[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.56,0:00:02.82,Default,,0000,0000,0000,,I'm going to talk about the strategizing brain.
Dialogue: 0,0:00:02.82,0:00:05.05,Default,,0000,0000,0000,,We're going to use an unusual combination of tools
Dialogue: 0,0:00:05.05,0:00:07.07,Default,,0000,0000,0000,,from game theory and neuroscience
Dialogue: 0,0:00:07.07,0:00:10.03,Default,,0000,0000,0000,,to understand how people interact socially when value is on the line.
Dialogue: 0,0:00:10.03,0:00:14.00,Default,,0000,0000,0000,,So game theory is a branch of, originally, applied mathematics,
Dialogue: 0,0:00:14.00,0:00:16.99,Default,,0000,0000,0000,,used mostly in economics and political science, a little bit in biology,
Dialogue: 0,0:00:16.99,0:00:20.28,Default,,0000,0000,0000,,that gives us a mathematical taxonomy of social life
Dialogue: 0,0:00:20.28,0:00:22.41,Default,,0000,0000,0000,,and it predicts what people are likely to do
Dialogue: 0,0:00:22.41,0:00:23.60,Default,,0000,0000,0000,,and believe others will do
Dialogue: 0,0:00:23.60,0:00:26.99,Default,,0000,0000,0000,,in cases where everyone's actions affect everyone else.
Dialogue: 0,0:00:26.99,0:00:30.47,Default,,0000,0000,0000,,That's a lot of things: competition, cooperation, bargaining,
Dialogue: 0,0:00:30.47,0:00:33.76,Default,,0000,0000,0000,,games like hide-and-seek, and poker.
Dialogue: 0,0:00:33.76,0:00:36.00,Default,,0000,0000,0000,,Here's a simple game to get us started.
Dialogue: 0,0:00:36.00,0:00:38.16,Default,,0000,0000,0000,,Everyone chooses a number from zero to 100,
Dialogue: 0,0:00:38.16,0:00:40.61,Default,,0000,0000,0000,,we're going to compute the average of those numbers,
Dialogue: 0,0:00:40.61,0:00:44.80,Default,,0000,0000,0000,,and whoever's closest to two-thirds of the average wins a fixed prize.
Dialogue: 0,0:00:44.80,0:00:47.07,Default,,0000,0000,0000,,So you want to be a little bit below the average number,
Dialogue: 0,0:00:47.07,0:00:49.31,Default,,0000,0000,0000,,but not too far below, and everyone else wants to be
Dialogue: 0,0:00:49.31,0:00:51.25,Default,,0000,0000,0000,,a little bit below the average number as well.
Dialogue: 0,0:00:51.25,0:00:53.83,Default,,0000,0000,0000,,Think about what you might pick.
Dialogue: 0,0:00:53.83,0:00:57.10,Default,,0000,0000,0000,,As you're thinking, this is a toy model of something like
Dialogue: 0,0:00:57.10,0:00:59.92,Default,,0000,0000,0000,,selling in the stock market during a rising market. Right?
Dialogue: 0,0:00:59.92,0:01:02.14,Default,,0000,0000,0000,,You don't want to sell too early, because you miss out on profits,
Dialogue: 0,0:01:02.14,0:01:04.32,Default,,0000,0000,0000,,but you don't want to wait too late
Dialogue: 0,0:01:04.32,0:01:06.72,Default,,0000,0000,0000,,to when everyone else sells, triggering a crash.
Dialogue: 0,0:01:06.72,0:01:09.60,Default,,0000,0000,0000,,You want to be a little bit ahead of the competition, but not too far ahead.
Dialogue: 0,0:01:09.60,0:01:13.21,Default,,0000,0000,0000,,Okay, here's two theories about how people might think about this,
Dialogue: 0,0:01:13.21,0:01:14.61,Default,,0000,0000,0000,,and then we'll see some data.
Dialogue: 0,0:01:14.61,0:01:16.80,Default,,0000,0000,0000,,Some of these will sound familiar because you probably are
Dialogue: 0,0:01:16.80,0:01:20.60,Default,,0000,0000,0000,,thinking that way. I'm using my brain theory to see.
Dialogue: 0,0:01:20.60,0:01:23.71,Default,,0000,0000,0000,,A lot of people say, "I really don't know what people are going to pick,
Dialogue: 0,0:01:23.71,0:01:25.38,Default,,0000,0000,0000,,so I think the average will be 50."
Dialogue: 0,0:01:25.38,0:01:27.29,Default,,0000,0000,0000,,They're not being really strategic at all.
Dialogue: 0,0:01:27.29,0:01:30.65,Default,,0000,0000,0000,,"And I'll pick two-thirds of 50. That's 33." That's a start.
Dialogue: 0,0:01:30.65,0:01:32.54,Default,,0000,0000,0000,,Other people who are a little more sophisticated,
Dialogue: 0,0:01:32.54,0:01:34.01,Default,,0000,0000,0000,,using more working memory,
Dialogue: 0,0:01:34.01,0:01:37.92,Default,,0000,0000,0000,,say, "I think people will pick 33 because they're going to pick a response to 50,
Dialogue: 0,0:01:37.92,0:01:40.89,Default,,0000,0000,0000,,and so I'll pick 22, which is two-thirds of 33."
Dialogue: 0,0:01:40.89,0:01:43.36,Default,,0000,0000,0000,,They're doing one extra step of thinking, two steps.
Dialogue: 0,0:01:43.36,0:01:45.98,Default,,0000,0000,0000,,That's better. And of course, in principle,
Dialogue: 0,0:01:45.98,0:01:47.81,Default,,0000,0000,0000,,you could do three, four or more,
Dialogue: 0,0:01:47.81,0:01:49.68,Default,,0000,0000,0000,,but it starts to get very difficult.
