WEBVTT - Ep1 "Does time really slow down when you're in fear for your life?" 0:00:04.600 --> 0:00:07.640 So you always hear people say things like I got 0:00:07.640 --> 0:00:10.239 in a car accident and the whole thing seemed to 0:00:10.280 --> 0:00:14.640 happen in slow motion. I saw the hood crumple and 0:00:14.720 --> 0:00:17.520 the rear view mirror fall off, and I was watching 0:00:17.520 --> 0:00:20.720 the other driver's expression. And it's the same thing with 0:00:20.800 --> 0:00:26.040 gunfights or skiing accidents or motorcycle crashes. But from a 0:00:26.120 --> 0:00:31.040 neuroscience perspective, is it true that time slows down? And 0:00:31.120 --> 0:00:34.120 how could you test that? And why does your drive 0:00:34.240 --> 0:00:36.159 to work on the first day seemed to take a 0:00:36.200 --> 0:00:39.160 long time, but after a while it takes no time 0:00:39.200 --> 0:00:41.519 at all. And why do the years seem to go 0:00:41.600 --> 0:00:47.600 by faster as we get older? Welcome to inner Cosmos 0:00:47.680 --> 0:00:52.280 with me, David Eagleman. I'm a neuroscientist and an author 0:00:52.320 --> 0:00:57.400 at Stanford University, and I've spent my whole career studying 0:00:57.440 --> 0:01:01.959 the intersection between how the rain works and how we 0:01:02.040 --> 0:01:11.360 experienced life. The first time I experienced time slowing down, 0:01:11.440 --> 0:01:14.720 I was eight years old. It was a Saturday, and 0:01:14.840 --> 0:01:17.800 my brother and I left the house to find something 0:01:17.840 --> 0:01:20.800 to do, and on the way out the door, our 0:01:20.840 --> 0:01:24.600 father warned us not to go near the house under construction, 0:01:24.880 --> 0:01:27.680 and so we told him we wouldn't, and being children, 0:01:27.760 --> 0:01:29.880 we of course went straight to the house under construction. 0:01:30.319 --> 0:01:34.080 So we poked around like kids do, and eventually we 0:01:34.120 --> 0:01:36.560 found a ladder and we went up onto the roof, 0:01:37.200 --> 0:01:40.480 and from there one could enjoy a wonderful view of 0:01:40.520 --> 0:01:44.880 the mountains of Albuquerque, New Mexico. And my brother wandered 0:01:44.920 --> 0:01:47.120 off to explore some other part of the roof, and 0:01:47.360 --> 0:01:51.440 I stepped forward to stand at the edge. Now I 0:01:51.560 --> 0:01:54.960 didn't know what tar paper was. I didn't know that 0:01:55.040 --> 0:01:58.800 it was stiff and that it extended past the edge 0:01:58.840 --> 0:02:02.400 of the roof on center construction. So when I thought 0:02:02.400 --> 0:02:04.880 I was stepping to the roof's edge, I was actually 0:02:04.880 --> 0:02:08.639 stepping on the tar paper, and I began to fall. 0:02:13.760 --> 0:02:18.480 As I fell, I thought about grabbing for the roof's edge, 0:02:18.560 --> 0:02:21.240 but some part of my brain recognized I was too 0:02:21.320 --> 0:02:25.680 late for that. So I found myself in a spread 0:02:25.680 --> 0:02:30.680 eagle position, looking way down to the red brick floor below, 0:02:31.919 --> 0:02:34.320 And as I fell towards what was likely to be 0:02:34.480 --> 0:02:39.400 my death, I was thinking calmly about how similar my 0:02:39.480 --> 0:02:43.239 fall was to that scene in Alice in Wonderland when 0:02:43.240 --> 0:02:47.320 she falls down the rabbit hole. It was totally calm 0:02:47.440 --> 0:02:51.240 and peaceful. I didn't have any fear or panic. I 0:02:51.360 --> 0:02:54.440 was just thinking about a moment from a children's story. 0:02:58.760 --> 0:03:01.160 So it won't surprise you that I lived. But it 0:03:01.200 --> 0:03:05.440 did surprise my parents and the emergency room physicians because 0:03:05.480 --> 0:03:08.840 I'd fallen twelve feet and landed on my face, on 0:03:08.880 --> 0:03:12.519 my nose, and I'd lost consciousness and a lot of blood, 0:03:12.520 --> 0:03:15.520 and I'd shattered all the cartilage in my nose. But 0:03:15.639 --> 0:03:19.320 what stayed with me wasn't anything about that or the pain. 0:03:19.480 --> 0:03:24.480 It was a fascination with what had happened. So fast 0:03:24.520 --> 0:03:27.640 forward seven years