WEBVTT - From the Vault: Inner Cosmos, with David Eagleman 0:00:06.040 --> 0:00:08.160 Hey, welcome to Stuff to Blow Your Mind. My name 0:00:08.240 --> 0:00:09.400 is Robert Lamb. 0:00:09.280 --> 0:00:12.120 And I am Joe McCormick. And today we are bringing 0:00:12.160 --> 0:00:15.840 you an episode from the Vault. This one originally published 0:00:16.079 --> 0:00:20.080 April thirteenth, twenty twenty three, and this was our conversation 0:00:20.239 --> 0:00:25.080 with David Eagleman, neuroscientist and host of the Inner Cosmos podcast. 0:00:25.400 --> 0:00:28.120 I remember this was a very interesting chat. We hope 0:00:28.120 --> 0:00:28.720 you enjoy it. 0:00:32.080 --> 0:00:38.560 Welcome to Stuff to Blow Your Mind, a production of iHeartRadio. 0:00:41.880 --> 0:00:44.400 Hey, welcome to Stuff to Blow your Mind. My name is. 0:00:44.440 --> 0:00:47.800 Robert Lamb and I'm Joe McCormick, and hey, welcome back, Rob. 0:00:48.320 --> 0:00:50.199 You were out sick earlier this week. It's good to 0:00:50.200 --> 0:00:50.680 have you back. 0:00:51.040 --> 0:00:52.720 It's good to be back now. 0:00:53.000 --> 0:00:56.000 Because you were outsick, we ended up putting a pause 0:00:56.240 --> 0:00:59.680 on an ongoing series we were doing on childhood amnesia. 0:01:00.600 --> 0:01:04.160 We ended up running a Vault episode on Tuesday, and 0:01:04.280 --> 0:01:06.399 I just wanted to assure people that we will be 0:01:06.520 --> 0:01:09.000 coming back to that subject. We will be resuming the series, 0:01:09.040 --> 0:01:12.959 probably for next week's core episodes, but because we already 0:01:13.000 --> 0:01:15.440 had it scheduled out this way, today's episode is going 0:01:15.480 --> 0:01:18.880 to be an interview. So in fact, we are talking 0:01:18.920 --> 0:01:23.360 to a return guest, the neuroscientist and author David Eagleman. 0:01:23.520 --> 0:01:26.520 This is actually the second time David has been a 0:01:26.520 --> 0:01:29.800 guest on the show. In September twenty twenty, Rob, you 0:01:30.040 --> 0:01:32.640 spoke to him about his book Live Wired, which is 0:01:32.680 --> 0:01:35.920 a popular science book on the subject of brain plasticity. 0:01:36.319 --> 0:01:38.720 Yeah. Absolutely. That was a fun episode. You can find 0:01:38.720 --> 0:01:41.200 it in the archives, and the book Live Wired is 0:01:41.360 --> 0:01:43.880 an absolute delight. If you're at all interested in anything 0:01:44.240 --> 0:01:47.680 you hear us discussing in this episode, pick up a 0:01:47.720 --> 0:01:48.560 copy of it. 0:01:48.320 --> 0:01:49.000 It's great. 0:01:49.480 --> 0:01:52.200 So this week we invited David back on the show 0:01:52.280 --> 0:01:57.120 because he now has a fantastic, brand new podcast on 0:01:57.160 --> 0:02:00.400 our very own network on the iHeart Network, and it 0:02:00.440 --> 0:02:04.560 is called Inner Cosmos with David Eagleman. So before we 0:02:04.600 --> 0:02:08.120 get started with our interview, I thought we should just 0:02:08.160 --> 0:02:10.880 share a bit of background about David. This is from 0:02:10.960 --> 0:02:11.800 his website. 0:02:11.960 --> 0:02:15.440 That's right. David Eagleman is a neuroscientist at Stanford University 0:02:15.520 --> 0:02:18.560 and an internationally best selling author. He's the co founder 0:02:18.800 --> 0:02:22.840 of two venture backed companies, Neosensory and brain Check, and 0:02:22.880 --> 0:02:25.200 he also directs the Center for Science and Law, a 0:02:25.320 --> 0:02:29.120 national nonprofit Institute. He's best known for his work on 0:02:29.400 --> 0:02:35.600 sensory substitution, time, perception, brain plasticity, synesthesia, and neurolaw. He 0:02:35.720 --> 0:02:38.720 is the writer and presenter of the international PBS series 0:02:38.720 --> 0:02:41.080 The Brain with David Eagleman and the author of the 0:02:41.080 --> 0:02:44.200 companion book, The Brain The Story of You. He's also 0:02:44.200 --> 0:02:47.280 the writer and presenter of The Creative Brain on Netflix. 