Dialogue: 0,0:01:49.68,0:01:52.27,Default,,0000,0000,0000,,Just like in language and other domains, we know that it's hard for people to parse
Dialogue: 0,0:01:52.27,0:01:55.90,Default,,0000,0000,0000,,very complex sentences with a kind of recursive structure.
Dialogue: 0,0:01:55.90,0:01:57.64,Default,,0000,0000,0000,,This is called a cognitive hierarchy theory, by the way.
Dialogue: 0,0:01:57.64,0:02:00.19,Default,,0000,0000,0000,,It's something that I've worked on and a few other people,
Dialogue: 0,0:02:00.19,0:02:02.41,Default,,0000,0000,0000,,and it indicates a kind of hierarchy along with
Dialogue: 0,0:02:02.41,0:02:04.67,Default,,0000,0000,0000,,some assumptions about how many people stop at different steps
Dialogue: 0,0:02:04.67,0:02:06.55,Default,,0000,0000,0000,,and how the steps of thinking are affected
Dialogue: 0,0:02:06.55,0:02:10.25,Default,,0000,0000,0000,,by lots of interesting variables and variant people, as we'll see in a minute.
Dialogue: 0,0:02:10.25,0:02:13.63,Default,,0000,0000,0000,,A very different theory, a much more popular one, and an older one,
Dialogue: 0,0:02:13.63,0:02:17.17,Default,,0000,0000,0000,,due largely to John Nash of "A Beautiful Mind" fame,
Dialogue: 0,0:02:17.17,0:02:19.41,Default,,0000,0000,0000,,is what's called equilibrium analysis.
Dialogue: 0,0:02:19.41,0:02:21.87,Default,,0000,0000,0000,,So if you've ever taken a game theory course at any level,
Dialogue: 0,0:02:21.87,0:02:23.58,Default,,0000,0000,0000,,you will have learned a little bit about this.
Dialogue: 0,0:02:23.58,0:02:26.44,Default,,0000,0000,0000,,An equilibrium is a mathematical state in which everybody
Dialogue: 0,0:02:26.44,0:02:28.88,Default,,0000,0000,0000,,has figured out exactly what everyone else will do.
Dialogue: 0,0:02:28.88,0:02:30.89,Default,,0000,0000,0000,,It is a very useful concept, but behaviorally,
Dialogue: 0,0:02:30.89,0:02:32.90,Default,,0000,0000,0000,,it may not exactly explain what people do
Dialogue: 0,0:02:32.90,0:02:35.63,Default,,0000,0000,0000,,the first time they play these types of economic games
Dialogue: 0,0:02:35.63,0:02:37.96,Default,,0000,0000,0000,,or in situations in the outside world.
Dialogue: 0,0:02:37.96,0:02:40.30,Default,,0000,0000,0000,,In this case, the equilibrium makes a very bold prediction,
Dialogue: 0,0:02:40.30,0:02:43.16,Default,,0000,0000,0000,,which is everyone wants to be below everyone else,
Dialogue: 0,0:02:43.16,0:02:45.45,Default,,0000,0000,0000,,therefore they'll play zero.
Dialogue: 0,0:02:45.45,0:02:48.46,Default,,0000,0000,0000,,Let's see what happens. This experiment's been done many, many times.
Dialogue: 0,0:02:48.46,0:02:50.34,Default,,0000,0000,0000,,Some of the earliest ones were done in the '90s
Dialogue: 0,0:02:50.34,0:02:52.99,Default,,0000,0000,0000,,by me and Rosemarie Nagel and others.
Dialogue: 0,0:02:52.99,0:02:55.97,Default,,0000,0000,0000,,This is a beautiful data set of 9,000 people who wrote in
Dialogue: 0,0:02:55.97,0:02:58.85,Default,,0000,0000,0000,,to three newspapers and magazines that had a contest.
Dialogue: 0,0:02:58.85,0:03:00.67,Default,,0000,0000,0000,,The contest said, send in your numbers
Dialogue: 0,0:03:00.67,0:03:03.82,Default,,0000,0000,0000,,and whoever is close to two-thirds of the average will win a big prize.
Dialogue: 0,0:03:03.82,0:03:06.91,Default,,0000,0000,0000,,And as you can see, there's so much data here, you can see the spikes very visibly.
Dialogue: 0,0:03:06.91,0:03:10.29,Default,,0000,0000,0000,,There's a spike at 33. Those are people doing one step.
Dialogue: 0,0:03:10.29,0:03:12.79,Default,,0000,0000,0000,,There is another spike visible at 22.
Dialogue: 0,0:03:12.79,0:03:15.08,Default,,0000,0000,0000,,And notice, by the way, that most people pick numbers right around there.
Dialogue: 0,0:03:15.08,0:03:17.59,Default,,0000,0000,0000,,They don't necessarily pick exactly 33 and 22.
Dialogue: 0,0:03:17.59,0:03:19.65,Default,,0000,0000,0000,,There's something a little bit noisy around it.
Dialogue: 0,0:03:19.65,0:03:21.12,Default,,0000,0000,0000,,But you can see those spikes, and they're there.
Dialogue: 0,0:03:21.12,0:03:22.84,Default,,0000,0000,0000,,There's another group of people who seem to have
Dialogue: 0,0:03:22.84,0:03:24.91,Default,,0000,0000,0000,,a firm grip on equilibrium analysis,
Dialogue: 0,0:03:24.91,0:03:27.30,Default,,0000,0000,0000,,because they're picking zero or one.
