1 00:00:05,040 --> 00:00:08,760 Speaker 1: When you look at medieval European art, why do the 2 00:00:08,840 --> 00:00:13,440 Speaker 1: people look fine but the lions look so strange? And 3 00:00:13,480 --> 00:00:16,720 Speaker 1: what does this have to do with Native American folklore 4 00:00:17,200 --> 00:00:20,959 Speaker 1: or I witness memory of a car accident, or what 5 00:00:21,079 --> 00:00:25,720 Speaker 1: a person remembers three years after watching the nine to 6 00:00:25,760 --> 00:00:28,680 Speaker 1: eleven attack on the World Trade Center, And what does 7 00:00:28,720 --> 00:00:32,239 Speaker 1: any of this have to do with flashbulb memories or 8 00:00:32,320 --> 00:00:37,320 Speaker 1: misinformation or the telephone game that you played as a child. 9 00:00:40,720 --> 00:00:43,760 Speaker 1: Welcome to Inner Cosmos with me, David Eagleman. I'm a 10 00:00:43,800 --> 00:00:47,320 Speaker 1: neuroscientist and an author at Stanford, and in these episodes 11 00:00:47,440 --> 00:00:50,960 Speaker 1: we sail deeply into our three pound universe to understand 12 00:00:51,120 --> 00:00:54,520 Speaker 1: why and how our lives look the way they do. 13 00:00:55,120 --> 00:00:58,400 Speaker 1: Today's episode is part one of a two parter about 14 00:00:58,600 --> 00:01:05,080 Speaker 1: memory and why it rifts. So I want to start 15 00:01:05,120 --> 00:01:08,200 Speaker 1: with this fascinating observation that you can notice if you 16 00:01:08,319 --> 00:01:12,760 Speaker 1: look across visual painting in Europe all through the Middle Ages. 17 00:01:13,440 --> 00:01:17,840 Speaker 1: Painters got better and better through time at painting architecture 18 00:01:18,200 --> 00:01:22,320 Speaker 1: and the human form and mountain scapes, but they were 19 00:01:22,400 --> 00:01:27,160 Speaker 1: absolutely terrible at painting lions. If you look at lions 20 00:01:27,319 --> 00:01:30,720 Speaker 1: in these medieval paintings, you'll see that they generally look 21 00:01:30,959 --> 00:01:36,240 Speaker 1: quite different from their real life counterparts. They have exaggerated 22 00:01:36,319 --> 00:01:40,679 Speaker 1: features like overly large heads and bodies that are too long, 23 00:01:41,319 --> 00:01:45,720 Speaker 1: and tufted tails that aren't really like actual lion tails, 24 00:01:46,160 --> 00:01:49,240 Speaker 1: and they often look more like large, fierce dogs or 25 00:01:49,280 --> 00:01:53,200 Speaker 1: mythical creatures. I'll put some pictures on eagleman dot com 26 00:01:53,200 --> 00:01:57,080 Speaker 1: slash podcasts so you can see how strange these lions are. 27 00:01:57,480 --> 00:02:02,160 Speaker 1: But why is this? The answer is the medieval European 28 00:02:02,240 --> 00:02:06,080 Speaker 1: painters spent a lot of time with architecture and with 29 00:02:06,400 --> 00:02:09,839 Speaker 1: people and with mountainscapes, but almost none of them had 30 00:02:09,919 --> 00:02:14,040 Speaker 1: ever been to Africa and therefore seen a real lion, 31 00:02:14,480 --> 00:02:16,400 Speaker 1: or for that matter, had been to India and seen 32 00:02:16,400 --> 00:02:21,440 Speaker 1: an asiatic lion. So they had the extremely tough challenge 33 00:02:21,480 --> 00:02:26,080 Speaker 1: of painting something they had never actually seen. Now, to 34 00:02:26,160 --> 00:02:29,160 Speaker 1: be clear, it's not that they had never seen a lion, 35 00:02:29,200 --> 00:02:32,160 Speaker 1: it's that they had never seen a real lion. All 36 00:02:32,200 --> 00:02:35,920 Speaker 1: they had ever seen were versions of lions painted by 37 00:02:36,000 --> 00:02:40,320 Speaker 1: other medieval painters, who presumably had seen pictures of lions 38 00:02:40,320 --> 00:02:43,400 Speaker 1: painted by other medieval painters, and so on back to 39 00:02:43,919 --> 00:02:47,840 Speaker 1: someone who had at some point seen a real lion, 40 00:02:48,280 --> 00:02:51,320 Speaker 1: and so This notion of what a lion looks like 41 00:02:51,800 --> 00:02:56,160 Speaker 1: gives us a visual example of the operator game. This 42 00:02:56,280 --> 00:02:59,880 Speaker 1: is also known as the telephone game or Russian scandal 43 00:03:00,320 --> 00:03:02,800 Speaker 1: or pass the secret. So you remember doing this as 44 00:03:02,840 --> 00:03:05,880 Speaker 1: a kid. One person whispers, let's say a word or 45 00:03:05,919 --> 00:03:08,720 Speaker 1: a little phrase in your ear, and then you whisper 46 00:03:08,800 --> 00:03:11,080 Speaker 1: it to the next person, and they whisper it to 47 00:03:11,160 --> 00:03:13,360 Speaker 1: the next person, and so on, and by the time 48 00:03:13,440 --> 00:03:16,120 Speaker 1: it gets to the last person, she shouts it out 49 00:03:16,360 --> 00:03:18,600 Speaker 1: and you all get to see if it's the same 50 00:03:18,720 --> 00:03:22,000 Speaker 1: word or phrase that the first person said. And the 51 00:03:22,120 --> 00:03:24,720 Speaker 1: joy of the game, of course, is that the message 52 00:03:24,760 --> 00:03:28,079 Speaker 1: gets distorted in transmission, and by the time it ends 53 00:03:28,160 --> 00:03:31,320 Speaker 1: up somewhere it can be very different from how it began. 54 00:03:32,320 --> 00:03:35,560 Speaker 1: So today and next week we're going to dive into 55 00:03:35,680 --> 00:03:40,960 Speaker 1: a strange question, how your own memories are like the 56 00:03:41,040 --> 00:03:45,680 Speaker 1: Operator game. In other words, we tend to erroneously believe 57 00:03:45,880 --> 00:03:49,200 Speaker 1: that when something happens, we record that in the brain. 58 00:03:49,280 --> 00:03:53,240 Speaker 1: It's written down in the brain as a memory, the 59 00:03:53,240 --> 00:03:56,080 Speaker 1: way that a computer might hold a little file. And 60 00:03:56,080 --> 00:03:59,240 Speaker 1: then every time we retrieve that memory, every time we 61 00:03:59,320 --> 00:04:02,600 Speaker 1: pull that back up, we are viewing that little movie again. 62 00:04:03,240 --> 00:04:06,080 Speaker 1: So it comes as a surprise that real human memory 63 00:04:06,120 --> 00:04:08,640 Speaker 1: in the brain is nothing like a movie, but much 64 00:04:08,680 --> 00:04:14,640 Speaker 1: more like the Operator game, wherein the message becomes increasingly distorted. 