0:02:47.639 --> 0:02:50.120 David Eagleman is the author of over one hundred and 0:02:50.160 --> 0:02:54.040 twenty academic publications and many many books of popular science. 0:02:54.520 --> 0:02:58.040 Eagleman is a TED speaker, a Guggenheim Fellow, and serves 0:02:58.080 --> 0:03:01.480 on several boards, including the America Brain Foundation and the 0:03:01.560 --> 0:03:05.520 long Now Foundation. He's the Chief Scientific Advisor of the 0:03:05.680 --> 0:03:09.480 Mind Science Foundation and the winner of the Claude Shannon 0:03:09.560 --> 0:03:13.320 Luminary Award from Bell Labs and the McGovern Award for 0:03:13.400 --> 0:03:18.080 Excellence in Biomedical Communication. He serves as the academic editor 0:03:18.120 --> 0:03:20.639 for the Journal of Science and Law. Was named Science 0:03:20.760 --> 0:03:24.000 Educator of the Year by this Society for Neuroscience and 0:03:24.200 --> 0:03:27.480 was featured as one of the quote Brightest Idea Guys 0:03:27.560 --> 0:03:31.680 by Italy's Style magazine. He served as the scientific advisor 0:03:31.720 --> 0:03:35.800 on several TV shows, including Westworld and Perception and has 0:03:35.800 --> 0:03:39.480 been profiled on The Colbert Report, Nova Science Now, The 0:03:39.520 --> 0:03:43.160 New Yorker, CNN's Next List, and many other venues. He 0:03:43.200 --> 0:03:47.320 appears regularly on radio and television to discuss literature and science, 0:03:47.600 --> 0:03:49.880 and I guess now he is going to start having 0:03:50.040 --> 0:03:54.640 to add podcasts to the end of his bio here, So, Robin, 0:03:54.680 --> 0:03:56.480 unless you have anything else, I think we should jump 0:03:56.560 --> 0:03:58.600 right into our conversation with David Eagleman. 0:04:01.640 --> 0:04:03.440 Hi, David, welcome back to the show. 0:04:03.480 --> 0:04:05.720 Great, Thanks Rob for having me again. It's a pleasure 0:04:05.720 --> 0:04:08.119 to be here. And hello, Joe, it's great to meet you. David. 0:04:08.440 --> 0:04:11.040 Now, you have a great new podcast series out Inner 0:04:11.080 --> 0:04:15.280 Cosmos through iHeart. How did you decide what path to 0:04:15.360 --> 0:04:17.200 take with the podcast format? 0:04:18.320 --> 0:04:21.560 You know, it's a great question. The truth is I 0:04:21.600 --> 0:04:26.000 had not listened to many podcasts at all. Now I have. 0:04:26.160 --> 0:04:28.480 But when I first was putting this together with iHeart, 0:04:28.520 --> 0:04:30.839 I thought, look, I want to do a forty five 0:04:30.839 --> 0:04:34.680 minute to hour long monologue every week. And that seemed 0:04:34.720 --> 0:04:38.240 like a terrific idea at first, and then my wife 0:04:38.279 --> 0:04:39.880 said she was going to kill me because it turns 0:04:39.880 --> 0:04:42.480 out that's a ton of work. It takes me about 0:04:42.800 --> 0:04:46.000 kind of about twelve hours a week to get a 0:04:46.040 --> 0:04:50.719 good monologue that's almost an hour long. So that's how 0:04:50.800 --> 0:04:54.520 I decided on the format because I thought it would 0:04:54.680 --> 0:04:58.400 be something special rather than you know, I've been on 0:04:58.600 --> 0:05:01.480 many different podcasts where we're doing interviews just like this, 0:05:01.600 --> 0:05:04.080 and it's super fun. But I wanted to do something different. 0:05:04.680 --> 0:05:08.159 So that's how I accidentally stumbled into that format. 0:05:08.560 --> 0:05:10.839 So I figure we should give people a taste of 0:05:10.839 --> 0:05:12.880 the kind of things you talk about on your show. 0:05:13.240 --> 0:05:15.200 I got a chance to listen to the episode you 0:05:15.240 --> 0:05:18.520 did about memory and the perception of time, and I 0:05:18.520 --> 0:05:20.560 thought it was great, by the way, a really great 0:05:20.560 --> 0:05:23.600 way to kick off the show. So your starting premise 0:05:23.800 --> 0:05:26.599 in that episode was that many people who have been 0:05:26.640 --> 0:05:30.200 through intense or life threatening events, maybe falling off of 0:05:30.240 --> 0:05:33.839 a building or seeing a car speeding toward them, report 0:05:33.920 --> 0:05:38.479 afterwards that time seemed to have somehow slowed down for 0:05:38.600 --> 0:05:41.440 them during the pivotal few seconds, almost as if they 0:05:41.440 --> 0:05:44.560 were able to inter a state of slow motion or 0:05:44.600 --> 0:05:47.840 bullet time, like from the matrix. Can you talk a 0:05:47.880 --> 0:05:50.760 bit about your research on this subject and what you 0:05:50.880 --> 0:05:52.360 discovered about this perception. 