WEBVTT - Ep103 "Could you ever know what it’s like to be someone else?" (Part 2) 0:00:05.000 --> 0:00:08.119 In the last episode, I tackled the question of whether 0:00:08.160 --> 0:00:11.680 we could really know what it's like to be someone else, 0:00:12.000 --> 0:00:15.640 as in empathize with them so completely that we actually 0:00:16.120 --> 0:00:19.560 really understand what it is to be in their shoes. Today, 0:00:19.560 --> 0:00:24.239 we're going to ask could technology help us to get there? 0:00:24.640 --> 0:00:29.600 Could we have dreams celebrities in which some people upload 0:00:29.640 --> 0:00:32.720 their dreams and other people watch them and a dream 0:00:32.760 --> 0:00:35.879 can go viral? How am I going to explain what 0:00:36.000 --> 0:00:41.000 consciousness actually feels like through four movies that got it wrong? 0:00:41.560 --> 0:00:44.200 Why don't you see your own blinks? 0:00:44.520 --> 0:00:47.360 What would it be like to numb exactly one half 0:00:47.400 --> 0:00:50.159 of your brain with barbituates? And what would it be 0:00:50.360 --> 0:00:56.560 like to become a horse? Welcome to Intercosmos with me 0:00:56.720 --> 0:01:00.240 David Eagelman. I'm a neuroscientist and author at Stanford and 0:01:00.280 --> 0:01:03.760 in these episodes we sail deeply into our three pound 0:01:03.880 --> 0:01:07.880 universe to understand why and how our lives look the 0:01:07.880 --> 0:01:27.560 way they do. Today's episode is about the question of 0:01:27.600 --> 0:01:29.840 whether we can ever really know what it is like 0:01:29.920 --> 0:01:33.200 to be someone else. In the last episode, we discussed 0:01:33.360 --> 0:01:36.720 why we humans are all so different on the inside 0:01:37.080 --> 0:01:41.960 and whether it's possible that the gaps are unbridgable, and 0:01:42.040 --> 0:01:44.440 we examine this from the point of view of neuroscience 0:01:44.480 --> 0:01:47.200 and philosophy and literature. But today we're going to turn 0:01:47.240 --> 0:01:50.960 to the angle of technology. Could new technology ever allow 0:01:51.080 --> 0:01:55.640 us to better understand other people? So let's start with 0:01:55.720 --> 0:01:58.640 an old movie that I saw back in nineteen ninety five. 0:01:58.720 --> 0:02:02.760 The movie is called Strange Days, and it explores the 0:02:02.840 --> 0:02:08.400 idea of wearing this special helmet, and the helmet records 0:02:08.480 --> 0:02:13.399 the activity in your brain, all of your memories, your feelings, 0:02:13.480 --> 0:02:17.600 your thoughts. It records that, and the recorded event is 0:02:17.760 --> 0:02:21.520 frozen in time on a data disk. It's like an 0:02:21.680 --> 0:02:25.000 MP four file, but one that captures not just audio 0:02:25.080 --> 0:02:29.200 and video but everything. And then another person can put 0:02:29.240 --> 0:02:33.160 on the helmet and they can experience it all. They 0:02:33.200 --> 0:02:38.320 remember your memories, they feel your feelings, they think your 0:02:38.520 --> 0:02:42.680 thoughts in that moment. In other words, you can live 0:02:42.880 --> 0:02:46.240 a moment in the life of another person, and you 0:02:46.280 --> 0:02:48.720 can also live the same moment of your life more 0:02:48.760 --> 0:02:52.760 than once. So in the movie, a guy named Lenny 0:02:52.840 --> 0:02:56.480 Nero is a former police officer who now works as 0:02:56.520 --> 0:03:00.760 a playback artist in Los Angeles and ends up finding 0:03:00.800 --> 0:03:04.880 a recording of a woman's last moments alive, and he 0:03:04.960 --> 0:03:08.280 becomes involved in a murder investigation, and this leads him 0:03:08.320 --> 0:03:11.400 to a group of people who are planning a terrorist attack, 0:03:11.880 --> 0:03:14.320 and so he has to use his skills as a 0:03:14.360 --> 0:03:18.280 playback artist to stop the attack and save the city. Okay, 0:03:18.280 --> 0:03:20.560 but here's the part I want to concentrate on. Could 0:03:20.639 --> 0:03:24.160 a helmet like this be possible? Could we get our 0:03:24.320 --> 0:03:28.320 neurotechnology to a point where you could record one person's 0:03:28.360 --> 0:03:32.800 experience and have a second person live it. And while 0:03:32.800 --> 0:03:35.760 we're holding that question, I want to give a related example. 