65 00:04:14,800 --> 00:04:17,800 Speaker 1: For example, let's say I show you a picture of 66 00:04:17,839 --> 00:04:21,080 Speaker 1: something that you're not super familiar with, like an old 67 00:04:21,480 --> 00:04:24,920 Speaker 1: Polynesian war mass with a sort of strange shape in 68 00:04:24,960 --> 00:04:27,240 Speaker 1: some different lines and circles on it, and then I 69 00:04:27,320 --> 00:04:32,120 Speaker 1: ask you to draw it. Later, your drawing will probably 70 00:04:32,279 --> 00:04:35,159 Speaker 1: drift from what you actually saw, and the next time 71 00:04:35,240 --> 00:04:37,560 Speaker 1: after that, when I ask you to draw it again, 72 00:04:38,240 --> 00:04:41,880 Speaker 1: your memory will presumably be influenced by what you drew 73 00:04:42,000 --> 00:04:44,440 Speaker 1: the last time. And if I ask you to do 74 00:04:44,480 --> 00:04:46,920 Speaker 1: this over and over again, let's say once a month, 75 00:04:47,000 --> 00:04:51,120 Speaker 1: there will be something of a steady progression from drawing 76 00:04:51,200 --> 00:04:55,560 Speaker 1: one to drawing ten, because you are playing the operator 77 00:04:55,640 --> 00:05:00,120 Speaker 1: game with yourself. Each time you retrieve the memory, it 78 00:05:00,200 --> 00:05:03,239 Speaker 1: is influenced by what you thought it was last time. 79 00:05:03,520 --> 00:05:06,160 Speaker 1: So to dig into this, we're going to start today's 80 00:05:06,200 --> 00:05:10,160 Speaker 1: episode with a short story. This is a Native American 81 00:05:10,440 --> 00:05:14,400 Speaker 1: folk story called the War of the Ghosts, and it's 82 00:05:14,440 --> 00:05:16,480 Speaker 1: read here by actor Sean Judge. 83 00:05:17,080 --> 00:05:21,560 Speaker 2: War of the Ghosts. One night, two young men from 84 00:05:21,640 --> 00:05:24,760 Speaker 2: Eguilak went down to the river to hunt seals, and 85 00:05:24,839 --> 00:05:28,960 Speaker 2: while they were there it became foggy and calm. Then 86 00:05:29,400 --> 00:05:32,720 Speaker 2: they heard war cries and they thought maybe this is 87 00:05:32,760 --> 00:05:35,920 Speaker 2: a war party. They escaped to the shore and hid 88 00:05:35,960 --> 00:05:39,599 Speaker 2: behind a log. Now canoes came up, and they heard 89 00:05:39,640 --> 00:05:42,440 Speaker 2: the noise of paddles and saw one canoe coming up 90 00:05:42,520 --> 00:05:45,560 Speaker 2: to them. There were five men in the canoe, and 91 00:05:45,640 --> 00:05:48,680 Speaker 2: they said, what do you think we wish to take 92 00:05:48,720 --> 00:05:50,760 Speaker 2: you along. We are going up the river to make 93 00:05:50,800 --> 00:05:53,880 Speaker 2: war on the people. One of the young men said, 94 00:05:54,480 --> 00:05:58,160 Speaker 2: I have no arrows. Arrows are in the canoe. They said, 95 00:05:59,120 --> 00:06:01,720 Speaker 2: I will not go along. I might be killed. My 96 00:06:01,839 --> 00:06:04,520 Speaker 2: relatives do not know where I have gone. But you, 97 00:06:04,880 --> 00:06:07,160 Speaker 2: he said, turning to the other, may go with them. 98 00:06:08,279 --> 00:06:10,760 Speaker 2: So one of the young men went, but the other 99 00:06:10,839 --> 00:06:14,800 Speaker 2: returned home, and the warriors went on up the river 100 00:06:14,920 --> 00:06:17,760 Speaker 2: to a town on the other side of Kalama. The 101 00:06:17,800 --> 00:06:20,119 Speaker 2: people came down to the water and they began to fight, 102 00:06:20,320 --> 00:06:23,960 Speaker 2: and many were killed. But presently the young man heard 103 00:06:24,000 --> 00:06:26,840 Speaker 2: one of the warriors say, quick, let us go home. 104 00:06:27,160 --> 00:06:31,960 Speaker 2: That Indian has been hit. Now he thought, oh, they 105 00:06:32,000 --> 00:06:36,080 Speaker 2: are ghosts. He did not feel sick, but they said 106 00:06:36,160 --> 00:06:40,120 Speaker 2: he had been shot. So the canoes went back to Aguilak, 107 00:06:40,279 --> 00:06:42,400 Speaker 2: and the young man went ashore to his house and 108 00:06:42,440 --> 00:06:46,400 Speaker 2: made a fire, and he told everybody and said, behold, 109 00:06:46,839 --> 00:06:49,960 Speaker 2: I accompanied the ghosts, and we went to fight. Many 110 00:06:50,040 --> 00:06:52,160 Speaker 2: of our fellows were killed, and many of those who 111 00:06:52,200 --> 00:06:55,279 Speaker 2: attacked us were killed. They said, I was hit, but 112 00:06:55,360 --> 00:06:58,760 Speaker 2: I did not feel sick. He told it all, and 113 00:06:58,800 --> 00:07:03,320 Speaker 2: then he became quiet. When the sun rose, he fell down. 114 00:07:04,279 --> 00:07:08,640 Speaker 2: Something black came out of his mouth, his face became contorted. 115 00:07:09,360 --> 00:07:12,840 Speaker 2: The people jumped up and cried he was dead. 116 00:07:13,640 --> 00:07:16,400 Speaker 1: This probably seems to you like a bit of a 117 00:07:16,440 --> 00:07:20,760 Speaker 1: weird story. It seems like it's not particularly well told 118 00:07:20,840 --> 00:07:25,120 Speaker 1: or clear. So given the strangeness of the story, why 119 00:07:25,120 --> 00:07:29,000 Speaker 1: did it become quite famous in the psychology community almost 120 00:07:29,040 --> 00:07:32,120 Speaker 1: a century ago in nineteen thirty two. It's because of 121 00:07:32,160 --> 00:07:36,560 Speaker 1: a researcher named Frederick Bartlett, who was a psychologist at 122 00:07:36,600 --> 00:07:40,640 Speaker 1: Cambridge University. He chose this story, the War of the Ghosts, 123 00:07:41,080 --> 00:07:45,960 Speaker 1: to examine the way that our memories change with time. Now, 124 00:07:46,000 --> 00:07:49,000 Speaker 1: he chose this particular folk tale because he wanted something 125 00:07:49,040 --> 00:07:52,560 Speaker 1: that wasn't crystal clear, so that it might be slightly 126 00:07:52,640 --> 00:07:57,440 Speaker 1: more susceptible to changes in the retelling. That way, he 127 00:07:57,480 --> 00:08:01,520 Speaker 1: could examine the way in which it changed in the retelling, 128 00:08:01,880 --> 00:08:04,760 Speaker 1: and the retelling after that, and so on into the future. 129 00:08:04,880 --> 00:08:08,000 Speaker 1: In other words, he used this story to see if 130 00:08:08,000 --> 00:08:12,920 Speaker 1: he could really shine a light on the constructive character 131 00:08:13,000 --> 00:08:15,800 Speaker 1: of memory. In other words, the way that recalling a 132 00:08:15,840 --> 00:08:22,360 Speaker 1: memory is something like reconstructing what happened your brain rebuilding 133 00:08:22,360 --> 00:08:25,320 Speaker 1: its best guess at a memory, rather than the way 134 00:08:25,400 --> 00:08:29,000 Speaker 1: a computer simply retrieves a file of zeros and ones 135 00:08:29,040 --> 00:08:33,439 Speaker 1: without loss. So in Bartlett's study, he had participants read 136 00:08:33,640 --> 00:08:36,600 Speaker 1: the War of the Ghosts. Then they were instructed to 137 00:08:36,679 --> 00:08:40,280 Speaker 1: recall and write down the story as perfectly as they could. 