later, I'm in high school physics, and 0:03:27.680 --> 0:03:31.360 I learned the formula D equals one half at squared, 0:03:31.400 --> 0:03:34.560 and that allows me to calculate how long the fall took. 0:03:35.480 --> 0:03:39.120 And I realized the fall had only taken point six 0:03:39.160 --> 0:03:42.880 of a second. What that couldn't be right. It seemed 0:03:42.880 --> 0:03:46.320 to have taken so much longer. So fast forward some 0:03:46.440 --> 0:03:49.800 more years and I become a neuroscientist, and my graduate 0:03:49.840 --> 0:03:53.120 thesis was a large computational model of a chunk of 0:03:53.160 --> 0:03:56.120 brain tissue and the signaling that happens in there. But 0:03:56.240 --> 0:04:02.400 the experience of my falls mysteriously long duration never left me. 0:04:03.080 --> 0:04:05.960 So once I became faculty, I started looking into this 0:04:06.440 --> 0:04:10.080 and I started collecting stories from people. So I'm going 0:04:10.120 --> 0:04:14.120 to start with one from a police officer. So one 0:04:14.160 --> 0:04:18.320 morning he got radio that two suspects were heading his 0:04:18.440 --> 0:04:22.159 way in a police car chase and that he should 0:04:22.279 --> 0:04:25.039 position his car in the middle of the road to 0:04:25.200 --> 0:04:28.800 stop them. So he does that, and he sees the 0:04:28.839 --> 0:04:31.359 car coming in from the distance, and he stands in 0:04:31.400 --> 0:04:34.000 the middle of the street and raises his hand for 0:04:34.040 --> 0:04:37.240 them to stop, but they just keep coming, and they're 0:04:37.240 --> 0:04:41.120 coming right at him. So he draws his revolver and 0:04:41.160 --> 0:04:44.159 he points it at the driver with the intention of 0:04:44.200 --> 0:04:47.799 shooting him through the windshield. And the car is so close, 0:04:47.960 --> 0:04:51.840 and for him, it seemed like time went into slow motion. 0:04:52.640 --> 0:04:56.799 And here's how he reports his thoughts. Now, wait a second, 0:04:57.360 --> 0:05:01.240 these are three fifty seven hollow points, and they should 0:05:01.279 --> 0:05:04.599 go right through the glass. But since the glass is angled, 0:05:04.680 --> 0:05:08.159 what if it ricochets off the glass and kills someone 0:05:08.200 --> 0:05:11.560 on the second story of that house over there. Anyway, 0:05:11.560 --> 0:05:14.640 he suddenly realizes that the car is almost on top 0:05:14.760 --> 0:05:17.320 of him, so he jumps out of the way, and 0:05:17.440 --> 0:05:20.240 at the same motion he squeezes off around at the 0:05:20.320 --> 0:05:24.600 driver's door, bang, and as the car goes by, he 0:05:24.680 --> 0:05:27.760 then pulls off a second round bang, and then as 0:05:27.800 --> 0:05:30.160 the car is almost all the way past him, he 0:05:30.200 --> 0:05:34.360 feels his finger pull off the third shot bang, and 0:05:34.560 --> 0:05:38.120 he assumes that he'd fired at the rear window, but 0:05:38.240 --> 0:05:42.080 he noticed that the glass hadn't broken, and so he 0:05:42.200 --> 0:05:45.159 starts to worry that maybe he'd missed, and maybe he'd 0:05:45.640 --> 0:05:49.640 shot a bystander down the road, and so he immediately 0:05:49.720 --> 0:05:53.640 is thinking about how his career might be over, And 0:05:53.680 --> 0:05:56.520 so his partner comes running up to him, and in 0:05:56.560 --> 0:06:01.400 the conversation afterwards, he realizes that his partner had witnessed 0:06:01.440 --> 0:06:06.160 a very different event. His partner said that the entire 0:06:06.279 --> 0:06:10.800 incident from the car approaching to when it went by, 0:06:11.200 --> 0:06:14.839 took maybe all of three seconds. And his partner said 0:06:14.880 --> 0:06:18.120 that the three shots sounded like bang bay bang, but 0:06:18.200 --> 0:06:22.160 it didn't feel that way to the officer firing the shots. 