Dialogue: 0,0:03:27.30,0:03:29.39,Default,,0000,0000,0000,,But they lose, right?
Dialogue: 0,0:03:29.39,0:03:32.59,Default,,0000,0000,0000,,Because picking a number that low is actually a bad choice
Dialogue: 0,0:03:32.59,0:03:35.41,Default,,0000,0000,0000,,if other people aren't doing equilibrium analysis as well.
Dialogue: 0,0:03:35.41,0:03:37.52,Default,,0000,0000,0000,,So they're smart, but poor.
Dialogue: 0,0:03:37.52,0:03:39.61,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:03:39.61,0:03:41.58,Default,,0000,0000,0000,,Where are these things happening in the brain?
Dialogue: 0,0:03:41.58,0:03:45.45,Default,,0000,0000,0000,,One study by Coricelli and Nagel gives a really sharp, interesting answer.
Dialogue: 0,0:03:45.45,0:03:46.96,Default,,0000,0000,0000,,So they had people play this game
Dialogue: 0,0:03:46.96,0:03:49.18,Default,,0000,0000,0000,,while they were being scanned in an fMRI,
Dialogue: 0,0:03:49.18,0:03:51.45,Default,,0000,0000,0000,,and two conditions: in some trials,
Dialogue: 0,0:03:51.45,0:03:52.96,Default,,0000,0000,0000,,they're told you're playing another person
Dialogue: 0,0:03:52.96,0:03:54.55,Default,,0000,0000,0000,,who's playing right now and we're going to match up
Dialogue: 0,0:03:54.55,0:03:56.75,Default,,0000,0000,0000,,your behavior at the end and pay you if you win.
Dialogue: 0,0:03:56.75,0:03:58.73,Default,,0000,0000,0000,,In the other trials, they're told, you're playing a computer.
Dialogue: 0,0:03:58.73,0:04:00.36,Default,,0000,0000,0000,,They're just choosing randomly.
Dialogue: 0,0:04:00.36,0:04:02.44,Default,,0000,0000,0000,,So what you see here is a subtraction
Dialogue: 0,0:04:02.44,0:04:05.19,Default,,0000,0000,0000,,of areas in which there's more brain activity
Dialogue: 0,0:04:05.19,0:04:08.17,Default,,0000,0000,0000,,when you're playing people compared to playing the computer.
Dialogue: 0,0:04:08.17,0:04:10.16,Default,,0000,0000,0000,,And you see activity in some regions we've seen today,
Dialogue: 0,0:04:10.16,0:04:13.40,Default,,0000,0000,0000,,medial prefrontal cortex, dorsomedial, however, up here,
Dialogue: 0,0:04:13.40,0:04:15.25,Default,,0000,0000,0000,,ventromedial prefrontal cortex,
Dialogue: 0,0:04:15.25,0:04:16.60,Default,,0000,0000,0000,,anterior cingulate, an area that's involved
Dialogue: 0,0:04:16.60,0:04:20.24,Default,,0000,0000,0000,,in lots of types of conflict resolution, like if you're playing "Simon Says,"
Dialogue: 0,0:04:20.24,0:04:24.05,Default,,0000,0000,0000,,and also the right and left temporoparietal junction.
Dialogue: 0,0:04:24.05,0:04:26.52,Default,,0000,0000,0000,,And these are all areas which are fairly reliably known
Dialogue: 0,0:04:26.52,0:04:28.84,Default,,0000,0000,0000,,to be part of what's called a "theory of mind" circuit,
Dialogue: 0,0:04:28.84,0:04:30.74,Default,,0000,0000,0000,,or "mentalizing circuit."
Dialogue: 0,0:04:30.74,0:04:34.12,Default,,0000,0000,0000,,That is, it's a circuit that's used to imagine what other people might do.
Dialogue: 0,0:04:34.12,0:04:36.36,Default,,0000,0000,0000,,So these were some of the first studies to see this
Dialogue: 0,0:04:36.36,0:04:38.39,Default,,0000,0000,0000,,tied in to game theory.
Dialogue: 0,0:04:38.39,0:04:40.63,Default,,0000,0000,0000,,What happens with these one- and two-step types?
Dialogue: 0,0:04:40.63,0:04:42.70,Default,,0000,0000,0000,,So we classify people by what they picked,
Dialogue: 0,0:04:42.70,0:04:44.37,Default,,0000,0000,0000,,and then we look at the difference between
Dialogue: 0,0:04:44.37,0:04:46.34,Default,,0000,0000,0000,,playing humans versus playing computers,
Dialogue: 0,0:04:46.34,0:04:48.24,Default,,0000,0000,0000,,which brain areas are differentially active.
Dialogue: 0,0:04:48.24,0:04:49.99,Default,,0000,0000,0000,,On the top you see the one-step players.
Dialogue: 0,0:04:49.99,0:04:51.51,Default,,0000,0000,0000,,There's almost no difference.
Dialogue: 0,0:04:51.51,0:04:54.45,Default,,0000,0000,0000,,The reason is, they're treating other people like a computer, and the brain is too.
Dialogue: 0,0:04:54.45,0:04:58.59,Default,,0000,0000,0000,,The bottom players, you see all the activity in dorsomedial PFC.
Dialogue: 0,0:04:58.59,0:05:00.64,Default,,0000,0000,0000,,So we know that those two-step players are doing something differently.
Dialogue: 0,0:05:00.64,0:05:03.74,Default,,0000,0000,0000,,Now if you were to step back and say, "What can we do with this information?"
