WEBVTT - Ep71 "Why do our memories drift? Part 2: Misremembering yourself" 0:00:05.200 --> 0:00:08.000 Is your notion of who you are built on a 0:00:08.520 --> 0:00:11.960 mountain of narrative that may or may not be totally accurate. 0:00:12.600 --> 0:00:16.600 If somebody told you a totally false story about yourself, 0:00:17.200 --> 0:00:19.720 could you come to believe it? And what does this 0:00:19.760 --> 0:00:22.520 have to do with six people who spent over a 0:00:22.640 --> 0:00:27.400 decade in prison together for a crime they didn't commit 0:00:27.920 --> 0:00:31.040 but believed that they had. And what does any of 0:00:31.040 --> 0:00:33.440 this have to do with why you are physically a 0:00:33.440 --> 0:00:36.960 different person every seven years, but why you can't easily 0:00:37.080 --> 0:00:40.320 see the changes in yourself through time, or what the 0:00:40.400 --> 0:00:48.440 effective technology will be on our sense of self. Welcome 0:00:48.479 --> 0:00:52.159 to Inner Cosmos with me David Eagleman. I'm a neuroscientist 0:00:52.240 --> 0:00:55.600 and an author at Stanford and in these episodes we 0:00:55.760 --> 0:01:00.240 sailed deeply into our three pound universe to understand why, why, 0:01:00.400 --> 0:01:12.200 and how our lives look the way they do. Today's 0:01:12.200 --> 0:01:17.039 episode is part two in the story of our drifting memories. 0:01:17.360 --> 0:01:21.600 So last week we talked about memory and its inaccuracies. 0:01:21.880 --> 0:01:26.839 I talked about how medieval European painters struggled to accurately 0:01:27.200 --> 0:01:30.520 depict lions because they had never seen a real lion. 0:01:30.720 --> 0:01:34.800 They'd only seen versions painted by other people, and as 0:01:34.880 --> 0:01:39.160 these sequences of paintings moved forward through history, they became 0:01:39.280 --> 0:01:43.520 more and more distorted from the original lion that someone 0:01:43.560 --> 0:01:47.240 had seen at some point, and the lions served as 0:01:47.240 --> 0:01:51.919 a metaphor for us to discuss how memories, like messages 0:01:51.960 --> 0:01:56.760 in the game of Telephone, become distorted over time. If 0:01:56.800 --> 0:01:59.240 you heard the episode, you'll remember I talked about a 0:01:59.400 --> 0:02:03.800 strange Native American folk tale called the War of the Ghosts, 0:02:04.240 --> 0:02:08.080 and this was used by the psychologist Frederick Bartlett. He 0:02:08.160 --> 0:02:12.639 had people read the story and then reconstruct it from 0:02:12.639 --> 0:02:17.000 their memory at various time points later to understand how 0:02:17.040 --> 0:02:20.400 their memory changed. And what he found is that over time, 0:02:20.960 --> 0:02:24.880 your memory of a story becomes more coherent with your 0:02:25.040 --> 0:02:28.160 internal model of the world and also more aligned with 0:02:28.400 --> 0:02:32.760 whatever your cultural norms are. So we saw that memories 0:02:32.840 --> 0:02:37.280 are not static recordings, but instead they are stored in 0:02:37.880 --> 0:02:43.359 vast constellations of neurons that are interconnected and dynamic, and 0:02:43.720 --> 0:02:48.000 new experiences can alter these neural connections, leading to changes 0:02:48.040 --> 0:02:52.120 in how memories are recalled, for example, in the context 0:02:52.120 --> 0:02:57.520 of eyewitness testimony. This understanding of memory is massively important 0:02:57.600 --> 0:03:01.040 because things that people say to you after you've witnessed 0:03:01.080 --> 0:03:04.760 an event. Whether this is cowitnesses talking to you, or 0:03:04.840 --> 0:03:09.440 psychologists or investigators, these can all change your memory of 0:03:09.480 --> 0:03:12.320 what you believe you saw at the time of the event. 