0:06:22.200 --> 0:06:24.800 It seemed like he had taken a lot of time 0:06:25.200 --> 0:06:29.320 to think about ricocheting, about people sitting in their living rooms, 0:06:29.400 --> 0:06:32.880 about whether the shot had hit the back window, about 0:06:32.880 --> 0:06:35.680 whether the shot would possibly hit a guy in a 0:06:35.800 --> 0:06:38.919 bar or some distance away, and in his mind the 0:06:39.000 --> 0:06:45.279 shots went bang bang bang, as though everything were happening 0:06:45.400 --> 0:06:49.359 at a much slower pace. So how is it that 0:06:49.480 --> 0:06:52.920 a bang bang bang from one guy is perceived by 0:06:52.920 --> 0:06:56.400 someone else's bang bay bang? How does that happen? Now? 0:06:56.440 --> 0:06:58.840 Here's another story from a doctor who got in a 0:06:58.880 --> 0:07:02.600 motorcycle accident. So he's going forty five miles an hour 0:07:02.720 --> 0:07:05.720 down the road. A car pulls out of the driveway 0:07:06.120 --> 0:07:09.720 and he comes off his bike and he hits the 0:07:09.840 --> 0:07:14.400 road and he rolls four or five times, and time 0:07:14.440 --> 0:07:19.000 appears to slow down, and he feels like he's rolling forever. 0:07:19.520 --> 0:07:23.200 So after he rolls twice, he thinks, gad, when am 0:07:23.200 --> 0:07:26.040 I ever going to stop rolling? So it seemed like 0:07:26.160 --> 0:07:28.440 time had slowed down for him. And when he was 0:07:28.480 --> 0:07:31.760 thinking about this later, he estimated it would take him 0:07:31.760 --> 0:07:34.480 about two and a half or three seconds to think 0:07:34.560 --> 0:07:37.960 that particular thought, and so that provided him with a 0:07:38.080 --> 0:07:42.640 timescale of the amount of time that a single roll 0:07:43.160 --> 0:07:47.679 seemed to take. So when he calculated this later in retrospect, 0:07:48.040 --> 0:07:50.920 he determined that the whole event seemed to have taken 0:07:50.960 --> 0:07:54.360 about fifteen seconds, but it couldn't have taken any longer 0:07:54.400 --> 0:07:58.320 than five or Another report I collected was from a 0:07:58.440 --> 0:08:02.440 mother who saw her three year old child fall into 0:08:02.480 --> 0:08:05.480 the shallow part of a lake at a little distance 0:08:05.520 --> 0:08:08.560 away at a park. So, like any parent would, she 0:08:08.680 --> 0:08:12.720 started immediately sprinting towards the lake, but it seemed to 0:08:12.760 --> 0:08:16.160 take forever to reach there. Now, her child was fine, 0:08:16.240 --> 0:08:18.840 and in fact it didn't take her that long, but 0:08:18.920 --> 0:08:23.160 she was haunted by remembering her thoughts during what seemed 0:08:23.200 --> 0:08:27.800 like a painfully slow process of reaching her child. And 0:08:27.880 --> 0:08:32.839 this impression that time runs slowly is not an uncommon occurrence. 0:08:33.280 --> 0:08:37.440 Other people I interviewed describe things like car accidents where 0:08:37.440 --> 0:08:41.360 they watched the whole event unfold slowly with a kind 0:08:41.360 --> 0:08:47.240 of inevitability, the car sliding towards them impacts and the 0:08:47.320 --> 0:08:51.080 door crushes and so on, Or the victim of a 0:08:51.240 --> 0:08:54.240 mugging describing the way that the mugger reaches into his 0:08:54.360 --> 0:08:58.520 jacket to draw a weapon, or a person who's been 0:08:58.559 --> 0:09:02.440 in an accident with a skateboard going towards the parked car. 0:09:02.600 --> 0:09:06.080 All of these things involve very short time windows that 0:09:06.120 --> 0:09:10.680 for some reason seem very lengthy, and these people, like me, 0:09:11.320 --> 0:09:14.520 reported that the sensation of time had seemed to proceed 0:09:15.240 --> 0:09:18.600 more slowly than normal, And so these reports made it 0:09:18.640 --> 0:09:23.120 seem possible to me that the brain has a capacity 0:09:23.160 --> 0:09:26.880 to operate at a higher frame rate, which is how 0:09:26.920 --> 0:09:31.000 filming slow motion in the movies works. You capture information 0:09:31.040 --> 0:09:33.880 at a higher frame rate and then you play it 0:09:33.920 --> 0:09:37.320 back at normal speed. But what if there was another 0:09:37.400 --> 0:09:41.520 possibility here? What if, for example, it's a trick of memory, 0:09:42.080 --> 0:09:45.440 such that you're laying down denser memories and when you 0:09:45.480 --> 0:09:49.680 read it back out, your brain's only conclusion is, well, 0:09:49.760 --> 0:09:53.520 if I have that much memory, that must correspond to 0:09:53.960 --> 0:09:56.920 five seconds, when in fact it only lasted one second. 