WEBVTT - Inner Cosmos, with David Eagleman 0:00:02.960 --> 0:00:06.760 Welcome to Stuff to Blow Your Mind, the production of iHeartRadio. 0:00:12.800 --> 0:00:14.960 Hey you welcome to Stuff to Blow your Mind. My 0:00:15.040 --> 0:00:17.840 name is Robert Lamb and I'm Joe McCormick, and hey, 0:00:17.880 --> 0:00:20.880 welcome back. Rob. You were outsick earlier this week. It's 0:00:20.920 --> 0:00:23.600 good to have you back. It's good to be back now. 0:00:23.960 --> 0:00:26.920 Because you were outsick, we ended up putting a pause 0:00:27.200 --> 0:00:30.640 on an ongoing series we were doing on childhood amnesia. 0:00:30.800 --> 0:00:34.680 So we ended up running a vault episode on Tuesday, 0:00:34.920 --> 0:00:37.200 and I just wanted to assure people that we will 0:00:37.280 --> 0:00:39.559 be coming back to that subject. We will be resuming 0:00:39.560 --> 0:00:43.360 the series, probably for next week's core episodes, but because 0:00:43.400 --> 0:00:46.000 we already had it scheduled out this way, today's episode 0:00:46.080 --> 0:00:48.800 is going to be an interview, so in fact, we 0:00:48.840 --> 0:00:53.240 are talking to a return guest, the neuroscientist and author 0:00:53.400 --> 0:00:57.160 David Eagleman. This is actually the second time David has 0:00:57.200 --> 0:01:00.600 been a guest on the show. In September twenty twenty, Rob, 0:01:00.680 --> 0:01:03.480 you spoke to him about his book Live Wired, which 0:01:03.520 --> 0:01:08.040 is a popular science book on the subject of brain plasticity. Yeah. Absolutely, 0:01:08.080 --> 0:01:09.840 that was a fun episode. You can find it in 0:01:09.880 --> 0:01:13.160 the archives, and the book Live Wired is an absolute delight. 0:01:13.200 --> 0:01:16.320 If you're at all interested in anything you hear us 0:01:16.319 --> 0:01:19.520 discussing in this episode, pick up a copy of it. 0:01:19.280 --> 0:01:22.679 It's great. So this week we invited David back on 0:01:22.720 --> 0:01:27.200 the show because he now has a fantastic, brand new 0:01:27.240 --> 0:01:30.960 podcast on our very own network, on the iHeart Network, 0:01:31.000 --> 0:01:35.119 and it is called Inner Cosmos with David Eagelman. So 0:01:35.160 --> 0:01:37.520 before we get started with our interview, I thought we 0:01:37.560 --> 0:01:41.240 should just share a bit of background about David. This 0:01:41.319 --> 0:01:44.400 is from his website. That's right. David Eagelman is a 0:01:44.440 --> 0:01:48.480 neuroscientist at Stanford University and an internationally best selling author. 0:01:48.560 --> 0:01:52.400 He's the co founder of two venture backed companies, Neosensory 0:01:52.440 --> 0:01:55.080 and brain Check, and he also directs the Center for 0:01:55.200 --> 0:01:59.280 Science and Law in national nonprofit Institute. He's best known 0:01:59.280 --> 0:02:05.320 for his work on sensory substitution, time perception, brain plasticity, synesthesia, 0:02:05.360 --> 0:02:08.240 and neuro law. He is the writer presenter of the 0:02:08.320 --> 0:02:11.400 international PBS series The Brain with David Eagleman and the 0:02:11.440 --> 0:02:14.240 author of the companion book The Brain The Story of You. 0:02:14.680 --> 0:02:17.480 He's also the writer and presenter of The Creative Brain 0:02:17.520 --> 0:02:20.680 on Netflix. David Eagleman is the author of over one 0:02:20.760 --> 0:02:23.960 hundred and twenty academic publications, and many many books of 0:02:24.040 --> 0:02:28.440 popular science. Eagleman is a TED speaker, a Guggenheim Fellow, 0:02:28.480 --> 0:02:32.000 and serves on several boards, including the American Brain Foundation 0:02:32.120 --> 0:02:36.080 and the long Now Foundation. He's the Chief Scientific Advisor 0:02:36.200 --> 0:02:39.400 of the Mind Science Foundation and the winner of the 0:02:39.639 --> 0:02:43.639 Claude Shannon Luminary Award from Bell Labs and the McGovern 0:02:43.760 --> 0:02:48.040 Award for Excellence in Biomedical Communication. He serves as the 0:02:48.080 --> 0:02:50.880 academic editor for the Journal of Science in Law. Was 0:02:51.000 --> 0:02:53.720 named Science Educator of the Year by the Society for 0:02:53.800 --> 0:02:57.480 Neuroscience and was featured as one of the quote Brightest 0:02:57.600 --> 0:03:01.600 Idea Guys by Italy's Style magazine. He served as the 0:03:01.680 --> 0:03:06.000 scientific advisor on several TV shows, including Westworld and Perception, 0:03:06.400 --> 0:03:10.240 and it's been profiled on The Colbert Report, Nova Science Now, 0:03:10.320 --> 0:03:13.680 The New Yorker, CNN's Next List, and many other venues. 