1 00:00:00,200 --> 00:00:02,400 Speaker 1: Hey, please take a second and leave us a review 2 00:00:02,480 --> 00:00:06,279 Speaker 1: on Apple Podcasts, Spotify, or wherever you listen to the podcast. 3 00:00:06,960 --> 00:00:10,840 Speaker 1: Thanks a lot. Hey, welcome to sign Stuff, a production 4 00:00:11,000 --> 00:00:16,160 Speaker 1: of iHeartRadio I'm More cham and today we're looking into amnesia. 5 00:00:16,239 --> 00:00:18,720 Speaker 1: How does it happen, why does it happen, and what 6 00:00:18,760 --> 00:00:21,959 Speaker 1: are some of the most dramatic cases of it in history. 7 00:00:22,520 --> 00:00:24,840 Speaker 1: It's part of a two part series on memory. So 8 00:00:24,960 --> 00:00:28,120 Speaker 1: if you haven't checked out the first episode about super memory, 9 00:00:28,440 --> 00:00:30,880 Speaker 1: go check it out. But in this episode, we're going 10 00:00:30,920 --> 00:00:33,599 Speaker 1: to explore what it means to edge and then erase 11 00:00:34,000 --> 00:00:36,960 Speaker 1: a memory. We're going to learn about a new technology 12 00:00:36,960 --> 00:00:40,680 Speaker 1: that can essentially suppress memories with the push of a button. 13 00:00:41,000 --> 00:00:43,360 Speaker 1: And we're going to look into amnesia and a condition 14 00:00:43,520 --> 00:00:49,080 Speaker 1: called severely deficient autobiographical memory, which once you hear about it, 15 00:00:49,320 --> 00:00:52,040 Speaker 1: you won't be able to forget. So tie a stringer 16 00:00:52,080 --> 00:00:55,080 Speaker 1: on your finger because we are going down a memory 17 00:00:55,120 --> 00:01:04,200 Speaker 1: hole to explore the science of amnesia. Enjoy. Hey everyone, 18 00:01:04,760 --> 00:01:09,240 Speaker 1: Today we're continuing our exploration of memory. In the previous episode, 19 00:01:09,360 --> 00:01:12,280 Speaker 1: we talked about the ability to remember a lot of things, 20 00:01:12,600 --> 00:01:16,520 Speaker 1: and now we're going to focus on we'regetting for example, 21 00:01:16,640 --> 00:01:19,080 Speaker 1: have you ever wondered what happens to a memory once 22 00:01:19,120 --> 00:01:23,040 Speaker 1: you can't remember it anymore? Or why sometimes, usually in 23 00:01:23,080 --> 00:01:26,160 Speaker 1: the worst possible moment, you can't remember an important piece 24 00:01:26,200 --> 00:01:29,320 Speaker 1: of information like your friend's name when you're introducing them 25 00:01:29,360 --> 00:01:32,600 Speaker 1: at a party. And then going further, what's actually happening 26 00:01:32,640 --> 00:01:36,640 Speaker 1: in people with amnesia or people who can't make new memories. 27 00:01:37,240 --> 00:01:40,200 Speaker 1: Have you seen the movie Memento or remember the character 28 00:01:40,240 --> 00:01:44,200 Speaker 1: of Dori and finding Nemo. Well, that actually happens in 29 00:01:44,240 --> 00:01:47,120 Speaker 1: real people. What's it like to be them and how 30 00:01:47,160 --> 00:01:49,800 Speaker 1: are they still able to function? We're going to tackle 31 00:01:49,840 --> 00:01:52,720 Speaker 1: all of these questions, starting with how memories are made 32 00:01:53,280 --> 00:01:56,440 Speaker 1: and how they're forgotten to tell us about the search 33 00:01:56,480 --> 00:01:59,720 Speaker 1: for the basic mechanism of memory. Talk to doctor Sarah 34 00:01:59,800 --> 00:02:02,760 Speaker 1: ro bin, a professor and the co director of the 35 00:02:02,800 --> 00:02:08,919 Speaker 1: Cognition Agency and Intelligence Center at Purdue University. Well, thank you, 36 00:02:08,960 --> 00:02:10,280 Speaker 1: doctor Robbins for joining us. 37 00:02:10,720 --> 00:02:13,520 Speaker 2: Yes, thank you for having me. I am Sarah Robbins. 38 00:02:13,600 --> 00:02:16,880 Speaker 2: I'm a philosopher and cognitive scientist of memory. So I 39 00:02:16,919 --> 00:02:19,040 Speaker 2: study and in particular the science of memory. 40 00:02:19,320 --> 00:02:22,600 Speaker 1: That's good that you remember all that I. 41 00:02:22,639 --> 00:02:24,640 Speaker 2: No longer have to write it down takes a little bit. 42 00:02:26,160 --> 00:02:31,040 Speaker 1: So that's an interesting mix between psychology and philosophy. Can 43 00:02:31,080 --> 00:02:33,480 Speaker 1: you tell us a little bit about that area in between. 44 00:02:33,880 --> 00:02:36,720 Speaker 2: Yeah, and it includes neuroscience very deeply as well, So 45 00:02:36,760 --> 00:02:39,200 Speaker 2: I think of it as sort of different ways of 46 00:02:39,400 --> 00:02:42,760 Speaker 2: researching and thinking about the mind and the brain. Historically 47 00:02:42,960 --> 00:02:47,160 Speaker 2: they were very intertwined, so early psychology was often called 48 00:02:47,240 --> 00:02:51,359 Speaker 2: natural philosophy, and I often see the philosopher's role as 49 00:02:51,360 --> 00:02:53,800 Speaker 2: someone who's paying attention to what every one of those 50 00:02:54,040 --> 00:02:56,760 Speaker 2: is doing and talking about the bigger questions that started 51 00:02:56,760 --> 00:02:57,959 Speaker 2: the science in the first place. 52 00:02:58,040 --> 00:03:00,400 Speaker 1: Feels a little like inceptions. It's like your researching what 53 00:03:00,520 --> 00:03:03,200 Speaker 1: we think of, how we think about, what we're learning about, 54 00:03:03,200 --> 00:03:03,600 Speaker 1: how we. 55 00:03:03,520 --> 00:03:06,560 Speaker 2: Think, yes, exactly, that's fun. 56 00:03:08,720 --> 00:03:11,440 Speaker 1: Okay. According to doctor Robins, scientists have been trying to 57 00:03:11,440 --> 00:03:14,960 Speaker 1: figure out how the brain records memories for a long time. 58 00:03:15,400 --> 00:03:18,600 Speaker 1: It's been a search for what scientists call the n gram. 59 00:03:19,520 --> 00:03:23,160 Speaker 2: So an ingram is really the neural mechanism that makes 60 00:03:23,240 --> 00:03:26,920 Speaker 2: remember impossible or by which memories are supported so that 61 00:03:27,000 --> 00:03:28,760 Speaker 2: they can later be remembered. 62 00:03:29,160 --> 00:03:33,960 Speaker 1: Okay, like how the brain stores information? Yeah, and I 63 00:03:33,960 --> 00:03:36,480 Speaker 1: guess for a long time people have been wondering like, 64 00:03:36,520 --> 00:03:37,680 Speaker 1: how does that work in the brain? 65 00:03:37,960 --> 00:03:40,440 Speaker 2: Exactly? Yeah, how is it? Where is it? Like what 66 00:03:40,680 --> 00:03:44,080 Speaker 2: could possibly be the case? So the zoologists that coined 67 00:03:44,120 --> 00:03:47,040 Speaker 2: the term, Richard Demmon, she first wrote the book where 68 00:03:47,040 --> 00:03:49,600 Speaker 2: he coined the term in nineteen oh four in German. 69 00:03:50,000 --> 00:03:52,640 Speaker 2: He's calling it like it's somewhere in the irritable substance, 70 00:03:52,840 --> 00:03:55,680 Speaker 2: which is how people thought about the kind of material 71 00:03:55,800 --> 00:03:58,320 Speaker 2: of the brain at the time, which I just disagree. 72 00:03:59,080 --> 00:04:02,400 Speaker 1: That's well, unfortunately I have a lot of irritable substance 73 00:04:02,480 --> 00:04:06,080 Speaker 1: in my brain we all, especially in the mornings. 74 00:04:06,640 --> 00:04:08,840 Speaker 3: Yes, it's especially irritable. 75 00:04:08,880 --> 00:04:09,960 Speaker 2: Then, absolutely there. 