0:03:12.760 --> 0:03:16.079 It alters your memory, but generally it doesn't change your 0:03:16.240 --> 0:03:19.800 confidence in your memory. And finally, we also saw in 0:03:19.800 --> 0:03:24.440 the last episode that even flashbulb memories, which are these vivid, 0:03:24.600 --> 0:03:30.120 emotionally charged recollections of big significant events, even these sorts 0:03:30.120 --> 0:03:34.440 of recollections become less accurate over time, as we saw 0:03:34.639 --> 0:03:38.480 with a long term follow up study after the terrorist 0:03:38.480 --> 0:03:41.880 attacks of September eleventh, two thousand and one. So this 0:03:41.960 --> 0:03:45.240 week we're going to talk about not just your memory 0:03:45.280 --> 0:03:47.960 of something external like a story you read or an 0:03:48.000 --> 0:03:51.840 event you saw. Instead, we're going to zoom in on 0:03:52.000 --> 0:03:56.760 what happens when those memories are about you. How do 0:03:56.880 --> 0:04:02.960 memory distortions through time change your notion of your personal identity. 0:04:03.280 --> 0:04:06.440 So let's start with a basic reality. Our brains and 0:04:06.480 --> 0:04:10.280 our bodies change so much during our life that, like 0:04:10.320 --> 0:04:14.480 a clock's our hand, it's difficult to detect the changes. 0:04:15.000 --> 0:04:18.440 So every seven years, for example, every cell in your 0:04:18.440 --> 0:04:22.160 body has been replaced. Physically, you are not you anymore. 0:04:22.160 --> 0:04:27.440 But you're a new you. Fortunately, there's one constant that 0:04:27.640 --> 0:04:31.240 links all these different versions of you together, and that 0:04:31.400 --> 0:04:37.080 is memory. Perhaps memory can serve as the thread that 0:04:37.279 --> 0:04:40.279 makes me who I am. It sits at the core 0:04:40.720 --> 0:04:45.680 of our identity. It provides a single, continuous sense of self. 0:04:46.400 --> 0:04:49.520 But given what we talked about in the last episode, 0:04:49.880 --> 0:04:53.839 there might be a problem here because could the continuity 0:04:53.839 --> 0:04:59.480 of memory be an illusion? So imagine that you walk 0:04:59.520 --> 0:05:03.080 into a room room, and you meet your self at 0:05:03.120 --> 0:05:06.920 different ages in your life. So there you are at 0:05:06.960 --> 0:05:10.680 age seven, and there's you as a teenager, and over 0:05:10.720 --> 0:05:13.960 here it's you in your late twenties and mid fifties 0:05:14.000 --> 0:05:16.920 and early seventies and all the way through your final years. 0:05:17.520 --> 0:05:21.600 Imagine that you all sit together and you share the 0:05:21.680 --> 0:05:25.640 stories about your life, and you tease out this single 0:05:25.800 --> 0:05:28.719 thread of your identity. Would you be able to find 0:05:28.760 --> 0:05:32.839 a core version of you? Well, it's tough to say, 0:05:33.320 --> 0:05:37.080 because you all possess the same name and the same history. 0:05:37.480 --> 0:05:41.000 But the fact is that you're all somewhat different people 0:05:41.400 --> 0:05:44.320 at all these different ages. You have different values and goals. 0:05:44.680 --> 0:05:46.920 And what we're going to talk about today is that 0:05:47.000 --> 0:05:52.720 your life's memories might have less in common than expected. 0:05:53.080 --> 0:05:56.960 Your memory when you look back and ask yourself who 0:05:57.040 --> 0:06:01.160 you were at fifteen is different to who you actually 0:06:01.200 --> 0:06:04.880 were at fifteen. And your sixty year old self and 0:06:04.880 --> 0:06:07.280 your forty year old self will look back on an 0:06:07.279 --> 0:06:09.679 important event that happened to your twenty year old self, 0:06:10.080 --> 0:06:14.800 but they may have different recollections of exactly what happened 0:06:14.880 --> 0:06:17.640 and in what order and who is there. And the 0:06:17.720 --> 0:06:21.600 question is, if you don't all agree on the same memories, 0:06:22.320 --> 0:06:25.520 are you really the same person? So first, let's start 0:06:25.520 --> 0:06:28.080 from the point of view of the brain to think 0:06:28.120 --> 0:06:32.200 about self identity. There's no single region in the brain 0:06:32.240 --> 0:06:37.599 that underpins the self. It's a vastly distributed property. But 0:06:37.720 --> 0:06:40.480 we can point to some large players in the game, 0:06:40.600 --> 0:06:45.239 like the prefrontal cortex located just behind your forehead, which 0:06:45.320 --> 0:06:50.040 generally navigates your planning, your decision making, your self reflection. 