0:03:14.000 --> 0:03:17.720 He appears regularly on radio and television to discuss literature 0:03:17.720 --> 0:03:19.880 and science. And I guess now he is going to 0:03:19.960 --> 0:03:23.600 start having to add podcasts to his to the end 0:03:23.639 --> 0:03:26.600 of his bio here, So Rob, unless you have anything else, 0:03:26.639 --> 0:03:28.840 I think we should jump right into our conversation with 0:03:28.919 --> 0:03:34.760 David Eagleman. Hi David, welcome back to the show. Great 0:03:34.800 --> 0:03:36.760 thanks Rob for having me again. It's a pleasure to 0:03:36.800 --> 0:03:39.560 be here. And hello Joe, it's great to meet you. David. Now, 0:03:39.560 --> 0:03:41.920 you have a great new podcast series out in our 0:03:42.040 --> 0:03:46.160 cosmos through iHeart. How did you decide what path to 0:03:46.280 --> 0:03:50.360 take with the podcast format? You know, it's a great 0:03:50.400 --> 0:03:54.120 question I did. Truth is, I had not listened to 0:03:55.160 --> 0:03:57.800 many podcasts at all. Now I have, but when I 0:03:57.840 --> 0:03:59.960 first was putting this together with iHeart, I thought, look, 0:04:00.040 --> 0:04:02.640 I want to do a forty five minute hour long 0:04:03.160 --> 0:04:07.320 monologue every week. And that seemed like a terrific idea 0:04:07.680 --> 0:04:09.760 at first, and then my wife says she was going 0:04:09.840 --> 0:04:11.760 to kill me because it turns out that's a ton 0:04:11.840 --> 0:04:14.280 of work. It takes me about, I don't know, about 0:04:14.320 --> 0:04:18.320 twelve hours a week to get a good monologue that's 0:04:18.360 --> 0:04:23.680 almost an hour long. So that's how I decided on 0:04:23.720 --> 0:04:27.800 the format, because I thought it would be something special 0:04:28.000 --> 0:04:30.680 rather than you know, I've been on many different podcasts 0:04:30.680 --> 0:04:33.640 where we're doing interviews just like this and it's super fun. 0:04:33.720 --> 0:04:36.280 But I wanted to do something different. So that's how 0:04:36.320 --> 0:04:40.600 I accidentally stumbled into that format. So I figure we 0:04:40.600 --> 0:04:42.440 should give people a taste of the kind of things 0:04:42.480 --> 0:04:44.919 you talk about on your show. I got a chance 0:04:44.960 --> 0:04:48.040 to listen to the episode you did about memory and 0:04:48.080 --> 0:04:50.160 the perception of time, and I thought it was great, 0:04:50.160 --> 0:04:52.120 by the way, a really great way to kick off 0:04:52.160 --> 0:04:55.840 the show. So your starting premise in that episode was 0:04:55.920 --> 0:04:59.280 that many people who have been through intense or life 0:04:59.279 --> 0:05:02.320 threatening event, maybe falling off of a building or seeing 0:05:02.360 --> 0:05:07.159 a car speeding toward them, report afterwards that time seemed 0:05:07.240 --> 0:05:10.880 to have somehow slowed down for them during the pivotal 0:05:10.920 --> 0:05:13.680 few seconds, almost as if they were able to enter 0:05:13.760 --> 0:05:16.840 a state of slow motion or bullet time like from 0:05:16.839 --> 0:05:19.880 the Matrix. Can you talk a bit about your research 0:05:19.920 --> 0:05:24.080 on this subject and what you discovered about this perception. Yeah, 0:05:24.160 --> 0:05:26.719 so my research, of course, started off very personal, which 0:05:26.760 --> 0:05:28.359 is that I fell off of a house and it 0:05:28.480 --> 0:05:30.839 seemed like things took a long time, and that's what 0:05:30.920 --> 0:05:33.120 got me interested in this. Then when I got older 0:05:33.120 --> 0:05:37.320 and became a neuroscientist, eventually I realized that I was 0:05:37.440 --> 0:05:41.360 hearing this story not uncommonly from people