1 00:00:06,760 --> 00:00:10,080 Speaker 1: Why do some people think that the Northern lights make 2 00:00:10,280 --> 00:00:13,640 Speaker 1: noise and other people say that that's impossible. And why 3 00:00:13,640 --> 00:00:19,840 Speaker 1: did Pythagoras think that numbers had colors and personality? And 4 00:00:19,880 --> 00:00:22,520 Speaker 1: what does any of that have to do with creators 5 00:00:22,560 --> 00:00:26,360 Speaker 1: like Vladimir Nabokoff and Billie Eilish, And why do you 6 00:00:26,360 --> 00:00:29,320 Speaker 1: think that a high note on the piano is brighter 7 00:00:29,360 --> 00:00:34,400 Speaker 1: than a low note. Welcome to Inner Cosmos with me, 8 00:00:34,640 --> 00:00:40,120 Speaker 1: David Eagleman. I'm a neuroscientist and an author at Stanford University, 9 00:00:41,479 --> 00:00:45,639 Speaker 1: and I've spent my whole career studying the intersection between 10 00:00:45,880 --> 00:00:55,000 Speaker 1: how the brain works and how we experience life. On 11 00:00:55,080 --> 00:00:58,160 Speaker 1: today's episode, we're going to talk about how we can 12 00:00:58,240 --> 00:01:02,959 Speaker 1: all experience reality a little bit differently. Okay, so this 13 00:01:03,000 --> 00:01:06,920 Speaker 1: story begins in the early nineteen thirties. You've heard about 14 00:01:06,920 --> 00:01:10,000 Speaker 1: the Northern lights, or maybe you've even seen them in person. 15 00:01:10,040 --> 00:01:15,039 Speaker 1: They're these rippling rivers of green blue light in the sky. 16 00:01:15,480 --> 00:01:18,520 Speaker 1: But here's the really strange part. About one hundred years 17 00:01:18,560 --> 00:01:22,319 Speaker 1: ago some people started to make the claim that the 18 00:01:22,360 --> 00:01:26,399 Speaker 1: northern lights make noise. In nineteen thirty one, in the 19 00:01:26,440 --> 00:01:30,800 Speaker 1: journal Nature, a scientist named Harold's Fairdrop wrote a short 20 00:01:30,840 --> 00:01:35,760 Speaker 1: paper that he called Audibility of the Aurora polaris, and 21 00:01:35,840 --> 00:01:40,000 Speaker 1: he wrote, quote, it cannot be doubted that many persons 22 00:01:40,000 --> 00:01:45,000 Speaker 1: have heard a distinct sound when watching a brilliant display 23 00:01:45,120 --> 00:01:50,520 Speaker 1: of aurora. Communications regarding the auroral sound appear now and then, 24 00:01:51,080 --> 00:01:51,800 Speaker 1: and recently. 25 00:01:52,200 --> 00:01:53,320 Speaker 2: Mister J. H. 26 00:01:53,440 --> 00:01:56,360 Speaker 1: Johnson has collected a great number of reports on the 27 00:01:56,440 --> 00:02:02,520 Speaker 1: auroral sound in his pamphlet concern the Aurora borealis. Then, 28 00:02:02,720 --> 00:02:06,280 Speaker 1: in nineteen thirty three in the journal Science, someone named 29 00:02:06,320 --> 00:02:10,080 Speaker 1: Clark Garber wrote another letter on the audibility of the 30 00:02:10,160 --> 00:02:15,320 Speaker 1: Aurora borealis, and Garber wrote quote, some scientists have claimed 31 00:02:15,400 --> 00:02:19,639 Speaker 1: with much positiveness that the aurora emits no audible sounds. 32 00:02:20,080 --> 00:02:22,880 Speaker 1: In my own mind, there can be no doubt left 33 00:02:23,320 --> 00:02:27,320 Speaker 1: as to the audibility of certain types of aurora, for 34 00:02:27,480 --> 00:02:30,480 Speaker 1: I have heard them under conditions when no other sound 35 00:02:30,560 --> 00:02:34,440 Speaker 1: could have been interpreted as such, for no other sounds 36 00:02:34,480 --> 00:02:37,680 Speaker 1: were present. And he goes on to say that he 37 00:02:37,800 --> 00:02:41,440 Speaker 1: first heard about the possibility that the aurora makes sounds 38 00:02:41,840 --> 00:02:44,720 Speaker 1: from the eskimos, and he says he was skeptical at first, 39 00:02:44,760 --> 