0:05:52.960 --> 0:05:55.520 Yeah, so my research, of course started off very personal 0:05:55.560 --> 0:05:57.320 which is that I fell off of a house and 0:05:57.360 --> 0:05:59.760 it seemed like things took a long time, and that's 0:05:59.800 --> 0:06:02.120 what got me interested in this. Then when I got older, 0:06:02.160 --> 0:06:06.400 it became a neuroscientist. Eventually I realized that I was 0:06:06.480 --> 0:06:10.400 hearing this story not uncommonly from people who had been 0:06:10.440 --> 0:06:14.200 in a you know, gunfight or some scary situation or 0:06:14.279 --> 0:06:17.240 car accident or whatever, and they felt that things took longer. 0:06:17.360 --> 0:06:19.080 And so I looked in the literature and there was 0:06:19.120 --> 0:06:22.640 not anything on this. So that's when I came to 0:06:22.640 --> 0:06:25.279 realize I was going to have to do this myself 0:06:25.279 --> 0:06:27.720 and figure out how to run an experiment on this. 0:06:27.880 --> 0:06:31.599 So you know, briefly, what I did is I built 0:06:31.640 --> 0:06:34.240 a device that I hooked to people's wrists that flashed 0:06:34.279 --> 0:06:36.919 information them at them met a certain way so that 0:06:36.960 --> 0:06:41.200 I could tell how rapidly their brain was perceiving, and 0:06:41.240 --> 0:06:44.000 that way I could test whether they were actually seeing 0:06:44.040 --> 0:06:47.440 in slow motion or The whole thing was a trick 0:06:47.480 --> 0:06:51.360 of memory, meaning when you were in an intense situation, 0:06:51.480 --> 0:06:53.359 you wrote down more memories. So when you said what 0:06:53.480 --> 0:06:56.320 just happened, when just happened, that it seemed like it 0:06:56.400 --> 0:06:59.080 must have taken longer because you have all these memories. 0:06:59.400 --> 0:07:01.720 So what I did then is dropped people from one 0:07:01.800 --> 0:07:05.280 hundred and fifty foot tall tower in free fall backwards 0:07:05.279 --> 0:07:09.880 into a net below, and I measured their perception of 0:07:09.920 --> 0:07:11.720 time on the way down this way. And what I 0:07:11.800 --> 0:07:15.280 found after, you know, I didn't sell myself, but then 0:07:15.320 --> 0:07:20.080 we dropped twenty three participants. What I found is that 0:07:20.240 --> 0:07:23.080 it is in fact a trick of memory, which is 0:07:23.120 --> 0:07:25.800 to say, when everything is hitting the fan, your brain 0:07:25.840 --> 0:07:28.720 writes down much denser memory, and when you read that 0:07:28.760 --> 0:07:31.000 back out, your brain has to make an assumption about 0:07:31.960 --> 0:07:35.120 you know, how much memory, how much footage maps onto 0:07:35.120 --> 0:07:38.440 how much time, and so it says, oh wow, that 0:07:38.480 --> 0:07:40.280 must have been five seconds, even though it was only 0:07:40.320 --> 0:07:42.640 one second worth. But the point is people were not 0:07:42.800 --> 0:07:45.280 able to see in slow motion, which, by the way, 0:07:45.400 --> 0:07:47.760 was disappointing for me because I already had. I was 0:07:47.760 --> 0:07:50.920 already talking with the military about building cockpits in a 0:07:50.960 --> 0:07:54.440 way that flashed information more rapidly at people when they 0:07:54.720 --> 0:07:57.600 be in some intense situation. But it turns out none 0:07:57.680 --> 0:07:59.800 of that makes the difference. You can't actually get information 0:08:00.120 --> 0:08:04.160 there faster, you can only remember it faster, So. 0:08:04.200 --> 0:08:09.840 There's not actually any any increased ability of perception. It's 0:08:10.000 --> 0:08:12.000 just a trick of the memory exactly. 