who had been 0:05:41.400 --> 0:05:45.760 in a gunfight or some scary situation or car accident 0:05:45.880 --> 0:05:48.400 or whatever, and they felt that things took longer, and 0:05:48.440 --> 0:05:50.200 so I looked in the literature and there was not 0:05:50.440 --> 0:05:54.080 anything on this. So that's when I came drialized. I 0:05:54.080 --> 0:05:56.679 was going to have to do this myself and figure 0:05:56.720 --> 0:06:00.719 out how to run an experiment on this. So you know, briefly, 0:06:00.720 --> 0:06:03.279 what I did is I built a device that I 0:06:03.279 --> 0:06:06.440 hooked to people's wrists that flashed information them at the 0:06:06.600 --> 0:06:09.400 met a certain way so that I could tell how 0:06:10.080 --> 0:06:12.880 rapidly their brain was perceiving, and that way I could 0:06:12.920 --> 0:06:17.039 test whether they were actually seeing in slow motion or 0:06:17.480 --> 0:06:20.680 The whole thing was a trick of memory, meaning when 0:06:20.680 --> 0:06:23.599 you were in an intense situation, you wrote down more memories. 0:06:23.600 --> 0:06:25.520 So when you said, what has happened, which has happened 0:06:26.120 --> 0:06:28.640 that it seemed like it must have taken longer because 0:06:28.680 --> 0:06:31.440 you have all these memories. So what I did then 0:06:31.480 --> 0:06:33.800 has dropped people from one hundred and fifty foot tall 0:06:33.839 --> 0:06:38.000 tower in free fall backwards into a net below, and 0:06:39.120 --> 0:06:41.880 I measured their perception of time on the way down 0:06:42.000 --> 0:06:45.120 this way. And what I found after, you know, I 0:06:45.200 --> 0:06:48.120 did this on myself, but then we dropped twenty three participants. 0:06:50.080 --> 0:06:52.680 What I found is that it is in fact a 0:06:52.680 --> 0:06:55.560 trick of memory, which is to say, when everything is 0:06:55.600 --> 0:06:58.880 hitting the fan, your brain writes down much denser memory, 0:06:58.920 --> 0:07:00.760 and when you read that back out, your brain has 0:07:00.760 --> 0:07:04.599 to make an assumption about, you know, how much memory, 0:07:04.640 --> 0:07:07.200 how much footage maps onto how much time, and so 0:07:07.240 --> 0:07:10.520 it says, oh, wow, that must have been five seconds, 0:07:10.560 --> 0:07:12.280 even though it was only one second worth. But the 0:07:12.320 --> 0:07:15.760 point is people were not able to see in slow motion, which, 0:07:15.800 --> 0:07:18.240 by the way, was disappointing for me because I already 0:07:18.240 --> 0:07:20.520 had I was already talking with the military about building 0:07:20.560 --> 0:07:24.840 cockpits in a way that flashed information more rapidly at 0:07:24.840 --> 0:07:27.520 people when they in some intense situation. But it turns 0:07:27.520 --> 0:07:30.160 out none of that makes the difference. You can't actually 0:07:30.160 --> 0:07:33.600 get information in there faster, you can only remember it faster. 0:07:34.880 --> 0:07:40.800 So there's not actually any increased ability of perception. It's 0:07:40.840 --> 0:07:43.880 just a trick of the memory exactly. Now, it is 0:07:43.920 --> 0:07:46.400 the case that you know a lot, You can do 0:07:46.480 --> 0:07:49.120 a lot of things pre consciously, by which I mean 0:07:49.200 --> 0:07:53.320 your conscious awareness of something is always the slowest thing 0:07:53.320 --> 0:07:55.920 on the ladder to ever get any information. So by 0:07:55.920 --> 0:07:58.640 the time your brain puts together all the signals and says, okay, 0:07:58.680 --> 0:08:02.360 this is what just happened, you know, that's at least 0:08:02.400 --> 0:08:06.280 half a second to a second behind real time. But 0:08:06.520 --> 0:08:09.280 the point is your body can react much faster than that. 0:08:09.320 --> 0:08:11.160 Your body can get signals and say, whoa, I got 0:08:11.160 --> 0:08:13.520 to do something about this right away, and so you 0:08:13.560 --> 0:08:16.880 can react, you know, often much faster than you can 0:08:16.880 --> 0:08:19.040 be consciously aware. So you know, I don't know if 0:08:19.040 --> 0:08:21.239 you've been on a I mean, this is what happened 