0:09:57.400 --> 0:10:00.400 So I wanted to understand what was happening here the brain, 0:10:00.520 --> 0:10:05.079 So I scoured the neuroscience literature, but it turned out 0:10:05.360 --> 0:10:07.960 no one had ever put the question of slow motion 0:10:08.040 --> 0:10:12.600 perception to the test. Why not, Well, it's because it 0:10:12.640 --> 0:10:17.880 would require placing volunteer subjects in life threatening situations, which 0:10:17.960 --> 0:10:21.320 is not a clear path to tenure for an academic. 0:10:21.920 --> 0:10:26.560 But without a rigorous scientific experiment, I realized it was 0:10:26.640 --> 0:10:31.000 difficult to know how to interpret these experiences, including my own, 0:10:31.440 --> 0:10:35.040 from a neuroscience point of view, and I was obsessed 0:10:35.080 --> 0:10:44.120 with figuring out how to test this first I needed 0:10:44.160 --> 0:10:48.840 something scary, so I packed up stop watches and pads 0:10:48.840 --> 0:10:51.200 of paper, and I took all the members of my 0:10:51.280 --> 0:10:55.200 laboratory to Astro World, which was the local amusement park, 0:10:56.360 --> 0:10:59.760 and we set out to find the most terrifying roller coaster. 0:11:04.600 --> 0:11:07.280 We had a fantastic time as a group, and we 0:11:07.360 --> 0:11:09.720 did a lot of laughing, but at the end of 0:11:09.760 --> 0:11:13.800 the day we couldn't find anything frightening enough to give 0:11:13.880 --> 0:11:17.320 us the impression that time had moved in slow motion. 0:11:17.960 --> 0:11:23.160 We needed something more terrifying, so we kept looking, and 0:11:23.520 --> 0:11:27.800 three weeks later, and three hundred miles away, we found it. 0:11:28.080 --> 0:11:37.520 SCAD diving Now SCAB stands for suspended catch air device. 0:11:38.360 --> 0:11:42.600 Imagine a huge metal tower. It's one hundred and fifty 0:11:42.600 --> 0:11:46.520 feet tall. It's kind of like a poor man's Eiffel Tower, 0:11:47.200 --> 0:11:50.480 and you step on a small platform that pulls you 0:11:50.640 --> 0:11:54.319 up like a small elevator, and you find yourself standing 0:11:54.360 --> 0:11:57.520 at the very top of the tower, looking down on 0:11:57.559 --> 0:12:01.920 the city. Now, you put a big leather harness on 0:12:01.960 --> 0:12:05.120 your back, and then you click the front of your 0:12:05.120 --> 0:12:09.200 harness into a bolet hook. You position yourself so that 0:12:09.240 --> 0:12:12.520 you're hanging from the hook, cradled in that piece of 0:12:12.640 --> 0:12:18.280 leather dangling in the air with a net one hundred 0:12:18.280 --> 0:12:23.199 and fifty feet below you, and then the hook releases 0:12:24.520 --> 0:12:30.040 and you are in free fall backwards, looking at the sky, 0:12:30.760 --> 0:12:34.240 falling backwards, not even able to see where the net 0:12:34.480 --> 0:12:38.440 is or how much time you have left. When you 0:12:38.520 --> 0:12:42.560 finally hit the net below, you're going seventy miles an hour, 0:12:43.400 --> 0:12:48.360 and the net catches you softly and you finally breathe again. 0:12:49.600 --> 0:12:53.800 This was sufficiently scary. Now I'm going to get back 0:12:53.840 --> 0:12:57.240 to the experiment in just a moment, but first I 0:12:57.320 --> 0:12:59.880 want to specify that this isn't your typical in the 0:13:00.080 --> 0:13:02.360 lab science experiments. So I had to do a lot 0:13:02.360 --> 0:13:05.120 of convincing to get the university to sign off. It 0:13:05.160 --> 0:13:10.480 took me seven months, but we were finally ready. So 0:13:10.559 --> 0:13:14.680 before we tested anyone, I took the plunge myself three 0:13:14.760 --> 0:13:17.480 times in a row, and I can tell you that 0:13:17.559 --> 0:13:22.640 each time was equally terrifying as the previous. There's no 0:13:22.840 --> 0:13:26.080 getting used to falling backwards from a height like that. 0:13:26.200 --> 0:13:29.679 It goes against every Darwinian instinct that you have in 0:13:29.800 --> 0:13:33.720 