0:08:12.360 --> 0:08:14.800 Now. It is the case that you know a lot. 0:08:15.040 --> 0:08:17.680 You can do a lot of things pre consciously, by 0:08:17.720 --> 0:08:21.520 which I mean your conscious awareness of something is always 0:08:21.520 --> 0:08:24.120 the slowest thing on the ladder to ever get any information. 0:08:24.240 --> 0:08:26.680 So by the time your brain puts together all the 0:08:26.680 --> 0:08:30.400 signals and says, okay, this is what just happened. You know, 0:08:30.440 --> 0:08:33.480 that's at least half a second to a second behind 0:08:33.640 --> 0:08:37.480 real time. But the point is your body can react 0:08:37.559 --> 0:08:39.880 much faster than that. Your body can get signals and say, whoa, 0:08:39.920 --> 0:08:42.120 I got to do something about this right away, And 0:08:42.200 --> 0:08:45.680 so you can react, you know, often much faster than 0:08:45.720 --> 0:08:47.920 you can be consciously aware. So you know, I don't 0:08:47.920 --> 0:08:49.880 know if you've been on a I mean, this is 0:08:49.880 --> 0:08:51.480 what happened to me recently. I was on a hike 0:08:51.559 --> 0:08:54.280 with a friend and a branch snapped back, and I was, 0:08:54.600 --> 0:08:57.040 you know, halfway into the move of ducking out of 0:08:57.080 --> 0:08:59.480 the way of the branch before I consciously realized it, 0:08:59.640 --> 0:09:02.840 or my foot gets halfway to the break of my 0:09:02.880 --> 0:09:05.559 truck before I realized that there's a car pulling out 0:09:05.600 --> 0:09:07.959 of the driveway ahead of me. In other words, consciousness 0:09:08.000 --> 0:09:09.679 is always the last guy on the ladder to get 0:09:09.720 --> 0:09:14.400 any information, and your body can almost always react much faster. 0:09:15.480 --> 0:09:17.280 In fact, wait, let me just say one more example 0:09:17.280 --> 0:09:19.520 of that, which is when I was younger, I used 0:09:19.520 --> 0:09:23.320 to play baseball, and my experience was always that, you know, 0:09:23.360 --> 0:09:27.439 I'd be waiting for the pitch, and then I would 0:09:27.679 --> 0:09:32.080 realize after it had happened that I had already hit 0:09:32.120 --> 0:09:34.760 the ball. And I would consciously realize, oh, I have 0:09:35.000 --> 0:09:37.199 just hit the ball. Now throw the bat and run. 0:09:38.559 --> 0:09:41.480 But you know, the whole thing, the ball moving from 0:09:41.480 --> 0:09:44.240 the mound to the plate, and the swing and the batting, 0:09:44.280 --> 0:09:47.680 that's all really fast process and it often happens pre consciously. 0:09:48.280 --> 0:09:53.680 Somewhat related to that, this raises questions about the different 0:09:53.840 --> 0:09:58.160 kinds of circumstances that would favor the perception of slow 0:09:58.200 --> 0:10:00.560 motion in intense situations or not. 0:10:01.360 --> 0:10:01.440 So. 0:10:01.800 --> 0:10:04.440 My example was there was one night years ago I 0:10:04.520 --> 0:10:07.560 was driving under an overpass and there was a sudden 0:10:07.600 --> 0:10:10.880 deafening sound and a shudder, And what my wife and 0:10:10.920 --> 0:10:14.520 I deduced later was that somehow like a brick had 0:10:14.559 --> 0:10:16.600 fallen from above and hit the roof of our car 0:10:16.760 --> 0:10:19.440 just above the windshield. As we passed under a highway 0:10:19.440 --> 0:10:21.880 speed and I don't know if somebody threw it or 0:10:21.880 --> 0:10:24.400 if it somehow just fell, But I not only don't 0:10:24.440 --> 0:10:27.439 recall a feeling of stretched time or a greater density 0:10:27.440 --> 0:10:31.360 of memories right before and after the impact, I felt 0:10:31.400 --> 0:10:35.840 almost a kind of retrospective amnesia, like a real paucity 0:10:35.920 --> 0:10:39.079 of detail. And it was like we were suddenly a 0:10:39.160 --> 0:10:42.559 good ways down the road and just trying to remember 0:10:42.720 --> 0:10:44.040 or figure out what had happened. 