0:08:21.240 --> 0:08:22.760 to me recently. I was on a hike with a 0:08:22.800 --> 0:08:25.720 friend and a branch snapped back, and I was, you know, 0:08:25.880 --> 0:08:28.280 halfway into the move of ducking out of the way 0:08:28.280 --> 0:08:31.200 of the branch before I consciously realized it. Or my 0:08:31.240 --> 0:08:34.439 foot gets halfway to the break of my truck before 0:08:34.480 --> 0:08:36.640 I realize that there's a car pulling out of the 0:08:36.720 --> 0:08:39.320 driveway ahead of me. In other words, consciousness is always 0:08:39.320 --> 0:08:41.400 the last guy on the ladder to get any information, 0:08:41.880 --> 0:08:46.800 and your body can almost always react much faster. In fact, 0:08:47.000 --> 0:08:48.720 let me just say what more example of that, which 0:08:48.800 --> 0:08:51.080 is when I was younger, I used to play baseball, 0:08:51.120 --> 0:08:54.600 and my experience was always that, you know, I'd be 0:08:54.640 --> 0:08:58.559 waiting for the for the pitch, and then I would 0:08:58.600 --> 0:09:03.000 realize after it had happened that I had already hit 0:09:03.080 --> 0:09:05.720 the ball, and I would consciously realize, oh, I have 0:09:05.840 --> 0:09:08.120 just hit the ball. Now throw the bat and run. 0:09:09.520 --> 0:09:12.400 But you know, the whole thing, the ball moving from 0:09:12.400 --> 0:09:15.199 the mound to the plate, and the swing and the batting, 0:09:15.200 --> 0:09:17.920 that's all a really fast process, and it often happens 0:09:17.920 --> 0:09:23.560 preconsciously somewhat related to that. This raises questions about the 0:09:24.280 --> 0:09:28.640 different kinds of circumstances that would favor the perception of 0:09:28.760 --> 0:09:33.440 slow motion in intense situations or not. So. My example 0:09:33.520 --> 0:09:36.040 was there was one night years ago I was driving 0:09:36.120 --> 0:09:39.480 under an overpass and there was a sudden deafening sound 0:09:39.559 --> 0:09:42.640 and a shutter, And what my wife and I deduced 0:09:42.760 --> 0:09:46.040 later was that somehow like a brick had fallen from 0:09:46.040 --> 0:09:48.040 above and hit the roof of our car just above 0:09:48.080 --> 0:09:51.440 the windshield as we passed under at highway speed. And 0:09:51.559 --> 0:09:53.000 I don't know if somebody threw it or if it 0:09:53.080 --> 0:09:55.840 somehow just fell, but I not only don't recall a 0:09:55.880 --> 0:09:59.000 feeling of stretched time or a greater density of memories 0:09:59.360 --> 0:10:02.760 right before and after the impact, I felt almost a 0:10:02.840 --> 0:10:07.480 kind of retrospective amnesia, like a real paucity of detail, 0:10:07.679 --> 0:10:10.600 And it was like we were suddenly a good ways 0:10:10.640 --> 0:10:14.079 down the road and just trying to remember or figure 0:10:14.080 --> 0:10:18.120 out what had happened. Yeah, that's exactly right. It's because 0:10:18.200 --> 0:10:20.520 you didn't write down any memory. And this is generally 0:10:20.559 --> 0:10:23.760 because as you are taking a drive down the highway, 0:10:23.800 --> 0:10:27.160 your brain is writing down very little stuff going on. 0:10:27.520 --> 0:10:31.040 In fact, the interesting part is that although we think 0:10:31.080 --> 0:10:33.560 about memory is being like a video recorder or something, 0:10:33.600 --> 0:10:36.719 in fact it's nothing like that. You write down very 0:10:36.800 --> 0:10:39.000 little of what happens in your life, especially when you're 0:10:39.080 --> 0:10:41.520 driving on a road you've been down before. So what 0:10:41.640 --> 0:10:45.480 happened is there's the deafening crash and suddenly thinking what 0:10:45.600 --> 0:10:47.520 just happened? What just happened? And you've got nothing to 0:10:47.600 --> 0:10:51.679 draw on. There's just no footage there. And by the way, 0:10:51.720 --> 0:10:53.360 just as a very quick side note, I think this 0:10:53.400 --> 0:10:57.040 is what happens to people when they are high on marijuana. 