76 00:04:11,680 --> 00:04:14,640 Speaker 1: So we've been looking for how the brain stores memories 77 00:04:14,800 --> 00:04:18,400 Speaker 1: for over a hundred years now. You might think, why 78 00:04:18,440 --> 00:04:20,880 Speaker 1: has it taken so long? Can we just open up 79 00:04:20,920 --> 00:04:24,640 Speaker 1: a brain and see what's going on? Well, it's not 80 00:04:24,800 --> 00:04:25,359 Speaker 1: that easy. 81 00:04:27,040 --> 00:04:29,159 Speaker 2: One is a challenge that is, like it's hard to 82 00:04:29,200 --> 00:04:32,720 Speaker 2: know what's in your memory outside of actually like being 83 00:04:32,720 --> 00:04:34,520 Speaker 2: able to look in there. Right, So if you can't 84 00:04:34,560 --> 00:04:36,760 Speaker 2: remember something, it's kind of a question of like is 85 00:04:36,760 --> 00:04:38,400 Speaker 2: it in there but you can't get it out? 86 00:04:38,920 --> 00:04:40,159 Speaker 3: Or is it not in there? 87 00:04:40,400 --> 00:04:43,200 Speaker 2: But like how do you tell Like how do we 88 00:04:43,279 --> 00:04:45,680 Speaker 2: know what's really in there until we get it out. 89 00:04:46,000 --> 00:04:49,239 Speaker 1: Yeah, it just made me realize what a difficult problem 90 00:04:49,279 --> 00:04:52,479 Speaker 1: this is because I think we're all familiar with memories. 91 00:04:52,520 --> 00:04:55,800 Speaker 1: We all have memories, we all remember things, but like, 92 00:04:55,839 --> 00:04:57,800 Speaker 1: how do you do an experiment on to figure out 93 00:04:57,839 --> 00:04:59,960 Speaker 1: how it works inside a brain as it's happening. 94 00:05:00,200 --> 00:05:03,080 Speaker 2: Absolutely, And I think that's why some of these memories, 95 00:05:03,560 --> 00:05:05,360 Speaker 2: like when they come to you kind of out of nowhere, 96 00:05:05,400 --> 00:05:07,640 Speaker 2: are so delightful. Like when you hear a song you 97 00:05:07,680 --> 00:05:10,240 Speaker 2: haven't heard for twenty years and you remember all the word. 98 00:05:10,320 --> 00:05:12,080 Speaker 2: You can have this kind of like oh my gosh 99 00:05:12,240 --> 00:05:14,560 Speaker 2: sort of reaction to that. Oh it was in there, 100 00:05:14,560 --> 00:05:18,320 Speaker 2: and you sort of had no idea that it was there. Right, 101 00:05:18,360 --> 00:05:20,080 Speaker 2: It's not like I can like, oh, what other fun 102 00:05:20,120 --> 00:05:22,840 Speaker 2: stuff isn't there? Like I'm not going to know until 103 00:05:22,880 --> 00:05:24,120 Speaker 2: that happens again. 104 00:05:24,440 --> 00:05:28,039 Speaker 1: Yeah, that is so tricky. In other words, it's hard 105 00:05:28,040 --> 00:05:31,239 Speaker 1: to study how the brain stores memories because you can't 106 00:05:31,279 --> 00:05:34,520 Speaker 1: just poke around someone's brain while they're making a memory 107 00:05:34,800 --> 00:05:37,799 Speaker 1: or trying to remember something. But all of that changed 108 00:05:37,880 --> 00:05:41,159 Speaker 1: about ten to fifteen years ago with the development of 109 00:05:41,200 --> 00:05:46,599 Speaker 1: a technology called optogenetics. I'll explain what that technology is 110 00:05:46,680 --> 00:05:50,040 Speaker 1: a little later. But first, here's what we've learned after 111 00:05:50,080 --> 00:05:54,360 Speaker 1: a century of science, but how the brain records a memory. 112 00:05:55,120 --> 00:05:58,480 Speaker 1: So you wrote in a paper that we found the nngram. 113 00:05:58,600 --> 00:05:59,920 Speaker 1: What does that mean that we've found it? 114 00:06:00,000 --> 00:06:02,279 Speaker 2: I think it's now the case that it's possible to 115 00:06:02,480 --> 00:06:06,719 Speaker 2: identify the set of neurons that are active in storing memories. 116 00:06:06,960 --> 00:06:09,960 Speaker 1: We'll step me through this. So I am walking around 117 00:06:10,240 --> 00:06:12,960 Speaker 1: and something incredible happens. The unicorn jumps out of the 118 00:06:13,160 --> 00:06:16,320 Speaker 1: manhole and then grows wings and flies off into the sky. 119 00:06:16,800 --> 00:06:19,960 Speaker 1: I'm definitely going to remember that. What's happening in my brain? 120 00:06:20,920 --> 00:06:23,120 Speaker 3: Yes, So what's happening? 121 00:06:23,200 --> 00:06:25,760 Speaker 1: I mean, I'll give you a second to process that image. 122 00:06:25,760 --> 00:06:26,080 Speaker 1: I just. 123 00:06:27,680 --> 00:06:30,200 Speaker 2: Well, the unicorn area of processing and the manual air 124 00:06:30,279 --> 00:06:32,800 Speaker 2: and not there yet. So there's a set of cells 125 00:06:32,880 --> 00:06:36,599 Speaker 2: in the hippocampus and surrounding structures that are kind of 126 00:06:36,640 --> 00:06:39,960 Speaker 2: responsible for being the ones that react to that experience 127 00:06:40,000 --> 00:06:42,920 Speaker 2: and kind of encode information about that experience in somewhay, 128 00:06:43,120 --> 00:06:44,840 Speaker 2: there's a whole lot of neurons in that area, and 129 00:06:44,880 --> 00:06:46,440 Speaker 2: a subset of them are going to say, like we've 130 00:06:46,440 --> 00:06:48,760 Speaker 2: got this one here. You know, we're going to take 131 00:06:48,800 --> 00:06:51,160 Speaker 2: hold of that and something about the way that they 132 00:06:51,200 --> 00:06:54,680 Speaker 2: activate together capture something about that events. 133 00:06:54,839 --> 00:06:57,320 Speaker 1: All right, So I see the unicorn. There are some 134 00:06:57,520 --> 00:07:01,159 Speaker 1: cells among the many, many, many many in my hippocampus 135 00:07:01,160 --> 00:07:03,200 Speaker 1: that are like I'm ready, I'm ready to remember things. 136 00:07:03,400 --> 00:07:06,760 Speaker 1: And then I see the unicorn. And it's what happens 137 00:07:06,800 --> 00:07:09,880 Speaker 1: to those cells. They sort of like change, they something 138 00:07:10,520 --> 00:07:11,560 Speaker 1: what happens. 139 00:07:11,360 --> 00:07:15,040 Speaker 2: So they like become better connected to each other. I'm 140 00:07:15,040 --> 00:07:16,960 Speaker 2: not sure how far I can go with this metaphor, 141 00:07:17,040 --> 00:07:20,280 Speaker 2: but this is just like a sea of willing people 142 00:07:20,320 --> 00:07:22,600 Speaker 2: to play on the team for whatever sport you have. 143 00:07:22,960 --> 00:07:25,240 Speaker 2: Each time there's an experience, you like send a team 144 00:07:25,280 --> 00:07:28,480 Speaker 2: out and like they play together and they kind of 145 00:07:28,480 --> 00:07:30,880 Speaker 2: form a bond that makes them a team that is 146 00:07:30,920 --> 00:07:31,960 Speaker 2: about the experience. 147 00:07:32,040 --> 00:07:34,840 Speaker 1: They lock hands, they're like, we got this memory. We're 148 00:07:34,880 --> 00:07:37,480 Speaker 1: going to remember that unicorn. We are the unicorn in 149 00:07:37,520 --> 00:07:37,840 Speaker 1: your head. 150 00:07:38,000 --> 00:07:39,920 Speaker 2: We got it exactly. And then they kind of go 151 00:07:40,000 --> 00:07:41,640 Speaker 2: back into the sea and you bring out a new 152 00:07:41,680 --> 00:07:44,480 Speaker 2: set to play the next game and they do their connecting. 153 00:07:45,600 --> 00:07:48,480 Speaker 1: So that, in a nutshell, is what we know about 154 00:07:48,480 --> 00:07:51,440 Speaker 1: how the brain records a memory, or at least a 155 00:07:51,480 --> 00:07:54,440 Speaker 1: memory of an event. There's an area in your brain 156 00:07:54,640 --> 00:07:57,720 Speaker 1: called the hippocampus, which sort of looks like two small 157 00:07:57,840 --> 00:08:01,920 Speaker 1: jalapeno peppers buried deep inside your with millions of neurons 158 00:08:01,960 --> 00:08:05,119 Speaker 1: in it, all connected to each other. And when something 159 00:08:05,200 --> 00:08:08,720 Speaker 1: memorable happens, some of those neurons, maybe a few hundred 160 00:08:08,800 --> 00:08:11,600 Speaker 1: of them, kind of get activated and they step up 161 00:08:11,840 --> 00:08:15,120 Speaker 1: to remember the event, and they do it by strengthening 162 00:08:15,160 --> 00:08:20,000 Speaker 1: the connections between them, which are called synopsis. The synopsis 163 00:08:20,040 --> 00:08:23,160 Speaker 1: get stronger, which means that network of cells is more 164 00:08:23,320 --> 00:08:27,000 Speaker 1: likely to activate together. As doctor Robin said, a good 165 00:08:27,040 --> 00:08:30,160 Speaker 1: analogy is to imagine a stadium full of people, and 166 00:08:30,200 --> 00:08:33,000 Speaker 1: when a new memory has to be recorded, as subset 167 00:08:33,080 --> 00:08:36,240 Speaker 1: of those people step up and they lock hands and 168 00:08:36,280 --> 00:08:41,000 Speaker 1: somehow that stores the memory. Okay, two quick things about that. First, 169 00:08:41,160 --> 00:08:44,439 Speaker 1: a neuron can be a part of multiple memories, not 170 00:08:44,600 --> 00:08:44,960 Speaker 1: just one. 171 00:08:46,640 --> 00:08:48,960 Speaker 2: And it's possible over time that some of these cells 172 00:08:49,000 --> 00:08:50,800 Speaker 2: will play on different teams. 