0:10:45.120 --> 0:10:48.040 Yeah, that's exactly right. It's because you didn't write down 0:10:48.040 --> 0:10:50.520 any memory. And this is generally because as you are 0:10:50.600 --> 0:10:53.680 taking a drive down the highway, your brain is writing 0:10:53.720 --> 0:10:58.000 down very little stuff going on. In fact, the interesting 0:10:58.040 --> 0:11:01.200 part is that although we think about memory as being 0:11:01.240 --> 0:11:03.520 like a video recorder or something, in fact it's nothing 0:11:03.640 --> 0:11:06.840 like that. You write down very little of what happens 0:11:06.840 --> 0:11:08.840 in your life, especially when you're driving on a road 0:11:08.880 --> 0:11:12.080 you've been down before. So what happened is there's the 0:11:12.080 --> 0:11:15.079 deafening crash and suddenly you're thinking what just happened? What 0:11:15.160 --> 0:11:17.439 just happened? And you've got nothing to draw on. There's 0:11:17.520 --> 0:11:21.000 just no footage there. And by the way, just as 0:11:21.040 --> 0:11:22.679 a very quick side note, I think this is what 0:11:22.760 --> 0:11:26.360 happens to people when they are high on marijuana, is 0:11:26.400 --> 0:11:28.360 they say, oh, my gosh, how long have I been 0:11:28.400 --> 0:11:30.680 standing here? It feels like I'm standing here forever, And 0:11:30.760 --> 0:11:34.600 it's because they're not writing down memories in the same way. 0:11:34.640 --> 0:11:37.320 So when their brain looks for how long have I 0:11:37.360 --> 0:11:41.559 been standing here, what it's looking for is footage in time, 0:11:41.720 --> 0:11:44.720 as in, Okay, I remember getting here, I remember this happening, 0:11:44.760 --> 0:11:46.760 someone said this. Then someone put the glass down and 0:11:46.760 --> 0:11:48.720 blah blah blah, so that it can estimate how long 0:11:48.760 --> 0:11:51.719 it's been there. But suddenly it can't grab on to 0:11:51.880 --> 0:11:55.040 any memories at all, and so suddenly people are lost 0:11:55.559 --> 0:12:00.000 in time anyway, So this is Joe exactly what happened 0:12:00.160 --> 0:12:04.320 pins when people suddenly are hit by a car that 0:12:04.360 --> 0:12:06.240 they don't see coming, like a car teet bones them 0:12:06.360 --> 0:12:09.800 or something. Or I might have mentioned in the podcast, 0:12:09.840 --> 0:12:12.000 I can't remember that, you know. I was once riding 0:12:12.040 --> 0:12:15.920 my bike and the wheel suddenly dropped in a pothole 0:12:15.960 --> 0:12:18.440 and I went flying over the handlebars. But because I 0:12:18.520 --> 0:12:22.160 didn't see that coming, I just had the sensation of suddenly, 0:12:22.240 --> 0:12:23.320 oh my god, what's is you know? 0:12:23.320 --> 0:12:23.480 Here? 0:12:23.480 --> 0:12:25.680 I'm lying on the asphalt, bloody, and I have no 0:12:25.720 --> 0:12:29.079 idea what just happened. And it's precisely because you're not 0:12:29.160 --> 0:12:31.360 running down any memories. So when your brain says what 0:12:31.520 --> 0:12:33.760 just happened, what just happened, there's nothing to draw on, 0:12:34.400 --> 0:12:37.000 as opposed to the brick sliding on ice towards the 0:12:37.000 --> 0:12:40.120 brick wall phenomenon, which is where you say, oh my gosh, 0:12:40.240 --> 0:12:43.160 I'm predicting what's going to happen and this is really 0:12:43.160 --> 0:12:44.920 gonna hurt, this is gonna be bad, And that's when 0:12:44.960 --> 0:12:46.360 you're writing down lots of stuff. 0:12:46.720 --> 0:12:48.920 So would you say you're more likely to have this 0:12:49.760 --> 0:12:55.120 memory density perception number one if you see the event 0:12:55.320 --> 0:12:58.640 coming ahead of time, there's there's expectation of it. But 0:12:58.840 --> 0:13:03.680 also if you're generally in a novel or unusual situation. 