0:10:57.240 --> 0:10:59.160 Is they say, oh, my gosh, how long have I 0:10:59.240 --> 0:11:01.679 been standing here? It's like I'm standing here forever. And 0:11:01.720 --> 0:11:05.520 it's because they're not writing down memories in the same way. 0:11:05.559 --> 0:11:08.280 So when their brain looks for how long have I 0:11:08.320 --> 0:11:12.520 been standing here, what it's looking for is footage in time, 0:11:12.679 --> 0:11:15.679 as in, Okay, I remember getting here, I remember this happening. 0:11:15.679 --> 0:11:17.720 Someone said this, and someone put the glass down and 0:11:17.720 --> 0:11:19.679 blah blah blah, so that I can estimate how long 0:11:19.720 --> 0:11:23.040 it's been there. But suddenly it can't grab onto any 0:11:23.120 --> 0:11:27.920 memories at all, and so suddenly people are lost in time. Anyway, 0:11:28.120 --> 0:11:33.679 So this is Joe exactly what happens when people suddenly 0:11:33.840 --> 0:11:36.199 are hit by a car that they don't see coming, 0:11:36.200 --> 0:11:39.679 like a car tee bones them or something. Or I 0:11:39.760 --> 0:11:41.520 might have mentioned in the podcast, I can't remember that, 0:11:41.720 --> 0:11:44.559 you know. I was once riding my bike and the 0:11:44.720 --> 0:11:47.560 wheel suddenly dropped in a pothole and I went flying 0:11:47.600 --> 0:11:50.720 over the handlebars. But because I didn't see that coming, 0:11:51.160 --> 0:11:53.680 I just had the sensation of suddenly, oh my god, 0:11:53.679 --> 0:11:56.200 what's just you know, here I'm lying on the asphalt, bloody, 0:11:56.200 --> 0:11:59.080 and I have no idea what just happened. And it's 0:11:59.120 --> 0:12:01.320 precisely because you're not running down any memories. So when 0:12:01.360 --> 0:12:03.680 your brain says, what does happened? Which has happened, there's 0:12:03.800 --> 0:12:07.120 nothing to draw on, as opposed to the brick sliding 0:12:07.160 --> 0:12:09.680 on ice towards the brick wall phenomenon, which is where 0:12:09.720 --> 0:12:12.640 you say, oh my gosh, I'm predicting what's going to 0:12:12.720 --> 0:12:15.040 happen and this is really gonna hurt, this is gonna 0:12:15.040 --> 0:12:17.320 be bad, And that's when you're writing down lots of stuff. 0:12:17.679 --> 0:12:19.920 So would you say you're more likely to have this 0:12:20.679 --> 0:12:26.080 memory density perception number one if you see the event 0:12:26.280 --> 0:12:29.679 coming ahead of time, there's there's expectation of it. But 0:12:29.800 --> 0:12:34.960 also if you're just generally in a novel or unusual situation, yeah, 0:12:35.000 --> 0:12:38.120 that's exactly right. Actually, so two aspects of that. One 0:12:38.280 --> 0:12:40.360 is that I just mentioned a moment ago that you 0:12:40.400 --> 0:12:43.600 write down very little memory, and that's because as an 0:12:43.679 --> 0:12:46.760 adult now, your brain has sort of figured out a 0:12:46.760 --> 0:12:49.440 pretty good model of the world, meaning you don't need 0:12:49.480 --> 0:12:52.720 to write stuff down because you've seen all the personalities before, 0:12:52.800 --> 0:12:56.840 you've seen different cities before, you've seen roads and people 0:12:56.960 --> 0:12:59.400 and events and television shows, and you sort of you 0:12:59.480 --> 0:13:02.840 sort of got it. But if something really novel happens, 0:13:02.960 --> 0:13:05.319 that's when your brain writes something down and says, whoa 0:13:05.360 --> 0:13:08.679 wait a minute, I'm surprised, And that's when stuff starts 0:13:08.679 --> 0:13:10.760 getting written down. So when you look back at the 0:13:11.000 --> 0:13:13.880 end of let's say a novel event, let's say you 0:13:13.920 --> 0:13:16.959 go on some really wild trip on the weekend to 0:13:17.040 --> 0:13:19.600 glopos islands and you see new things and so on, 0:13:19.960 --> 0:13:21.839 then it seems like forever since you were at work 0:13:21.920 --> 0:13:23.920 on Friday. But if you just go off for a 0:13:23.960 --> 0:13:26.520 normal weekend and you come back to work, you think, oh, 0:13:26.520 --> 0:13:28.400 I was just here because he didn't lay down any 0:13:28.440 --> 0:13:33.560 new memories over the weekend. So it is true that 0:13:33.720 --> 0:13:37.080 things that are novel generally seem to last longer. However, 0:13:37.280 --> 0:13:41.240 