138 00:08:41,160 --> 00:08:43,559 Speaker 1: Now it's only been about a minute since you heard 139 00:08:43,640 --> 00:08:47,400 Speaker 1: the story, Think about how you would retell it now, 140 00:08:47,480 --> 00:08:51,160 Speaker 1: what details you would remember from that story. Not surprisingly, 141 00:08:51,240 --> 00:08:55,480 Speaker 1: Bartlett found that the story drifted from the original upon 142 00:08:55,600 --> 00:08:59,000 Speaker 1: the retelling. Here, for example, is a person who is 143 00:08:59,080 --> 00:09:03,120 Speaker 1: asked to remember and reproduce the story, and he did 144 00:09:03,120 --> 00:09:07,199 Speaker 1: this multiple times. Here he is on his tenth reproduction. 145 00:09:07,080 --> 00:09:10,440 Speaker 2: War of the Ghosts. Two Indians were out fishing for 146 00:09:10,520 --> 00:09:13,760 Speaker 2: seals in the Bay of Manpapan when along came five 147 00:09:13,840 --> 00:09:17,360 Speaker 2: other Indians in a war canoe. They were going fighting. 148 00:09:18,120 --> 00:09:20,520 Speaker 2: Come with us, said five of the two, and fight. 149 00:09:21,440 --> 00:09:23,760 Speaker 2: I cannot come, was the answer of the one, for 150 00:09:23,880 --> 00:09:25,760 Speaker 2: I have an old mother at home who has dependent 151 00:09:25,840 --> 00:09:28,560 Speaker 2: on me. The other also said he could not come 152 00:09:28,640 --> 00:09:31,880 Speaker 2: because he had no arms. That is no difficulty. The 153 00:09:31,920 --> 00:09:34,800 Speaker 2: others replied, for we have plenty in the canoe with us. 154 00:09:35,640 --> 00:09:38,840 Speaker 2: So he got into the canoe and went with them 155 00:09:39,120 --> 00:09:42,760 Speaker 2: in a fight. Soon afterwards, this Indian received a mortal wound. 156 00:09:43,679 --> 00:09:46,240 Speaker 2: Finding that his hour was come, he cried out that 157 00:09:46,280 --> 00:09:49,440 Speaker 2: he was about to die. Nonsense, said one of the others. 158 00:09:49,720 --> 00:09:53,079 Speaker 2: You will not die, But he did now. 159 00:09:53,160 --> 00:09:56,400 Speaker 1: Bartlett also had other participants read the story and then 160 00:09:56,480 --> 00:09:59,960 Speaker 1: reproduce it at intervals very far apart. In some cases 161 00:10:00,000 --> 00:10:03,760 Speaker 1: this is over years. So here's another participant. This is 162 00:10:03,920 --> 00:10:07,720 Speaker 1: subject p on his first reproduction. 163 00:10:07,679 --> 00:10:11,560 Speaker 2: War of the Ghosts. Two youths were standing by a 164 00:10:11,640 --> 00:10:14,560 Speaker 2: river about to start seal catching when a boat appeared 165 00:10:14,559 --> 00:10:17,960 Speaker 2: with five men in it. They were all armed for war. 166 00:10:18,880 --> 00:10:21,760 Speaker 2: The youths were at first frightened, but they were asked 167 00:10:21,800 --> 00:10:23,720 Speaker 2: by the men to come and help them fight some 168 00:10:23,880 --> 00:10:26,720 Speaker 2: enemies on the other bank. One youth said that he 169 00:10:26,720 --> 00:10:29,320 Speaker 2: could not come, as his relations would be anxious about him. 170 00:10:29,840 --> 00:10:32,360 Speaker 2: The other said he would go and entered the boat. 171 00:10:33,320 --> 00:10:35,880 Speaker 2: In the evening, he returned to his hut and told 172 00:10:35,920 --> 00:10:38,800 Speaker 2: his friends that he had been in a battle. A 173 00:10:38,880 --> 00:10:41,800 Speaker 2: great many had been slain, and he had been wounded 174 00:10:41,840 --> 00:10:44,959 Speaker 2: by an arrow. He had not felt any pain, he said. 175 00:10:45,640 --> 00:10:47,440 Speaker 2: They told him that he must have been fighting a 176 00:10:47,480 --> 00:10:51,920 Speaker 2: battle of ghosts. Then he remembered that it had been queer, 177 00:10:52,240 --> 00:10:56,439 Speaker 2: and he was very excited. In the morning, however, he 178 00:10:56,480 --> 00:11:00,720 Speaker 2: became ill, and his friends gathered round. He fell down 179 00:11:00,840 --> 00:11:05,880 Speaker 2: and his face became very pale. Then he writhed and shrieked, 180 00:11:06,240 --> 00:11:09,920 Speaker 2: and his friends were filled with terror. At last he 181 00:11:10,000 --> 00:11:14,679 Speaker 2: became calm. Something hard and black came out of his mouth, 182 00:11:15,480 --> 00:11:17,839 Speaker 2: and he lay contorted and dead. 183 00:11:18,360 --> 00:11:21,760 Speaker 1: And here he is again when he's asked to reproduce 184 00:11:21,840 --> 00:11:24,160 Speaker 1: the story. After thirty months. 185 00:11:24,520 --> 00:11:28,600 Speaker 2: War of the ghosts, some warriors went to wage war 186 00:11:28,679 --> 00:11:31,760 Speaker 2: against the ghosts. They fought all day, and one of 187 00:11:31,800 --> 00:11:35,280 Speaker 2: their number was wounded. They returned home in the evening 188 00:11:35,600 --> 00:11:39,240 Speaker 2: bearing their sick comrade. As the day drew to a close, 189 00:11:39,400 --> 00:11:42,520 Speaker 2: he became rapidly worse, and the villagers came round him. 190 00:11:43,520 --> 00:11:47,480 Speaker 2: As sunset, he sighed something black came out of his mouth. 191 00:11:48,880 --> 00:12:00,280 Speaker 3: He was dead. 192 00:12:05,320 --> 00:12:08,120 Speaker 1: So what he generally found is that the story became 193 00:12:08,600 --> 00:12:12,200 Speaker 1: shorter with each reproduction. But here was the key. He 194 00:12:12,320 --> 00:12:15,640 Speaker 1: realized that this was more than just the telephone game, 195 00:12:15,920 --> 00:12:21,040 Speaker 1: where a signal just becomes noisier each time it's repeated. Instead, 196 00:12:21,080 --> 00:12:23,720 Speaker 1: with the War of the Ghosts, he found there was 197 00:12:23,800 --> 00:12:27,840 Speaker 1: a pattern to the way the story changed. First of all, 198 00:12:28,240 --> 00:12:33,920 Speaker 1: it typically became more coherent to the speaker, as Bartlett wrote, 199 00:12:34,200 --> 00:12:39,000 Speaker 1: quote no trace of an odd or supernatural element is left. 200 00:12:39,240 --> 00:12:43,440 Speaker 1: We have a perfectly straightforward story of a fight and 201 00:12:43,559 --> 00:12:47,880 Speaker 1: a death end quote. So Bartlett studied the character of 202 00:12:47,920 --> 00:12:52,640 Speaker 1: the changes, and he found that these happened by transforming 203 00:12:52,800 --> 00:12:57,120 Speaker 1: details into things that are more familiar and conventional to 204 00:12:57,280 --> 00:13:01,400 Speaker 1: the person doing the remembering. Sometimes the order of events 205 00:13:01,440 --> 00:13:05,640 Speaker 1: would change, and things would commonly get omitted, like the 206 00:13:05,679 --> 00:13:08,480 Speaker 1: ghosts getting sliced out of the story pretty early on, 207 00:13:09,120 --> 00:13:13,040 Speaker 1: or the wound becoming a matter of flesh not spirit. 