terms of staying alive. But back to the question, we've 0:13:33.760 --> 0:13:37.600 now found something sufficiently scary. How do we do the 0:13:37.679 --> 0:13:42.000 experiment to see if people are overclocking or having a 0:13:42.040 --> 0:13:48.120 faster frame rate in the moment. So in my lab 0:13:48.120 --> 0:13:51.800 we engineered a wristband that we called the eagle eye, 0:13:52.280 --> 0:13:56.320 or more technically the perceptual chronometer, which is just a 0:13:56.360 --> 0:13:59.720 fancy way of saying something that can measure the speed 0:13:59.760 --> 0:14:03.200 of your perception, in other words, how fast you're taking 0:14:03.240 --> 0:14:07.040 in information from the world. So picture this. It's like 0:14:07.080 --> 0:14:10.480 a watch with a big face, and it has a 0:14:10.520 --> 0:14:16.560 rectangular screen of small LED lights. So we can display 0:14:16.600 --> 0:14:18.960 a number on it, let's say the number twenty seven, 0:14:19.560 --> 0:14:23.240 by turning on the LEDs that make that number. But 0:14:23.400 --> 0:14:26.840 here's the trick. We now switch the lights so that 0:14:26.960 --> 0:14:30.280 in the next moment, all the LEDs that are on 0:14:30.440 --> 0:14:33.960 turn off, and all the ones off turn on, So 0:14:34.000 --> 0:14:36.920 that still shows you a twenty seven. But now it's 0:14:36.960 --> 0:14:39.840 like a negative photograph where the background is lit but 0:14:39.880 --> 0:14:42.120 the number isn't, so you can still easily read that 0:14:42.200 --> 0:14:45.920 as twenty seven. Now what we do is we alternate 0:14:46.000 --> 0:14:49.400 the positive and negative images rapidly, so all the lights 0:14:49.400 --> 0:14:52.760 are blinking on and off and at a fast pace. 0:14:52.880 --> 0:14:55.640 You can still easily see that the number being displayed 0:14:55.800 --> 0:14:58.440 is twenty seven, But if we make it just a 0:14:58.440 --> 0:15:01.520 little bit faster than that, you can't see any number 0:15:01.520 --> 0:15:05.080 at all, because the speed is such that the positive 0:15:05.080 --> 0:15:08.600 and negative images fuse together, and it looks like just 0:15:08.640 --> 0:15:11.160 a bunch of LEDs that are on, and you can't 0:15:11.200 --> 0:15:14.840 distinguish that number twenty seven from any other number that 0:15:14.960 --> 0:15:18.160 might be displayed. So this speed is known as the 0:15:18.240 --> 0:15:23.080 flicker fusion frequency. Things are flickering so fast that they 0:15:23.120 --> 0:15:27.880 all fuse together. Perceptually, now we know that even though 0:15:27.920 --> 0:15:31.160 you can't see the number anymore, there are cells in 0:15:31.200 --> 0:15:35.120 your visual cortex that can follow flicker at much higher 0:15:35.240 --> 0:15:38.840 rates than your consciousness can. So the question was this, 0:15:39.560 --> 0:15:43.320 if you're in a terrifying event, can you actually see 0:15:43.320 --> 0:15:46.680 in slow motion like Neo in the matrix who sees 0:15:46.720 --> 0:15:50.960 in bullet time, and can you therefore distinguish the flashing 0:15:51.080 --> 0:15:53.840 numbers at a faster rate than you would be able 0:15:53.880 --> 0:15:57.320 to normally. In other words, we set the pace of 0:15:57.400 --> 0:16:01.840 alternating lights just faster than you can normally see, just 0:16:01.960 --> 0:16:06.400 beyond the flicker fusion frequency. So if your vision speeds 0:16:06.560 --> 0:16:09.680 up like a slow motion camera taking in more frames 0:16:09.760 --> 0:16:13.160 per second, then you should be able to report the 0:16:13.280 --> 0:16:16.720 number that was being flashed. If, on the other hand, 0:16:17.040 --> 0:16:20.400 you're not actually seeing in slow motion but instead just 0:16:20.480 --> 0:16:24.360 laying down more memory, you'd be no faster at reading 0:16:24.360 --> 0:16:26.920 the display and it wouldn't look like anything to you. 0:16:27.800 --> 0:16:31.760 So we got twenty three volunteer participants to do the fall, 0:16:32.280 --> 0:16:35.840 and here's how it works. Imagine you're the volunteer. First, 0:16:35.920 --> 0:16:41.720 we measure your flicker fusion threshold under a normal relaxed circumstances, 0:16:41.760 --> 0:16:45.560 in other words, how fast I can alternate these numbers 0:16:45.560 --> 0:16:49.640 before you can't see them anymore. Then we put you 0:16:49.720 --> 0:16:54.680 on the platform that's winched fifteen stories up above the ground. 