0:03:36.200 --> 0:03:39.880 Some years ago, a futurist named Michael Andisimov proposed the 0:03:39.920 --> 0:03:44.720 idea of dream celebrities. The idea here was that someday 0:03:44.760 --> 0:03:48.680 in the future, presumably using nano robotics, people would be 0:03:48.720 --> 0:03:52.080 able to record and upload their dreams and then other 0:03:52.120 --> 0:03:56.520 people could watch them. So, could these versions of the 0:03:56.560 --> 0:03:59.960 future be possible even though people are so different on 0:04:00.160 --> 0:04:05.640 the inside, Could we leverage this imaginary futuristic tech in 0:04:05.680 --> 0:04:07.360 this way to know what it is like to be 0:04:07.480 --> 0:04:09.840 someone else? Now, I'm not speaking of this just in 0:04:09.920 --> 0:04:13.120 terms of empathy, which I talked about in the last episode, 0:04:13.240 --> 0:04:16.440 but in terms of uploading the experience of one person 0:04:16.480 --> 0:04:21.359 and then downloading it into the head of another. So 0:04:21.880 --> 0:04:25.240 let's start today's journey with an idea that I started 0:04:25.279 --> 0:04:27.200 chewing on a very long time ago when I was 0:04:27.200 --> 0:04:30.920 in graduate school and learned about a medical procedure called 0:04:31.320 --> 0:04:35.839 the Wata test WADA. Now, this is something that was 0:04:35.880 --> 0:04:40.520 commonly used before brain surgery when the neurosurgeon is trying 0:04:40.560 --> 0:04:45.240 to determine which side of the brain, which hemisphere is 0:04:45.320 --> 0:04:49.480 responsible for language, because you want to make sure, as 0:04:49.520 --> 0:04:54.039 the surgeon, not to damage critical areas involved in speech. 0:04:54.760 --> 0:04:59.040 So what you do is inject a sedative, usually sodium 0:04:59.040 --> 0:05:03.760 amma barbitol, into one hemisphere of the brain and that 0:05:03.880 --> 0:05:08.160 hemisphere essentially goes to sleep for about five or ten minutes, 0:05:08.400 --> 0:05:11.120 while the other hemisphere, the other half of your brain, 0:05:11.520 --> 0:05:15.359 remains active. And this is what allows the neurosurgeon to 0:05:15.520 --> 0:05:19.880 test which side of the brain is dominant for language. 0:05:20.400 --> 0:05:24.599 While one half of the brain is anesthetized, the patient 0:05:24.680 --> 0:05:27.960 is asked to speak, to count, to name objects, to 0:05:28.000 --> 0:05:32.560 follow commands, to recognize pictures, and you see if language 0:05:32.560 --> 0:05:36.920 is impaired, and if so, then whichever hemisphere is anesthetized 0:05:37.120 --> 0:05:40.680 is the one dominant for speech. Now, after the barbiturate 0:05:40.760 --> 0:05:43.559 wears off, wham, then you do it on the other side, 0:05:43.600 --> 0:05:46.280 putting the other half of the brain to sleep and 0:05:46.360 --> 0:05:50.239 testing everything again. Now you might say, isn't language always 0:05:50.279 --> 0:05:53.480 in the left hemisphere. No, it's about fifty to fifty 0:05:53.480 --> 0:05:56.400 for left handed people. But also some people have a 0:05:56.520 --> 0:06:00.600 typical brain organization, for example, if they've had early brain injuries, 0:06:00.800 --> 0:06:03.000 so their language areas might end up in the right 0:06:03.040 --> 0:06:05.520 hemisphere instead of the left. So this is why you 0:06:05.560 --> 0:06:08.640 really want to make sure you know where language is 0:06:09.120 --> 0:06:12.600 before you go cutting around in the brain, because obviously 0:06:12.880 --> 0:06:14.960 one of the worst things you can do to somebody 0:06:15.360 --> 0:06:19.760 is damage their ability to communicate with the outside world. Okay, 0:06:20.080 --> 0:06:22.760 so what I told you is that this water test 0:06:23.360 --> 0:06:27.400 temporarily shuts down one hemisphere at a time so that 0:06:27.440 --> 0:06:30.320 you can assess things. Now, the first time I heard 0:06:30.360 --> 0:06:33.599 about this as a student, I wondered if it would 0:06:33.600 --> 0:06:39.520 be possible to repurpose and expand this technique. For example, 0:06:39.680 --> 0:06:43.960 a cat's brain is a lot like ours, except that 0:06:44.040 --> 0:06:49.680 we have an enormous cerebrum while they have a larger cerebellum. 