0:06:50.800 --> 0:06:56.080 It helps you evaluate your action and give some narrative 0:06:56.240 --> 0:06:59.760 to your intention, and all this contributes to a coherent 0:07:00.240 --> 0:07:03.880 self concept and more generally, the prefrontal cortex is part 0:07:03.920 --> 0:07:07.719 of a broader coalition of areas that we summarize as 0:07:07.839 --> 0:07:11.360 the default mode network. Now, this is a network of 0:07:11.360 --> 0:07:15.440 brain regions that are active when you're at rest and 0:07:15.480 --> 0:07:18.280 not focused on something in the outside world. And this 0:07:18.400 --> 0:07:22.680 network seems to be involved in self referential thinking and 0:07:22.800 --> 0:07:27.480 daydreaming and reflecting on your own life and experiences, so 0:07:27.520 --> 0:07:30.720 it seems to be involved in maintaining a stable sense 0:07:30.760 --> 0:07:33.960 of self. And you have other areas involved, like the amygdala, 0:07:34.040 --> 0:07:37.840 which is involved in processing emotions and that influences how 0:07:37.920 --> 0:07:41.800 you react to your environment and shapes your emotional identity. 0:07:42.440 --> 0:07:45.040 But while we can point to all these brain areas 0:07:45.080 --> 0:07:49.640 as being involved, there's something else massively important. Your identity 0:07:49.800 --> 0:07:54.800 is fundamentally rooted in your memories. This tells you your 0:07:54.840 --> 0:07:58.440 whole life narrative. There are many types of memory, like 0:07:58.480 --> 0:08:01.640 short term and long term, and please listen to episode 0:08:01.680 --> 0:08:04.360 forty three to learn more about these different types. But 0:08:04.440 --> 0:08:09.720 the subtype we care about today is autobiographical memory, which 0:08:09.760 --> 0:08:13.920 is your memory of personal experiences and events. This type 0:08:13.920 --> 0:08:18.320 of memory plays an absolutely crucial role in shaping your identity. 0:08:18.440 --> 0:08:21.760 By recalling these memories and reflecting on these memories, you 0:08:21.880 --> 0:08:27.400 create this continuously changing narrative that defines who you are now. 0:08:27.680 --> 0:08:30.440 The reason that your memory is and your overarching narrative 0:08:30.560 --> 0:08:34.760 can always change is because of neuroplasticity, which is the 0:08:34.800 --> 0:08:39.160 brain's ability to adapt. Your brain is flexible. All the 0:08:39.600 --> 0:08:43.680 tens of billions of neurons in your head are always 0:08:43.720 --> 0:08:49.360 wiring and rewiring and disconnecting and seeking new partners and reconnecting, 0:08:49.600 --> 0:08:52.960 and they're doing this every moment of your life. I 0:08:53.040 --> 0:08:56.679 call this live wiring, and this, of course underlies the 0:08:56.720 --> 0:09:00.480 fluid nature of our identity. If you did didn't have 0:09:00.600 --> 0:09:04.960 this kind of flexibility in your brain, you would be 0:09:05.400 --> 0:09:09.360 stuck in time. You would never reorganize in response to 0:09:10.000 --> 0:09:14.199 new experiences, you would never learn, you would never change 0:09:14.600 --> 0:09:18.760 in response to trauma or education, or the relationships you have, 0:09:19.440 --> 0:09:21.920 or more generally, you wouldn't change from the politics and 0:09:21.960 --> 0:09:25.520 culture and the wider world around you. Now, if this 0:09:25.600 --> 0:09:28.160 were just a matter of the world getting poured into 0:09:28.200 --> 0:09:32.000 your nervous system as you mature, that's one thing. But 0:09:32.120 --> 0:09:35.840 the deeper, amazing issue that we're talking about today is 0:09:35.880 --> 0:09:40.760 that your past is not a faithful record. Instead, it's 0:09:40.800 --> 0:09:46.439 a reconstruction, and sometimes it borders on mythology. When we 0:09:46.640 --> 0:09:49.640 review our life memories, we should do so with the 0:09:49.679 --> 0:09:53.800 awareness that not all the details are accurate. Some of 0:09:53.840 --> 0:09:57.360 the details come from stories that people told us about ourselves. 0:09:57.960 --> 0:10:01.400 Others were filled in with what we think must have happened. 