0:16:55.360 --> 0:16:59.280 You strap the perceptual chronometer to your wrist, and then 0:16:59.280 --> 0:17:02.760 you're attacked to this bolet hook that's dangling way above 0:17:02.800 --> 0:17:06.320 the net, and we set the speed of alternation of 0:17:06.359 --> 0:17:09.320 the lights to just slightly faster than you can see 0:17:09.359 --> 0:17:12.800 any number on there, and you're instructed to keep your 0:17:12.800 --> 0:17:15.960 eyes on your wrist in front of you. And then 0:17:16.119 --> 0:17:22.560 at a moment you're not expecting the hook releases during 0:17:22.600 --> 0:17:26.119 the fall, your only job is to identify the random 0:17:26.200 --> 0:17:29.720 number flashing on the watch. That's it. If you're having 0:17:29.880 --> 0:17:34.159 higher temporal resolution. During the free fall, the rate of 0:17:34.200 --> 0:17:38.040 alternation should appear slowed, which would allow you to read 0:17:38.080 --> 0:17:42.399 the numbers that would otherwise be unreadable. But that was 0:17:42.480 --> 0:17:45.720 only one part of the experiment. After the fall, we 0:17:45.840 --> 0:17:51.880 had participants retrospectively reproduce how long they're fall took using 0:17:51.880 --> 0:17:55.200 a stop watch. So you think back on your fall 0:17:55.640 --> 0:17:58.560 and you start the stopwatch when you picture the hook 0:17:58.640 --> 0:18:01.919 being released, and you stop when you think you hit 0:18:01.960 --> 0:18:06.120 the net, so you're reproducing it in your mind. And 0:18:06.160 --> 0:18:08.639 then what you also do is you watch other people 0:18:08.680 --> 0:18:12.359 take the fall and you reproduce that memory on your 0:18:12.400 --> 0:18:15.080 stop watch as well, so the moment they were released 0:18:15.320 --> 0:18:18.399 to the moment they hit the net in your memory. 0:18:18.440 --> 0:18:22.200 And what we found here, consistent with the verbal reports, 0:18:22.640 --> 0:18:25.840 is that everyone estimates to the duration of their own 0:18:26.000 --> 0:18:29.920 fall to be longer than when they're remembering someone else's 0:18:29.920 --> 0:18:33.400 fall the same fall. On average, people felt that their 0:18:33.440 --> 0:18:36.960 own falls took at least thirty percent longer. But the 0:18:37.040 --> 0:18:42.320 surprise came with the results from the perceptual chronometer. No 0:18:42.359 --> 0:18:45.119 one was able to read the numbers in free fall 0:18:45.480 --> 0:18:47.920 at a faster rate than they could when they were 0:18:47.960 --> 0:18:51.080 standing calmly on the ground. And it is not because 0:18:51.119 --> 0:18:53.760 they closed their eyes or didn't pay attention. We monitored 0:18:53.760 --> 0:18:58.880 for that carefully, but because they couldn't, after all, see 0:18:58.920 --> 0:19:04.040 time and slow motion. So despite my subjective experience of 0:19:04.119 --> 0:19:07.760 falling from the roof, I hadn't after all seen my 0:19:07.880 --> 0:19:12.320 surroundings in bullet time like NEO. Now, this wasn't necessarily 0:19:12.359 --> 0:19:15.720 the result I was expecting. So we analyzed this data 0:19:15.800 --> 0:19:18.000 every which way to make sure there wasn't a mistake, 0:19:18.080 --> 0:19:22.359 and there wasn't. People weren't actually seeing in slow motion, 0:19:22.680 --> 0:19:25.840 and this was the first step to realizing the link 0:19:25.920 --> 0:19:32.399 between time and memory. The reason participants reported a longer 0:19:32.480 --> 0:19:36.320 duration for their own fall, even though they were seeing 0:19:36.640 --> 0:19:41.200 no faster than normal, comes down to a walnut sized 0:19:41.240 --> 0:20:06.440 area of the brain called the amygdala. When there's an 0:20:06.440 --> 0:20:11.679 emergency situation, the amygdala kicks into high year and it 0:20:11.840 --> 0:20:15.000 commandeers the resources of the rest