208 00:13:13,559 --> 00:13:16,240 Speaker 1: All in all, he was interested in the way that people, 209 00:13:16,760 --> 00:13:21,199 Speaker 1: through time made the parts grow more coherent for themselves. 210 00:13:21,200 --> 00:13:26,280 Speaker 1: In other words, the distortions were driven by a person's schema. Now, 211 00:13:26,280 --> 00:13:28,520 Speaker 1: what does that mean. It means that people morphed the 212 00:13:28,559 --> 00:13:32,160 Speaker 1: story to make it consistent with what's going on in 213 00:13:32,200 --> 00:13:35,240 Speaker 1: their heads. In other words, the changes you make to 214 00:13:35,280 --> 00:13:38,520 Speaker 1: the story are navigated by your internal model, or what 215 00:13:38,559 --> 00:13:44,559 Speaker 1: psychologists call your schema, your mental framework for organizing knowledge 216 00:13:44,720 --> 00:13:49,439 Speaker 1: and guiding perception. This is your brain's unique way of 217 00:13:49,559 --> 00:13:53,080 Speaker 1: seeing the world. So the way the story was distorted 218 00:13:53,520 --> 00:13:56,440 Speaker 1: in terms of the plot and characters and events is 219 00:13:56,559 --> 00:14:00,280 Speaker 1: different in your brain versus someone else's brain. There's a 220 00:14:00,280 --> 00:14:04,800 Speaker 1: lot of differences between individual schema, which is to say, 221 00:14:04,920 --> 00:14:07,920 Speaker 1: if you read the story to someone who's really into boats, 222 00:14:07,960 --> 00:14:11,400 Speaker 1: they might remember something differently than someone who's really into 223 00:14:11,800 --> 00:14:15,280 Speaker 1: Native American history, or someone who's a physician and thinks 224 00:14:15,320 --> 00:14:18,640 Speaker 1: about what causes a person to die. And by the way, 225 00:14:18,679 --> 00:14:22,680 Speaker 1: it's not just individual differences, but also your culture plays 226 00:14:22,680 --> 00:14:26,200 Speaker 1: a massive role in shaping the way that you interpret 227 00:14:26,240 --> 00:14:31,080 Speaker 1: and remember information. So as you recall a story, you 228 00:14:31,520 --> 00:14:35,520 Speaker 1: unconsciously mold it to align with your cultural background and 229 00:14:35,560 --> 00:14:39,120 Speaker 1: your beliefs and your expectations. So this all has to 230 00:14:39,120 --> 00:14:43,120 Speaker 1: do with the differences in internal models. Bartlet's study the 231 00:14:43,160 --> 00:14:47,480 Speaker 1: way that people can't label something until it is recognizable, 232 00:14:47,840 --> 00:14:52,920 Speaker 1: So transformations moved in the direction of the conventions in 233 00:14:52,960 --> 00:14:57,360 Speaker 1: their head. So I think about Bartlett's study all the time, 234 00:14:57,480 --> 00:15:01,560 Speaker 1: for example, and how we consume news. Any news story 235 00:15:01,600 --> 00:15:05,640 Speaker 1: we read this month is remembered differently by you than 236 00:15:05,680 --> 00:15:09,600 Speaker 1: by someone else who reads it through a different political lens. 237 00:15:10,240 --> 00:15:12,640 Speaker 1: Watch anything on the news, and then talk to anyone 238 00:15:12,680 --> 00:15:15,480 Speaker 1: you know who sees the world a little differently, and 239 00:15:15,520 --> 00:15:19,400 Speaker 1: you'll find that it's not impossible that they remember different 240 00:15:19,440 --> 00:15:22,040 Speaker 1: parts of the story than you did, and or they 241 00:15:22,080 --> 00:15:27,680 Speaker 1: remembered them differently. Their distortions in the story are not accidental, 242 00:15:27,760 --> 00:15:31,480 Speaker 1: and nor are yours. They are ways of making things 243 00:15:31,680 --> 00:15:36,320 Speaker 1: internally consistent. Now, psychologists have a lot of ways of 244 00:15:36,440 --> 00:15:41,000 Speaker 1: talking about this, like confirmation bias, which means we tend 245 00:15:41,040 --> 00:15:45,160 Speaker 1: to seek out and remember information that is consistent with 246 00:15:45,280 --> 00:15:48,480 Speaker 1: our internal models, and there are other ways of talking 247 00:15:48,480 --> 00:15:52,160 Speaker 1: about this. I recently did an episode on conspiracy theories, 248 00:15:52,360 --> 00:15:55,120 Speaker 1: and one of the things I highlighted is the way 249 00:15:55,120 --> 00:15:58,880 Speaker 1: that we are attracted to theories that reduce our cognitive 250 00:15:58,920 --> 00:16:02,160 Speaker 1: load or our cog of dissonance. In other words, we 251 00:16:02,320 --> 00:16:05,920 Speaker 1: prefer a clear and easy story, and all this is 252 00:16:06,000 --> 00:16:10,080 Speaker 1: consistent with what Bartlett found in nineteen thirty two. We 253 00:16:10,240 --> 00:16:13,400 Speaker 1: don't remember the story as it is presented to us, 254 00:16:13,840 --> 00:16:17,840 Speaker 1: but rather as our filters allow us to store it 255 00:16:17,960 --> 00:16:21,920 Speaker 1: and recall it. And when I think about the driftiness 256 00:16:22,080 --> 00:16:25,560 Speaker 1: of memory, there are other angles that need to be surfaced. 