173 00:08:51,640 --> 00:08:54,480 Speaker 1: Right, It's like I'm the unicorn cell with these group 174 00:08:54,559 --> 00:08:57,120 Speaker 1: of cells, but with these group of cells, I am 175 00:08:57,280 --> 00:09:02,000 Speaker 1: the I am the purple crocodile, or is another. 176 00:09:01,760 --> 00:09:04,800 Speaker 3: Day exactly exactly And. 177 00:09:04,720 --> 00:09:07,880 Speaker 1: Two that's what we see happening in the hippocampus during 178 00:09:07,880 --> 00:09:10,520 Speaker 1: an event, but we don't actually know if that's where 179 00:09:10,520 --> 00:09:13,880 Speaker 1: the memory is stored. Is a hippocampus kind of like 180 00:09:13,920 --> 00:09:16,199 Speaker 1: the hard drive of the brain, or is it more 181 00:09:16,280 --> 00:09:19,080 Speaker 1: like the relay of the brain, or like what's happening? 182 00:09:19,800 --> 00:09:21,560 Speaker 3: I think that's a question of live debate. 183 00:09:21,760 --> 00:09:25,240 Speaker 2: So it could be that it's individually storing each memory 184 00:09:25,280 --> 00:09:28,120 Speaker 2: and holding them and they stay in the hippocampus long term. 185 00:09:28,320 --> 00:09:30,400 Speaker 2: That is a view that some people hold. It could 186 00:09:30,400 --> 00:09:32,200 Speaker 2: be that it is just kind of a relay, like 187 00:09:32,280 --> 00:09:35,440 Speaker 2: it's the place that keeps tags or recipes, right, but 188 00:09:35,520 --> 00:09:38,000 Speaker 2: all the content is distributed elsewhere. 189 00:09:38,920 --> 00:09:41,559 Speaker 1: Okay, that's what we know about how memories are formed. 190 00:09:42,000 --> 00:09:45,679 Speaker 1: Now the question is how do memories get forgotten and 191 00:09:45,840 --> 00:09:49,000 Speaker 1: what's happening in people with amnesia. We'll get to that, 192 00:09:49,400 --> 00:09:51,640 Speaker 1: but first I wanted to dig deeper into how we 193 00:09:51,760 --> 00:09:55,040 Speaker 1: know this is how memories are formed, because the answer 194 00:09:55,160 --> 00:10:01,439 Speaker 1: is pretty cool. It involves a fairly recent technology called optogenetics, 195 00:10:01,640 --> 00:10:05,640 Speaker 1: which basically lets you control memories with the push of 196 00:10:05,720 --> 00:10:06,319 Speaker 1: a button. 197 00:10:07,880 --> 00:10:10,559 Speaker 2: And so that's changed in the last few decades thanks 198 00:10:10,600 --> 00:10:14,320 Speaker 2: to a range of sort of technological tool innovations. A 199 00:10:14,360 --> 00:10:18,240 Speaker 2: central one of which is something called optogenetics, which is 200 00:10:18,320 --> 00:10:24,240 Speaker 2: a technique for making neurons responsive to light. So, colloquially speaking, 201 00:10:24,559 --> 00:10:27,040 Speaker 2: you're putting a light switch on neurons. You make it 202 00:10:27,080 --> 00:10:29,320 Speaker 2: so that you can turn them on and off in 203 00:10:29,360 --> 00:10:34,920 Speaker 2: a living, behaving organism. So you can make certain neurons 204 00:10:35,000 --> 00:10:37,960 Speaker 2: fire action potentials, make them active, or you can inhibit 205 00:10:37,960 --> 00:10:43,560 Speaker 2: them keep them from firing action potentials. Wow, it's incredible. 206 00:10:44,440 --> 00:10:46,800 Speaker 1: Okay, we can probably spend the whole episode just on 207 00:10:46,840 --> 00:10:51,959 Speaker 1: this technology because it's pretty wild. Basically, scientists can now 208 00:10:52,120 --> 00:10:55,080 Speaker 1: hack into the DNA of neurons and make it so 209 00:10:55,120 --> 00:10:58,640 Speaker 1: that when the neurons are activated, they produce a protein 210 00:10:58,679 --> 00:11:02,520 Speaker 1: that makes the neurons sensitive to light, and scientists can 211 00:11:02,600 --> 00:11:05,360 Speaker 1: time when this happens so that it only happens to 212 00:11:05,480 --> 00:11:10,720 Speaker 1: neurons in a specific brain area and during a specific event. So, 213 00:11:10,800 --> 00:11:13,120 Speaker 1: for example, you could make it so that everything you 214 00:11:13,200 --> 00:11:16,800 Speaker 1: experience in the next hour or so gets etched into 215 00:11:16,840 --> 00:11:20,320 Speaker 1: neurons in your hippocampus, and any neurons that get recruited 216 00:11:20,360 --> 00:11:25,199 Speaker 1: to remember those memories become light sensitive to you. Nothing 217 00:11:25,200 --> 00:11:27,760 Speaker 1: would change, You would simply have that memory as you 218 00:11:27,840 --> 00:11:30,760 Speaker 1: normally would. But now if I take a tiny fiber 219 00:11:30,760 --> 00:11:33,840 Speaker 1: optic flashlight and I thread it into your brain and 220 00:11:33,920 --> 00:11:37,120 Speaker 1: turn the light on. Those neurons that recorded that memory 221 00:11:37,360 --> 00:11:42,520 Speaker 1: would turn on and you would suddenly and involuntarily get 222 00:11:42,559 --> 00:11:45,680 Speaker 1: a flashback of what happened. And if you press the 223 00:11:45,679 --> 00:11:49,520 Speaker 1: button again, those neurons would activate again and you would 224 00:11:49,559 --> 00:11:53,959 Speaker 1: get a flashback again. Essentially, you could relive that memory 225 00:11:54,080 --> 00:11:57,640 Speaker 1: by just pressing that bun and scientists can also do 226 00:11:57,760 --> 00:12:01,320 Speaker 1: the reverse, which is to make to produced proteins that 227 00:12:01,400 --> 00:12:05,040 Speaker 1: make them stop working when they sense light. So you 228 00:12:05,080 --> 00:12:08,040 Speaker 1: could do the opposite, which is to make a memory 229 00:12:08,280 --> 00:12:11,520 Speaker 1: and then suppress that memory by simply turning on the light. 230 00:12:12,240 --> 00:12:14,800 Speaker 1: The scientists could make you forget something you just saw 231 00:12:15,040 --> 00:12:19,000 Speaker 1: by simply pushing on a button. It's pretty wild stuff, 232 00:12:19,320 --> 00:12:22,480 Speaker 1: and it involves things like immediate early genes and special 233 00:12:22,559 --> 00:12:25,880 Speaker 1: antibiotics to suppress these genes, which we don't have time 234 00:12:25,920 --> 00:12:28,840 Speaker 1: to cover this, but this is essentially what has unlocked 235 00:12:28,840 --> 00:12:31,920 Speaker 1: a lot of the memory research in the last ten years. 236 00:12:34,640 --> 00:12:36,880 Speaker 1: I didn't know we were that advance in this kind 237 00:12:36,920 --> 00:12:39,199 Speaker 1: of manipulation of neural activity. 