0:06:50.080 --> 0:06:54.520 So could you put a very specific pattern of sedatives 0:06:54.560 --> 0:06:58.240 into the brain in just the right regions to mold 0:06:58.320 --> 0:07:02.120 your brain to be like a cat's. Now, this is 0:07:02.160 --> 0:07:04.200 just fantasy, of course, no one's ever done this, and 0:07:04.240 --> 0:07:05.040 it's hard to know. 0:07:05.279 --> 0:07:07.480 How you would even know if you're doing it right. 0:07:08.040 --> 0:07:11.440 If I do something and I get a very strange feeling, 0:07:11.760 --> 0:07:14.480 how can I ever know that that's exactly what a 0:07:14.520 --> 0:07:19.440 cat feels, as opposed to just some other interesting, weird feeling. Nonetheless, 0:07:19.600 --> 0:07:22.960 you could get closer in theory than you might otherwise. 0:07:23.440 --> 0:07:27.920 But there's a fundamental problem with this idea. And I 0:07:27.960 --> 0:07:30.040 was chewing on this many years ago, and this became 0:07:30.440 --> 0:07:34.240 the intellectual seed for one of my short stories in 0:07:34.280 --> 0:07:38.880 my book some called Descent of Species. Now, I read 0:07:38.920 --> 0:07:40.920 this story on the podcast about a year and a 0:07:40.960 --> 0:07:42.920 half ago, but I'm going to read it again now 0:07:43.200 --> 0:07:45.600 for a different purpose. And I'd like you to keep 0:07:45.640 --> 0:07:50.040 your ears out for what the problem is about turning 0:07:50.080 --> 0:07:54.240 your brain into someone else's. So here's the story descentive 0:07:54.280 --> 0:07:58.280 Species from some in the afterlife, you are treated to 0:07:58.360 --> 0:08:02.400 a generous opportunity. You can choose whatever you would like 0:08:02.480 --> 0:08:05.120 to be in the next life. Would you like to 0:08:05.160 --> 0:08:09.400 be a member of the opposite sex, born into royalty 0:08:10.080 --> 0:08:15.400 a philosopher with bottomless profundity, a soldier facing triumphant battles. 0:08:15.680 --> 0:08:19.360 But perhaps you've just returned here from a hard life. 0:08:19.680 --> 0:08:24.040 Perhaps you were tortured by the enormity of the decisions 0:08:24.080 --> 0:08:28.280 and responsibilities that surrounded you. And now there's only one 0:08:28.360 --> 0:08:33.640 thing you yearn for, simplicity that's permissible. So for the 0:08:33.679 --> 0:08:38.439 next round, you choose to be a horse. You covet 0:08:38.520 --> 0:08:42.880 the bliss of that simple life afternoons of grazing in 0:08:42.960 --> 0:08:47.360 grassy fields, the handsome angles of your skeleton and the 0:08:47.400 --> 0:08:51.920 prominence of your muscles, the piece of the slow flicking tail, 0:08:52.480 --> 0:08:55.959 or the steam rifling through your nostrils. As you lope 0:08:56.080 --> 0:09:02.320 across snow blanketed planes. You announce your decision. Incantations are muttered, 0:09:02.559 --> 0:09:06.240 a wand is waved, and your body begins to metamorphose 0:09:06.559 --> 0:09:11.600 into a horse. Your muscles start to bulge, A mat 0:09:11.679 --> 0:09:15.520 of strong hair erupts to cover you like a comfortable 0:09:15.559 --> 0:09:19.600 blanket in winter. The thickening and lengthening of your neck 0:09:19.880 --> 0:09:24.280 immediately feels normal as it comes about. Your carotid arteries 0:09:24.440 --> 0:09:29.960 grow in diameter, your fingers blend hoofward, your knees stiffen, 0:09:30.400 --> 0:09:35.040 your hips strengthen, and meanwhile, as your skull lengthens into 0:09:35.160 --> 0:09:39.199 its new shape, your brain races in its changes. Your 0:09:39.240 --> 0:09:44.679 cortex retreats as your cerebellum grows, the homunculus melts man 0:09:44.760 --> 0:09:50.199 to horse. Neurons redirect, synapses, unplug and replug on their 0:09:50.240 --> 0:09:55.400 way to equestrian patterns, and your dream of understanding what 0:09:55.640 --> 0:09:58.520 it is like to be a horse gallops towards you 0:09:58.600 --> 0:10:03.200 from the distance. Your