Dialogue: 0,0:05:03.74,0:05:05.56,Default,,0000,0000,0000,,you might be able to look at brain activity and say,
Dialogue: 0,0:05:05.56,0:05:07.06,Default,,0000,0000,0000,,"This person's going to be a good poker player,"
Dialogue: 0,0:05:07.06,0:05:08.98,Default,,0000,0000,0000,,or, "This person's socially naive,"
Dialogue: 0,0:05:08.98,0:05:10.26,Default,,0000,0000,0000,,and we might also be able to study things
Dialogue: 0,0:05:10.26,0:05:11.86,Default,,0000,0000,0000,,like development of adolescent brains
Dialogue: 0,0:05:11.86,0:05:15.21,Default,,0000,0000,0000,,once we have an idea of where this circuitry exists.
Dialogue: 0,0:05:15.21,0:05:17.83,Default,,0000,0000,0000,,Okay. Get ready.
Dialogue: 0,0:05:17.83,0:05:19.95,Default,,0000,0000,0000,,I'm saving you some brain activity,
Dialogue: 0,0:05:19.95,0:05:22.76,Default,,0000,0000,0000,,because you don't need to use your hair detector cells.
Dialogue: 0,0:05:22.76,0:05:25.65,Default,,0000,0000,0000,,You should use those cells to think carefully about this game.
Dialogue: 0,0:05:25.65,0:05:27.58,Default,,0000,0000,0000,,This is a bargaining game.
Dialogue: 0,0:05:27.58,0:05:30.14,Default,,0000,0000,0000,,Two players who are being scanned using EEG electrodes
Dialogue: 0,0:05:30.14,0:05:33.02,Default,,0000,0000,0000,,are going to bargain over one to six dollars.
Dialogue: 0,0:05:33.02,0:05:35.68,Default,,0000,0000,0000,,If they can do it in 10 seconds, they're going to actually earn that money.
Dialogue: 0,0:05:35.68,0:05:38.72,Default,,0000,0000,0000,,If 10 seconds goes by and they haven't made a deal, they get nothing.
Dialogue: 0,0:05:38.72,0:05:40.40,Default,,0000,0000,0000,,That's kind of a mistake together.
Dialogue: 0,0:05:40.40,0:05:43.22,Default,,0000,0000,0000,,The twist is that one player, on the left,
Dialogue: 0,0:05:43.22,0:05:45.91,Default,,0000,0000,0000,,is informed about how much on each trial there is.
Dialogue: 0,0:05:45.91,0:05:48.14,Default,,0000,0000,0000,,They play lots of trials with different amounts each time.
Dialogue: 0,0:05:48.14,0:05:50.38,Default,,0000,0000,0000,,In this case, they know there's four dollars.
Dialogue: 0,0:05:50.38,0:05:52.26,Default,,0000,0000,0000,,The uninformed player doesn't know,
Dialogue: 0,0:05:52.26,0:05:54.31,Default,,0000,0000,0000,,but they know that the informed player knows.
Dialogue: 0,0:05:54.31,0:05:56.37,Default,,0000,0000,0000,,So the uninformed player's challenge is to say,
Dialogue: 0,0:05:56.37,0:05:57.84,Default,,0000,0000,0000,,"Is this guy really being fair
Dialogue: 0,0:05:57.84,0:05:59.69,Default,,0000,0000,0000,,or are they giving me a very low offer
Dialogue: 0,0:05:59.69,0:06:02.77,Default,,0000,0000,0000,,in order to get me to think that there's only one or two dollars available to split?"
Dialogue: 0,0:06:02.77,0:06:05.93,Default,,0000,0000,0000,,in which case they might reject it and not come to a deal.
Dialogue: 0,0:06:05.93,0:06:08.88,Default,,0000,0000,0000,,So there's some tension here between trying to get the most money
Dialogue: 0,0:06:08.88,0:06:11.45,Default,,0000,0000,0000,,but trying to goad the other player into giving you more.
Dialogue: 0,0:06:11.45,0:06:13.78,Default,,0000,0000,0000,,And the way they bargain is to point on a number line
Dialogue: 0,0:06:13.78,0:06:15.58,Default,,0000,0000,0000,,that goes from zero to six dollars,
Dialogue: 0,0:06:15.58,0:06:18.56,Default,,0000,0000,0000,,and they're bargaining over how much the uninformed player gets,
Dialogue: 0,0:06:18.56,0:06:20.15,Default,,0000,0000,0000,,and the informed player's going to get the rest.
Dialogue: 0,0:06:20.15,0:06:22.72,Default,,0000,0000,0000,,So this is like a management-labor negotiation
Dialogue: 0,0:06:22.72,0:06:25.46,Default,,0000,0000,0000,,in which the workers don't know how much profits
Dialogue: 0,0:06:25.46,0:06:28.12,Default,,0000,0000,0000,,the privately held company has, right,
Dialogue: 0,0:06:28.12,0:06:30.49,Default,,0000,0000,0000,,and they want to maybe hold out for more money,
Dialogue: 0,0:06:30.49,0:06:32.33,Default,,0000,0000,0000,,but the company might want to create the impression
Dialogue: 0,0:06:32.33,0:06:35.26,Default,,0000,0000,0000,,that there's very little to split: "I'm giving you the most that I can."
Dialogue: 0,0:06:35.26,0:06:39.49,Default,,0000,0000,0000,,First some behavior. So a bunch of the subject pairs, they play face to face.
Dialogue: 0,0:06:39.49,0:06:41.33,Default,,0000,0000,0000,,We have some other data where they play across computers.
Dialogue: 0,0:06:41.33,0:06:43.06,Default,,0000,0000,0000,,That's an interesting difference, as you might imagine.