0:10:01.920 --> 0:10:06.280 Others are based on rewrites that make the overarching story 0:10:06.320 --> 0:10:09.719 more consistent. So if your answer to who you are 0:10:09.800 --> 0:10:13.199 is based simply on your memories, that makes your identity 0:10:13.360 --> 0:10:19.800 something of a strange, ongoing, mutable narrative. So how do 0:10:20.000 --> 0:10:37.320 our personal memories influence who we think we are? Let's 0:10:37.400 --> 0:10:41.400 return to the memory researcher Elizabeth Loftis. Last week I 0:10:41.440 --> 0:10:43.960 told you that in one of her experiments, she showed 0:10:44.240 --> 0:10:48.840 that the way questions are phrased influences people's memories. For example, 0:10:48.880 --> 0:10:52.040 if you ask people how fast a couple of cars 0:10:52.040 --> 0:10:54.920 are going when they hit each other, the people will 0:10:54.920 --> 0:10:57.880 give different speed estimates than if you ask them how 0:10:57.960 --> 0:11:01.080 fast the cars were going when they mashed into each other. 0:11:01.840 --> 0:11:05.840 The word smashed illicits higher speed estimates because it distorts 0:11:05.880 --> 0:11:10.960 something about people's memories. So, because Lostess was intrigued by 0:11:11.000 --> 0:11:15.680 the way that leading questions could contaminate memory, she decided 0:11:15.679 --> 0:11:19.120 to go further. She asked this question, would it be 0:11:19.360 --> 0:11:25.120 possible to implant entirely false memories into a person? So 0:11:25.160 --> 0:11:28.720 to find out, she recruited a bunch of participants and 0:11:28.840 --> 0:11:33.600 had her team contact their families to get information about 0:11:33.600 --> 0:11:37.760 events in their past, and then, armed with this information, 0:11:38.120 --> 0:11:44.000 the researcher team put together four stories about each participant's childhood. 0:11:44.280 --> 0:11:47.600 Three of the stories were true, and the fourth story 0:11:47.679 --> 0:11:52.640 contained plausible information, but it was entirely made up. This 0:11:52.800 --> 0:11:56.800 fourth story was about getting lost at a shopping mall 0:11:57.000 --> 0:12:01.240 as a child, being found by a kind elderly person, 0:12:01.720 --> 0:12:06.320 and finally being reunited with a parent. In a series 0:12:06.360 --> 0:12:11.480 of interviews, participants were told these four stories about their childhood, 0:12:11.920 --> 0:12:14.839 and at least a quarter of them claimed that they 0:12:14.880 --> 0:12:18.360 could remember the incident of being lost in the mall, 0:12:18.760 --> 0:12:23.200 even though it hadn't actually happened and it didn't stop there. Because, 0:12:23.240 --> 0:12:27.920 as Loftus describes it, the participant may start to feel 0:12:27.960 --> 0:12:30.360 like they remember a little bit about it, and then 0:12:30.360 --> 0:12:33.040 when they come back a week later, they're starting to 0:12:33.120 --> 0:12:36.840 remember more. Maybe they tell some details about the older 0:12:36.880 --> 0:12:40.920 woman who rescued them, and over time, more and more 0:12:41.000 --> 0:12:45.040 details creep into this false memory, like someone will say 0:12:45.080 --> 0:12:49.000 that the older woman had a particular hat that they remember, 0:12:49.280 --> 0:12:52.040 or they'll say they remember that they had their favorite 0:12:52.080 --> 0:12:55.280 toy with them, or they'll say they remember their mother 0:12:55.440 --> 0:12:58.800 was so mad or so glad when they were reunited. 0:13:00.000 --> 0:13:03.520 Only was it possible to implant false new memories in 0:13:03.559 --> 0:13:09.079 the brain, but people embraced and embellished those memories. They 0:13:09.080 --> 0:13:14.439 were unknowingly weaving fantasy into the fabric of their identity. 0:13:14.840 --> 0:13:18.600 Now we're all susceptible to this kind of memory manipulation, 0:13:19.320 --> 0:13:23.400 And it turns out this is true of even Elizabeth 0:13:23.440 --> 0:13:27.920 Loftus herself. So, when Elizabeth was a child, her mother 0:13:28.200 --> 0:13:31.880 had drowned in a swimming pool. And years later she 0:13:31.920 --> 0:13:36.439 was having a conversation with a relative, and that conversation 0:13:36.559 --> 0:13:41.120 brought out this extraordinary fact that Elizabeth had been the 0:13:41.120 --> 0:13:45.520 one to find her mother's body in the pool. Now 0:13:45.520 --> 0:13:48.360 that news came as a total shock to her because 0:13:48.400 --> 0:13:51.320 she hadn't known that, and in fact, she didn't believe it. 0:13:51.760 --> 0:13:55.360 But she describes, quote, I went home from that birthday 0:13:55.720 --> 0:13:58.800 and I started to think, maybe I did. I started 0:13:58.800 --> 0:14:01.840 to think about others. There are things that I did remember, 0:14:02.120 --> 0:14:05.600 like when the fireman came, they gave me oxygen. Maybe 0:14:05.640 --> 0:14:08.320 I needed the oxygen because I was so upset that 0:14:08.360 --> 0:14:11.120 I found the body. Now soon she was able to 0:14:11.280 --> 0:14:16.600 visualize finding her mother's body in the swimming pool. But 0:14:16.840 --> 0:14:19.880 then her relative called her up to say he'd made 0:14:19.920 --> 0:14:23.840 a mistake. It wasn't the young Elizabeth after all who 0:14:23.840 --> 0:14:27.720 had found the body. It had been Elizabeth's aunt. And 0:14:27.760 --> 0:14:32.080 that's how Loftus had the opportunity to experience what it 0:14:32.160 --> 0:14:36.680 was like to possess her own false memory, richly detailed 0:14:37.160 --> 0:14:42.320 and deeply felt. So your memories are not a faithful record. Instead, 0:14:42.360 --> 0:14:46.760 they are a constant reconstruction. Now it might feel to 0:14:46.800 --> 0:14:50.800 you almost inconceivable that you could somehow misremember your own 0:14:50.920 --> 0:14:54.680 life narrative. But this is precisely what happened in the 0:14:54.720 --> 0:14:59.680 small town of Beatrice, Nebraska, to multiple people in a 0:14:59.680 --> 0:15:03.800 way that that affected a combined seventy five years of 0:15:03.840 --> 0:15:07.560 their lives. So here is what happened. There was an 0:15:07.640 --> 0:15:12.200 elderly woman, a grandmother, named Helen Wilson, who was raped 0:15:12.280 --> 0:15:15.880 and murdered in her apartment in nineteen eighty five, and 0:15:15.960 --> 0:15:19.440 for four years the police searched, but they couldn't come 0:15:19.520 --> 0:15:23.160 up with who had done this. By nineteen eighty nine, 0:15:23.360 --> 0:15:28.080 they were looking for any suspects who seemed sexually unconventional 0:15:28.080 --> 0:15:31.320 because a profiler at the FBI suggested that's who they 0:15:31.320 --> 0:15:34.480 should be looking for. So they finally found two people, 0:15:34.600 --> 0:15:37.880 a man and a woman who fit that general description. 0:15:38.160 --> 0:15:42.400 He had been a pornographic filmmaker and she had met 0:15:42.440 --> 0:15:45.080 him in California where they filmed together, and the two 0:15:45.120 --> 0:15:48.440 of them had come back to Beatrice, Nebraska and started 0:15:48.440 --> 0:15:51.880 filming pornography again. So the police picked them up and 0:15:52.120 --> 0:15:55.680 interviewed them. Now, he denied that he had anything to 0:15:55.720 --> 0:15:58.240 do with this murder that he was being accused of. 0:15:58.320 --> 0:16:00.320 He was baffled, and he said, why am I a 0:16:00.400 --> 0:16:03.760 suspect in this case of murder? He said he didn't 0:16:03.800 --> 0:16:06.280 even know the victim they were talking about, or anything 0:16:06.320 --> 0:16:10.640 about this crime. But according to the transcripts, the detective 0:16:10.680 --> 0:16:15.080 said to him, you're having a hard time remembering. Maybe 0:16:15.120 --> 0:16:18.480 it's because you don't want to remember. Could that be it? Joe? 0:16:18.720 --> 0:16:21.960 He kept denying it, and the detectives kept telling him 0:16:22.280 --> 0:16:25.160 they would be able to prove his guilt. But that's 0:16:25.200 --> 0:16:27.800 not the mind blowing part of the story, which was 0:16:27.800 --> 0:16:31.320 taking place in the neighboring room where they were interviewing 0:16:31.320 --> 0:16:34.600 the woman. The detectives told her that she was at 0:16:34.640 --> 0:16:37.760 the apartment of this elderly woman that's grandmother, and they 0:16:37.880 --> 0:16:42.880 quote worked on bringing back little bits of memory to her. 0:16:43.640 --> 0:16:47.359 She didn't remember anything about this grandmother, or the apartment, 0:16:47.480 --> 0:16:49.320 or what the woman was wearing, or even why she 0:16:49.400 --> 0:16:52.320 would have been there or gone inside, but the police 0:16:52.400 --> 0:16:56.040 kept telling her, according to the transcript, quote, let me 0:16:56.160 --> 0:17:00.640 try and help you refresh your memory. They told her 0:17:00.840 --> 0:17:05.680 her memories were repressed because the whole event was so awful. 