concern about human affairs begins to 0:10:03.280 --> 0:10:08.320 slip away, your cynicism about human behavior melts, and even 0:10:08.360 --> 0:10:12.959 your human way of thinking begins to drift away from you. Suddenly, 0:10:13.280 --> 0:10:17.000 for just a moment, you are aware of the problem 0:10:17.080 --> 0:10:21.400 you overlooked. The more you become a horse, the more 0:10:21.480 --> 0:10:25.880 you forget the original wish. You forget what it was 0:10:26.080 --> 0:10:28.920 like to be a human wondering what it was like 0:10:29.120 --> 0:10:32.319 to be a horse. This moment of lucidity does not 0:10:32.480 --> 0:10:36.640 last long, but it serves as the punishment for your sins. 0:10:37.120 --> 0:10:42.800 A Promethean entrails pecking moment, crouching half horse, half man, 0:10:43.320 --> 0:10:47.760 with the knowledge that you cannot appreciate the destination without 0:10:47.920 --> 0:10:51.920 knowing the starting point. You cannot revel in the simplicity 0:10:52.360 --> 0:10:56.319 unless you remember the alternatives. And that's not the worst 0:10:56.360 --> 0:10:59.640 of your revelation. You realize that the next time you 0:10:59.679 --> 0:11:03.960 reach here with your thick horse brain, you won't have 0:11:04.040 --> 0:11:07.199 the capacity to ask to become a human again. 0:11:07.800 --> 0:11:10.520 You won't understand what a human is. 0:11:11.200 --> 0:11:16.280 Your choice to slide down the intelligent ladder is irreversible, 0:11:17.000 --> 0:11:21.560 and just before you lose your final human faculties, you 0:11:21.600 --> 0:11:28.920 painfully ponder what magnificent extraterrestrial creature, enthralled with the idea 0:11:29.320 --> 0:11:33.440 of finding a simpler life chose in the last round 0:11:33.760 --> 0:11:40.640 to become a human that was dessentive species from my 0:11:40.679 --> 0:11:43.240 book sum and the punchline of the story tells you 0:11:43.280 --> 0:11:46.840 everything you need to know for the context of today's question, 0:11:47.320 --> 0:11:50.640 Can you really know what it's like to be something 0:11:50.640 --> 0:11:54.000 else or someone else? The problem is, the more your 0:11:54.040 --> 0:11:57.600 brain becomes something else, then the less you would be 0:11:57.640 --> 0:12:01.599 able to keep track of the original you who was 0:12:01.840 --> 0:12:05.680 asking the question. So could you modify your brain to 0:12:05.720 --> 0:12:08.160 make it like a cat's brain? When you got there, 0:12:08.480 --> 0:12:12.080 you wouldn't be able to remember what the original question was. 0:12:12.480 --> 0:12:14.800 So let's think about this and extend this. This is 0:12:14.840 --> 0:12:18.400 the same as saying I want to be the actor 0:12:18.520 --> 0:12:22.040 John Malkovich. If you were actually being John Malkovich, you 0:12:22.080 --> 0:12:25.920 wouldn't remember what it was like to be you, wondering 0:12:25.960 --> 0:12:28.440 what it was like to be he. And this is 0:12:28.520 --> 0:12:33.960 the same problem with the movie Strange Days. During playback 0:12:34.000 --> 0:12:37.800 with this helmet, the conceit is that the observer temporarily 0:12:37.920 --> 0:12:41.840 quits his own memories in state of consciousness and takes 0:12:41.880 --> 0:13:03.160 on that of someone else. Okay, so you can't change 0:13:03.160 --> 0:13:06.640 your brain to be exactly someone else's and still retain 0:13:06.800 --> 0:13:07.880 any notion of you. 0:13:08.720 --> 0:13:11.120 But could you have an experience. 0:13:10.600 --> 0:13:14.360 More like VR where you're still you, but you are 0:13:14.559 --> 0:13:18.079 experiencing someone else's senses, like you're. 0:13:17.920 --> 0:13:21.000 Seeing through their eyes. Well sort of. 0:13:21.640 --> 0:13:24.800 But there's a very interesting thing that happens here which 0:13:24.840 --> 0:13:29.160 exposes something very deep about perception. So to understand this, 0:13:29.240 --> 0:13:33.079 we're gonna dive into four movies that try to do this, because, 0:13:33.120 --> 0:13:35.760 as we'll see, this is actually a tougher challenge than 0:13:35.800 --> 0:13:38.640 you might imagine. Okay, so, there was in fact a 0:13:38.760 --> 0:13:41.880 movie called Being John Malkovich. You may have seen it. 0:13:42.240 --> 0:13:46.440 In that movie, there's a struggling puppeteer who discovers a 0:13:46.559 --> 0:13:50.920 hidden door that leads directly into the mind of the 0:13:50.960 --> 0:13:54.360 actor John Malkovich. So for fifteen minutes at a time, 0:13:54.480 --> 0:13:59.720 people can experience the world through Malkovich's eyes until they're 0:14:00.080 --> 0:14:02.720 ejected onto the side of the New Jersey Turnpike. 