257 00:16:25,600 --> 00:16:27,400 Speaker 1: And here's the main thing that we're going to talk 258 00:16:27,400 --> 00:16:32,760 Speaker 1: about today. Rather than memory being an accurate video recording 259 00:16:32,920 --> 00:16:35,880 Speaker 1: of a moment in your life, it is a fragile 260 00:16:36,200 --> 00:16:39,760 Speaker 1: brain state from a bygone time that has to be 261 00:16:40,240 --> 00:16:45,280 Speaker 1: resurrected for you to remember. So here's an example. You're 262 00:16:45,360 --> 00:16:48,720 Speaker 1: at a restaurant with a couple that you know who 263 00:16:48,840 --> 00:16:54,160 Speaker 1: are visiting town, and everything you experience triggers particular patterns 264 00:16:54,200 --> 00:16:57,760 Speaker 1: of activity in your brain. For example, there's a particular 265 00:16:58,000 --> 00:17:02,040 Speaker 1: pattern of activity sparked into life by the conversation between 266 00:17:02,080 --> 00:17:05,680 Speaker 1: you and your friends. Another pattern is activated by the 267 00:17:05,720 --> 00:17:09,680 Speaker 1: smell of the coffee. Another pattern is activated by the 268 00:17:09,760 --> 00:17:13,479 Speaker 1: taste of a madeleine cookie. The fact that the waiter 269 00:17:13,720 --> 00:17:16,560 Speaker 1: is limping with a cast on his leg is another 270 00:17:17,080 --> 00:17:21,119 Speaker 1: memorable detail, and that's represented by a different configuration of 271 00:17:21,160 --> 00:17:25,879 Speaker 1: neurons firing. All of these constellations become linked with one another, 272 00:17:26,280 --> 00:17:31,440 Speaker 1: in a vast network of neurons that the hippocampus replays 273 00:17:31,560 --> 00:17:36,399 Speaker 1: over and over until the associations between these scattered neurons, 274 00:17:36,440 --> 00:17:40,479 Speaker 1: these distant points of light, this all becomes fixed into place. 275 00:17:41,280 --> 00:17:44,640 Speaker 1: The neurons that are active at the same time will 276 00:17:44,720 --> 00:17:50,320 Speaker 1: establish stronger connections between them. Sells that fire together wire together. 277 00:17:50,880 --> 00:17:55,680 Speaker 1: The resulting network is the unique signature of that event, 278 00:17:55,840 --> 00:18:00,919 Speaker 1: and it represents your memory of the dinner with them. Now, 279 00:18:01,320 --> 00:18:04,600 Speaker 1: let's imagine that six months later, you taste one of 280 00:18:04,640 --> 00:18:07,840 Speaker 1: those Madeleine cookies just like the one you tasted at 281 00:18:07,880 --> 00:18:12,240 Speaker 1: the dinner with the couple. This very specific key can 282 00:18:12,400 --> 00:18:18,280 Speaker 1: unlock the whole web of associations. The original constellation lights 283 00:18:18,400 --> 00:18:21,719 Speaker 1: up like the lights of a city coming online, and 284 00:18:21,880 --> 00:18:27,120 Speaker 1: suddenly your back in that memory. But although we don't 285 00:18:27,160 --> 00:18:30,840 Speaker 1: always realize it, the memory is not as rich as 286 00:18:30,880 --> 00:18:34,119 Speaker 1: you might have expected. You know that your two friends 287 00:18:34,119 --> 00:18:36,600 Speaker 1: were there, and he must have been wearing a button 288 00:18:36,680 --> 00:18:38,919 Speaker 1: up shirt because he always wears a button up shirt, 289 00:18:39,400 --> 00:18:42,919 Speaker 1: and she was wearing a blue dress, or maybe it 290 00:18:42,960 --> 00:18:46,879 Speaker 1: was purple, might have been green. If you really probe 291 00:18:46,920 --> 00:18:50,360 Speaker 1: the memory, you'll realize that you can't remember the details 292 00:18:50,359 --> 00:18:52,520 Speaker 1: of any of the other diners at the restaurant, even 293 00:18:52,560 --> 00:18:56,240 Speaker 1: though the place was full. So your memory of their 294 00:18:56,240 --> 00:19:01,240 Speaker 1: dinner visit has started to fade. Why well, you have 295 00:19:01,320 --> 00:19:05,000 Speaker 1: a finite number of neurons and they are each required 296 00:19:05,040 --> 00:19:09,680 Speaker 1: to multitask. Every neuron in your head participates in different 297 00:19:09,800 --> 00:19:15,440 Speaker 1: constellations at different times. Your neurons operate in a dynamic 298 00:19:15,720 --> 00:19:20,320 Speaker 1: matrix of shifting relationships, and heavy demand is always placed 299 00:19:20,320 --> 00:19:23,840 Speaker 1: on them to wire with others. So your memory of 300 00:19:23,880 --> 00:19:27,960 Speaker 1: the dinner has become muddied as the neurons involved have 301 00:19:28,080 --> 00:19:33,199 Speaker 1: become co opted to participate in other memory constellations. The 302 00:19:33,560 --> 00:19:39,320 Speaker 1: enemy of memory isn't time, it's other memories. Each new 303 00:19:39,320 --> 00:19:44,359 Speaker 1: event needs to establish new relationships among a finite number 304 00:19:44,400 --> 00:19:48,840 Speaker 1: of neurons. Now, the surprise is that a faded memory 305 00:19:49,280 --> 00:19:53,640 Speaker 1: doesn't feel faded to you. You assume, or at least 306 00:19:53,720 --> 00:19:57,320 Speaker 1: you into it, that the full picture is there. And 307 00:19:57,400 --> 00:20:00,640 Speaker 1: the situation is even worse than this, because because it's 308 00:20:00,680 --> 00:20:04,919 Speaker 1: not just that the memory is fading, it's actually drifting. 309 00:20:05,400 --> 00:20:09,719 Speaker 1: So imagine that in the intervening year since the dinner, 310 00:20:10,040 --> 00:20:14,119 Speaker 1: your two friends have broken up. Thinking back on the dinner, 311 00:20:14,160 --> 00:20:20,280 Speaker 1: you might now misremember sensing red flags. Wasn't he more 312 00:20:20,400 --> 00:20:24,120 Speaker 1: quiet than usual that night? Weren't there moments of awkward 313 00:20:24,240 --> 00:20:27,399 Speaker 1: silence between the two? Well, it'll be difficult to know 314 00:20:27,560 --> 00:20:31,200 Speaker 1: for certain, because the knowledge that's in your network now, 315 00:20:31,600 --> 00:20:34,879 Speaker 1: now that they've broken up, that changes the memory that 316 00:20:35,000 --> 00:20:40,160 Speaker 1: corresponds to. Then you can't help but have your present 317 00:20:40,760 --> 00:20:46,040 Speaker 1: color your past, so an event may be perceived somewhat 318 00:20:46,080 --> 00:20:50,080 Speaker 1: differently by you at different moments in your life now. 319 00:20:50,200 --> 00:20:54,800 Speaker 1: Psychologists have been studying the malleability of memory for many decades, 320 00:20:54,840 --> 00:20:58,000 Speaker 1: and one of the pioneers in the field is Elizabeth 321 00:20:58,119 --> 00:21:02,199 Speaker 1: Loftis at the University of California, Irvine. She transformed the 322 00:21:02,240 --> 00:21:07,000 Speaker 1: field of memory research by showing how susceptible memories are. 323 00:21:07,280 --> 00:21:09,960 Speaker 1: So one of her experiments goes like this. She has 324 00:21:10,040 --> 00:21:14,679 Speaker 1: people watch films of car crashes and then she asks 325 00:21:14,720 --> 00:21:17,560 Speaker 1: them a series of questions to test what they remembered. 