0:17:06.000 --> 0:17:11.800 With time, she ended up wholeheartedly believing that she had 0:17:11.880 --> 0:17:16.439 done the crime, and she confessed that she suffocated the 0:17:16.480 --> 0:17:21.200 woman with a pillow while the man had performed the rape. Now, 0:17:21.240 --> 0:17:25.800 this was a very manipulative interrogation and subsequent confession, and 0:17:25.840 --> 0:17:28.840 maybe it would have ended there. But the problem was 0:17:28.840 --> 0:17:31.080 that at the scene of the crime they had found 0:17:31.280 --> 0:17:35.080 type B blood, and neither of these two had type 0:17:35.160 --> 0:17:38.160 B blood. So the police felt that maybe the solution 0:17:38.960 --> 0:17:41.360 was that there were other people involved, and they kept 0:17:41.359 --> 0:17:45.400 pushing the woman to generate recollections. She ended up telling 0:17:45.400 --> 0:17:48.480 the police that she thought maybe there was another man 0:17:48.520 --> 0:17:51.159 with her during the crime, so they showed her a 0:17:51.200 --> 0:17:55.040 lineup of photographs and she ended up picking a high 0:17:55.080 --> 0:17:58.840 school friend of hers, who then got arrested too, and 0:17:58.880 --> 0:18:01.359 maybe it would have ended there, but he didn't have 0:18:01.520 --> 0:18:05.879 typebe blood either. Then a fourth suspect was arrested, another 0:18:05.880 --> 0:18:08.480 woman who tended to hang out with the group. She 0:18:08.640 --> 0:18:12.480 had a number of interviews with the police psychologist, and 0:18:12.560 --> 0:18:16.280 she was also brought around to the idea that she 0:18:16.359 --> 0:18:20.080 had committed this horrible crime and had repressed her memory, 0:18:20.600 --> 0:18:24.320 so she ended up giving a confession of guilt. Then 0:18:24.359 --> 0:18:27.040 she had a dream about this whole thing, and in 0:18:27.080 --> 0:18:30.880 her dream she saw a fifth man there. So he 0:18:30.920 --> 0:18:34.840 got arrested and also had interviews with the psychologist, and 0:18:35.040 --> 0:18:39.320 he eventually also came to the conclusion that his psyche 0:18:39.720 --> 0:18:45.320 had simply forgotten or repressed this whole terrible event. Then 0:18:45.600 --> 0:18:48.760 he and the second woman to be arrested each had 0:18:48.760 --> 0:18:51.639 a dream that there was another woman at the scene, 0:18:52.080 --> 0:18:55.639 and that woman was arrested. Now she was certain that 0:18:55.720 --> 0:18:58.440 she was doing laundry on the night of February fifth, 0:18:58.520 --> 0:19:02.040 nineteen eighty five, but a police psychologist told her that 0:19:02.119 --> 0:19:05.040 she had witnessed this murder but simply couldn't remember it. 0:19:05.480 --> 0:19:09.560 He said to her, have you ever had memory problems before? 0:19:10.280 --> 0:19:12.960 So she thought about it and insisted that she did 0:19:13.000 --> 0:19:16.840 not have any memory problems. He asked, how about something 0:19:17.320 --> 0:19:22.240 really terribly frightening, like something that really had an impact emotionally. 0:19:23.040 --> 0:19:26.080 So she kept denying this and felt quite certain that 0:19:26.119 --> 0:19:31.639 she couldn't possibly forget a rape and murder scene. She said, quote, 0:19:31.840 --> 0:19:35.480 I just don't understand. I mean, this isn't something I 0:19:35.520 --> 0:19:38.880 would not say anything about. I'm not saying I'm perfect here, 0:19:38.920 --> 0:19:41.960 and I've done my share of little sins, but we're 0:19:42.000 --> 0:19:45.840 talking about killing an old person. End quote. As it 0:19:45.880 --> 0:19:50.080 turned out she had type BE blood and so she 0:19:50.200 --> 0:19:54.560 got charged anyway. Now, there were six people charged for 0:19:54.680 --> 0:19:58.360 this crime, and they became known as the Beatrice Six. 0:19:59.160 --> 0:20:03.560 The first man pled innocence, two more pled no contest, 0:20:04.119 --> 0:20:08.960 but three of the six people pled guilty. They all 0:20:09.000 --> 0:20:12.200 went to jail for well over a decade of their lives, 0:20:12.440 --> 0:20:15.560 and the man who kept insisting on his innocence kept 0:20:15.600 --> 0:20:18.119 trying to get a DNA test done. But it was 0:20:18.160 --> 0:20:20.359 only in two thousand and seven that he was able 0:20:20.400 --> 0:20:24.000 to finally get the Nebraska Supreme Court to make it happen. 