0:14:03.080 --> 0:14:04.400 Now, how did the. 0:14:04.400 --> 0:14:08.920 Director Spike Jones actually implement this on camera? Well, when 0:14:08.960 --> 0:14:12.720 a character enters the portal, the film switches to a 0:14:13.120 --> 0:14:17.800 first person perspective, literally showing what John Malkovich sees through 0:14:17.840 --> 0:14:21.720 his eyes. Now, to simulate the feeling of inhabiting another 0:14:21.800 --> 0:14:25.640 person's body, what the camera does is mimic the movement 0:14:25.840 --> 0:14:29.960 of the head and it shows us when Malkovich is blinking. 0:14:30.480 --> 0:14:33.560 Essentially the curtain drops because we're on the inside of 0:14:33.600 --> 0:14:36.600 his head and we're seeing those eyelids. And there's also 0:14:36.640 --> 0:14:40.360 a confined feeling of a tunnel. In these shots. The 0:14:40.480 --> 0:14:43.640 edges of the frame are darker, giving the sense that 0:14:43.680 --> 0:14:47.920 you're looking through a peopole or wearing blinkers. Now, this 0:14:47.960 --> 0:14:52.600 is very interesting, right, because that's not actually your experience 0:14:52.680 --> 0:14:56.400 of the world when you're inside your own head. So first, 0:14:56.440 --> 0:15:00.680 what is the reason that you don't see your own blinks? 0:15:01.200 --> 0:15:05.240 Is it because a blink is too fast to notice? 0:15:05.440 --> 0:15:09.320 After all, it only takes eighty milliseconds. Well, no, that's 0:15:09.400 --> 0:15:12.200 not it, because if you are looking out in a 0:15:12.240 --> 0:15:14.760 well lit room and I flick the lights on it 0:15:14.840 --> 0:15:18.040 off for just eighty milliseconds, you have no problem at 0:15:18.080 --> 0:15:20.640 all detecting that. In fact, you can detect something much 0:15:20.680 --> 0:15:22.960 shorter than that. So what's going on why don't you 0:15:23.000 --> 0:15:25.200 see your own blinks? Well, the answer is that you 0:15:25.320 --> 0:15:29.240 have circuitry in your midbrain that sends the motor command 0:15:29.440 --> 0:15:32.640 to blink your eyelids, and it also sends a copy 0:15:32.680 --> 0:15:35.600 of this command to your visual system so that it 0:15:35.760 --> 0:15:39.440 knows a blink is coming. But there's even a deeper 0:15:39.560 --> 0:15:42.360 answer here. The general story, as you have heard me 0:15:42.440 --> 0:15:45.160 talk about in many other episodes, is that you're not 0:15:45.440 --> 0:15:49.160 seeing the world out there. Exactly what you're seeing is 0:15:49.200 --> 0:15:52.680 your internal model of what you believe is out there. 0:15:52.760 --> 0:15:57.000 It's a construction of your brain. Only five percent of 0:15:57.040 --> 0:16:00.000 the input to your visual cortex is coming from the eye. 0:16:00.520 --> 0:16:05.720 All the rest is feedback. It's internally generated activity telling 0:16:05.760 --> 0:16:10.040 you what you expect to see given your entire history 0:16:10.080 --> 0:16:13.120 with the world. And it turns out you don't need 0:16:13.240 --> 0:16:16.800 your eyes at all for vision. You can have full, 0:16:17.080 --> 0:16:20.920 rich visual experience even with your eyes closed. This is 0:16:20.960 --> 0:16:25.520 the experience you have every night when you're dreaming, So 0:16:25.600 --> 0:16:29.080 you only see your internal model of the world. And 0:16:29.120 --> 0:16:32.160 this is why a blink does not disrupt your vision 0:16:32.200 --> 0:16:35.080 because your brain knows it's coming, and so your model 0:16:35.200 --> 0:16:37.440 that I am in this room or I'm walking along 0:16:37.480 --> 0:16:41.720 the sidewalk, that show continues on even though the data 0:16:41.800 --> 0:16:44.640 is interrupted every few seconds. So all this is to 0:16:44.680 --> 0:16:48.120 say that if you were inside someone else's sensory experience, 0:16:48.360 --> 0:16:52.720 you wouldn't see blinks, and also you wouldn't have tunnel vision. 