326 00:21:17,880 --> 00:21:20,439 Speaker 1: And what she found is that just the way she 327 00:21:20,800 --> 00:21:25,480 Speaker 1: asks the question influences the answer she gets back. So 328 00:21:25,600 --> 00:21:28,920 Speaker 1: if she asks how fast were the cars going when 329 00:21:28,920 --> 00:21:32,080 Speaker 1: they hit each other, she gets an estimate of the speed. 330 00:21:32,440 --> 00:21:35,439 Speaker 1: But if she asks how fast were the cars going 331 00:21:35,800 --> 00:21:40,439 Speaker 1: when they smashed into each other, witnesses give a different estimate. 332 00:21:40,800 --> 00:21:45,000 Speaker 1: Not surprisingly, they believe the cars were going faster when 333 00:21:45,040 --> 00:21:48,000 Speaker 1: she uses the word smashed. Now, if you heard my 334 00:21:48,119 --> 00:21:51,760 Speaker 1: episode on eyewitness testimony, you know that these sorts of 335 00:21:51,840 --> 00:21:54,479 Speaker 1: problems are seen all the time in the legal system. 336 00:21:54,560 --> 00:21:59,679 Speaker 1: For example, there's a related issue known as the misinformation 337 00:21:59,720 --> 00:22:03,120 Speaker 1: of effect. If you witness an event, but then later 338 00:22:03,160 --> 00:22:05,520 Speaker 1: you're told something about that event in terms of what 339 00:22:05,760 --> 00:22:08,359 Speaker 1: happened at the scene, or who is there or what 340 00:22:08,400 --> 00:22:11,640 Speaker 1: they look like, that will become part of your memory too, 341 00:22:12,000 --> 00:22:14,240 Speaker 1: and you may not be able to distinguish what you've 342 00:22:14,280 --> 00:22:18,200 Speaker 1: been told from what actually happened. So Loftus and her 343 00:22:18,240 --> 00:22:21,679 Speaker 1: team study this, for example, by showing people a picture 344 00:22:21,720 --> 00:22:24,960 Speaker 1: of a car at a stop sign, and then afterwards, 345 00:22:25,040 --> 00:22:28,639 Speaker 1: after the picture is removed, they give a text description 346 00:22:28,760 --> 00:22:31,560 Speaker 1: of the same picture, but in the text they say 347 00:22:31,640 --> 00:22:34,879 Speaker 1: it was a yield sign. And then they have people 348 00:22:35,320 --> 00:22:38,840 Speaker 1: draw the picture as they remember it, and people tend 349 00:22:38,880 --> 00:22:42,320 Speaker 1: to draw the original scene with a yield sign. So 350 00:22:42,480 --> 00:22:46,920 Speaker 1: even after an memory is encoded, new information coming in 351 00:22:47,440 --> 00:22:51,120 Speaker 1: like that it was a yield sign will change the retrieval. 352 00:22:51,680 --> 00:22:54,639 Speaker 1: You'll believe that the whole time you saw a yield 353 00:22:54,680 --> 00:23:13,000 Speaker 1: sign there instead of a stop sign. Now all the 354 00:23:13,119 --> 00:23:16,280 Speaker 1: sounds surprising at first. You think I can distinguish my 355 00:23:16,440 --> 00:23:20,680 Speaker 1: own memory from something someone else said, But it turns 356 00:23:20,680 --> 00:23:24,119 Speaker 1: out we can't. And we'll dive more into this in 357 00:23:24,160 --> 00:23:27,919 Speaker 1: a quite shocking way in next week's episode. But I 358 00:23:27,960 --> 00:23:29,840 Speaker 1: want to give you a deeper sense of this now, 359 00:23:29,880 --> 00:23:34,760 Speaker 1: about the changeability of memories. So here's another problem. It's 360 00:23:34,800 --> 00:23:39,280 Speaker 1: a relative of the misinformation effect that psychologists and legal 361 00:23:39,320 --> 00:23:44,160 Speaker 1: theorists have studied, and this is the issue of cowitness contamination. 362 00:23:44,359 --> 00:23:47,159 Speaker 1: The idea is that if you see a crime and 363 00:23:47,240 --> 00:23:49,639 Speaker 1: I'm standing there and I see it too, and then 364 00:23:49,680 --> 00:23:52,960 Speaker 1: we start talking with one another about it, we can't 365 00:23:53,000 --> 00:23:57,720 Speaker 1: help but influence each other's memories. If you remember that 366 00:23:58,200 --> 00:24:00,800 Speaker 1: she had curly hair, but I say I'm pretty sure 367 00:24:00,840 --> 00:24:04,520 Speaker 1: she had straight hair. Or if you think she was unathletic, 368 00:24:04,600 --> 00:24:07,119 Speaker 1: but I say, no, she was really athletic, each of 369 00:24:07,160 --> 00:24:11,480 Speaker 1: our statements become part of each other's memory, and we 370 00:24:11,600 --> 00:24:16,080 Speaker 1: more and more come to believe things that we didn't originally. 371 00:24:16,680 --> 00:24:19,480 Speaker 1: And we see these kinds of memory problems all the time. 372 00:24:19,640 --> 00:24:23,880 Speaker 1: In police lineups. For starters, it's really difficult to remember 373 00:24:24,359 --> 00:24:27,679 Speaker 1: the face of a perpetrator in a crime scene. So 374 00:24:27,880 --> 00:24:32,200 Speaker 1: police and researchers have tried every which way for people 375 00:24:32,240 --> 00:24:36,159 Speaker 1: to have an easier time reconstructing a face. You maybe 376 00:24:36,200 --> 00:24:39,800 Speaker 1: describe it to an artist, or you reassemble the face 377 00:24:39,840 --> 00:24:42,880 Speaker 1: from a selection of different possible eyes and nose shapes 378 00:24:42,920 --> 00:24:45,840 Speaker 1: and mouths, and in the last decades you can do 379 00:24:45,880 --> 00:24:48,880 Speaker 1: this with three D avatars on a computer. But whatever 380 00:24:48,960 --> 00:24:53,160 Speaker 1: tech is introduced, it doesn't matter. People's performance is terrible. 381 00:24:53,359 --> 00:24:58,879 Speaker 1: Why because memories are not like photographs. So one issue 382 00:24:58,920 --> 00:25:02,600 Speaker 1: that researchers started noticing and studying in the nineteen sixties 383 00:25:03,320 --> 00:25:08,399 Speaker 1: was police suggestibility. So imagine you're shown a lineup with 384 00:25:08,480 --> 00:25:11,560 Speaker 1: several people and you have to decide which person you 385 00:25:11,720 --> 00:25:15,680 Speaker 1: saw doing the crime. But imagine that the police already 386 00:25:15,720 --> 00:25:19,200 Speaker 1: have their man in mind. They already think that it's Steve. 