238 00:12:39,520 --> 00:12:42,880 Speaker 2: It's absolutely incredible to see what sorts of work could 239 00:12:42,920 --> 00:12:44,840 Speaker 2: be done in this way. And there are people that 240 00:12:44,880 --> 00:12:47,080 Speaker 2: have been using these similar techniques to sort of figure 241 00:12:47,080 --> 00:12:48,840 Speaker 2: out which neurons are trying to be a part of 242 00:12:48,880 --> 00:12:50,800 Speaker 2: the memory, and you can kind of follow them around 243 00:12:50,880 --> 00:12:53,199 Speaker 2: and again find the ngram in this way and then 244 00:12:53,400 --> 00:12:54,719 Speaker 2: activate and manipulate it. 245 00:12:55,840 --> 00:12:59,240 Speaker 1: Okay, that is how we make memories. When we come back, 246 00:12:59,320 --> 00:13:02,000 Speaker 1: we'll get to the ession of how we forget memories 247 00:13:02,360 --> 00:13:04,640 Speaker 1: and what's happening in the brain of people with amnesia 248 00:13:05,120 --> 00:13:10,280 Speaker 1: and something called severely deficient autobiographical memory. We'll get to 249 00:13:10,320 --> 00:13:13,560 Speaker 1: all of that, So don't blink out. Lock in this memory. 250 00:13:14,160 --> 00:13:29,200 Speaker 1: We'll be right back. Hey, welcome back. We're talking about 251 00:13:29,240 --> 00:13:32,360 Speaker 1: the size of amnesia, and so far we've talked about 252 00:13:32,360 --> 00:13:35,280 Speaker 1: how the brain makes memories. Now we're going to talk 253 00:13:35,280 --> 00:13:38,960 Speaker 1: about how the brain forgets memories. As it turns out, 254 00:13:39,040 --> 00:13:42,160 Speaker 1: there's a big mystery about how we actually forget that 255 00:13:42,320 --> 00:13:45,040 Speaker 1: scientists haven't figured it out. To take us through this, 256 00:13:45,280 --> 00:13:49,559 Speaker 1: here's doctor DANIELA. Palombo, Professor of psychology at the University 257 00:13:49,600 --> 00:13:53,840 Speaker 1: of British Columbia. Well, thank you doctor Palombo for joining 258 00:13:53,920 --> 00:13:54,319 Speaker 1: us again. 259 00:13:54,600 --> 00:13:55,559 Speaker 3: Yeah, my pleasure. 260 00:13:55,800 --> 00:13:58,440 Speaker 1: So I thought it'd be interesting to talk about the 261 00:13:58,480 --> 00:14:00,840 Speaker 1: absence of memories what are some of the different ways 262 00:14:00,880 --> 00:14:02,440 Speaker 1: that we can lose memories. 263 00:14:02,720 --> 00:14:05,360 Speaker 4: Yeah, that's a really good question. So I guess I'll 264 00:14:05,400 --> 00:14:08,280 Speaker 4: start by saying that any of us can lose our memories. 265 00:14:09,280 --> 00:14:12,520 Speaker 1: Okay. According to doctor Palombo, there are several kinds of 266 00:14:12,679 --> 00:14:16,440 Speaker 1: memory loss. First is the casual kind that we all 267 00:14:16,520 --> 00:14:19,440 Speaker 1: experience every day in our memory slips. 268 00:14:20,560 --> 00:14:23,240 Speaker 4: So in our day to day lives, you know, whether 269 00:14:23,280 --> 00:14:26,680 Speaker 4: we're young or older, we see that we experience memory 270 00:14:26,680 --> 00:14:29,840 Speaker 4: slips where we think we should have access to something 271 00:14:29,880 --> 00:14:32,480 Speaker 4: we don't, and that happens to all of us all 272 00:14:32,520 --> 00:14:34,960 Speaker 4: the time. I'm sure you've experienced this many times. And 273 00:14:35,080 --> 00:14:37,840 Speaker 4: so I have a very vivid memory of a time 274 00:14:37,880 --> 00:14:39,960 Speaker 4: where I was introducing a bunch of people at a 275 00:14:39,960 --> 00:14:42,920 Speaker 4: party and I had a coworker over who I knew 276 00:14:43,040 --> 00:14:47,320 Speaker 4: very well, and I just temporarily forgot my coworkers seeing 277 00:14:48,000 --> 00:14:50,640 Speaker 4: and he was staring at me in shock and disbelief, 278 00:14:50,760 --> 00:14:56,080 Speaker 4: and I was also very very surprised and embarrassed, and 279 00:14:56,120 --> 00:14:58,080 Speaker 4: then you know, a few minutes later, it popped back 280 00:14:58,120 --> 00:15:01,960 Speaker 4: into my mind. So that type of loss refers to 281 00:15:02,600 --> 00:15:06,920 Speaker 4: temporary and access to information, and it certainly happens as 282 00:15:06,920 --> 00:15:09,640 Speaker 4: we get older and This is all part of healthy aging. 283 00:15:09,960 --> 00:15:11,760 Speaker 1: I see, are you still friends with this person or 284 00:15:12,360 --> 00:15:14,560 Speaker 1: that relationship? 285 00:15:14,640 --> 00:15:16,200 Speaker 3: They did forgive me thanks leady. 286 00:15:16,640 --> 00:15:19,600 Speaker 1: They forgot about it. Well, this makes the question about 287 00:15:19,720 --> 00:15:22,320 Speaker 1: in the situations where we can get at a memory, 288 00:15:22,320 --> 00:15:25,880 Speaker 1: but later on we remember, like what happens there? Like 289 00:15:25,920 --> 00:15:27,840 Speaker 1: where does that memory go that I can't excess it? 290 00:15:28,240 --> 00:15:31,280 Speaker 4: So sometimes it's simply due to interference. So we're in 291 00:15:31,320 --> 00:15:34,320 Speaker 4: a situation where we're just not searching for the memory 292 00:15:34,360 --> 00:15:36,840 Speaker 4: in the right way, and then later on something in 293 00:15:36,880 --> 00:15:40,880 Speaker 4: our environment might trigger that memory. Sometimes it's because we're 294 00:15:41,040 --> 00:15:44,160 Speaker 4: feeling very stressed. It can be feeling a bit anxious 295 00:15:44,160 --> 00:15:44,720 Speaker 4: in the moment. 296 00:15:45,640 --> 00:15:49,200 Speaker 1: So that's a memory slip where we have temporary trouble 297 00:15:49,440 --> 00:15:53,800 Speaker 1: accessing a memory. There's also just forgetting something over time. 298 00:15:55,560 --> 00:15:59,160 Speaker 1: Is there just plain forgetting? Like is it possible for 299 00:15:59,520 --> 00:16:01,880 Speaker 1: me to have stored a memory in my brain cells 300 00:16:02,000 --> 00:16:04,480 Speaker 1: but over time they just sort of, you know, like 301 00:16:04,520 --> 00:16:07,080 Speaker 1: the hard drive gets corrupted or erased. 302 00:16:07,320 --> 00:16:11,000 Speaker 4: Yes, so forgetting is a pretty loaded term. But you're 303 00:16:11,120 --> 00:16:13,640 Speaker 4: right that we can form memories and then over time 304 00:16:13,760 --> 00:16:18,440 Speaker 4: those memories become difficult to access. And one hypothesis is 305 00:16:18,440 --> 00:16:22,240 Speaker 4: that that's because there's lots of interfering new information that 306 00:16:22,280 --> 00:16:25,440 Speaker 4: we're encoding and needing to retrieve, and so the more 307 00:16:25,480 --> 00:16:28,840 Speaker 4: memories we form over our lifetime, the more competition there is. 308 00:16:29,160 --> 00:16:29,360 Speaker 2: Right. 309 00:16:29,960 --> 00:16:33,400 Speaker 4: Another hypothesis is that just as our lives change and 310 00:16:33,440 --> 00:16:36,280 Speaker 4: we grow, et cetera, the retrieval cues that we use 311 00:16:36,360 --> 00:16:40,120 Speaker 4: to access those really old memories are not as close 312 00:16:40,160 --> 00:16:44,040 Speaker 4: to our fingertips anymore. So you've moved on from your 313 00:16:44,120 --> 00:16:48,000 Speaker 4: childhood home, et cetera, so it's harder to access those memories. 314 00:16:48,600 --> 00:16:52,040 Speaker 1: I see, you sort of lose the path to those memories. 315 00:16:52,200 --> 00:16:53,120 Speaker 3: Yeah, exactly. 316 00:16:54,880 --> 00:16:57,120 Speaker 1: So some things you can lose a memory because you 317 00:16:57,160 --> 00:16:59,560 Speaker 1: lose a connection to it. It's still in your brain, 318 00:16:59,680 --> 00:17:02,720 Speaker 1: but because it's simply not relevant to you, you never 319 00:17:02,760 --> 00:17:06,080 Speaker 1: find your way to it again. Now, memory slips and 320 00:17:06,160 --> 00:17:10,600 Speaker 1: losing connections to your memories over time are both natural processes. 321 00:17:10,880 --> 00:17:13,240 Speaker 1: They happen to anyone. But now we get to the 322 00:17:13,320 --> 00:17:17,399 Speaker 1: kind of memory loss that's due to something specific. 