0:16:52.960 --> 0:16:56.400 Why not? After all, your visual field is only. 0:16:56.280 --> 0:16:59.160 About one hundred and twenty degrees across out of the 0:16:59.160 --> 0:17:01.680 three hundred and six degree world. You're only seeing a 0:17:01.720 --> 0:17:04.720 slice of about a third of the vision that's available 0:17:04.760 --> 0:17:08.040 around you. So why do we feel like the world 0:17:08.240 --> 0:17:12.400 doesn't have edges. It's because what you experience is your 0:17:12.480 --> 0:17:16.520 internal model of a full three hundred and sixty degree world. 0:17:16.720 --> 0:17:19.680 And that's because you've looked around and you've filled in 0:17:19.720 --> 0:17:22.919 the picture, sometimes with very low resolution and sometimes just 0:17:23.000 --> 0:17:26.080 with assumption. But in any case, you have a sense 0:17:26.119 --> 0:17:29.720 of a full world around you. So again, if you 0:17:29.760 --> 0:17:34.480 were actually experiencing someone else's vision, it wouldn't look like 0:17:34.840 --> 0:17:37.919 a tunnel. So this is a very difficult problem to 0:17:38.119 --> 0:17:40.959 solve if you are Spike Jones or any movie director 0:17:41.000 --> 0:17:44.840 and you're given this challenge of presenting what it would 0:17:44.880 --> 0:17:49.560 be like to be inside someone else's head experiencing their vision. 0:17:49.840 --> 0:17:52.040 And in fact, something that struck me is that Jones 0:17:52.080 --> 0:17:54.760 put in the blinks and the tunnel vision, but he 0:17:54.920 --> 0:17:58.360 didn't display, for example, the fact that your eyes are 0:17:58.400 --> 0:18:02.200 making large jump three times a second. These are called 0:18:02.240 --> 0:18:05.600 the CODs. Even when you feel like you're just calmly 0:18:05.680 --> 0:18:08.280 observing the world in front of you, your eyes are 0:18:08.400 --> 0:18:13.080 constantly dashing around to find new information. Again, we're not 0:18:13.160 --> 0:18:17.360 aware of this because all we experience is our internal model, 0:18:17.640 --> 0:18:20.520 and our eyes are just seeking new data to put 0:18:20.560 --> 0:18:22.879 into that. By the way, if it doesn't feel like 0:18:22.920 --> 0:18:24.760 your eyes are always dashing around, just get in the 0:18:24.800 --> 0:18:27.639 habit of watching other people's eyes and you'll see that 0:18:27.640 --> 0:18:30.760 they're making large jumps every third of a second. 0:18:30.920 --> 0:18:32.239 So look, I want you to try this. 0:18:32.480 --> 0:18:35.439 Take the video camera on your phone and record the 0:18:35.440 --> 0:18:39.600 scene around you, but jerk the camera around three times 0:18:39.640 --> 0:18:42.560 a second, just like your eyes are doing. Now play 0:18:42.560 --> 0:18:45.800 the video back, and you're gonna see that. It looks terrible. 0:18:45.920 --> 0:18:50.439 It's nauseating to try to watch this. Why because you're 0:18:50.480 --> 0:18:55.840 not experiencing those movements. You're just experiencing your internal model. 0:18:56.320 --> 0:18:59.000 And if your spike Jones and you really really wanted 0:18:59.000 --> 0:19:03.479 to capture the information directly from somebody's eyeballs, you'd have 0:19:03.520 --> 0:19:06.959 to take into account that you only have color vision 0:19:07.080 --> 0:19:09.959 right at the very center of your visual field, because 0:19:10.280 --> 0:19:13.919 that's where you have cones, the color photoreceptors, and your 0:19:13.960 --> 0:19:17.959 retina and everything in your periphery is taken care of 0:19:18.040 --> 0:19:19.360 by rods. 0:19:19.520 --> 0:19:23.040 So that's black and white vision. Most of your. 0:19:23.000 --> 0:19:25.560 Vision is black and white. But you never noticed this. 0:19:25.960 --> 0:19:29.760 You think the whole world is in color simply because 0:19:30.080 --> 0:19:33.080 you are moving your eyes around and your internal model 0:19:33.119 --> 0:19:36.520 is keeping track of everything in color. Again, if you 0:19:36.520 --> 0:19:39.400 don't believe me on this, ask your friend to take 0:19:39.440 --> 0:19:42.879 some colored dry erase markers and hold them in his 0:19:42.960 --> 0:19:45.800 hand and whatever order he wants to put them in. Now, 0:19:45.880 --> 0:19:47.920 stand just a few feet away from him and look 0:19:47.960 --> 0:19:51.040 straight at his nose, and have him hold the markers 0:19:51.080 --> 0:19:54.760 out at his arm's length, but don't look at the markers. 