0:13:03.720 --> 0:13:06.920 Yeah, that's exactly right. Actually, So two aspects of that. 0:13:06.960 --> 0:13:09.280 One is that I just mentioned a moment ago that 0:13:09.360 --> 0:13:12.480 you write down very little memory, and that's because as 0:13:12.559 --> 0:13:15.719 an adult now, your brain has sort of figured out 0:13:15.760 --> 0:13:18.319 a pretty good model of the world, meaning you don't 0:13:18.360 --> 0:13:20.760 need to write stuff down because you've seen all the 0:13:20.760 --> 0:13:25.360 personalities before, you've seen different cities before, you've seen roads, 0:13:25.360 --> 0:13:28.320 and people and events and television shows and you sort 0:13:28.360 --> 0:13:32.200 of got it. But if something really novel happens, that's 0:13:32.200 --> 0:13:34.600 when your brain writes something down and says, WHOA, wait 0:13:34.640 --> 0:13:38.000 a minute, I'm surprised, And that's when stuff starts getting 0:13:38.000 --> 0:13:40.199 written down. So when you look back at the end 0:13:40.240 --> 0:13:43.040 of let's say a novel event. Let's say you go 0:13:43.120 --> 0:13:46.640 on some really wild trip on the weekend to Glockos 0:13:46.679 --> 0:13:49.160 Islands and you see new things and so on, then 0:13:49.200 --> 0:13:51.600 it seems like forever since you were at work on Friday. 0:13:51.840 --> 0:13:53.840 But if you just go off for a normal weekend 0:13:54.160 --> 0:13:55.680 and you come back to work, you think, oh, I 0:13:55.720 --> 0:13:57.720 was just here because you didn't lay down any new 0:13:57.760 --> 0:14:03.080 memories over the weekend. So it is true that things 0:14:03.080 --> 0:14:06.440 that are novel generally seem to last longer. However, it 0:14:06.440 --> 0:14:10.319 should be noted that when things are actually life threatening, 0:14:10.800 --> 0:14:14.520 you have essentially an emergency response memory system that kicks 0:14:14.520 --> 0:14:18.520 into gear. That is a secondary track on which you 0:14:18.559 --> 0:14:22.000 write down memory. And this is underpinned by a part 0:14:22.000 --> 0:14:24.760 of the brain called the amigla, and its job is 0:14:24.800 --> 0:14:28.840 to say, WHOA, everything is going really bad and scary here, 0:14:29.200 --> 0:14:30.960 and I got to write this down because that after 0:14:31.000 --> 0:14:33.720 all is the point of memory is to make sure 0:14:33.720 --> 0:14:37.000 that you write down stuff that is important and specifically 0:14:37.120 --> 0:14:38.600 life threateningly important. 0:14:38.880 --> 0:14:41.960 So if the normal memory system, would that be the 0:14:42.160 --> 0:14:46.520 hippocampal memory system exactly? If that's the normal memory system, 0:14:46.520 --> 0:14:51.160 and then the amygdala tends to be recruited in intense situations. 0:14:51.600 --> 0:14:55.200 Do we know generally if there is any if there 0:14:55.200 --> 0:15:00.120 are any characteristic differences between how memories are recorded in 0:15:00.160 --> 0:15:01.920 the hippocampus versus the Amygdalah. 0:15:02.600 --> 0:15:06.400 Yeah, And it turns out it's a tragic one, which 0:15:06.440 --> 0:15:12.960 is that amygdala memories are uneaseable, whereas hippocampbel memories can 0:15:13.040 --> 0:15:15.960 be erased. So let me unpack this because there's two 0:15:16.040 --> 0:15:18.720 surprising parts here. So first of all, the fact that 0:15:18.800 --> 0:15:23.440 hippocampal memories can be erased is terrifying and weird and wild. 0:15:23.520 --> 0:15:27.480 Which is, if I ask you to recall the name 0:15:27.560 --> 0:15:33.600 of your fifth grade teacher and then suddenly that brick 0:15:33.680 --> 0:15:36.520 drops off the highway bridge and hits you in the head. 0:15:36.560 --> 0:15:40.960 God forbid, let's say that happens. You will now have 0:15:41.080 --> 0:15:45.080 amnesia for that one fact, You will not remember anything 0:15:45.160 --> 0:15:48.120 about your fifth grade teacher anymore about the at least 0:15:48.120 --> 0:15:52.120 the fifth grade teacher's name. Why it's because the name 0:15:52.160 --> 0:15:54.280 of your fifth grade teacher is stored deep in the 0:15:54.280 --> 0:15:56.280 structure of your brain, and when I ask you to 0:15:56.360 --> 0:16:01.800 recall it, you're actually transferring it from that structural form 0:16:02.360 --> 0:16:05.920 into activity, you know, spikes in the brain. And that's 0:16:05.960 --> 0:16:09.480 