of the brain and 0:20:15.040 --> 0:20:19.840 it forces everything to attend to the situation at hand. Now, 0:20:19.920 --> 0:20:22.840 what's emerged in neuroscience in the last few decades is 0:20:22.840 --> 0:20:26.920 that when the amigdala gets involved, memories are laid down 0:20:27.119 --> 0:20:30.879 on a secondary memory system. This is not your normal 0:20:30.920 --> 0:20:33.959 memory system, for everyday stuff which is taken care of 0:20:34.040 --> 0:20:40.119 by the hippocampus, but a secondary track because that's what 0:20:40.280 --> 0:20:45.119 memories are. Four. In an emergency situation, when everything is 0:20:45.200 --> 0:20:47.399 hitting the fan, that's when you want to make sure 0:20:47.800 --> 0:20:50.679 that you write down all the details for future reference. 0:20:51.359 --> 0:20:55.960 Now here's the key. When you play these memories back out, 0:20:56.760 --> 0:21:00.960 your brain interprets the higher density of data as a 0:21:01.119 --> 0:21:08.240 longer duration. So under normal everyday circumstances, most of what 0:21:08.400 --> 0:21:12.040 happens to you passes right through your system and very 0:21:12.040 --> 0:21:15.800 little gets retained. You don't remember much of anything about 0:21:15.800 --> 0:21:18.240 the details of who you passed on the street today, 0:21:18.680 --> 0:21:21.520 or all the billboards you saw on your drive, or 0:21:21.520 --> 0:21:23.720 the color of the car in front of you, or 0:21:24.080 --> 0:21:25.520 who is in front of you in line at the 0:21:25.560 --> 0:21:30.120 coffee shop, or much else. When you're judging how long 0:21:30.280 --> 0:21:33.000 something lasted, the only way you can do it is 0:21:33.040 --> 0:21:37.840 by looking back and essentially counting up memories. Your brain 0:21:37.920 --> 0:21:40.800 doesn't get time information for free. It's not like it 0:21:40.880 --> 0:21:43.960 has a built in clock. It's made up of billions 0:21:44.000 --> 0:21:46.200 of cells and that's all it has to work with. 0:21:50.240 --> 0:21:54.720 So through experience it figures out how to make correlations. 0:21:55.280 --> 0:21:57.520 If I have this much memory I can draw on, 0:21:57.920 --> 0:22:02.119 then that event must have lasted ten seconds, or ten months, 0:22:02.240 --> 0:22:05.800 or ten years. And in this way, duration is always 0:22:05.880 --> 0:22:10.400 a retrospective estimate and is totally dependent on how much 0:22:10.560 --> 0:22:15.680 memory you have, what landmarks you can identify in your 0:22:15.720 --> 0:22:20.800 memory landscape. And this is why time and memory are linked. 0:22:21.320 --> 0:22:25.400 But here's what's really important to know about this consciousness. 0:22:25.840 --> 0:22:28.920 Your experience of the world right now, it's always a 0:22:29.000 --> 0:22:34.800 story that's told retrospectively. You're not conscious of anything in 0:22:34.840 --> 0:22:38.760 the moment in real time. But consciousness is always about 0:22:38.800 --> 0:22:42.240 your brain asking itself what does happened? What has happened? 0:22:42.720 --> 0:22:46.320 And it pulls the appropriate signals from whatever is available 0:22:46.400 --> 0:22:50.440 to answer that question. So the reason that police officer 0:22:50.560 --> 0:22:55.000 remembered his gunshots as being far apart in time is 0:22:55.040 --> 0:22:58.800 because he was laying down so many details of the footage, 0:22:58.840 --> 0:23:03.360 so many memories. The car is approaching him, he jumps 0:23:03.440 --> 0:23:05.880 out of the way, he hits the ground, he's shooting 0:23:05.880 --> 0:23:09.159 at the side, he shoots at the back window, the 0:23:09.240 --> 0:23:13.960 closeness of the squealing tires, one hundred other details. All 0:23:14.000 --> 0:23:19.000 that gets stored by this emergency memory storage system. And 0:23:19.080 --> 0:23:22.359 so when his brain says, what has happened? What has happened? 