00:02:48,919 Speaker 1: but then he experienced this sound himself. Now I stumbled 40 00:02:48,960 --> 00:02:51,680 Speaker 1: on these papers a few years ago, and I was 41 00:02:51,720 --> 00:02:56,840 Speaker 1: surprised because the problem is that it's not scientifically possible 42 00:02:57,000 --> 00:03:01,400 Speaker 1: for the Aurora to make sound. The Northern Lights happen 43 00:03:01,520 --> 00:03:06,040 Speaker 1: because photons from the Sun are banging into gases in 44 00:03:06,040 --> 00:03:09,720 Speaker 1: the Earth's upper atmosphere, and that causes all that amazing light. 45 00:03:10,080 --> 00:03:13,720 Speaker 1: But those collisions are happening eighty kilometers up in the sky, 46 00:03:14,600 --> 00:03:17,639 Speaker 1: which means that even if there were sound, it would 47 00:03:17,720 --> 00:03:20,960 Speaker 1: take about four minutes for that sound to get down here. 48 00:03:21,440 --> 00:03:24,600 Speaker 1: And yet people who claim to hear the sound say 49 00:03:24,639 --> 00:03:28,240 Speaker 1: they see it happening in lockstep with the lights. And 50 00:03:28,320 --> 00:03:31,760 Speaker 1: more importantly, for sound to travel it needs a medium 51 00:03:32,120 --> 00:03:35,360 Speaker 1: like air, and that's because sound moves as compression of 52 00:03:35,400 --> 00:03:38,240 Speaker 1: the air. In other words, molecules in the air get 53 00:03:38,280 --> 00:03:41,240 Speaker 1: pushed closer together and farther apart, and that's what a 54 00:03:41,360 --> 00:03:45,560 Speaker 1: sound wave is. But at the altitude where the Northern 55 00:03:45,640 --> 00:03:49,960 Speaker 1: Lights come into being, the atmosphere is essentially a vacuum. 56 00:03:50,520 --> 00:03:52,280 Speaker 2: So this means there's probably no. 57 00:03:52,360 --> 00:03:56,040 Speaker 1: Sound happening even up there, and if there were, it 58 00:03:56,080 --> 00:03:56,800 Speaker 1: couldn't get all. 59 00:03:56,800 --> 00:03:58,520 Speaker 2: The way to us until four minutes later. 60 00:03:58,920 --> 00:04:02,600 Speaker 1: So this became a top of debate because as time 61 00:04:02,680 --> 00:04:07,280 Speaker 1: went on, thousands of Arctic explorers listened carefully for these 62 00:04:07,280 --> 00:04:11,120 Speaker 1: sounds but didn't hear anything. So this idea of the 63 00:04:11,160 --> 00:04:15,600 Speaker 1: northern lights making noise came to be understood as a superstition. 64 00:04:16,279 --> 00:04:20,400 Speaker 1: So what was happening here? Were some people simply lying 65 00:04:20,560 --> 00:04:25,240 Speaker 1: in scientific journals It's happened before, But it seems that 66 00:04:25,320 --> 00:04:29,719 Speaker 1: some people really believed and still believe, the lights make sound, 67 00:04:30,279 --> 00:04:33,400 Speaker 1: even though the physics don't seem to allow that. So 68 00:04:33,600 --> 00:04:37,440 Speaker 1: worse Ferdrup and Garber lying, were they looking for attention 69 00:04:38,120 --> 00:04:41,560 Speaker 1: that they somehow have better hearing? Even today? This is 70 00:04:41,680 --> 00:04:46,880 Speaker 1: contentious in geophysics. Some people argue from their personal experience 71 00:04:46,960 --> 00:04:51,480 Speaker 1: that it happens, and others point out that it simply can't. 72 00:04:52,200 --> 00:04:56,320 Speaker 1: To unpack this mystery, let's jump back even farther back 73 00:04:56,400 --> 00:05:01,800 Speaker 1: another twenty five hundred years to Pythagoras. Pythagoras was one 74 00:05:01,839 --> 00:05:06,680 Speaker 1: of Greece's most famous philosophers, and he massively influenced the 75 00:05:06,800 --> 00:05:11,680 Speaker 1: trajectory of Western thought through his religious teachings his political teachings. 