Dialogue: 0,0:06:43.06,0:06:45.27,Default,,0000,0000,0000,,But a bunch of the face-to-face pairs
Dialogue: 0,0:06:45.27,0:06:48.96,Default,,0000,0000,0000,,agree to divide the money evenly every single time.
Dialogue: 0,0:06:48.96,0:06:51.86,Default,,0000,0000,0000,,Boring. It's just not interesting neurally.
Dialogue: 0,0:06:51.86,0:06:54.38,Default,,0000,0000,0000,,It's good for them. They make a lot of money.
Dialogue: 0,0:06:54.38,0:06:57.05,Default,,0000,0000,0000,,But we're interested in, can we say something about
Dialogue: 0,0:06:57.05,0:06:59.59,Default,,0000,0000,0000,,when disagreements occur versus don't occur?
Dialogue: 0,0:06:59.59,0:07:01.94,Default,,0000,0000,0000,,So this is the other group of subjects who often disagree.
Dialogue: 0,0:07:01.94,0:07:04.71,Default,,0000,0000,0000,,So they have a chance of -- they bicker and disagree
Dialogue: 0,0:07:04.71,0:07:06.02,Default,,0000,0000,0000,,and end up with less money.
Dialogue: 0,0:07:06.02,0:07:09.94,Default,,0000,0000,0000,,They might be eligible to be on "Real Housewives," the TV show.
Dialogue: 0,0:07:09.94,0:07:11.87,Default,,0000,0000,0000,,You see on the left,
Dialogue: 0,0:07:11.87,0:07:14.54,Default,,0000,0000,0000,,when the amount to divide is one, two or three dollars,
Dialogue: 0,0:07:14.54,0:07:16.18,Default,,0000,0000,0000,,they disagree about half the time,
Dialogue: 0,0:07:16.18,0:07:18.38,Default,,0000,0000,0000,,and when the amount is four, five, six, they agree quite often.
Dialogue: 0,0:07:18.38,0:07:20.25,Default,,0000,0000,0000,,This turns out to be something that's predicted
Dialogue: 0,0:07:20.25,0:07:22.45,Default,,0000,0000,0000,,by a very complicated type of game theory
Dialogue: 0,0:07:22.45,0:07:25.26,Default,,0000,0000,0000,,you should come to graduate school at CalTech and learn about.
Dialogue: 0,0:07:25.26,0:07:27.44,Default,,0000,0000,0000,,It's a little too complicated to explain right now,
Dialogue: 0,0:07:27.44,0:07:30.85,Default,,0000,0000,0000,,but the theory tells you that this shape kind of should occur.
Dialogue: 0,0:07:30.85,0:07:33.07,Default,,0000,0000,0000,,Your intuition might tell you that too.
Dialogue: 0,0:07:33.07,0:07:35.31,Default,,0000,0000,0000,,Now I'm going to show you the results from the EEG recording.
Dialogue: 0,0:07:35.31,0:07:37.66,Default,,0000,0000,0000,,Very complicated. The right brain schematic
Dialogue: 0,0:07:37.66,0:07:40.52,Default,,0000,0000,0000,,is the uninformed person, and the left is the informed.
Dialogue: 0,0:07:40.52,0:07:43.32,Default,,0000,0000,0000,,Remember that we scanned both brains at the same time,
Dialogue: 0,0:07:43.32,0:07:45.72,Default,,0000,0000,0000,,so we can ask about time-synced activity
Dialogue: 0,0:07:45.72,0:07:48.94,Default,,0000,0000,0000,,in similar or different areas simultaneously,
Dialogue: 0,0:07:48.94,0:07:51.20,Default,,0000,0000,0000,,just like if you wanted to study a conversation
Dialogue: 0,0:07:51.20,0:07:53.14,Default,,0000,0000,0000,,and you were scanning two people talking to each other
Dialogue: 0,0:07:53.14,0:07:55.50,Default,,0000,0000,0000,,and you'd expect common activity in language regions
Dialogue: 0,0:07:55.50,0:07:57.88,Default,,0000,0000,0000,,when they're actually kind of listening and communicating.
Dialogue: 0,0:07:57.88,0:08:01.81,Default,,0000,0000,0000,,So the arrows connect regions that are active at the same time,
Dialogue: 0,0:08:01.81,0:08:03.85,Default,,0000,0000,0000,,and the direction of the arrows flows
Dialogue: 0,0:08:03.85,0:08:06.33,Default,,0000,0000,0000,,from the region that's active first in time,
Dialogue: 0,0:08:06.33,0:08:09.90,Default,,0000,0000,0000,,and the arrowhead goes to the region that's active later.
Dialogue: 0,0:08:09.90,0:08:12.12,Default,,0000,0000,0000,,So in this case, if you look carefully,
Dialogue: 0,0:08:12.12,0:08:13.97,Default,,0000,0000,0000,,most of the arrows flow from right to left.
Dialogue: 0,0:08:13.97,0:08:17.25,Default,,0000,0000,0000,,That is, it looks as if the uninformed brain activity
Dialogue: 0,0:08:17.25,0:08:19.21,Default,,0000,0000,0000,,is happening first,
Dialogue: 0,0:08:19.21,0:08:22.73,Default,,0000,0000,0000,,and then it's followed by activity in the informed brain.
Dialogue: 0,0:08:22.73,0:08:26.42,Default,,0000,0000,0000,,And by the way, these were trials where their deals were made.
Dialogue: 0,0:08:26.42,0:08:28.20,Default,,0000,0000,0000,,This is from the first two seconds.