323 00:17:17,920 --> 00:17:21,119 Speaker 4: And that can happen in the context of disease. So 324 00:17:21,200 --> 00:17:25,440 Speaker 4: you've probably heard about different forms of dementia, like Alzheimer's disease, 325 00:17:25,880 --> 00:17:30,800 Speaker 4: where you can see quite profound, albeit progressive memory loss. 326 00:17:31,560 --> 00:17:35,040 Speaker 4: And then there's another condition called amnesia. Then this is 327 00:17:35,119 --> 00:17:38,240 Speaker 4: often due to a brain injury of virus. It can 328 00:17:38,320 --> 00:17:41,720 Speaker 4: happen in the context of a stroke, and here. 329 00:17:41,560 --> 00:17:44,600 Speaker 1: We get to amnesia. Now, the thing about amnesia is 330 00:17:44,600 --> 00:17:48,040 Speaker 1: that it typically happens because of an event. It could 331 00:17:48,040 --> 00:17:51,200 Speaker 1: be a stroke or a traumatic brain injury, or sometimes 332 00:17:51,240 --> 00:17:54,960 Speaker 1: it's a virus that infects your brain. Whatever the cause, 333 00:17:55,200 --> 00:17:58,120 Speaker 1: most cases of amnesia have something in common. 334 00:17:59,400 --> 00:18:02,760 Speaker 4: Yeah, lots of different causes to amnesia, but one thing 335 00:18:02,880 --> 00:18:06,040 Speaker 4: that they have in common is that they affect really 336 00:18:06,160 --> 00:18:08,600 Speaker 4: similar networks in the brain. And there's one area of 337 00:18:08,600 --> 00:18:12,320 Speaker 4: the brain in particular that's quite vulnerable to whether it's 338 00:18:12,359 --> 00:18:15,920 Speaker 4: a virus or certain kinds of stroke, certain kinds of 339 00:18:15,960 --> 00:18:19,280 Speaker 4: traumatic brain injury, et cetera, epilepsy, and that's a region 340 00:18:19,280 --> 00:18:22,199 Speaker 4: of the brain called the hippocampus. And so when that 341 00:18:22,359 --> 00:18:25,200 Speaker 4: area of the brain is affected, regardless of the cause, 342 00:18:25,640 --> 00:18:28,080 Speaker 4: you see a profound loss of memory. 343 00:18:30,840 --> 00:18:33,560 Speaker 1: Yes, the thing most cases when anesia have in common 344 00:18:33,800 --> 00:18:37,320 Speaker 1: is that they affect the hippok campus. Now, once the 345 00:18:37,400 --> 00:18:41,720 Speaker 1: hippocampus's damaged, two basic things can happen. One, you can 346 00:18:41,760 --> 00:18:45,199 Speaker 1: lose past memories that you had before the event the 347 00:18:45,320 --> 00:18:49,800 Speaker 1: damage to hippocampus. For example, childhood memories, the names of people, 348 00:18:50,240 --> 00:18:53,760 Speaker 1: those could all be gone. And two, you can also 349 00:18:53,840 --> 00:18:57,560 Speaker 1: lose the ability to make new memories after the event, 350 00:18:58,200 --> 00:19:01,240 Speaker 1: and both of these kinds of anesia have different names. 351 00:19:01,640 --> 00:19:06,240 Speaker 1: Using memories you had before the event is called retrograde anesia, 352 00:19:06,400 --> 00:19:09,399 Speaker 1: and losing the ability to make new memories is called 353 00:19:09,800 --> 00:19:14,200 Speaker 1: terograde anesia. You're probably familiar with these kinds of anesia 354 00:19:14,320 --> 00:19:17,639 Speaker 1: just from popular culture. In a soap opera, when someone 355 00:19:17,680 --> 00:19:20,160 Speaker 1: has an accident and they can't remember who they are 356 00:19:20,280 --> 00:19:24,399 Speaker 1: or anything about their history, that's retrograde anesia. And in 357 00:19:24,440 --> 00:19:28,040 Speaker 1: the movie Memento or with Dory and Finding Nemo, where 358 00:19:28,040 --> 00:19:30,880 Speaker 1: the character seems to forget everything that happens to them 359 00:19:31,040 --> 00:19:36,320 Speaker 1: and everything seems new to them, that's anterograde anesia. Now, 360 00:19:36,359 --> 00:19:38,760 Speaker 1: there are a couple of fascinating things to talk about 361 00:19:38,840 --> 00:19:41,520 Speaker 1: in each of these kinds of anesia. We'll start with 362 00:19:41,640 --> 00:19:46,359 Speaker 1: retrograde anesia, where you lose your past memories. The fascinating 363 00:19:46,400 --> 00:19:49,840 Speaker 1: thing is that scientists aren't really sure if you actually 364 00:19:49,920 --> 00:19:51,480 Speaker 1: lose your memories. 365 00:19:52,800 --> 00:19:54,600 Speaker 4: Yeah, so this is a question that a lot of 366 00:19:54,640 --> 00:19:57,560 Speaker 4: memory scientists have what does it actually mean to have 367 00:19:57,840 --> 00:20:01,600 Speaker 4: loss of memory? And so the one hypothesis is that 368 00:20:02,000 --> 00:20:04,600 Speaker 4: the places in the brain where the memories are stored 369 00:20:04,800 --> 00:20:08,359 Speaker 4: are damaged and so those memories are gone. And another 370 00:20:08,440 --> 00:20:11,400 Speaker 4: hypothesis that you're getting at is that the memories are 371 00:20:11,480 --> 00:20:15,119 Speaker 4: still stored somewhere in the brain, but via damage to 372 00:20:15,119 --> 00:20:17,919 Speaker 4: the hippocampus, those memories cannot be accessed. 373 00:20:18,359 --> 00:20:19,920 Speaker 1: Wow, So the memories are still. 374 00:20:19,760 --> 00:20:23,480 Speaker 4: In there potentially potentially Yeah, Because remember last time we spoke, 375 00:20:23,520 --> 00:20:26,320 Speaker 4: I sort of described this idea that the hippocampus in 376 00:20:26,359 --> 00:20:30,200 Speaker 4: particular is a pointer to different parts of the brain 377 00:20:30,280 --> 00:20:32,840 Speaker 4: where the memories are kind of stored within a network, 378 00:20:33,680 --> 00:20:36,480 Speaker 4: and so when that index pointer is not working anymore, 379 00:20:36,600 --> 00:20:39,920 Speaker 4: those memories are not accessible. Now we don't know for sure, 380 00:20:40,000 --> 00:20:41,960 Speaker 4: because there's a lot about memory and the brain that 381 00:20:42,000 --> 00:20:44,920 Speaker 4: we don't yet understand, but that is one idea that's 382 00:20:44,920 --> 00:20:45,760 Speaker 4: been put out there. 383 00:20:47,040 --> 00:20:50,480 Speaker 1: Yes, if you have retrograde amnesia, your memories might still 384 00:20:50,520 --> 00:20:53,600 Speaker 1: be intact in your brain and what you lose is 385 00:20:53,680 --> 00:20:57,560 Speaker 1: actually the ability to access them, although that doesn't mean 386 00:20:57,600 --> 00:20:59,000 Speaker 1: you could get them back. 387 00:21:00,480 --> 00:21:03,919 Speaker 4: Some cases, like in soap operas for example, sometimes it 388 00:21:03,920 --> 00:21:06,640 Speaker 4: does involve an injury to the head, and so you'll 389 00:21:06,640 --> 00:21:10,200 Speaker 4: see a situation where somebody got bonked on the head. 390 00:21:10,600 --> 00:21:13,359 Speaker 4: They can't remember anything, including who they are, for a 391 00:21:13,400 --> 00:21:15,840 Speaker 4: period of time, and then oftentimes they get bonked on 392 00:21:15,880 --> 00:21:18,800 Speaker 4: the head again and that sort of shakes them out 393 00:21:18,840 --> 00:21:22,680 Speaker 4: of the amnesic syndrome. And so that's not an accurate 394 00:21:22,680 --> 00:21:24,720 Speaker 4: depiction of what looks like. 395 00:21:24,920 --> 00:21:29,240 Speaker 1: Oh no. Now, for people with anterograde amnesia, or the 396 00:21:29,359 --> 00:21:33,200 Speaker 1: inability to make new memories, there are two fascinating things 397 00:21:33,200 --> 00:21:36,080 Speaker 1: about them. The first is that because they can't make 398 00:21:36,160 --> 00:21:40,560 Speaker 1: new episodic memories, they live in a constant state of surprise, 399 00:21:40,840 --> 00:21:43,199 Speaker 1: as if they are just waking up every so often, 400 00:21:43,400 --> 00:21:47,000 Speaker 1: because anything that's happened to them recently they don't remember. 