is currently being
Speaker 1: studied and this could end up being quite effective. This
Speaker 1: involves giving real time feedback during brain imaging. So you're
Speaker 1: allowing a person who's addicted to drugs to view their
Speaker 1: brain activity and learn how to regulate it. So let
Speaker 1: me tell you how this works. Imagine there's someone call
Speaker 1: her Susan, who is addicted to heroin. So you put
Speaker 1: Susan into the brain scanner. This is using functional magnetic
Speaker 1: resonance imaging, also known as fMRI, and you show Susan
Speaker 1: pictures of heroin and you say to her, I want
Speaker 1: you to go ahead and crave this. Well, that's easy
Speaker 1: for her to do, and it activates particular regions of
Speaker 1: her brain that we can summarize as the craving network.
Speaker 1: Then we ask her to suppress her craving. We asked
Speaker 1: her to think about the cost that heroin has had
Speaker 1: her in terms of finances, in terms of relation ships
Speaker 1: in terms of employment. So that activates a different set
Speaker 1: of brain areas, which we can summarize as the suppression network.
Speaker 1: Now here's the key. The craving and the suppression networks
Speaker 1: are always battling it out for supremacy, and whichever wins
Speaker 1: at any moment determines what Susan does when she's offered heroin.
Speaker 1: So in the scanner we can measure which network is winning.
Speaker 1: The short term thinking of the craving network where the
Speaker 1: long term thinking of the impulse control or suppression network.
Speaker 1: So we give Susan real time visual feedback in the
Speaker 1: form of a speedometer, so she can see how the
Speaker 1: battle is going. When her craving is winning, the needle
Speaker 1: is up in the red zone, and as she successfully
Speaker 1: suppresses the craving, the needle moves to the blue zone.
Speaker 1: So she can then use different mental approaches to discover
Speaker 1: what works to take the balance of these networks. In
Speaker 1: other words, we're giving her visual feedback about how the
Speaker 1: battle is going on the inside, and by practicing over
Speaker 1: and over, Susan gets better at understanding what she needs
Speaker 1: to do to move that needle. She may or may
Speaker 1: not be consciously aware of how she's doing it, but
Speaker 1: by repeated practice, she can strengthen the neural circuitry that
Speaker 1: allows her to suppress. So this technique is still in
Speaker 1: its infancy, but the hope is that when she's next
Speaker 1: offered heroin, she'll have the cognitive tools to overcome her
Speaker 1: immediate cravings if she wants to. Now, the interesting part
Speaker 1: about an approach like this, I think, is that this
Speaker 1: training doesn't force Susan to behave in any particular way.
Speaker 1: It simply gives her the cognitive skills to have more
Speaker 1: control over her choice rather than to be a slave
Speaker 1: of her impulses. And the heart of new approaches like
Speaker 1: this is the understanding that drug addiction is a problem
Speaker 1: for millions of people, but prisons aren't necessarily the place
Speaker 1: to solve that problem. As we develop in understanding of
Speaker 1: how human brains actually make decisions, we can develop new
Speaker 1: approaches beyond just straight up punishment. As we come to
Speaker 1: better understand the operations inside our brains, we can better
Speaker 1: align our behavior with our best intentions, and even more generally,
Speaker 1: as we get better at understanding decision making, we can
Speaker 1: improve other aspects of our criminal justice system beyond addiction.
Speaker 1: Putting into place policies which are more humane and more
Speaker 1: cost effective. So what would that look like. It would
Speaker 1: begin with an emphasis on rehabilitation over mass incarceration. So,
Speaker 1: just as one example, young people don't have a fully
Speaker 1: developed prefrontal cortex, and so they often make decisions impulsively
Speaker 1: without a meaningful consideration of future consequences. And so facilities
Speaker 1: with good rehab programs work to train people to improve
Speaker 1: their self control. You can do this with mentoring and
Speaker 1: counseling and rewards, but all of this is to simply
Speaker 1: train young people to pause and consider the future outcome
Speaker 1: of any choice they might make. You encourage them to
Speaker 1: run stimulations of what might happen, and this is how
Speaker 1: you strengthen the neural connections that can override the immediate
Speaker 1: gratification of impulses. I'm going to come back to this
Speaker 1: in a future episode. I'm going to talk about a
Speaker 1: group called the Interrupters in Chicago that work to lower
Speaker 1: crime on the streets with essentially a version of the
Speaker 1: same technique. When some young person gets all hot headed
Speaker 1: and wants to take revenge on someone else, the interrupter
Speaker 1: poses questions that forces them to think about the future,
Speaker 1: like hey, who's going to be with your girl when
Speaker 1: you're sitting in jail. Ah? Okay, fine, I won't shoot
Speaker 1: the guy now. Okay? Why because he was just confronted
Speaker 1: with a future simulation that tipped the battle of the
Speaker 1: decision making. The fact is that poor impulse control is
Speaker 1: a hallmark characteristic of the majority of criminals in the
Speaker 1: prison system. Most of the people on the wrong side
Speaker 1: of the law generally know the difference between right and
Speaker 1: wrong actions, and they understand the threat of punishment, but
Speaker 1: they're hamstrung by poor impulse control. They see an opportunity
Speaker 1: for something and they take it. They don't pause to
Speaker 1: consider other options. The temptation of the now overrides any
Speaker 1: consideration of the future consequences. Our current style of punishment
Speaker 1: rests on a bedrock of personal volition and blame, because
Speaker 1: the fact is we're all deeply wired with impulses to punish.
Speaker 1: But as we get better at understanding decision making, we
Speaker 1: can start to imagine a different kind of criminal justice system,
Speaker 1: one with a closer relationship to the neuroscience of decisions.
Speaker 1: It wouldn't let anybody off the hook. People who break
Speaker 1: the law still need to get taken off the streets,
Speaker 1: but the system we could evolve toward would be more
Speaker 1: concerned with how to deal with law breakers with an
Speaker 1: eye toward their future, rather than writing them off because
Speaker 1: of their past. Again, people who break the social contracts
Speaker 1: need to be off the streets for the safety of society.
Speaker 1: But what happens in prison does not have to be
Speaker 1: based only on bloodlust, but also on meaningful rehabilitation, and,
Speaker 1: in the context of today's episode, rehabilitation based on an
Speaker 1: increasingly better understanding of how the brain makes decisions. So
Speaker 1: let's wrap up what we saw in these last two
Speaker 1: episodes is that decision making lies at the heart of
Speaker 1: everything about who we are and what we do. Without
Speaker 1: the ability to weigh alternatives, we would be hostages to
Speaker 1: our most basic drives. We wouldn't be able to wisely
Speaker 1: navigate the now or plan our future lives. As we
Speaker 1: keep gaining more and more insight into how choices battle
Speaker 1: it out in the brain, we can learn to make
Speaker 1: better choices for ourselves and for our society. Go to
Speaker 1: Eagleman dot com slash podcast more information and to find
Speaker 1: further reading. Send me an email at podcasts at eagleman
Speaker 1: dot com with questions or discussion and check out and
Speaker 1: subscribe to Inner Cosmos on YouTube for videos of each
Speaker 1: episode and to leave comments until next time. I'm David Eagleman,
Speaker 1: and you have made the nice decision to join me
Speaker 1: here in the Inner Cosmos.