it should be noted that when things are actually life threatening, 0:13:41.720 --> 0:13:45.440 you have essentially an emergency response memory system that kicks 0:13:45.440 --> 0:13:49.480 into gear. That is a secondary track on which you 0:13:49.520 --> 0:13:52.959 write down memory. And this is underpinned by a part 0:13:52.960 --> 0:13:55.720 of the brain called the amygla and its job is 0:13:55.760 --> 0:13:59.760 to say, WHOA, everything is going really bad and scary here, 0:14:00.160 --> 0:14:02.120 and I got to write this down because that, after all, 0:14:02.240 --> 0:14:04.800 is the point of memory, is to make sure that 0:14:04.840 --> 0:14:08.320 you write down stuff that is important and specifically life 0:14:08.400 --> 0:14:12.720 threateningly important. So if the normal memory system, would that 0:14:12.720 --> 0:14:16.760 be the hippocampal memory system exactly, If that's the normal 0:14:16.800 --> 0:14:20.320 memory system, and then the amygdala tends to be recruited 0:14:20.440 --> 0:14:24.520 in intense situations. Do we know generally if there is 0:14:24.600 --> 0:14:30.320 any if there are any characteristic differences between how memories 0:14:30.320 --> 0:14:34.440 are recorded in the hipocampus versus the amygdala. Yeah, and 0:14:34.640 --> 0:14:37.040 it turns out it's a it's a it's a tragic one, 0:14:37.120 --> 0:14:43.680 which is that amygdala memories are uneasable, whereas hippocampal memories 0:14:43.720 --> 0:14:46.800 can be erased. So let me unpack this because there's 0:14:46.800 --> 0:14:49.600 two surprising parts here. So first of all, the fact 0:14:49.600 --> 0:14:53.960 that hippocampal memories can be erased is terrifying and weird 0:14:54.000 --> 0:14:57.960 and wild, which is, if I ask you to recall 0:14:58.040 --> 0:15:02.760 the name of your fifth grade teacher and then suddenly 0:15:04.000 --> 0:15:07.000 that brick drops off the highway bridge and hits you 0:15:07.040 --> 0:15:10.200 in the head. God forbid, let's say that happens. You 0:15:10.240 --> 0:15:14.400 will now have amnesia. For that one fact. You will 0:15:14.440 --> 0:15:18.240 not remember anything about your fifth grade teacher anymore about 0:15:18.280 --> 0:15:21.320 the at least the fifth grade teacher's name. Why. It's 0:15:21.360 --> 0:15:24.600 because the name of your fifth grade teacher is stored 0:15:24.720 --> 0:15:26.720 deep in the structure of your brain, and when I 0:15:26.720 --> 0:15:30.640 ask you to recall it, you're actually transferring it from 0:15:30.680 --> 0:15:36.520 that structural form into activity, you know, spikes in the brain. 0:15:36.600 --> 0:15:40.240 And that's how you're remembering the name of your teacher. Now, 0:15:40.280 --> 0:15:44.000 when you're done remembering it, it has to get reconsolidated 0:15:44.080 --> 0:15:46.440 back into its physical form, and if you get hit 0:15:46.520 --> 0:15:51.400 in the head during that moment, it's gone. It's now 0:15:51.800 --> 0:15:53.840 you know, it's been transferred from the physical to the 0:15:54.560 --> 0:15:57.800 you know, activity in spikes and if you you know, 0:15:57.840 --> 0:16:00.600 before it gets transferred back into the physical, it is 0:16:00.640 --> 0:16:04.560 susceptible to erasure, which is weird and terrifying. And by 0:16:04.560 --> 0:16:07.800 the way, this can also be done with protein synthesis inhibitors. 0:16:08.360 --> 0:16:11.160 So people do this in rats. They've been doing this 0:16:11.200 --> 0:16:13.400 for decades, where you know, you train a rat how 0:16:13.440 --> 0:16:16.400 to run different mazes, and then you put the rat 0:16:16.520 --> 0:16:19.160 on a particular maze where the rat has to remember, oh, yeah, 0:16:19.200 --> 0:16:21.720 that's this one, and then you just feed the rat 0:16:21.760 --> 0:16:26.400 a protein synthesis inhibitor, and now it cannot reconsolidate that 0:16:26.480 --> 0:16:31.080 memory into physical form. So number one is hypocampal memories 0:16:31.120 --> 0:16:34.160 can be erased. The number two point is that amiglo 0:16:34.240 --> 0:16:37.000 memories cannot be erased, which is to say, when you 0:16:37.120 --> 0:16:41.680 recruit the emergency control system to say, wow, this is 0:16:41.720 --> 0:16:46.720 really important, write this down, then those are permanent. Which 0:16:46.880 --> 0:16:49.960 the reason I say that's unfortunate is because those are 0:16:49.960 --> 0:16:51.840 the ones that people want to race. In other words. 