0:23:22.560 --> 0:23:26.160 He has such a density of memory that his brain 0:23:26.280 --> 0:23:30.160 concludes naturally that the event must have been spread out 0:23:30.200 --> 0:23:33.480 over a long time. And the same goes for that 0:23:33.760 --> 0:23:38.360 doctor in the motorcycle accident. In a normal five seconds 0:23:38.400 --> 0:23:41.359 of riding along on the road, not much as getting 0:23:41.359 --> 0:23:44.520 written down in your memory. But when you're on the road, 0:23:44.760 --> 0:23:48.800 rolling on the asphalt, and possibly about to die, your 0:23:48.840 --> 0:23:52.560 brain is keeping track of everything it can. So when 0:23:52.640 --> 0:23:55.919 your brain says what just happened, it has such a 0:23:56.119 --> 0:24:01.359 density of memories that it assumes the event lasted long. Now, 0:24:01.520 --> 0:24:04.959 getting back to the test that I conducted. After I 0:24:05.040 --> 0:24:09.840 published these results, several people independently said to me, Hey, 0:24:09.880 --> 0:24:12.520 I read your paper, but I think you're wrong because 0:24:12.560 --> 0:24:16.919 I know that I experienced the car accident in slow motion. 0:24:17.560 --> 0:24:20.560 So I just asked them, look, the person who was 0:24:20.560 --> 0:24:23.560 sitting next to you on the passenger seat, did it 0:24:23.680 --> 0:24:29.960 really sound like they were saying, Because if not, then 0:24:30.040 --> 0:24:34.440 you weren't actually experiencing the world in slow motion. And 0:24:34.520 --> 0:24:37.480 they have to allow that if time were really stretched out, 0:24:37.920 --> 0:24:41.080 everything would have to be in slow motion like a movie. 0:24:41.800 --> 0:24:44.800 So I want to add there are some interesting exceptions 0:24:44.840 --> 0:24:48.960 to the slow motion effect. It only happens in certain circumstances, 0:24:49.480 --> 0:24:52.919 and the reason is because it depends on whether or 0:24:53.000 --> 0:24:57.639 not you are expecting or foreseeing the disaster that's heading 0:24:57.680 --> 0:25:00.959 your way. This is what I call the sliding on 0:25:01.080 --> 0:25:05.080 ice towards a brickwall phenomenon. If you're in that situation 0:25:05.760 --> 0:25:09.119 and you see what's coming, then all of your attention 0:25:09.240 --> 0:25:13.520 is riveted on the details, and so as we just saw, 0:25:13.640 --> 0:25:17.840 you're capturing them for later analysis in your memory. So 0:25:17.880 --> 0:25:21.720 you have the retrospective impression that it all must have 0:25:21.800 --> 0:25:27.040 taken a long time. But interestingly, when something unexpected happens, 0:25:27.040 --> 0:25:30.080 when you don't see it coming at all, you don't 0:25:30.119 --> 0:25:33.480 have time to put your attentional systems on it and 0:25:33.520 --> 0:25:36.919 write down the memories, and in retrospect, it seems like 0:25:36.960 --> 0:25:40.280 it happened with no time at all. Once, when I 0:25:40.320 --> 0:25:43.919 was biking, my front tire went into a pothole and 0:25:43.960 --> 0:25:46.879 I went flying over the handlebars. But I don't remember 0:25:46.920 --> 0:25:49.000 anything from the event because the whole thing came as 0:25:49.040 --> 0:25:51.919 a surprise. I didn't see it coming. And this is 0:25:51.960 --> 0:25:55.480 what happens when people are t boned in their car 0:25:55.640 --> 0:25:59.359 by a vehicle that they didn't see the event doesn't 0:25:59.359 --> 0:26:02.800 seem to run slow motion, but instead it's as though 0:26:02.880 --> 0:26:06.359 time is gone. They were driving along through the intersection, 0:26:06.680 --> 0:26:09.280 and in the next moment their car was pinned up 0:26:09.320 --> 0:26:13.480 against the lamp post without any notion of what the 0:26:13.520 --> 0:26:17.600 heck just happened. So I noticed when I interviewed people 0:26:17.640 --> 0:26:21.120 that they described all the predictable things as though they 0:26:21.160 --> 0:26:24.560 happened in slow motion because they had so many detailed 0:26:24.600 --> 0:26:29.399 memories about them. But they don't describe the airbags coming 0:26:29.400 --> 0:26:33.760 out in slow motion because that happens totally unexpectedly. Now, 0:26:33.840 --> 0:26:36.240 let me get back to the big question. What is 0:26:36.280 --> 0:26:39.879 this link between time and memory have to do with 0:26:39.920 --> 0:26:46.719