401 00:21:48,359 --> 00:21:50,720 Speaker 4: What we tend to see is this kind of profound 402 00:21:50,800 --> 00:21:54,320 Speaker 4: loss of episodic memory. And that's kind of the most 403 00:21:54,320 --> 00:21:56,959 Speaker 4: striking feature of amnesia. And what I mean by that 404 00:21:57,119 --> 00:21:59,800 Speaker 4: is if you're sitting with an m music participant and 405 00:21:59,840 --> 00:22:02,480 Speaker 4: you're having a conversation and you leave the room for 406 00:22:02,520 --> 00:22:05,479 Speaker 4: a few minutes and you return, they're not necessarily going 407 00:22:05,520 --> 00:22:08,080 Speaker 4: to remember that conversation. They're not going to remember that 408 00:22:08,119 --> 00:22:11,280 Speaker 4: you met them, what you talked about, et cetera, and 409 00:22:11,320 --> 00:22:15,680 Speaker 4: they also have difficulty remembering new facts, even though they 410 00:22:15,760 --> 00:22:20,239 Speaker 4: actually can access semantic memories from before their injury, so 411 00:22:20,280 --> 00:22:22,679 Speaker 4: they know who they are, they know lots about the world, 412 00:22:23,160 --> 00:22:23,679 Speaker 4: et cetera. 413 00:22:24,880 --> 00:22:27,280 Speaker 1: One of the most extreme examples of this kind of 414 00:22:27,280 --> 00:22:31,359 Speaker 1: amnesia is a man named Clive Wearing. He's still alive today. 415 00:22:31,560 --> 00:22:34,280 Speaker 1: He's eighty seven years old now, but when he was 416 00:22:34,359 --> 00:22:37,960 Speaker 1: forty seven, a virus got into his brain and destroyed 417 00:22:38,000 --> 00:22:41,080 Speaker 1: a lot of his hip hook campus. This prevents him 418 00:22:41,119 --> 00:22:46,959 Speaker 1: from remembering anything that happens beyond about seven seconds. So 419 00:22:47,240 --> 00:22:49,800 Speaker 1: you can have a conversation with him, but after a 420 00:22:49,800 --> 00:22:52,919 Speaker 1: short while, he won't remember who you are, what you 421 00:22:52,960 --> 00:22:55,080 Speaker 1: were talking about, or even how he got to the 422 00:22:55,119 --> 00:22:58,760 Speaker 1: place where he is right now now. Before the virus, 423 00:22:58,960 --> 00:23:02,760 Speaker 1: mister Wearing was a musicologist and an orchestra conductor, so 424 00:23:02,800 --> 00:23:05,680 Speaker 1: he still remembers how to play music, and he also 425 00:23:05,720 --> 00:23:08,399 Speaker 1: remembers his wife and the fact that he has kids, 426 00:23:08,600 --> 00:23:11,440 Speaker 1: but he only remembers his kids from when they were little. 427 00:23:12,160 --> 00:23:14,800 Speaker 1: Try to imagine what it would be like to be yourself, 428 00:23:15,240 --> 00:23:17,879 Speaker 1: but to find yourself in a constant state of not 429 00:23:18,000 --> 00:23:20,560 Speaker 1: knowing where you are or how anything around you got 430 00:23:20,600 --> 00:23:23,159 Speaker 1: to where it was we're not being able to recognize 431 00:23:23,200 --> 00:23:26,040 Speaker 1: any of the people around you, even though they act 432 00:23:26,080 --> 00:23:28,720 Speaker 1: perfectly normal, as if they've been hanging out with you 433 00:23:28,920 --> 00:23:33,080 Speaker 1: for a while. It's pretty mind boggling. But here's the 434 00:23:33,160 --> 00:23:37,320 Speaker 1: other fascinating thing about people with anteror grade amnesia. They 435 00:23:37,320 --> 00:23:41,719 Speaker 1: can often still learn new skills. We'll get to what 436 00:23:41,760 --> 00:23:44,879 Speaker 1: that means and how we know that after the break. 437 00:23:45,480 --> 00:24:02,160 Speaker 1: Stay with us, we'll be right back. Hey, welcome back. 438 00:24:02,720 --> 00:24:05,680 Speaker 1: We're talking about the science of forgetting, and so far 439 00:24:05,840 --> 00:24:09,119 Speaker 1: we talked about anesia and the different kinds of it. 440 00:24:09,520 --> 00:24:11,920 Speaker 1: There's a kind where you don't remember memories you had 441 00:24:11,960 --> 00:24:16,439 Speaker 1: before the injury that caused the amnesia. That's called retrograde amnesia. 442 00:24:16,480 --> 00:24:18,760 Speaker 1: And there's a kind where you can't make new memories 443 00:24:18,960 --> 00:24:23,000 Speaker 1: starting from the time of the injury. That's called anterograde amnesia. 444 00:24:23,400 --> 00:24:26,360 Speaker 1: And we also talked about several fascinating things about each 445 00:24:26,400 --> 00:24:30,280 Speaker 1: of these kinds. Now, another fascinating thing about anterograde amnesia, 446 00:24:30,440 --> 00:24:33,359 Speaker 1: where someone can't make new episodic memories like in the 447 00:24:33,400 --> 00:24:36,919 Speaker 1: movie Memento or Dory from Finding Nemo, came from one 448 00:24:36,920 --> 00:24:39,800 Speaker 1: of the first cases of this kind of anesia ever studied, 449 00:24:40,000 --> 00:24:45,600 Speaker 1: which was a man named Henry Mollison. Henry Mollison, Yeah, 450 00:24:45,680 --> 00:24:47,080 Speaker 1: the famous patient HM. 451 00:24:47,359 --> 00:24:51,879 Speaker 4: Yes, exactly. So he was studied for many decades and 452 00:24:51,920 --> 00:24:55,119 Speaker 4: this first began in the nineteen fifties. So he had 453 00:24:55,160 --> 00:24:59,240 Speaker 4: a surgery in nineteen fifty three to remove parts of 454 00:24:59,240 --> 00:25:01,600 Speaker 4: the brain that are really important for memory, such as 455 00:25:01,640 --> 00:25:05,959 Speaker 4: the hippocampus as well as the surrounding medial tempor lobe structures, 456 00:25:06,280 --> 00:25:09,479 Speaker 4: and all of that was removed in HM in this 457 00:25:09,760 --> 00:25:15,600 Speaker 4: surgery to help relieve intractable epilepsies. So after HM surgery, 458 00:25:15,640 --> 00:25:18,960 Speaker 4: at first blush, it appeared that the removal of this 459 00:25:19,040 --> 00:25:22,679 Speaker 4: tissue had kind of little impact on his cognition, but 460 00:25:22,960 --> 00:25:26,199 Speaker 4: it soon became clear that his memory was sort of 461 00:25:26,280 --> 00:25:28,520 Speaker 4: somewhat selectively and deeply affected. 462 00:25:29,040 --> 00:25:30,600 Speaker 3: He was profound me in music. 463 00:25:31,560 --> 00:25:35,399 Speaker 1: So Henry Mullison had severe and terror grade amnesia, just 464 00:25:35,480 --> 00:25:38,800 Speaker 1: like dor and finding Nemo or Clive Wearing the music 465 00:25:38,800 --> 00:25:41,680 Speaker 1: conductor I talked about before, if you met Henry, he 466 00:25:41,720 --> 00:25:44,560 Speaker 1: would forget about you within a few minutes of meeting you, 467 00:25:45,119 --> 00:25:47,560 Speaker 1: which meant he lived in a constant state of not 468 00:25:47,680 --> 00:25:50,960 Speaker 1: knowing where he was or how he got there, But scientists, 469 00:25:51,200 --> 00:25:55,480 Speaker 1: namely a researcher called Brenda Milner, soon figured out something amazing. 470 00:25:56,000 --> 00:25:58,280 Speaker 1: Henry could learn new skills. 