0:16:51.840 --> 0:16:54.400 You know, let's say a rape victim or something like that. 0:16:54.400 --> 0:16:56.960 That is the one thing that she wants to forget 0:16:57.400 --> 0:17:00.960 more than anything, but cannot. Now, I was checking out 0:17:02.080 --> 0:17:03.760 the show as well, and I was listening to your 0:17:03.800 --> 0:17:05.679 I believe this is an episode from just earlier this 0:17:05.720 --> 0:17:09.560 week on the topic of animal uplift, which I don't 0:17:09.560 --> 0:17:12.119 think is a term that I was familiar with. Can 0:17:12.160 --> 0:17:14.399 you give us a brief taste, a brief overview of 0:17:14.480 --> 0:17:18.680 what animal uplift is. Yeah, it's this idea that you know, look, 0:17:18.800 --> 0:17:21.840 the human brain is made out of exactly the same 0:17:21.880 --> 0:17:24.840 stuff that a mouse brain, the dog brain, the giraffe brain. 0:17:24.920 --> 0:17:26.520 You know, it's all the same stuff. It's got the 0:17:26.560 --> 0:17:29.399 same anatomy, same general structure. We just have more of 0:17:29.440 --> 0:17:34.280 this wrinkly outer bit called the cortex. And but somehow 0:17:35.000 --> 0:17:37.720 we are you know, we've taken over the whole planet 0:17:37.760 --> 0:17:39.560 as a species. We've gotten off the planet, We've made 0:17:39.640 --> 0:17:43.480 vaccines and internet and quantum mechanics and so like, there's 0:17:43.480 --> 0:17:47.240 some real difference in what we are doing versus our 0:17:47.280 --> 0:17:52.000 neighbors in the animal kingdom, But the genetic differences, as 0:17:52.040 --> 0:17:54.040 you know, are not that much. I mean, we have 0:17:54.359 --> 0:17:57.440 enormous similarity with almost every Like if you're building a giraffe, 0:17:57.440 --> 0:17:58.960 you've got to build the heart and the lungs and 0:17:59.000 --> 0:18:01.439 the brain and then theophagus, and all that stuff is 0:18:01.760 --> 0:18:04.520 really the same stuff. And so it's just some small 0:18:04.600 --> 0:18:08.640 algorithmic difference in the DNA that's making our brain run 0:18:08.680 --> 0:18:11.240 in a more souped up way. Okay, the idea of 0:18:11.280 --> 0:18:14.800 animal uplift is if we can figure that out, and 0:18:14.840 --> 0:18:16.840 this won't happen, you know, for at least a few 0:18:16.840 --> 0:18:19.760 more decades, but if we can figure out, ah, here's 0:18:19.800 --> 0:18:22.200 the sequence of a's and seas and teas and geese 0:18:22.520 --> 0:18:27.199 that gives us this high intelligence. The question is should 0:18:27.280 --> 0:18:34.520 we give this to animals? Should we help animals become intelligent? Now, 0:18:34.640 --> 0:18:38.640 let me just mention this is an area that bioethicists 0:18:38.640 --> 0:18:42.359 and philosophers and neuroscientists have been talking about for a while, 0:18:42.640 --> 0:18:45.159 and there's plenty of debate about it. On one end 0:18:45.160 --> 0:18:47.320 of the spectrum. You have people say that's a terrible idea, 0:18:47.320 --> 0:18:49.520 we wouldn't want to give intelligence animals, and other people 0:18:49.560 --> 0:18:52.719 say it's a moral obligation in the same way that 0:18:52.920 --> 0:18:56.240 you know, if we know how to fix some viral 0:18:56.320 --> 0:18:58.800 disease or fix a broken leg or something. Of course 0:18:58.840 --> 0:19:00.920 you should do this for your dog instead of let 0:19:00.920 --> 0:19:04.840 your dog, you know, not have the medical advances that 0:19:04.880 --> 0:19:07.800 we have made. So anyway, it's a big debate. But 0:19:07.840 --> 0:19:10.440 this is the idea of animal uplift. You make an 0:19:10.480 --> 0:19:14.320 animal as intelligent as a human. And I just find 0:19:14.359 --> 0:19:18.879 this area fascinating. And you know, as I proposed in 0:19:18.920 --> 0:19:23.320 the podcast, what would the consequences of this be in 