0:19:54.800 --> 0:19:57.720 Stay fixed right on his nose and try to name 0:19:58.119 --> 0:20:01.800 the order of the colors of the markers, and what 0:20:01.840 --> 0:20:04.880 you'll see is that you can't even see the colors. 0:20:05.400 --> 0:20:08.280 If you're actually trying to do a task that involves 0:20:08.320 --> 0:20:11.040 color out in your periphery, you just can't do it 0:20:11.080 --> 0:20:14.199 because there is no color out there. You have to 0:20:14.320 --> 0:20:20.159 move your eyes there to see any color. Okay, So 0:20:20.280 --> 0:20:23.760 let's get back to being John Malkovich. So Spike Jones 0:20:23.800 --> 0:20:28.720 didn't include all these other flourishes about ciccads and black 0:20:28.720 --> 0:20:31.680 and white vision in the periphery, but obviously it wouldn't 0:20:31.720 --> 0:20:33.760 have helped if he did, it would have just made 0:20:33.800 --> 0:20:38.920 it worse, because real vision is nothing like seeing blinks 0:20:39.119 --> 0:20:42.679 and looking down a tunnel and seeing siccads and seeing 0:20:42.680 --> 0:20:45.199 most of the world in black and white. Instead, the 0:20:45.320 --> 0:20:51.680 experience of vision is like being embedded directly in a full, rich, 0:20:51.880 --> 0:20:56.119 colorful world. So this is a tough challenge for a 0:20:56.200 --> 0:20:59.920 movie director to make an attempt to step into someone 0:21:00.080 --> 0:21:03.639 else's head. And it's not just being John Malkovich, but 0:21:03.800 --> 0:21:06.760 lots of movies try this sort of thing, trying to 0:21:06.800 --> 0:21:10.320 show what it's like for you to be inside someone 0:21:10.359 --> 0:21:14.640 else experiencing what it's like to be them. So let's 0:21:14.640 --> 0:21:17.679 return to the movie Strange Days. As I mentioned earlier, 0:21:17.720 --> 0:21:21.080 in that movie, you can record an experience from someone, 0:21:21.160 --> 0:21:24.440 let's say, while they're committing a robbery, and so we'll 0:21:24.440 --> 0:21:26.880 put aside the problem that you can't experience the whole thing, 0:21:26.920 --> 0:21:29.439 the emotions, the thoughts, the feelings. But again, we're just 0:21:29.480 --> 0:21:32.200 going to ask what the movie director did to make 0:21:32.280 --> 0:21:35.520 us feel like we were inside the visual system of another. 0:21:36.320 --> 0:21:39.159 So when the director needed to show us this, he 0:21:39.280 --> 0:21:42.280 showed us from a first person point of view, because 0:21:42.320 --> 0:21:44.760 after all, that's what was being sold in the helmet. 0:21:45.400 --> 0:21:48.639 And what we saw was the camera bouncing up and down, 0:21:48.880 --> 0:21:51.240 indicating that the first person point of view we were 0:21:51.280 --> 0:21:55.800 in was running on foot from the cops. Now, that 0:21:55.840 --> 0:21:59.600 cracked me up because it represents a basic error of 0:21:59.640 --> 0:22:03.520 what it's really like to be running. When you are running, 0:22:04.040 --> 0:22:07.679 your visible world does not bounce up and down. Your 0:22:07.760 --> 0:22:11.800 visual system takes account of the movement of your muscles 0:22:12.080 --> 0:22:15.639 and it compensates for that. As a result, your view 0:22:15.760 --> 0:22:19.880 of the outside world is steady. And this is because 0:22:19.920 --> 0:22:24.400 your conscious view is a notion of the world outside 0:22:24.400 --> 0:22:28.160 of you. Your visual system isn't simply there to register 0:22:28.280 --> 0:22:31.360 the data coming in. Whatever hits your eyes is simply 0:22:31.720 --> 