76 00:05:12,080 --> 00:05:14,880 Speaker 1: In part this was due to his influence on Plato 77 00:05:14,960 --> 00:05:18,560 Speaker 1: and Aristotle. But you've probably heard of Pythagoras because of 78 00:05:18,600 --> 00:05:24,159 Speaker 1: his love of numbers. He loved geometry and theories about 79 00:05:24,240 --> 00:05:28,800 Speaker 1: instrument tuning and the theory of proportions, and you'll probably 80 00:05:28,839 --> 00:05:33,880 Speaker 1: remember the Pythagorean theorem from school in a right triangle, 81 00:05:34,360 --> 00:05:38,080 Speaker 1: A squared plus B squared equals C squared. But there 82 00:05:38,120 --> 00:05:43,760 Speaker 1: was something very odd about Pythagoras's relationship with numbers. I'm 83 00:05:43,800 --> 00:05:47,760 Speaker 1: going to quote from the Yale historian Robert Brumbaugh, who 84 00:05:47,800 --> 00:05:53,800 Speaker 1: notes that for Pythagoras quote, each number had its own personality, 85 00:05:54,560 --> 00:06:02,760 Speaker 1: masculine or feminine, perfect or incomplete, beautiful or ugly. For Pythagoras, 86 00:06:02,839 --> 00:06:07,320 Speaker 1: ten was the very best number. This feeling modern mathematics 87 00:06:07,320 --> 00:06:11,640 Speaker 1: has deliberately eliminated, but we still find overtones of it 88 00:06:11,839 --> 00:06:20,159 Speaker 1: in fiction and poetry. Now, how could numbers have gender 89 00:06:20,360 --> 00:06:25,880 Speaker 1: and personality? Did Pythagoras have fundamental insight about numbers that 90 00:06:25,920 --> 00:06:29,080 Speaker 1: the rest of us couldn't see? Or was he making 91 00:06:29,160 --> 00:06:32,240 Speaker 1: up stuff to impress his followers, or was he mentally 92 00:06:32,279 --> 00:06:36,920 Speaker 1: ill or taking drugs. The way that he personified numbers 93 00:06:37,080 --> 00:06:41,599 Speaker 1: is traditionally discussed as an interesting oddity, or occasionally you'll 94 00:06:41,640 --> 00:06:46,400 Speaker 1: find numerologists who cite Pythagoras's view as evidence that he 95 00:06:46,440 --> 00:06:49,800 Speaker 1: had a cosmic insight into the true natures of numbers. 96 00:06:50,240 --> 00:06:55,919 Speaker 1: I've seen websites that springboard from Pythagoras's number personalities to 97 00:06:56,080 --> 00:06:59,080 Speaker 1: sell new age models of the nature of the universe. 98 00:06:59,400 --> 00:07:02,760 Speaker 1: But most people don't believe that the number five has 99 00:07:02,800 --> 00:07:06,240 Speaker 1: a gender or a personality. So what was going on 100 00:07:06,360 --> 00:07:08,719 Speaker 1: here and what does this have to do with the 101 00:07:08,760 --> 00:07:12,560 Speaker 1: scientists who claim to hear sounds from the Northern Lights. 102 00:07:12,840 --> 00:07:16,080 Speaker 1: The answer to both these mysteries is related to something 103 00:07:16,440 --> 00:07:19,560 Speaker 1: I'm going to discuss a lot across many episodes of 104 00:07:19,600 --> 00:07:25,320 Speaker 1: this podcast, and that is the difference in people's internal worlds. 105 00:07:25,800 --> 00:07:28,160 Speaker 1: We all like to believe that our experience of the 106 00:07:28,160 --> 00:07:31,239 Speaker 1: world is the same as everyone else's. But the key 107 00:07:31,440 --> 00:07:35,440 Speaker 1: to unlocking the mystery of the Northern Lights or Pythagoras's 108 00:07:35,520 --> 00:07:38,960 Speaker 1: view of numbers is to understand that people can have 109 00:07:39,240 --> 00:07:44,840 Speaker 1: very different realities on the inside. The interesting part, as 110 00:07:44,880 --> 00:07:49,200 Speaker 1: we'll see, is that we accept the reality presented to us. 111 00:07:49,560 --> 00:07:53,160 Speaker 1: Your brain constructs a story about what's going on out there, 112 00:07:53,680 --> 00:07:57,880 Speaker 1: and you accept that as your reality. So imagine I 113 00:07:58,080 --> 00:08:00,680 Speaker 1: showed you a picture of a crowd of people. If 114 00:08:00,680 --> 00:08:04,440 Speaker 1: you're color blind, all you see are shades of gray. 115 00:08:04,600 --> 00:08:07,400 Speaker 1: If you're not colorblind, you see it in full color. 