0:20:24.640 --> 0:20:28.080 And the incredible result is that he and his five 0:20:28.240 --> 0:20:32.760 co defendants were finally exonerated. They were all found to 0:20:32.800 --> 0:20:38.720 be innocent. Another DNA test revealed the actual perpetrator, a 0:20:38.760 --> 0:20:42.560 Beatrice resident who had died in nineteen ninety two, and 0:20:42.600 --> 0:20:45.760 it appears that he had acted alone in the rape 0:20:45.800 --> 0:20:49.280 and murder. So what this case represents is something so 0:20:50.080 --> 0:20:55.320 stunning about our memory and its stability and its manipulability. 0:20:55.920 --> 0:20:59.800 Although these six people all denied having ever been in 0:20:59.800 --> 0:21:03.000 that woman's apartment, much less committing this crime, several of 0:21:03.040 --> 0:21:07.240 them were able to be convinced that they had repressed 0:21:07.359 --> 0:21:11.160 the memory because it was so traumatic. The psychologist told 0:21:11.200 --> 0:21:14.200 them over and over that the memories of the murder 0:21:14.359 --> 0:21:17.600 would probably come back to them when they were thinking 0:21:17.640 --> 0:21:19.920 deeply about it or having a dream, but it might 0:21:19.960 --> 0:21:22.440 take a while. As it turns out, it didn't even 0:21:22.480 --> 0:21:26.760 take that long. Half the suspects ended up completely believing 0:21:26.880 --> 0:21:29.679 in their guilt, even though they were not there and 0:21:29.720 --> 0:21:32.920 had nothing to do with this. Now, as a side note, 0:21:32.920 --> 0:21:36.960 this whole notion about memory suppression was floating around in 0:21:37.000 --> 0:21:39.760 psychology circles at that time, and there were actually a 0:21:39.840 --> 0:21:44.119 whole bunch of convictions passed down based on this idea, 0:21:44.840 --> 0:21:47.520 Like maybe an adult who comes to believe, let's say, 0:21:47.560 --> 0:21:52.320 through hypnosis that twenty years earlier she was sexually abused 0:21:52.320 --> 0:21:56.000 by someone and that memory had been repressed and she 0:21:56.080 --> 0:21:59.280 had never remembered it until just this moment. And there 0:21:59.320 --> 0:22:00.920 was a window of time I am in the nineteen 0:22:00.960 --> 0:22:03.520 eighties and nineties when a number of people were convicted 0:22:03.640 --> 0:22:07.280 based on this kind of memory testimony. And while it's 0:22:07.320 --> 0:22:10.800 theoretically possible that someone could repress the memory for decades 0:22:10.840 --> 0:22:14.679 and then it pops up, essentially all these repressed memory 0:22:14.680 --> 0:22:20.320 cases were eventually overturned as strong evidence like DNA evidence 0:22:20.400 --> 0:22:23.400 got introduced into the court system, and many of these 0:22:23.400 --> 0:22:27.639 accusations were found to be totally false. But this case 0:22:27.800 --> 0:22:32.480 of the Beatrice six was especially amazing because here people 0:22:32.480 --> 0:22:37.360 who were innocent ended up believing, truly believing that they 0:22:37.480 --> 0:22:41.880 themselves were guilty for three of the six. They absolutely 0:22:41.920 --> 0:22:45.159 believed in their own guilt, and they suffered deep regret 0:22:45.320 --> 0:22:49.479 and shame. These new beliefs they had became just a 0:22:49.520 --> 0:22:54.560 new sedimentary layer in the history of their identity. So 0:22:54.640 --> 0:22:58.399 this is just like Elizabeth loftis receiving misinformation about finding 0:22:58.440 --> 0:23:01.560 her mother's body in the pool, and she came to 0:23:01.600 --> 0:23:05.000 have a memory of it. This is also like Lofts's experiments, 0:23:05.000 --> 0:23:09.200 where she plants false information into the narrative of participants 0:23:09.280 --> 0:23:12.720 in the laboratory. I'm going to link a New Yorker 0:23:12.800 --> 0:23:15.399 article about the Beatrice six in the show notes on 0:23:15.440 --> 0:23:19.840 Eagleman dot com slash podcast, and also an HBO documentary 0:23:19.840 --> 0:23:22.359 about this, so check it out there for more. But 0:23:22.440 --> 0:23:24.680 the point I want to make for now is that 0:23:24.920 --> 0:23:30.320 all these cases demonstrate the malleability and the manipulability of 0:23:30.400 --> 0:23:33.639 our memory, not only about an external