0:22:36.080 contributing to the model of a stable outside world. And 0:22:36.119 --> 0:22:37.600 as I said, a lot of this has to do 0:22:37.880 --> 0:22:41.520 with your body making predictions about how the world will 0:22:41.600 --> 0:22:45.080 change when it moves. Just as one quick example of this, 0:22:45.760 --> 0:22:48.200 do you think it would have helped if the director 0:22:48.320 --> 0:22:53.359 in Strange Days had the protagonist's hands reaching in in 0:22:53.440 --> 0:22:56.560 front of the camera. Would this look more realistic as 0:22:56.560 --> 0:22:59.040 though your own hands were coming into your field of view. 0:23:00.359 --> 0:23:03.400 That would have made things even worse, even less convincing, 0:23:03.960 --> 0:23:07.440 because although we do see our own hands reaching from 0:23:07.440 --> 0:23:11.160 below our visual fields, we are the ones controlling them, 0:23:11.440 --> 0:23:14.600 and that makes all the difference. We can predict exactly 0:23:14.680 --> 0:23:18.520 where they are and when they'll appear, because the regions 0:23:18.520 --> 0:23:21.560 of your brain that sends commands out to your body 0:23:21.920 --> 0:23:25.280 also sends copies of those commands all around to the 0:23:25.280 --> 0:23:28.320 rest of your brain, so that your visual system, for example, 0:23:28.720 --> 0:23:31.920 knows what's coming. If you want to read more about this, 0:23:31.920 --> 0:23:34.840 this is what's known as the motor efherence copy. Let 0:23:34.880 --> 0:23:36.760 me give you a good example of this point. So 0:23:36.880 --> 0:23:40.159 let's look at the movie Hatchi. This movie is about 0:23:40.240 --> 0:23:45.240 a college professor Richard Gere, who finds an abandoned puppy 0:23:45.320 --> 0:23:47.960 at a train station and takes them home, and they 0:23:48.000 --> 0:23:51.920 form a very close bond. And every day Hotchi waits 0:23:52.119 --> 0:23:55.679 at the train station for the Professor to return from work. 0:23:56.040 --> 0:24:02.280 But then the Professor dies unexpectedly, but Hotchie continues to 0:24:02.400 --> 0:24:07.359 return to the train station every day, waiting faithfully for 0:24:07.400 --> 0:24:11.199 nearly a decade, unaware that his owner is gone. It's 0:24:11.240 --> 0:24:14.800 a total tear jerker. Now here's the thing. The director 0:24:14.880 --> 0:24:18.680 wanted to show some of the shots from the dog's 0:24:18.800 --> 0:24:21.439 point of view, so here's how he went about this. 0:24:21.840 --> 0:24:24.359 First, he films the dog lying on. 0:24:24.280 --> 0:24:27.879 The grass with legs stretched in front and chin on 0:24:27.920 --> 0:24:32.040 the ground, watching the professor clipping the rose bushes, and 0:24:32.119 --> 0:24:35.000 suddenly we cut to the dog's point of view. We 0:24:35.080 --> 0:24:38.439 see the professor from a very low angle and in 0:24:38.480 --> 0:24:42.119 black and white. Okay, fine, but to drive this point home, 0:24:42.800 --> 0:24:45.520 we are then back outside the dog and we see 0:24:45.560 --> 0:24:49.160 the dog roll over sideways onto the grass, and then 0:24:49.200 --> 0:24:53.280 the director cuts to the internal dog camera and we 0:24:53.320 --> 0:24:57.320 see the horizon rotate to vertical, and then we're back 0:24:57.359 --> 0:25:00.280 outside the dog and we see the dog roll over 0:25:00.400 --> 0:25:02.760 until his paws are sticking up in the air and 0:25:02.800 --> 0:25:05.720 his head is upside down. And now the camera jumps 0:25:05.760 --> 0:25:08.199 back into the dog and shows us the world of 0:25:08.320 --> 0:25:10.240 the garden flipped. 0:25:09.880 --> 0:25:11.120 One hundred and eighty degrees. 0:25:12.000 --> 0:25:14.199 Now, this seems like a clever way to use the 0:25:14.280 --> 0:25:17.080 camera to personalize the dog's experience. 0:25:17.240 --> 0:25:18.200 Right wrong. 0:25:18.280 --> 0:25:22.160 There's an interesting rookie error of perception here. When your 0:25:22.200 --> 0:25:27.080 head turns sideways, the world doesn't turn sideways. Try it. 0:25:27.680 --> 0:25:30.679 Try it turning your head the world remains stable, and 0:25:30.720 --> 0:25:33.600