116 00:08:07,800 --> 00:08:11,360 Speaker 1: But either way, that's the reality that you know. And 117 00:08:11,400 --> 00:08:14,360 Speaker 1: we now know that a very tiny fraction of the 118 00:08:14,400 --> 00:08:19,800 Speaker 1: female population doesn't just have three types of color photoreceptors 119 00:08:19,840 --> 00:08:22,600 Speaker 1: in their eyes, but they have four types because of 120 00:08:22,640 --> 00:08:27,440 Speaker 1: a mutation, and as a result, they perceive colors that 121 00:08:27,520 --> 00:08:31,800 Speaker 1: the rest of us can't even imagine. Their reality is different. 122 00:08:32,400 --> 00:08:36,840 Speaker 1: So the key is we accept whatever reality our brains 123 00:08:37,080 --> 00:08:40,679 Speaker 1: serve up to us. Okay, So this all leads to 124 00:08:40,720 --> 00:08:44,440 Speaker 1: a very old philosophical question which I think everyone has 125 00:08:44,480 --> 00:08:47,080 Speaker 1: asked at some point in their lives. How do you 126 00:08:47,320 --> 00:08:50,960 Speaker 1: know that what I see as blue is what you 127 00:08:51,120 --> 00:08:54,840 Speaker 1: see as blue? My parents taught me to call that 128 00:08:54,960 --> 00:08:58,960 Speaker 1: thing blue, and your parents taught you to call it blue. 129 00:08:59,480 --> 00:09:01,760 Speaker 2: Two. But inside your. 130 00:09:01,640 --> 00:09:05,640 Speaker 1: Head and inside my head, it might be a different experience. 131 00:09:05,760 --> 00:09:05,960 Speaker 2: Right. 132 00:09:06,080 --> 00:09:08,120 Speaker 1: I might be seeing it as what you would think 133 00:09:08,160 --> 00:09:12,040 Speaker 1: of as green, But it doesn't matter, and we'd never 134 00:09:12,160 --> 00:09:16,040 Speaker 1: know as long as we can transact in the outside world. 135 00:09:16,320 --> 00:09:18,600 Speaker 1: In other words, if I say, hey, can you pass 136 00:09:18,640 --> 00:09:21,640 Speaker 1: me that blue thing, and we both call it blue, 137 00:09:22,240 --> 00:09:25,960 Speaker 1: then the word suffices, even if we're having a different 138 00:09:26,280 --> 00:09:30,240 Speaker 1: internal experience and it turns out. The situation might be 139 00:09:30,360 --> 00:09:32,760 Speaker 1: even worse than that. It may be that what I 140 00:09:32,920 --> 00:09:36,400 Speaker 1: call vision and what you call vision are totally different. 141 00:09:36,640 --> 00:09:39,800 Speaker 1: I might see the world completely upside down from the 142 00:09:39,800 --> 00:09:43,160 Speaker 1: way that you see the world, and it wouldn't matter 143 00:09:43,520 --> 00:09:46,160 Speaker 1: as long as we can agree on things out there, 144 00:09:46,200 --> 00:09:48,360 Speaker 1: and I can throw a ball and you can catch it. 145 00:09:48,679 --> 00:09:50,679 Speaker 1: So what my colleagues and I have worked on for 146 00:09:50,840 --> 00:09:55,199 Speaker 1: years is taking this question or we having different lives 147 00:09:55,240 --> 00:09:59,040 Speaker 1: on the inside and elevating that from the realm of 148 00:09:59,600 --> 00:10:05,040 Speaker 1: phys sophical speculation to actual scientific experiment. And one way 149 00:10:05,080 --> 00:10:07,640 Speaker 1: to get at that this was something my lab is 150 00:10:07,679 --> 00:10:14,000 Speaker 1: studied for fifteen years called sinnesthesia. Synesthesia is a condition 151 00:10:14,559 --> 00:10:18,040 Speaker 1: in which one person might be seeing reality a little 152 00:10:18,040 --> 00:10:22,200 Speaker 1: bit differently from another. So you know the word anesthesia, 153 