387 00:25:19,359 --> 00:25:22,119 Speaker 1: Whether or not that's correct, they believe it's Steve, and 388 00:25:22,160 --> 00:25:24,119 Speaker 1: they want you to say it's Steve. There are all 389 00:25:24,280 --> 00:25:26,399 Speaker 1: kinds of ways that they can suggest that to you, 390 00:25:26,600 --> 00:25:29,400 Speaker 1: even if it's unconscious on their part. So for example, 391 00:25:29,880 --> 00:25:34,280 Speaker 1: positive feedback. If you say I think that's the guy, 392 00:25:34,400 --> 00:25:37,280 Speaker 1: they say, yeah, good job, that's what we think. Also, 393 00:25:37,800 --> 00:25:42,400 Speaker 1: it turns out that the positive feedback influences the confidence 394 00:25:42,560 --> 00:25:46,240 Speaker 1: of the eyewitness, and then when the trial starts months later, 395 00:25:46,400 --> 00:25:50,159 Speaker 1: the eyewitness says, I'm absolutely certain that it was Steve, 396 00:25:50,400 --> 00:25:53,919 Speaker 1: even though he doesn't remember that. He was not certain 397 00:25:54,000 --> 00:25:57,159 Speaker 1: at all, but because of the positive feedback, which can 398 00:25:57,200 --> 00:26:01,159 Speaker 1: even be quite subtle, his confidence goes way up. And 399 00:26:01,320 --> 00:26:05,280 Speaker 1: decades of psychology studies in the laboratory have verified the 400 00:26:05,440 --> 00:26:08,280 Speaker 1: power of this kind of suggestibility. The main thing that 401 00:26:08,640 --> 00:26:13,560 Speaker 1: everybody's worried about with lineups is false identification. In other words, 402 00:26:13,760 --> 00:26:16,600 Speaker 1: if the perpetrator is in the lineup and you miss him, 403 00:26:16,600 --> 00:26:20,000 Speaker 1: that's one kind of problem, But the deeper problem is 404 00:26:20,080 --> 00:26:24,640 Speaker 1: sending an innocent person to prison with the false certainty 405 00:26:25,119 --> 00:26:29,600 Speaker 1: that you remember his face. Now, a particularly interesting study 406 00:26:29,640 --> 00:26:32,800 Speaker 1: was done by my colleague Elizabeth Phelps and her collaborators 407 00:26:32,920 --> 00:26:37,879 Speaker 1: at New York University. On September eleventh, two thousand and one, 408 00:26:38,160 --> 00:26:42,199 Speaker 1: Phelps saw the World Trade Center towers collapse from inside 409 00:26:42,240 --> 00:26:45,480 Speaker 1: her offices, and she, like everyone else in downtown New 410 00:26:45,560 --> 00:26:48,840 Speaker 1: York and around the nation, was completely horrified and thrown 411 00:26:48,920 --> 00:26:53,040 Speaker 1: off balance by the events. But Elizabeth is a neuroscientist, 412 00:26:53,040 --> 00:26:58,440 Speaker 1: and she started thinking about this issue of flashbulb memories. Now, 413 00:26:58,480 --> 00:27:00,400 Speaker 1: this is an idea that's been around for a while 414 00:27:00,440 --> 00:27:05,240 Speaker 1: that maybe really important, shocking public events get flashed into 415 00:27:05,280 --> 00:27:08,639 Speaker 1: the brain in a different way than normal memory, like 416 00:27:09,000 --> 00:27:12,159 Speaker 1: a flashbulb on an old camera that lights up a 417 00:27:12,240 --> 00:27:15,760 Speaker 1: room and captures the moment. And the idea of flashbulb 418 00:27:15,800 --> 00:27:19,480 Speaker 1: memories is that maybe them more consistent. But this sort 419 00:27:19,520 --> 00:27:22,359 Speaker 1: of thing is very difficult to test because you can't 420 00:27:22,520 --> 00:27:27,679 Speaker 1: give people genuinely horrifying experiences in the laboratory, so you 421 00:27:27,720 --> 00:27:30,479 Speaker 1: have to wait for something to happen in real life. 422 00:27:30,840 --> 00:27:34,159 Speaker 1: And Elizabeth and her colleagues realized that this might be 423 00:27:34,359 --> 00:27:36,879 Speaker 1: such a moment to be able to put this to 424 00:27:36,960 --> 00:27:41,840 Speaker 1: the test, So she and another researcher, John Gabrielli, rapidly 425 00:27:41,880 --> 00:27:44,800 Speaker 1: developed a survey, and within a week a whole group 426 00:27:44,800 --> 00:27:48,679 Speaker 1: of researchers from her lab were in the city surveying 427 00:27:48,720 --> 00:27:52,399 Speaker 1: people on what they remembered. And the important part is 428 00:27:52,400 --> 00:27:56,680 Speaker 1: that they conducted this survey one week after September eleventh, 429 00:27:57,080 --> 00:27:59,439 Speaker 1: But then they called up all these people again a 430 00:27:59,520 --> 00:28:02,439 Speaker 1: year later and gave them the same survey, And then 431 00:28:02,480 --> 00:28:05,520 Speaker 1: they did the same thing three years after the attack. 432 00:28:05,880 --> 00:28:09,439 Speaker 1: And eventually they did a follow up study ten years later, 433 00:28:09,840 --> 00:28:12,760 Speaker 1: and this involved more than three thousand participants. Now, the 434 00:28:12,840 --> 00:28:16,959 Speaker 1: key was these events from nine to eleven were highly emotional, 435 00:28:17,400 --> 00:28:20,200 Speaker 1: and in those cases you lay down memory on essentially 436 00:28:20,480 --> 00:28:24,200 Speaker 1: a secondary memory track controlled by the amygdala. So it's 437 00:28:24,240 --> 00:28:28,880 Speaker 1: not just your normal hippocampus mediated memories. These were flashball memories. 438 00:28:29,080 --> 00:28:32,560 Speaker 1: And the question is do emotional memories like this, Are 439 00:28:32,640 --> 00:28:36,280 Speaker 1: they unforgettable or in other words, are they less likely 440 00:28:36,359 --> 00:28:39,680 Speaker 1: to find themselves drifting with time. Well, I'll tell you 441 00:28:39,760 --> 00:28:42,360 Speaker 1: the results, but let's start with asking the question of 442 00:28:42,400 --> 00:28:46,200 Speaker 1: how confident are people in the accuracy of their memory. 443 00:28:46,240 --> 00:28:49,560 Speaker 1: It turns out that if the memory is emotional, you 444 00:28:49,680 --> 00:28:53,440 Speaker 1: have a much higher confidence in its accuracy, but it 445 00:28:53,480 --> 00:28:58,760 Speaker 1: turns out that doesn't necessarily improve the accuracy itself. What 446 00:28:58,880 --> 00:29:02,880 Speaker 1: the study found is that the accuracy of personal recollections 447 00:29:02,920 --> 00:29:06,720 Speaker 1: of nine to eleven decreased over time. So what you 448 00:29:06,800 --> 00:29:10,520 Speaker 1: measure is the consistency of the details, like does the 449 00:29:10,560 --> 00:29:14,520 Speaker 1: person tell the same story that they did originally, And 450 00:29:14,600 --> 00:29:18,080 Speaker 1: what they found was that the consistency was only sixty 451 00:29:18,200 --> 00:29:22,240 Speaker 1: three percent after one year and fifty seven percent after 452 00:29:22,480 --> 00:29:28,520 Speaker 1: three years. People's memories about their emotions were particularly inaccurate, 453 00:29:28,520 --> 00:29:33,640 Speaker 1: with only about