471 00:26:00,080 --> 00:26:02,280 Speaker 4: Come into the laboratory, and he'd be given a new 472 00:26:02,320 --> 00:26:05,920 Speaker 4: skill task, but he wouldn't remember ever having been exposed 473 00:26:05,920 --> 00:26:07,879 Speaker 4: to the task. He'd come in day after day and 474 00:26:07,920 --> 00:26:09,640 Speaker 4: he would perform it as though it was a brand 475 00:26:09,680 --> 00:26:12,440 Speaker 4: new task for him, even though he was getting better 476 00:26:12,480 --> 00:26:13,040 Speaker 4: over time. 477 00:26:14,080 --> 00:26:17,680 Speaker 1: So scientists learned they could teach Henry new skills, but 478 00:26:18,080 --> 00:26:21,439 Speaker 1: he wouldn't remember having learned those skills. For example, you 479 00:26:21,440 --> 00:26:24,360 Speaker 1: could teach him to play the piano or to play tennis, 480 00:26:24,440 --> 00:26:27,400 Speaker 1: and he wouldn't remember taking the lessons, But the next 481 00:26:27,440 --> 00:26:29,040 Speaker 1: time he would sit in front of a piano or 482 00:26:29,040 --> 00:26:31,600 Speaker 1: pick up a tennis racket, he'd be amazed that he 483 00:26:31,720 --> 00:26:34,199 Speaker 1: knew how to use them. And this is because, as 484 00:26:34,240 --> 00:26:37,119 Speaker 1: we talked about before, there are different kinds of memory 485 00:26:37,240 --> 00:26:40,320 Speaker 1: in your brain. Remembering things that happened to you, or 486 00:26:40,400 --> 00:26:43,639 Speaker 1: the fact that you took music or tennis lessons are explicit, 487 00:26:43,760 --> 00:26:47,520 Speaker 1: episodic or semantic memories, but knowing how to hit the 488 00:26:47,600 --> 00:26:50,000 Speaker 1: keys on a piano or how to swing a tennis 489 00:26:50,080 --> 00:26:54,879 Speaker 1: racket are implicit motor memories. This case of Henry Mullyson 490 00:26:55,160 --> 00:26:57,520 Speaker 1: unlocked a lot of what we now know about the 491 00:26:57,560 --> 00:27:01,360 Speaker 1: different memory systems in our brain. Now, I talked about 492 00:27:01,400 --> 00:27:04,399 Speaker 1: the two basic kinds of anesia, losing old memories and 493 00:27:04,600 --> 00:27:07,000 Speaker 1: not being able to form new memories, as if there 494 00:27:07,000 --> 00:27:10,240 Speaker 1: are different kinds of anesia, and they are, but according 495 00:27:10,280 --> 00:27:15,080 Speaker 1: to doctor Palombo, they often happened together. Patient HM Henry 496 00:27:15,080 --> 00:27:19,240 Speaker 1: Mollison had both, as well as Clive Wearing and Dori 497 00:27:19,520 --> 00:27:22,159 Speaker 1: in finding Nemo. Okay, we're now going to get to 498 00:27:22,240 --> 00:27:25,320 Speaker 1: the last kind of forgetting, which is a condition called 499 00:27:25,600 --> 00:27:30,960 Speaker 1: severely deficient autobiographical memory. According to doctor Palombo, this is 500 00:27:31,000 --> 00:27:34,880 Speaker 1: similar to interrograde anesia, except it's a condition that some 501 00:27:34,920 --> 00:27:37,040 Speaker 1: people seem to be born with. 502 00:27:39,440 --> 00:27:42,439 Speaker 4: So I did some work on what we refer to 503 00:27:42,480 --> 00:27:47,480 Speaker 4: as severely deficient autobiographical memory. And my work on STAM 504 00:27:47,840 --> 00:27:51,680 Speaker 4: was done in collaboration with doctor Brian Levine, and we 505 00:27:51,760 --> 00:27:56,560 Speaker 4: studied a group of three individuals who contacted us and 506 00:27:56,720 --> 00:27:59,720 Speaker 4: shared with us that they had profound difficulty or even 507 00:27:59,760 --> 00:28:04,120 Speaker 4: an inability to vividly recollect events from their past wow, 508 00:28:04,240 --> 00:28:08,000 Speaker 4: but were otherwise healthy and high functioning. And so we 509 00:28:08,080 --> 00:28:12,159 Speaker 4: brought these individuals into our lab and we studied them 510 00:28:12,200 --> 00:28:15,359 Speaker 4: for a few years, and we studied the way that 511 00:28:15,400 --> 00:28:19,000 Speaker 4: they remember episodes to you know, try to see what 512 00:28:19,080 --> 00:28:22,600 Speaker 4: we can sort of understand about memory from studying these 513 00:28:22,640 --> 00:28:25,480 Speaker 4: individuals who fall at the kind of other end of 514 00:28:25,480 --> 00:28:27,680 Speaker 4: the extreme to that of age SAM, who are as 515 00:28:27,720 --> 00:28:30,200 Speaker 4: we remember, people who remember quite a lot. 516 00:28:31,359 --> 00:28:34,560 Speaker 1: Okay, if you remember, in our last episode about super memory, 517 00:28:34,800 --> 00:28:39,400 Speaker 1: we talked about people with something called highly superior autobiographical 518 00:28:39,440 --> 00:28:43,160 Speaker 1: memory or h SAM, who could remember everything that's ever 519 00:28:43,240 --> 00:28:46,560 Speaker 1: happened to them in their lives. Well, people with severely 520 00:28:46,640 --> 00:28:50,760 Speaker 1: deficient autobiographical memory or as DAM, are sort of the 521 00:28:50,920 --> 00:28:55,840 Speaker 1: opposite of that condition. They can't remember anything that happens 522 00:28:55,880 --> 00:28:56,960 Speaker 1: to them. 523 00:28:57,680 --> 00:29:00,600 Speaker 4: And so I'll say early days with us as it 524 00:29:00,640 --> 00:29:03,680 Speaker 4: is with h SAM, And so our scientific understanding of 525 00:29:03,840 --> 00:29:06,760 Speaker 4: SDAM is quite limited. But what we do know so 526 00:29:06,920 --> 00:29:10,480 Speaker 4: far is that it seems like individuals with SDAM access 527 00:29:10,560 --> 00:29:13,280 Speaker 4: their past in a different way. And so rather than 528 00:29:13,560 --> 00:29:17,520 Speaker 4: reliving episodes from their past in vivid and rich detail, 529 00:29:18,280 --> 00:29:22,000 Speaker 4: they tend to access their past more through semantic remembering. 530 00:29:22,320 --> 00:29:24,800 Speaker 1: I see it. Could you describe the condition, like what 531 00:29:24,920 --> 00:29:25,920 Speaker 1: is it like for them? 532 00:29:26,320 --> 00:29:29,160 Speaker 4: So it kind of depends on the person, and so 533 00:29:29,320 --> 00:29:33,880 Speaker 4: some people will describe having difficulty accessing visual images through 534 00:29:33,920 --> 00:29:37,840 Speaker 4: their memory. And so it's mainly that this sort of 535 00:29:38,040 --> 00:29:42,840 Speaker 4: conscious access to reexperiencing the past is limited or absent. 536 00:29:43,440 --> 00:29:47,920 Speaker 4: But yet nonetheless they can access their knowledge about the 537 00:29:47,920 --> 00:29:51,880 Speaker 4: world and through facts. And so oftentimes you'll hear individuals 538 00:29:51,880 --> 00:29:55,760 Speaker 4: with SDAMS say that they just know their past, but 539 00:29:55,800 --> 00:30:00,240 Speaker 4: they're not reliving it in that sort of rich episodic format. 540 00:30:00,240 --> 00:30:02,719 Speaker 1: Like I remember I went to college at the University 541 00:30:02,720 --> 00:30:06,480 Speaker 1: of Toronto, but I have no memories of being there 542 00:30:06,640 --> 00:30:08,480 Speaker 1: or what it was like exactly. 543 00:30:08,720 --> 00:30:12,400 Speaker 4: Yes, the episodes that can be relived. 544 00:30:13,880 --> 00:30:16,920 Speaker 1: Yes, there are people out there that can remember facts 545 00:30:16,960 --> 00:30:20,560 Speaker 1: about their lives, but they don't actually remember living it. 546 00:30:20,880 --> 00:30:22,880 Speaker 1: They don't seem to be able to record the kind 547 00:30:22,920 --> 00:30:26,360 Speaker 1: of memory that lets you relive your past. They know 548 00:30:26,440 --> 00:30:31,560 Speaker 1: they were there, but they don't remember being there. Uh. 549 00:30:32,280 --> 00:30:35,240 Speaker 1: It's like I know I had a kid, and I 550 00:30:35,280 --> 00:30:37,120 Speaker 1: know they were really young, but I have no memories 551 00:30:37,160 --> 00:30:39,400 Speaker 1: of those early days taking care of newbore. 552 00:30:39,640 --> 00:30:40,440 Speaker 3: Yes, exactly. 553 00:30:40,480 --> 00:30:42,960 Speaker 4: And so you have lots of information about your lives, 554 00:30:43,000 --> 00:30:45,960 Speaker 4: about your loved ones, et cetera, but it's just you're 555 00:30:46,000 --> 00:30:48,880 Speaker 4: not accessing that information through episodic memory. 556 00:30:49,320 --> 00:30:52,200 Speaker 1: Uh, like my record button just wasn't on. 557 00:30:52,680 --> 00:30:55,120 Speaker 4: Possibly it could be that the record button was on, 558 00:30:55,360 --> 00:30:58,600 Speaker 4: but it's a different pathway towards accessing those memories. So 559 00:30:58,640 --> 00:31:00,760 Speaker 4: that could be right from the get go, that memories 560 00:31:00,800 --> 00:31:05,719 Speaker 4: are being laid down in a more factual conceptual way. 561 00:31:06,280 --> 00:31:07,600 Speaker 4: That's a very open question. 