00:10:22,280 --> 00:10:28,679 Speaker 1: that means no feeling. Synesthesia means joined feeling. It's a 154 00:10:28,760 --> 00:10:33,560 Speaker 1: blending of the senses. Now, there are many forms of synesthesia, 155 00:10:33,600 --> 00:10:35,959 Speaker 1: and one of the most common is where a person 156 00:10:36,559 --> 00:10:40,800 Speaker 1: looks at numbers or letters and that triggers an internal 157 00:10:40,840 --> 00:10:45,680 Speaker 1: experience of color. So for a given synesthete, her eight 158 00:10:46,120 --> 00:10:49,800 Speaker 1: might trigger the experience of blue. She still sees the 159 00:10:49,880 --> 00:10:52,160 Speaker 1: number eight on the page. There if I were to 160 00:10:52,400 --> 00:10:54,880 Speaker 1: write eight with black ink on a white page, she'd 161 00:10:54,920 --> 00:10:57,640 Speaker 1: say that she can see the number, but seeing the 162 00:10:57,720 --> 00:11:02,800 Speaker 1: number eight triggers a blue experience, an internal experience of blue. 163 00:11:03,679 --> 00:11:06,400 Speaker 1: And it's just self evidently true for her that eight 164 00:11:06,800 --> 00:11:12,040 Speaker 1: and blue are connected. Now this isn't just a memorized 165 00:11:12,080 --> 00:11:15,640 Speaker 1: thing that she says, but it's an actual experience. And 166 00:11:15,760 --> 00:11:20,640 Speaker 1: for her, maybe five is yellow, and Saturday is orange, 167 00:11:20,840 --> 00:11:27,000 Speaker 1: and November is purple and so on. Now, the first 168 00:11:27,040 --> 00:11:30,360 Speaker 1: thing to note is that sequences that we learn, like 169 00:11:30,559 --> 00:11:34,160 Speaker 1: letters and numbers and weekdays and months, these are drilled 170 00:11:34,200 --> 00:11:36,600 Speaker 1: into the brain really deeply. They're known in the field 171 00:11:36,640 --> 00:11:42,440 Speaker 1: as overlearned sequences, and these are the things that trigger synesthesia. 172 00:11:42,800 --> 00:11:47,600 Speaker 1: And interestingly, this often goes beyond color in when flavor 173 00:11:47,640 --> 00:11:52,839 Speaker 1: of synesthesia, sequences come to have gender and personality and 174 00:11:52,920 --> 00:11:58,160 Speaker 1: other qualities. So one cynesthete describes the number three as 175 00:11:58,480 --> 00:12:04,760 Speaker 1: a vain, elitist girl, while seven is a shy, wimpy boy. 176 00:12:05,160 --> 00:12:08,640 Speaker 1: This same cynisthe described by my colleague Sean Day. She 177 00:12:08,800 --> 00:12:13,000 Speaker 1: also noted that she doesn't like certain number combinations, like 178 00:12:13,320 --> 00:12:14,079 Speaker 1: ninety four. 179 00:12:14,840 --> 00:12:17,000 Speaker 2: That quote result. 180 00:12:16,559 --> 00:12:20,960 Speaker 1: In putting four, which is a plain but decent, hardworking 181 00:12:21,000 --> 00:12:25,480 Speaker 1: older woman and nine together as they greatly dislike each 182 00:12:25,520 --> 00:12:28,440 Speaker 1: other and do not get along well. And this is 183 00:12:28,480 --> 00:12:31,800 Speaker 1: what was going on with Pythagoras. He had this not 184 00:12:32,120 --> 00:12:36,480 Speaker 1: uncommon form of synesthesia, but his followers didn't know this, 185 00:12:36,920 --> 00:12:40,760 Speaker 1: so they presumably thought he was tapped into some cosmic 186 00:12:40,840 --> 00:12:44,680 Speaker 1: truth about numbers. He obviously liked numbers, but that doesn't 187 00:12:44,720 --> 00:12:49,400 Speaker 1: mean he had access to some deeper significance that others didn't. 188 00:12:49,920 --> 00:12:53,000 Speaker 1: How do we know that, Because each person with this 189 00:12:53,080 --> 00:12:57,760 Speaker 1: particular type of synesthesia has a different association between a 190 00:12:57,760 --> 00:13:02,280 Speaker 1: particular number and a gender personality. So you might think 191 00:13:02,480 --> 00:13:06,000 Speaker 1: three is male and kind, and someone else might think 192 00:13:06,320 --> 00:13:09,160 Speaker 1: three is female and a bit of a comic, and 193 00:13:09,200 --> 00:13:12,680 Speaker 1: so on. There is no right answer. So we're gonna 194 00:13:12,720 --> 00:13:14,520 Speaker 1: come back to this in a moment, But first I 195 00:13:14,559 --> 00:13:17,800 Speaker 1: want to tell you about some other forms of synesthesia. 