Dialogue: 0,0:08:28.20,0:08:30.18,Default,,0000,0000,0000,,We haven't finished analyzing this data,
Dialogue: 0,0:08:30.18,0:08:32.08,Default,,0000,0000,0000,,so we're still peeking in, but the hope is
Dialogue: 0,0:08:32.08,0:08:34.64,Default,,0000,0000,0000,,that we can say something in the first couple of seconds
Dialogue: 0,0:08:34.64,0:08:36.36,Default,,0000,0000,0000,,about whether they'll make a deal or not,
Dialogue: 0,0:08:36.36,0:08:38.41,Default,,0000,0000,0000,,which could be very useful in thinking about avoiding litigation
Dialogue: 0,0:08:38.41,0:08:40.34,Default,,0000,0000,0000,,and ugly divorces and things like that.
Dialogue: 0,0:08:40.34,0:08:43.22,Default,,0000,0000,0000,,Those are all cases in which a lot of value is lost
Dialogue: 0,0:08:43.22,0:08:46.20,Default,,0000,0000,0000,,by delay and strikes.
Dialogue: 0,0:08:46.20,0:08:48.22,Default,,0000,0000,0000,,Here's the case where the disagreements occur.
Dialogue: 0,0:08:48.22,0:08:50.40,Default,,0000,0000,0000,,You can see it looks different than the one before.
Dialogue: 0,0:08:50.40,0:08:52.65,Default,,0000,0000,0000,,There's a lot more arrows.
Dialogue: 0,0:08:52.65,0:08:54.16,Default,,0000,0000,0000,,That means that the brains are synced up
Dialogue: 0,0:08:54.16,0:08:56.71,Default,,0000,0000,0000,,more closely in terms of simultaneous activity,
Dialogue: 0,0:08:56.71,0:08:58.72,Default,,0000,0000,0000,,and the arrows flow clearly from left to right.
Dialogue: 0,0:08:58.72,0:09:00.96,Default,,0000,0000,0000,,That is, the informed brain seems to be deciding,
Dialogue: 0,0:09:00.96,0:09:03.25,Default,,0000,0000,0000,,"We're probably not going to make a deal here."
Dialogue: 0,0:09:03.25,0:09:06.48,Default,,0000,0000,0000,,And then later there's activity in the uninformed brain.
Dialogue: 0,0:09:06.48,0:09:08.98,Default,,0000,0000,0000,,Next I'm going to introduce you to some relatives.
Dialogue: 0,0:09:08.98,0:09:11.24,Default,,0000,0000,0000,,They're hairy, smelly, fast and strong.
Dialogue: 0,0:09:11.24,0:09:14.43,Default,,0000,0000,0000,,You might be thinking back to your last Thanksgiving.
Dialogue: 0,0:09:14.43,0:09:17.12,Default,,0000,0000,0000,,Maybe if you had a chimpanzee with you.
Dialogue: 0,0:09:17.12,0:09:20.58,Default,,0000,0000,0000,,Charles Darwin and I and you broke off from the family tree
Dialogue: 0,0:09:20.58,0:09:22.84,Default,,0000,0000,0000,,from chimpanzees about five million years ago.
Dialogue: 0,0:09:22.84,0:09:24.81,Default,,0000,0000,0000,,They're still our closest genetic kin.
Dialogue: 0,0:09:24.81,0:09:26.55,Default,,0000,0000,0000,,We share 98.8 percent of the genes.
Dialogue: 0,0:09:26.55,0:09:29.35,Default,,0000,0000,0000,,We share more genes with them than zebras do with horses.
Dialogue: 0,0:09:29.35,0:09:31.06,Default,,0000,0000,0000,,And we're also their closest cousin.
Dialogue: 0,0:09:31.06,0:09:34.07,Default,,0000,0000,0000,,They have more genetic relation to us than to gorillas.
Dialogue: 0,0:09:34.07,0:09:36.59,Default,,0000,0000,0000,,So how humans and chimpanzees behave differently
Dialogue: 0,0:09:36.59,0:09:39.05,Default,,0000,0000,0000,,might tell us a lot about brain evolution.
Dialogue: 0,0:09:39.05,0:09:41.65,Default,,0000,0000,0000,,So this is an amazing memory test
Dialogue: 0,0:09:41.65,0:09:44.47,Default,,0000,0000,0000,,from Nagoya, Japan, Primate Research Institute,
Dialogue: 0,0:09:44.47,0:09:46.24,Default,,0000,0000,0000,,where they've done a lot of this research.
Dialogue: 0,0:09:46.24,0:09:48.58,Default,,0000,0000,0000,,This goes back quite a ways. They're interested in working memory.
Dialogue: 0,0:09:48.58,0:09:50.36,Default,,0000,0000,0000,,The chimp is going to see, watch carefully,
Dialogue: 0,0:09:50.36,0:09:52.56,Default,,0000,0000,0000,,they're going to see 200 milliseconds' exposure
Dialogue: 0,0:09:52.56,0:09:54.55,Default,,0000,0000,0000,,— that's fast, that's eight movie frames —
Dialogue: 0,0:09:54.55,0:09:56.50,Default,,0000,0000,0000,,of numbers one, two, three, four, five.
Dialogue: 0,0:09:56.50,0:09:58.50,Default,,0000,0000,0000,,Then they disappear and they're replaced by squares,
Dialogue: 0,0:09:58.50,0:10:00.26,Default,,0000,0000,0000,,and they have to press the squares
Dialogue: 0,0:10:00.26,0:10:02.58,Default,,0000,0000,0000,,that correspond to the numbers from low to high
Dialogue: 0,0:10:02.58,0:10:03.92,Default,,0000,0000,0000,,to get an apple reward.