0:19:23.440 --> 0:19:26.760 terms of, you know, will World War five be fought 0:19:26.840 --> 0:19:31.240 by other animal species not just humans? And you know, 0:19:31.440 --> 0:19:35.199 and the way I sort of introduced the podcast is 0:19:35.720 --> 0:19:37.920 with this question of what don't my kids look back 0:19:37.920 --> 0:19:41.520 on or my grandkids. Obviously there's lots of things that 0:19:41.560 --> 0:19:45.080 will be very different about our world right now and 0:19:45.520 --> 0:19:47.600 their world and let's say fifty years from now, but 0:19:47.720 --> 0:19:50.800 one of them is will they look back and say, Wow, 0:19:50.840 --> 0:19:53.160 I can't believe there was a time when humans were 0:19:53.160 --> 0:19:55.640 the only species on Earth that was really doing anything 0:19:56.080 --> 0:19:59.320 and now we've got all these other you know, crows 0:19:59.480 --> 0:20:05.920 running unit versities, and donkeys programming computers and whatever, gophers 0:20:05.960 --> 0:20:20.959 in the Senate so on. So one idea of yours 0:20:21.280 --> 0:20:23.159 that I came across because Rob senate to me and 0:20:23.200 --> 0:20:28.200 I found really interesting was from a paper you published 0:20:28.240 --> 0:20:31.560 in twenty twenty one. I think maybe in Frontiers and Neuroscience, 0:20:31.560 --> 0:20:37.080 offering a hypothesis about the adaptive function of dreams, which 0:20:37.160 --> 0:20:42.160 you call the defensive activation theory. Could could you lay 0:20:42.160 --> 0:20:46.080 out what is the basic controversy about the biological function 0:20:46.160 --> 0:20:50.520 of dreams and how your proposed solution here would would 0:20:50.880 --> 0:20:53.760 answer this question. Yes, so it turns out there is 0:20:53.840 --> 0:20:58.800 no controversy about the purpose of dreams because nobody knows, right, everyone, 0:20:59.560 --> 0:21:01.960 I mean in the sense of everyone's got a little 0:21:02.040 --> 0:21:07.000 hypothesis about it, but really it's it's complicated, and people think, well, 0:21:07.040 --> 0:21:08.720 maybe it has something to do with learning and memory. 0:21:08.760 --> 0:21:12.640 Maybe it just has to do with, you know, energy restoration. 0:21:12.840 --> 0:21:16.320 Maybe it has to do with you know. Obviously, the 0:21:16.320 --> 0:21:19.199 Freudians thought that there was some important meaning in the 0:21:19.280 --> 0:21:21.880 content of dreams and so on, but no one really knows, 0:21:21.920 --> 0:21:25.359 and certainly no one has a quantitative hypothesis that can 0:21:25.400 --> 0:21:27.959 make predictions about dreams and how much dream time we have. 0:21:28.960 --> 0:21:33.760 But my student and I developed a theory that actually 0:21:33.800 --> 0:21:37.760 does make quantitative predictions across animal species about it predicts 0:21:37.800 --> 0:21:42.320 actually how much each animal species will dream. And to 0:21:42.359 --> 0:21:44.800 explain something to take one step back, which is about 0:21:45.280 --> 0:21:49.320 brain plasticity, which is this term that we use to 0:21:49.440 --> 0:21:52.560 explain that the brain is very malleable, the human brain 0:21:52.600 --> 0:21:56.760 in particular, and it's constantly reconfiguring its own circuitry and 0:21:56.800 --> 0:22:00.080 that's how it learns and remembers, and that's how it 0:22:00.160 --> 0:22:03.600 learns new skills and all that. So it turns out, 0:22:03.840 --> 0:22:06.000 this is what my last book, Live Wired was about, 0:22:06.600 --> 0:22:10.400 is the massive flexibility of the brain. It turns out 0:22:10.960 --> 0:22:14.000 is probably a lot of people already into it. If 0:22:14.040 --> 0:22:18.280 you go blind at a young age, the visual part 0:22:18.280 --> 0:22:21.320 of your brain gets taken over, and in fact, if 0:22:21.320 --> 0:22:25.280 you're born blind, that takeover is complete. The rest of 0:22:25.320 --> 0:22:28.679 the territories in your brain involved in hearing and touch 0:22:28.800 --> 0:22:32.240 and other things, these all take over what we would 0:22:32.280 --> 0:22:35.280 normally think of as the visual cortex, and it's no 0:22:35.359 --> 0:22:39.840