196 00:13:18,320 --> 00:13:22,120 Speaker 1: It's not just colors or genders or personalities triggered by 197 00:13:22,559 --> 00:13:27,240 Speaker 1: overlearned sequences. There's also a flavor of synesthesia in which 198 00:13:27,640 --> 00:13:32,160 Speaker 1: what you hear causes a visual experience. So you might 199 00:13:32,559 --> 00:13:35,840 Speaker 1: listen to music and that causes you to see moving 200 00:13:36,000 --> 00:13:41,640 Speaker 1: shapes or colors. In my book, Wednesday's Indigo Blue. I 201 00:13:41,679 --> 00:13:44,040 Speaker 1: have a picture of a shape that looks like a 202 00:13:44,080 --> 00:13:48,640 Speaker 1: colorful caterpillar, and this is what one synesthete sees. She 203 00:13:48,720 --> 00:13:52,240 Speaker 1: actually sees this when her furnace kicks on and goes whoosh. 204 00:13:52,600 --> 00:13:56,160 Speaker 1: She has this visual experience that flashes for her. Her 205 00:13:56,360 --> 00:14:01,240 Speaker 1: visual system gets tickled by the noise, and senses can 206 00:14:01,280 --> 00:14:05,000 Speaker 1: be triggered in the other direction, where something visual leads 207 00:14:05,040 --> 00:14:08,720 Speaker 1: to a sound. For some people, when they watch movement 208 00:14:08,920 --> 00:14:13,280 Speaker 1: like a swarm of moving birds or an electric sign blinking, 209 00:14:13,880 --> 00:14:16,920 Speaker 1: they feel like they hear a sound with it. They 210 00:14:16,920 --> 00:14:20,760 Speaker 1: don't see the motion by itself. Their brain imposes sound 211 00:14:20,840 --> 00:14:24,320 Speaker 1: on top of that. It's impossible to separate the motion 212 00:14:24,480 --> 00:14:27,160 Speaker 1: and the sound. And I've proposed that this is the 213 00:14:27,280 --> 00:14:32,040 Speaker 1: solution to the mystery of the Northern lights. It's impossible 214 00:14:32,040 --> 00:14:34,200 Speaker 1: from a physics point of view for the lights to 215 00:14:34,240 --> 00:14:37,840 Speaker 1: be making synchronized noise. But what is possible is for 216 00:14:37,960 --> 00:14:42,760 Speaker 1: a small fraction of the population to be cinnesthetic, such 217 00:14:42,800 --> 00:14:47,400 Speaker 1: that when they see the beautiful moving lights, they hear sound. 218 00:14:48,280 --> 00:14:51,320 Speaker 1: And because of their assumption that our senses tell us 219 00:14:51,360 --> 00:14:54,920 Speaker 1: the truth and that everyone should be having the same experience, 220 00:14:55,480 --> 00:14:58,000 Speaker 1: this has led to over a century of debate about 221 00:14:58,000 --> 00:15:01,280 Speaker 1: whether the lights make noise or not, because if your 222 00:15:01,600 --> 00:15:04,240 Speaker 1: sphare drop or Gerber or any of the others who 223 00:15:04,360 --> 00:15:07,000 Speaker 1: hear the sounds, you'll sit down and you'll write a 224 00:15:07,120 --> 00:15:11,120 Speaker 1: letter to nature or science and insist that you can 225 00:15:11,160 --> 00:15:16,680 Speaker 1: hear it. The important lesson is that we all assume 226 00:15:17,040 --> 00:15:20,680 Speaker 1: our senses tell us the truth and that everyone is 227 00:15:20,720 --> 00:15:24,520 Speaker 1: tapped into the same reality. But when we realize that's 228 00:15:24,520 --> 00:15:28,160 Speaker 1: not necessarily the case, we can take a higher view 229 00:15:28,200 --> 00:15:31,200 Speaker 1: on the scientific literature and look at all these papers 230 00:15:31,240 --> 00:15:34,440 Speaker 1: going back and forth about whether the northern lights make noise, 231 00:15:35,040 --> 00:15:38,080 Speaker 1: and we can understand the game at a different level. 