how you're remembering the name of your teacher. Now, when 0:16:09.520 --> 0:16:13.400 you're done remembering it, it has to get reconsolidated back 0:16:13.440 --> 0:16:15.640 into its physical form. And if you get hit in 0:16:15.680 --> 0:16:21.040 the head during that moment, it's gone. It's now you know, 0:16:21.080 --> 0:16:23.880 it's been transferred from the physical to the you know, 0:16:24.000 --> 0:16:27.320 activity in spikes. And if you you know, before it 0:16:27.360 --> 0:16:29.640 gets transferred back into the physical, it can it is 0:16:29.680 --> 0:16:33.600 susceptible to erasure, which is weird and terrifying. And by 0:16:33.600 --> 0:16:36.840 the way, this can also be done with protein synthesis inhibitors. 0:16:37.440 --> 0:16:40.200 So people do this in rats. They've been doing this 0:16:40.240 --> 0:16:42.480 for decades, where you know, you train a rat how 0:16:42.480 --> 0:16:45.480 to run different maases and then you put the rat 0:16:45.520 --> 0:16:48.200 on a particular maze where the rat has to remember, oh, yeah, 0:16:48.240 --> 0:16:50.760 that's this one, and then you just feed the rat 0:16:50.800 --> 0:16:55.440 a protein synthesis inhibitor and now it cannot reconsolidate that 0:16:55.520 --> 0:16:59.960 memory into physical form. So number one is hippocampal memory 0:17:00.160 --> 0:17:03.200 can be erased. The number two point is that amigla 0:17:03.280 --> 0:17:06.040 memories cannot be erased, which is to say, when you 0:17:06.200 --> 0:17:10.680 recruit the emergency control system to say, wow, this is 0:17:10.760 --> 0:17:15.760 really important, write this down. Than those are permanent, which 0:17:15.920 --> 0:17:18.959 the reason I say that's unfortunate is because those are 0:17:19.000 --> 0:17:20.840 the ones that people want to erase. In other words, 0:17:20.880 --> 0:17:23.439 you know, let's say a rape victim or something like that, 0:17:23.440 --> 0:17:26.000 that is the one thing that she wants to forget 0:17:26.440 --> 0:17:27.840 more than anything, but cannot. 0:17:28.640 --> 0:17:31.840 Now, I was checking out the show as well, and 0:17:31.880 --> 0:17:33.560 I was listening to your I believe this is an 0:17:33.560 --> 0:17:35.840 episode from just earlier this week on the topic of 0:17:36.400 --> 0:17:39.320 animal uplift, which I don't think is a term that 0:17:39.400 --> 0:17:42.439 I was familiar with. Can you give us a brief taste, 0:17:42.440 --> 0:17:45.040 a brief overview of what animal uplift is. 0:17:45.720 --> 0:17:48.919 Yeah, it's this idea that you know, look, the human 0:17:49.000 --> 0:17:51.439 brain is made out of exactly the same stuff that 0:17:51.880 --> 0:17:54.080 a mouse brain, the dog brain, the giraft brain. You know, 0:17:54.200 --> 0:17:56.200 it's all the same stuff. It's got the same anatomy, 0:17:56.280 --> 0:17:59.560 same general structure. We just have more of this wrinkly 0:17:59.640 --> 0:18:05.320 outer bit called the cortex. But somehow we are you know, 0:18:05.359 --> 0:18:07.560 we've taken over the whole planet as a species. We've 0:18:07.560 --> 0:18:10.960 gotten off the planet. We've made vaccines and internet and 0:18:11.040 --> 0:18:14.280 quantum mechanics and so like. There's some real difference in 0:18:14.359 --> 0:18:17.679 what we are doing versus our neighbors in the animal kingdom. 0:18:18.320 --> 0:18:22.440 But the genetic differences, as you know, are not that much. 0:18:22.520 --> 0:18:25.320 I mean, we have enormous similarity with almost every Like 0:18:25.359 --> 0:18:27.199 if you're building a giraffe, you got to build the 0:18:27.200 --> 0:18:28.879 heart and the lungs and the brain and then the 0:18:29.000 --> 0:18:32.000 esophagus and all that stuff is really the same stuff. 0:18:32.040 --> 0:18:35.399 And so it's just some small algorithmic difference in the 0:18:35.480 --> 0:18:38.439 DNA that's making our brain run in a more souped 0:18:38.480 --> 0:18:42.640 up way. Okay, the idea of animal uplift is if 0:18:42.680 --> 0:18:44.879 we can figure that out. And this won't happen, you know, 0:18:44.960 --> 0:18:47.000 for at least a few more decades, but if we 0:18:47.040 --> 0:18:50.000 can figure out, ah, here's the sequence of a's and 0:18:50.080 --> 0:18:54.280 c's and t's and g's that gives us this high intelligence. 