story or picture 0:23:33.720 --> 0:23:36.960 or terrorist attack, but even when the memories are about 0:23:37.040 --> 0:23:56.919 our own lives. The writer John Dufresny once wrote that 0:23:57.600 --> 0:24:01.399 memory is a myth making machine. What we do is 0:24:01.600 --> 0:24:05.800 keep revising our past to keep it consistent with who 0:24:05.840 --> 0:24:08.800 we think we are. So think about the narrative of 0:24:08.800 --> 0:24:13.840 your own life. Which parts have you conveniently forgotten because 0:24:13.880 --> 0:24:17.520 they didn't mesh well with the overarching story. What parts 0:24:17.520 --> 0:24:20.199 have you told so many times that they've taken on 0:24:20.240 --> 0:24:24.040 a reality of their own, perhaps a little unanchored from 0:24:24.080 --> 0:24:27.480 what actually went down. Last week I told the story 0:24:27.560 --> 0:24:30.520 of a group of my colleagues who studied what happened 0:24:30.520 --> 0:24:33.680 with memories of nine to eleven. The bottom line was 0:24:33.720 --> 0:24:38.800 that memories drifted. People were given these detailed surveys one 0:24:38.840 --> 0:24:41.080 week after the attack, and then they were tracked down 0:24:41.160 --> 0:24:44.359 a year later and regiven the survey, and it was 0:24:44.400 --> 0:24:48.480 found that accuracy of recall was lower than expected, and 0:24:48.520 --> 0:24:50.800 it got even lower at three years after the event 0:24:50.840 --> 0:24:53.879 and then ten years after the event. But here's the 0:24:53.960 --> 0:24:58.600 important thing to surface. What drifted were the memories about 0:24:58.640 --> 0:25:02.679 the self. The factual memories like who is president at 0:25:02.720 --> 0:25:05.480 the time and how many planes there were? Those were 0:25:05.560 --> 0:25:09.119 essentially stable over time. Why is there some difference in 0:25:09.160 --> 0:25:11.600 the brain and the way they're stored. No, it's because 0:25:11.600 --> 0:25:16.000 those event facts were discussed endlessly in the media and 0:25:16.080 --> 0:25:21.720 in daily conversations, and so any misremembering got automatically corrected 0:25:21.800 --> 0:25:25.160 by the wider environment. In fact, as I mentioned last week, 0:25:25.240 --> 0:25:29.720 the researchers could predict the accuracy of memories just based 0:25:29.760 --> 0:25:33.359 on how much media attention and ensuing conversation there was 0:25:33.440 --> 0:25:38.679 around something. But if you have some flashball memory that 0:25:38.840 --> 0:25:43.160 is inconsistent, like exactly what you were thinking or feeling, 0:25:43.280 --> 0:25:45.480 or even where you were standing or what you saw, 0:25:45.920 --> 0:25:48.840 you're really likely to repeat that a lot over the 0:25:48.880 --> 0:25:53.320 next decade. Digging that story in but that's not likely 0:25:53.440 --> 0:25:57.520 to get corrected by anybody, So the canyon of that 0:25:57.640 --> 0:26:02.640 memory gets etched deep and deeper into the neural landscape, 0:26:03.000 --> 0:26:06.240 even if the river is not flowing in the right spot. 0:26:06.480 --> 0:26:10.400 So personal memories drift, but event memories get corrected back 0:26:10.440 --> 0:26:13.000 into place. And I was thinking about this the other 0:26:13.119 --> 0:26:16.720 day because now it's more than two decades after the 0:26:16.800 --> 0:26:20.240 nine to eleven attacks, and I'm fascinated by how our 0:26:20.400 --> 0:26:26.800 increasing technology might influence our personal memories. So when I 0:26:26.840 --> 0:26:31.640 think about my past, I have some handful of photographs 0:26:31.640 --> 0:26:35.040 that pin me down to reality, at least in particular 0:26:35.119 --> 0:26:38.000 moments when the shutter clicked. In other words, I can't 0:26:38.200 --> 0:26:41.680 misremember those moments in my life too much because there's 0:26:41.720 --> 0:26:45.400 some objective evidence of what I looked like, or what 0:26:45.520 --> 0:26:48.040 I wore, or what the house behind me looked like, 0:26:48.200 --> 0:26:52.000 or what my parents' car looked like. So these photos 0:26:52.480 --> 0:26:58.280 constrain my otherwise drifty memory. They tie my memory to 0:26:58.400 --> 0:27:01.600 some factual version that I can move too far from. 0:27:01.840 --> 0:27:04.840