562 00:31:08,080 --> 00:31:10,880 Speaker 1: Oh, I see they might have the record but on, 563 00:31:11,160 --> 00:31:14,080 Speaker 1: but maybe the camera works a little bit different. 564 00:31:14,280 --> 00:31:15,240 Speaker 3: That's right exactly. 565 00:31:15,600 --> 00:31:19,400 Speaker 1: I see, what do you think and this might not 566 00:31:19,440 --> 00:31:22,360 Speaker 1: be a scientific question, but what is it like too? 567 00:31:23,480 --> 00:31:26,040 Speaker 4: Yeah, so I think you're asking a little bit about 568 00:31:26,120 --> 00:31:30,240 Speaker 4: sort of what the lived experience of ASBM is. 569 00:31:30,720 --> 00:31:30,920 Speaker 1: Yeah. 570 00:31:30,960 --> 00:31:33,200 Speaker 4: I think that's such an important question. And I think 571 00:31:33,280 --> 00:31:37,080 Speaker 4: as scientists sometimes we get wrapped up in studying the 572 00:31:37,480 --> 00:31:39,840 Speaker 4: nuts and bolts of what memory might look like in 573 00:31:39,880 --> 00:31:43,080 Speaker 4: a particular group of individuals, and I think it's important 574 00:31:43,080 --> 00:31:45,240 Speaker 4: to take a step back and think about what those 575 00:31:45,280 --> 00:31:49,040 Speaker 4: lived experiences are like for our participants. Anecdotally, I guess 576 00:31:49,120 --> 00:31:52,920 Speaker 4: I'll say that for some individuals, lacking this re experiencing 577 00:31:53,080 --> 00:31:55,880 Speaker 4: component of memory can be hard for them and for 578 00:31:56,000 --> 00:31:58,840 Speaker 4: others less so. And so I think in the individuals 579 00:31:58,880 --> 00:32:02,440 Speaker 4: we studied, they were high functioning in terms of their 580 00:32:02,600 --> 00:32:05,440 Speaker 4: day to day and they were by all accounts healthy. 581 00:32:06,160 --> 00:32:09,720 Speaker 4: You know, I think that individuals with STAM feel in 582 00:32:09,800 --> 00:32:12,720 Speaker 4: the moment probably as richly and profoundly as the rest 583 00:32:12,800 --> 00:32:15,400 Speaker 4: of us do. But it could be that just the 584 00:32:15,440 --> 00:32:19,080 Speaker 4: way that one reflects on their past, that there's individual 585 00:32:19,080 --> 00:32:21,960 Speaker 4: differences there. So it could be that when you don't 586 00:32:21,960 --> 00:32:25,840 Speaker 4: have access to the past in terms of re experiencing episodes, 587 00:32:25,880 --> 00:32:28,480 Speaker 4: it might help you move on from the past when 588 00:32:28,560 --> 00:32:29,520 Speaker 4: things were difficult. 589 00:32:30,440 --> 00:32:32,640 Speaker 1: This brings us to the last question I had for 590 00:32:32,760 --> 00:32:36,480 Speaker 1: doctor Palumbo, which is, why do we forget in the 591 00:32:36,560 --> 00:32:40,920 Speaker 1: first place. If it's possible to remember everything that happens 592 00:32:40,920 --> 00:32:43,120 Speaker 1: to you in your life, as some people would super 593 00:32:43,160 --> 00:32:48,040 Speaker 1: memory prove, why didn't we all evolve disability to remember everything? 594 00:32:48,600 --> 00:32:50,800 Speaker 1: What's the point of forgetting? 595 00:32:53,000 --> 00:32:57,120 Speaker 4: Yes, exactly. And that might seem strange because we would 596 00:32:57,120 --> 00:32:59,960 Speaker 4: hope that our memory systems would be a perfect record 597 00:33:00,160 --> 00:33:02,960 Speaker 4: the past. That would be really helpful in many situations. 598 00:33:03,320 --> 00:33:07,160 Speaker 4: But in fact, memory researchers would argue that it is 599 00:33:07,240 --> 00:33:11,840 Speaker 4: actually adaptive to forget, and we sort of have this 600 00:33:12,120 --> 00:33:16,960 Speaker 4: sweet spot of remembering just enough so we live. We 601 00:33:17,040 --> 00:33:20,400 Speaker 4: are encoding experiences at every moment, and a lot of 602 00:33:20,440 --> 00:33:23,760 Speaker 4: things repeat in our environment, so we're picking up patterns 603 00:33:23,920 --> 00:33:26,840 Speaker 4: in the world, and it's that kind of information that's 604 00:33:26,880 --> 00:33:30,400 Speaker 4: really useful to us when we're thinking about decisions we 605 00:33:30,480 --> 00:33:33,000 Speaker 4: need to make in the moment or planning out our future, 606 00:33:33,000 --> 00:33:37,680 Speaker 4: et cetera. So we actually think that having an imperfect 607 00:33:37,760 --> 00:33:41,880 Speaker 4: memory system, a memory system that's flexible and reconstructive, is 608 00:33:41,880 --> 00:33:43,120 Speaker 4: actually really good for us. 609 00:33:43,720 --> 00:33:47,280 Speaker 1: Yeah, I guess the idea is that your memory is 610 00:33:47,280 --> 00:33:49,840 Speaker 1: meant to be a little fuzzy so that you can 611 00:33:49,920 --> 00:33:52,320 Speaker 1: see the larger patterns in your life. 612 00:33:52,480 --> 00:33:54,040 Speaker 3: Yeah, that's a really good way to put it. 613 00:33:54,240 --> 00:33:56,640 Speaker 1: So you don't miss the forest for the trees. 614 00:33:57,280 --> 00:34:00,600 Speaker 4: Kind yes, exactly exactly, because we all didn't have to 615 00:34:00,640 --> 00:34:04,880 Speaker 4: make really quick decisions, especially if we're being threatened by something, 616 00:34:04,960 --> 00:34:07,400 Speaker 4: and so we want to know how things generally occur, 617 00:34:08,120 --> 00:34:10,600 Speaker 4: not necessarily how they occurred just once. 618 00:34:11,160 --> 00:34:13,920 Speaker 1: I see, like, we don't get hung up on whether 619 00:34:14,040 --> 00:34:16,480 Speaker 1: the tiger running at you have the same stripes as 620 00:34:16,480 --> 00:34:19,960 Speaker 1: the last tiger you saw a few weeks ago. You 621 00:34:20,040 --> 00:34:21,719 Speaker 1: just want to remember it it's a tiger. At least 622 00:34:21,760 --> 00:34:22,359 Speaker 1: you run away. 623 00:34:22,760 --> 00:34:23,719 Speaker 3: That's exactly right. 624 00:34:23,840 --> 00:34:27,640 Speaker 1: Yes, oh interesting, So there's a reason I'm forget that. 625 00:34:27,640 --> 00:34:29,520 Speaker 1: What we're saying, there's there's a good reason, very. 626 00:34:29,440 --> 00:34:30,719 Speaker 3: Good reason you're forgetful. 627 00:34:30,840 --> 00:34:34,719 Speaker 1: Yeah, yeah, all right. That was a lot of information 628 00:34:34,880 --> 00:34:38,880 Speaker 1: about memory, amnesia and forgetting. But the good news is 629 00:34:38,920 --> 00:34:41,800 Speaker 1: that if you don't exactly remember the things we talked about, 630 00:34:42,200 --> 00:34:45,440 Speaker 1: you can just get the replay button and you'll get 631 00:34:45,480 --> 00:34:49,000 Speaker 1: to relive these conversations all over again. It's like our 632 00:34:49,040 --> 00:34:53,080 Speaker 1: phones and our computers are now part of our extended memory. 633 00:34:53,600 --> 00:34:56,760 Speaker 1: Thanks for joining us, don't forget to come back next week. 634 00:34:57,480 --> 00:35:03,520 Speaker 1: See then you've been listening to science Stuff. The production 635 00:35:03,640 --> 00:35:08,160 Speaker 1: of iHeartRadio written and produced by me Or Hitcham, edited 636 00:35:08,160 --> 00:35:12,200 Speaker 1: by Rose Seguda, executive producer Jerry Rowland, and audio engineer 637 00:35:12,200 --> 00:35:15,040 Speaker 1: and mixer Kasey Pegram. And you can follow me on 638 00:35:15,080 --> 00:35:18,279 Speaker 1: social media. Just search for PhD Comics and the name 639 00:35:18,360 --> 00:35:21,040 Speaker 1: of your favorite platform. Be sure to subscribe to Sign 640 00:35:21,080 --> 00:35:24,319 Speaker 1: Stuff on the iHeartRadio app, Apple Podcasts, or wherever you 641 00:35:24,360 --> 00:35:27,480 Speaker 1: get your podcasts, and please tell your friends we'll be 642 00:35:27,520 --> 00:35:29,880 Speaker 1: back next Wednesday with another episode.