0:18:55.160 --> 0:18:59.600 The question is should we give this to animals? Should 0:18:59.600 --> 0:19:04.480 we help animals become intelligent? Now, let me just mention 0:19:04.600 --> 0:19:09.480 this is an area that bioethicists and philosophers and neuroscientists 0:19:09.560 --> 0:19:12.399 have been talking about for a while, and there's you know, 0:19:12.480 --> 0:19:14.240 plenty of debate about it. And on one end of 0:19:14.280 --> 0:19:16.320 the spectrum you have people say that's a terrible idea, 0:19:16.400 --> 0:19:18.280 We wouldn't want to give intelligence to animals, and other 0:19:18.320 --> 0:19:21.640 people say it's a moral obligation in the same way 0:19:21.640 --> 0:19:24.680 that you know, if we know how to fix some 0:19:24.920 --> 0:19:27.639 viral disease or fix a broken leg or something, of 0:19:27.640 --> 0:19:29.720 course you should do this for your dog instead of 0:19:29.800 --> 0:19:33.720 let your dog, you know, not have the medical advances 0:19:33.760 --> 0:19:36.720 that we have made. So anyway, it's a big debate, 0:19:36.760 --> 0:19:39.120 but this is the idea of animal uplift. You make 0:19:39.320 --> 0:19:43.040 an animal as intelligent as a human. And I just 0:19:43.119 --> 0:19:47.880 find this area fascinating. And you know, as I proposed 0:19:47.960 --> 0:19:52.359 the podcast, what would the consequences of this be in 0:19:52.440 --> 0:19:55.840 terms of, you know, will World War five be fought 0:19:55.880 --> 0:20:00.800 by other animal species not just humans? You know, And 0:20:01.080 --> 0:20:04.879 the way I sort of introduced the podcast is with 0:20:04.960 --> 0:20:07.080 this question of what will my kids look back on? 0:20:07.400 --> 0:20:10.760 Are my grandkids Obviously there's lots of things that will 0:20:10.800 --> 0:20:15.160 be very different about our world right now and their world, 0:20:15.160 --> 0:20:17.159 and let's say fifty years from now. But one of 0:20:17.200 --> 0:20:19.960 them is will they look back and say, Wow, I 0:20:19.960 --> 0:20:22.320 can't believe there was a time when humans were the 0:20:22.359 --> 0:20:25.240 only species on Earth that was really doing anything, and 0:20:25.680 --> 0:20:29.600 now we've got all these other you know, crows running universities, 0:20:29.680 --> 0:20:35.600 and donkeys' programming computers and whatever, gophers in the Senate 0:20:35.640 --> 0:20:36.080 and so on. 0:20:47.359 --> 0:20:51.240 So one idea of yours that I came across because 0:20:51.320 --> 0:20:53.520 Rob sent it to me and I found really interesting 0:20:54.280 --> 0:20:58.120 was from a paper you published in twenty twenty one, 0:20:58.160 --> 0:21:02.040 I think maybe in Frontiers and Neuroscience, offering a hypothesis 0:21:02.119 --> 0:21:07.800 about the adaptive function of dreams, which you call the 0:21:07.880 --> 0:21:12.439 defensive activation theory, Could you lay out what is the 0:21:12.480 --> 0:21:17.000 basic controversy about the biological function of dreams and how 0:21:17.080 --> 0:21:20.840 your proposed solution here would answer this question. 0:21:21.359 --> 0:21:24.359 Yes, so it turns out there is no controversy about 0:21:24.400 --> 0:21:28.720 the purpose of dreams because nobody knows, right, everyone, I 0:21:28.760 --> 0:21:31.840 mean in the sense of everyone's got a little hypothesis 0:21:31.880 --> 0:21:36.040 about it. But really it's complicated, and people think, well, 0:21:36.080 --> 0:21:37.720 maybe it has something to do with learning and memory. 0:21:37.800 --> 0:21:41.600 Maybe it just has to do with you know, energy restoration. 0:21:41.880 --> 0:21:45.359 Maybe it has to do with you know, obviously the 0:21:45.359 --> 0:21:48.280 Freudians thought that there was some important meaning in the 0:21:48.320 --> 0:21:50.960