Dialogue: 0,0:10:03.92,0:10:08.69,Default,,0000,0000,0000,,Let's see how they can do it.
Dialogue: 0,0:10:16.39,0:10:17.88,Default,,0000,0000,0000,,This is a young chimp. The young ones
Dialogue: 0,0:10:17.88,0:10:20.67,Default,,0000,0000,0000,,are better than the old ones, just like humans.
Dialogue: 0,0:10:20.67,0:10:22.26,Default,,0000,0000,0000,,And they're highly experienced, so they've done this
Dialogue: 0,0:10:22.26,0:10:23.69,Default,,0000,0000,0000,,thousands and thousands of time.
Dialogue: 0,0:10:23.69,0:10:26.58,Default,,0000,0000,0000,,Obviously there's a big training effect, as you can imagine.
Dialogue: 0,0:10:27.93,0:10:29.27,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:10:29.27,0:10:31.21,Default,,0000,0000,0000,,You can see they're very blasé and kind of effortless.
Dialogue: 0,0:10:31.21,0:10:35.14,Default,,0000,0000,0000,,Not only can they do it very well, they do it in a sort of lazy way.
Dialogue: 0,0:10:35.14,0:10:38.57,Default,,0000,0000,0000,,Right? Who thinks you could beat the chimps?
Dialogue: 0,0:10:38.57,0:10:40.17,Default,,0000,0000,0000,,Wrong. (Laughter)
Dialogue: 0,0:10:40.17,0:10:42.60,Default,,0000,0000,0000,,We can try. We'll try. Maybe we'll try.
Dialogue: 0,0:10:42.60,0:10:45.19,Default,,0000,0000,0000,,Okay, so the next part of this study
Dialogue: 0,0:10:45.19,0:10:46.79,Default,,0000,0000,0000,,I'm going to go quickly through
Dialogue: 0,0:10:46.79,0:10:49.48,Default,,0000,0000,0000,,is based on an idea of Tetsuro Matsuzawa.
Dialogue: 0,0:10:49.48,0:10:52.51,Default,,0000,0000,0000,,He had a bold idea that -- what he called the cognitive trade-off hypothesis.
Dialogue: 0,0:10:52.51,0:10:53.80,Default,,0000,0000,0000,,We know chimps are faster and stronger.
Dialogue: 0,0:10:53.80,0:10:55.48,Default,,0000,0000,0000,,They're also very obsessed with status.
Dialogue: 0,0:10:55.48,0:10:58.44,Default,,0000,0000,0000,,His thought was, maybe they've preserved brain activities
Dialogue: 0,0:10:58.44,0:11:00.61,Default,,0000,0000,0000,,and they practice them in development
Dialogue: 0,0:11:00.61,0:11:02.46,Default,,0000,0000,0000,,that are really, really important to them
Dialogue: 0,0:11:02.46,0:11:04.67,Default,,0000,0000,0000,,to negotiate status and to win,
Dialogue: 0,0:11:04.67,0:11:07.67,Default,,0000,0000,0000,,which is something like strategic thinking during competition.
Dialogue: 0,0:11:07.67,0:11:09.25,Default,,0000,0000,0000,,So we're going to check that out
Dialogue: 0,0:11:09.25,0:11:11.68,Default,,0000,0000,0000,,by having the chimps actually play a game
Dialogue: 0,0:11:11.68,0:11:14.31,Default,,0000,0000,0000,,by touching two touch screens.
Dialogue: 0,0:11:14.31,0:11:16.75,Default,,0000,0000,0000,,The chimps are actually interacting with each other through the computers.
Dialogue: 0,0:11:16.75,0:11:18.36,Default,,0000,0000,0000,,They're going to press left or right.
Dialogue: 0,0:11:18.36,0:11:20.48,Default,,0000,0000,0000,,One chimp is called a matcher.
Dialogue: 0,0:11:20.48,0:11:22.46,Default,,0000,0000,0000,,They win if they press left, left,
Dialogue: 0,0:11:22.46,0:11:25.63,Default,,0000,0000,0000,,like a seeker finding someone in hide-and-seek, or right, right.
Dialogue: 0,0:11:25.63,0:11:26.86,Default,,0000,0000,0000,,The mismatcher wants to mismatch.
Dialogue: 0,0:11:26.86,0:11:29.93,Default,,0000,0000,0000,,They want to press the opposite screen of the chimp.
Dialogue: 0,0:11:29.93,0:11:32.48,Default,,0000,0000,0000,,And the rewards are apple cube rewards.
Dialogue: 0,0:11:32.48,0:11:35.00,Default,,0000,0000,0000,,So here's how game theorists look at these data.
Dialogue: 0,0:11:35.00,0:11:36.62,Default,,0000,0000,0000,,This is a graph of the percentage of times
Dialogue: 0,0:11:36.62,0:11:39.24,Default,,0000,0000,0000,,the matcher picked right on the x-axis,
Dialogue: 0,0:11:39.24,0:11:40.75,Default,,0000,0000,0000,,and the percentage of times they predicted right
Dialogue: 0,0:11:40.75,0:11:43.62,Default,,0000,0000,0000,,by the mismatcher on the y-axis.
Dialogue: 0,0:11:43.62,0:11:46.82,Default,,0000,0000,0000,,So a point here is the behavior by a pair of players,
Dialogue: 0,0:11:46.82,0:11:49.04,Default,,0000,0000,0000,,one trying to match, one trying to mismatch.