forty percent consistency after one year. Despite 454 00:29:33,680 --> 00:29:37,800 Speaker 1: all this, confidence in these memories remained high. So here's 455 00:29:37,800 --> 00:29:42,640 Speaker 1: the thing. Participants were better at remembering factual details about 456 00:29:42,640 --> 00:29:47,160 Speaker 1: the attack which were supported by external reminders, So, for example, 457 00:29:47,480 --> 00:29:52,880 Speaker 1: the number of planes that were involved, that accuracy remains high. Why. Well, 458 00:29:52,920 --> 00:29:56,080 Speaker 1: it turns out this is because there are many facts 459 00:29:56,120 --> 00:29:58,840 Speaker 1: that you learned from all the news around an event, 460 00:29:59,200 --> 00:30:04,600 Speaker 1: and all this external corroboration corrects your memory. But other 461 00:30:04,680 --> 00:30:08,080 Speaker 1: things that are just about your own personal recall these 462 00:30:08,320 --> 00:30:11,760 Speaker 1: drift around in time. In other words, the researchers found 463 00:30:11,800 --> 00:30:15,600 Speaker 1: that they could predict the accuracy of memories just based 464 00:30:15,600 --> 00:30:20,200 Speaker 1: on how much media attention and ensuing conversation there was 465 00:30:20,640 --> 00:30:23,600 Speaker 1: around an event. So if you're asking how many planes 466 00:30:23,640 --> 00:30:26,400 Speaker 1: crashed into the towers, you might get a lot of 467 00:30:26,440 --> 00:30:29,880 Speaker 1: confusion and even misterymembering in the heat of the moment, 468 00:30:30,280 --> 00:30:33,160 Speaker 1: But after a while that all gets straightened out because 469 00:30:33,200 --> 00:30:36,360 Speaker 1: it's a fact that everybody has seen, and conversations and 470 00:30:36,440 --> 00:30:41,680 Speaker 1: news stories can come to eventually agree. In contrast, if 471 00:30:41,720 --> 00:30:45,600 Speaker 1: you have some flashball memory about where you were standing 472 00:30:45,880 --> 00:30:48,520 Speaker 1: and how you were feeling and what you were thinking 473 00:30:49,400 --> 00:30:54,200 Speaker 1: that might drift into inconsistency. There's no one there to 474 00:30:54,240 --> 00:30:58,040 Speaker 1: give you a firm correction on that, and therefore it 475 00:30:58,120 --> 00:31:01,840 Speaker 1: can keep on drifting off in its own direction. And 476 00:31:01,880 --> 00:31:05,800 Speaker 1: as we can extrapolate from Bartlett's War of the Ghost's study, 477 00:31:06,280 --> 00:31:09,720 Speaker 1: the story moves in a direction consistent with who you 478 00:31:09,800 --> 00:31:12,040 Speaker 1: think you are. And this is going to lead us 479 00:31:12,080 --> 00:31:14,680 Speaker 1: into part two. In next week's episode, I'm going to 480 00:31:14,720 --> 00:31:18,880 Speaker 1: talk about what all this means for our identities, as 481 00:31:18,960 --> 00:31:22,280 Speaker 1: most of that data about our personal lives never gets 482 00:31:22,360 --> 00:31:26,520 Speaker 1: correction from the outside. So let's wrap up. I want 483 00:31:26,560 --> 00:31:29,480 Speaker 1: you to take a moment to think about the War 484 00:31:29,680 --> 00:31:33,360 Speaker 1: of the Ghost's story and see what you really remember. 485 00:31:33,440 --> 00:31:35,480 Speaker 1: Take a moment to think about what was in the 486 00:31:35,520 --> 00:31:38,880 Speaker 1: original story, and then rewind to the beginning of this 487 00:31:38,960 --> 00:31:43,600 Speaker 1: episode to see if your memory was actually consistent. What 488 00:31:43,760 --> 00:31:48,160 Speaker 1: the War of the Ghost's Study highlights is the constructive 489 00:31:48,280 --> 00:31:51,560 Speaker 1: nature of memory and the impact of our own internal 490 00:31:51,600 --> 00:31:55,400 Speaker 1: model on the way that we remember narratives. The key 491 00:31:55,600 --> 00:31:58,520 Speaker 1: is that we build our memory, and we are simply 492 00:31:58,560 --> 00:32:01,680 Speaker 1: not built out of the right of machinery to track 493 00:32:01,760 --> 00:32:05,960 Speaker 1: events like perfect records. Instead, we are built of cells 494 00:32:06,360 --> 00:32:09,840 Speaker 1: which have a totally different algorithmic scheme than our computers, 495 00:32:10,080 --> 00:32:13,920 Speaker 1: and as a result, the past can only leave a 496 00:32:14,160 --> 00:32:20,160 Speaker 1: record by modifying the details of neurons and their genetic expression, 497 00:32:20,720 --> 00:32:24,880 Speaker 1: which is a mind blowingly ingenious property of these particular cells. 498 00:32:25,280 --> 00:32:28,400 Speaker 1: But it ain't a hard drive or a video recorder 499 00:32:28,720 --> 00:32:34,640 Speaker 1: that records things accurately, and that's why memory always drifts. 500 00:32:35,040 --> 00:32:37,200 Speaker 1: As I mentioned, in the next episode, we're going to 501 00:32:37,280 --> 00:32:41,880 Speaker 1: zoom in on our personal identity because, after all, who 502 00:32:41,920 --> 00:32:46,280 Speaker 1: we are, who we consider ourselves to be, is fundamentally 503 00:32:46,320 --> 00:32:50,520 Speaker 1: grounded in our memory. Where we've been, what we've done, 504 00:32:50,880 --> 00:32:53,840 Speaker 1: who we were with what happened to us. And this 505 00:32:53,880 --> 00:32:57,200 Speaker 1: is fascinating in the light of what we're talking about today, 506 00:32:57,320 --> 00:33:01,000 Speaker 1: because we've seen that memories are not simply a replaying 507 00:33:01,080 --> 00:33:04,480 Speaker 1: of the past, or not often that accurate. So please 508 00:33:04,520 --> 00:33:07,600 Speaker 1: tune into part two, where we're gonna understand whether our 509 00:33:07,720 --> 00:33:11,320 Speaker 1: notion of the self is based on a mountain of 510 00:33:11,520 --> 00:33:20,040 Speaker 1: narrative that continually drifts from what actually happened. Go to 511 00:33:20,080 --> 00:33:23,400 Speaker 1: Eagleman dot com slash podcast for more information and to 512 00:33:23,480 --> 00:33:27,040 Speaker 1: find further reading. Send me an email at podcasts at 513 00:33:27,080 --> 00:33:30,520 Speaker 1: eagleman dot com with questions or discussion and check out 514 00:33:30,600 --> 00:33:33,800 Speaker 1: Subscribe to Inner Cosmos on YouTube for videos of each 515 00:33:33,840 --> 00:33:38,240 Speaker 1: episode and to leave comments until next time. I'm David Eagleman, 516 00:33:38,480 --> 00:33:50,280 Speaker 1: and we have been drifting together in the Inner Cosmos.