Dialogue: 0,0:11:49.04,0:11:52.32,Default,,0000,0000,0000,,The NE square in the middle -- actually NE, CH and QRE --
Dialogue: 0,0:11:52.32,0:11:54.77,Default,,0000,0000,0000,,those are three different theories of Nash equilibrium, and others,
Dialogue: 0,0:11:54.77,0:11:57.20,Default,,0000,0000,0000,,tells you what the theory predicts,
Dialogue: 0,0:11:57.20,0:11:59.47,Default,,0000,0000,0000,,which is that they should match 50-50,
Dialogue: 0,0:11:59.47,0:12:01.64,Default,,0000,0000,0000,,because if you play left too much, for example,
Dialogue: 0,0:12:01.64,0:12:04.35,Default,,0000,0000,0000,,I can exploit that if I'm the mismatcher by then playing right.
Dialogue: 0,0:12:04.35,0:12:07.12,Default,,0000,0000,0000,,And as you can see, the chimps, each chimp is one triangle,
Dialogue: 0,0:12:07.12,0:12:10.96,Default,,0000,0000,0000,,are circled around, hovering around that prediction.
Dialogue: 0,0:12:10.96,0:12:12.74,Default,,0000,0000,0000,,Now we move the payoffs.
Dialogue: 0,0:12:12.74,0:12:16.18,Default,,0000,0000,0000,,We're actually going to make the left, left payoff for the matcher a little bit higher.
Dialogue: 0,0:12:16.18,0:12:17.70,Default,,0000,0000,0000,,Now they get three apple cubes.
Dialogue: 0,0:12:17.70,0:12:20.50,Default,,0000,0000,0000,,Game theoretically, that should actually make the mismatcher's behavior shift,
Dialogue: 0,0:12:20.50,0:12:22.09,Default,,0000,0000,0000,,because what happens is, the mismatcher will think,
Dialogue: 0,0:12:22.09,0:12:23.90,Default,,0000,0000,0000,,oh, this guy's going to go for the big reward,
Dialogue: 0,0:12:23.90,0:12:26.96,Default,,0000,0000,0000,,and so I'm going to go to the right, make sure he doesn't get it.
Dialogue: 0,0:12:26.96,0:12:28.63,Default,,0000,0000,0000,,And as you can see, their behavior moves up
Dialogue: 0,0:12:28.63,0:12:32.08,Default,,0000,0000,0000,,in the direction of this change in the Nash equilibrium.
Dialogue: 0,0:12:32.08,0:12:34.39,Default,,0000,0000,0000,,Finally, we changed the payoffs one more time.
Dialogue: 0,0:12:34.39,0:12:35.58,Default,,0000,0000,0000,,Now it's four apple cubes,
Dialogue: 0,0:12:35.58,0:12:37.76,Default,,0000,0000,0000,,and their behavior again moves towards the Nash equilibrium.
Dialogue: 0,0:12:37.76,0:12:39.79,Default,,0000,0000,0000,,It's sprinkled around, but if you average the chimps out,
Dialogue: 0,0:12:39.79,0:12:41.98,Default,,0000,0000,0000,,they're really, really close, within .01.
Dialogue: 0,0:12:41.98,0:12:45.18,Default,,0000,0000,0000,,They're actually closer than any species we've observed.
Dialogue: 0,0:12:45.18,0:12:48.37,Default,,0000,0000,0000,,What about humans? You think you're smarter than a chimpanzee?
Dialogue: 0,0:12:48.37,0:12:51.94,Default,,0000,0000,0000,,Here's two human groups in green and blue.
Dialogue: 0,0:12:51.94,0:12:55.68,Default,,0000,0000,0000,,They're closer to 50-50. They're not responding to payoffs as closely,
Dialogue: 0,0:12:55.68,0:12:57.13,Default,,0000,0000,0000,,and also if you study their learning in the game,
Dialogue: 0,0:12:57.13,0:12:59.12,Default,,0000,0000,0000,,they aren't as sensitive to previous rewards.
Dialogue: 0,0:12:59.12,0:13:00.48,Default,,0000,0000,0000,,The chimps are playing better than the humans,
Dialogue: 0,0:13:00.48,0:13:02.90,Default,,0000,0000,0000,,better in the sense of adhering to game theory.
Dialogue: 0,0:13:02.90,0:13:04.32,Default,,0000,0000,0000,,And these are two different groups of humans
Dialogue: 0,0:13:04.32,0:13:07.52,Default,,0000,0000,0000,,from Japan and Africa. They replicate quite nicely.
Dialogue: 0,0:13:07.52,0:13:10.76,Default,,0000,0000,0000,,None of them are close to where the chimps are.
Dialogue: 0,0:13:10.76,0:13:12.51,Default,,0000,0000,0000,,So here are some things we learned today.
Dialogue: 0,0:13:12.51,0:13:14.45,Default,,0000,0000,0000,,People seem to do a limited amount of strategic thinking
Dialogue: 0,0:13:14.45,0:13:16.26,Default,,0000,0000,0000,,using theory of mind.
Dialogue: 0,0:13:16.26,0:13:18.18,Default,,0000,0000,0000,,We have some preliminary evidence from bargaining
Dialogue: 0,0:13:18.18,0:13:20.67,Default,,0000,0000,0000,,that early warning signs in the brain might be used to predict
Dialogue: 0,0:13:20.67,0:13:22.89,Default,,0000,0000,0000,,whether there will be a bad disagreement that costs money,
Dialogue: 0,0:13:22.89,0:13:24.73,Default,,0000,0000,0000,,and chimps are better competitors than humans,
Dialogue: 0,0:13:24.73,0:13:27.20,Default,,0000,0000,0000,,as judged by game theory.
Dialogue: 0,0:13:27.20,0:13:29.06,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:13:29.06,0:13:32.63,Default,,0000,0000,0000,,(Applause)