232 00:15:38,720 --> 00:15:42,120 Speaker 1: For most people the answer is no, they don't make noise, 233 00:15:42,560 --> 00:15:47,200 Speaker 1: and for some it's yes. Beyond the relationship of sound 234 00:15:47,240 --> 00:15:51,560 Speaker 1: and vision, there are dozens of forms of synesthesia. My 235 00:15:51,680 --> 00:15:54,680 Speaker 1: colleagues and I have found that essentially any sense that 236 00:15:54,720 --> 00:15:57,880 Speaker 1: you can imagine can be mixed with another. One form 237 00:15:57,920 --> 00:16:03,240 Speaker 1: of synesthesia involves tastes shapes, So when people taste something, 238 00:16:03,320 --> 00:16:06,680 Speaker 1: it makes them feel like they're touching something with their fingertips. 239 00:16:07,200 --> 00:16:09,880 Speaker 1: So you might take a sip of soup and you 240 00:16:09,920 --> 00:16:13,160 Speaker 1: feel something cold and pointy on your fingertips. Or one 241 00:16:13,200 --> 00:16:16,120 Speaker 1: guy determines whether his chicken is cooked right this way. 242 00:16:16,200 --> 00:16:19,600 Speaker 1: He tastes it and judges by what he's feeling on 243 00:16:19,680 --> 00:16:24,480 Speaker 1: his fingertips, is it smooth or glassy or spiky. He 244 00:16:24,520 --> 00:16:26,720 Speaker 1: comes to be a good cook that way. And there's 245 00:16:26,720 --> 00:16:31,600 Speaker 1: also musical synesthesia. For a lot of people, different notes 246 00:16:31,600 --> 00:16:36,360 Speaker 1: of the scale will trigger a color experience. For one 247 00:16:36,400 --> 00:16:39,680 Speaker 1: cynisthee that I test in the lab, when she hits 248 00:16:39,720 --> 00:16:44,520 Speaker 1: the note A on the piano, that's pink, the note 249 00:16:44,600 --> 00:16:51,440 Speaker 1: B is blue. C is goldish white like sunlight. B 250 00:16:52,160 --> 00:16:58,240 Speaker 1: is silvery white like moonlight. E is fiery orange, and 251 00:16:58,280 --> 00:17:02,480 Speaker 1: so on, So she experiences very specific colors that get 252 00:17:02,520 --> 00:17:06,679 Speaker 1: triggered when she hears specific notes. And I know a 253 00:17:06,680 --> 00:17:10,400 Speaker 1: professional drum tuner who goes around for all the famous 254 00:17:10,480 --> 00:17:13,520 Speaker 1: rock and roll bands and tunes their drums, and he 255 00:17:13,560 --> 00:17:16,560 Speaker 1: does it with color, so he can tell if the 256 00:17:16,640 --> 00:17:18,560 Speaker 1: drum is a little bit sharp or a little bit 257 00:17:18,600 --> 00:17:22,239 Speaker 1: flat by the color that he sees in response to 258 00:17:22,359 --> 00:17:26,840 Speaker 1: the sound. Now, not all people with music synesthesia have 259 00:17:27,000 --> 00:17:31,600 Speaker 1: their percepts triggered by a pitch a note. For some people, 260 00:17:31,720 --> 00:17:36,360 Speaker 1: it's the interval between notes like a chord that matters. 261 00:17:36,760 --> 00:17:41,720 Speaker 1: So for one woman, different chords trigger different, very particular 262 00:17:41,880 --> 00:17:45,199 Speaker 1: tastes in the mouth. In a paper in the journal Nature, 263 00:17:45,600 --> 00:17:50,640 Speaker 1: she reported that she uses these sinnesthetic associations to identify 264 00:17:50,760 --> 00:17:54,240 Speaker 1: which chord was just played. And synesthesia can also be 265 00:17:54,359 --> 00:17:57,880 Speaker 1: triggered by an instrument's tamber, the way that it sounds. 266 00:17:58,359 --> 00:18:01,400 Speaker 1: So when a person hears the music of a violin 267 00:18:01,760 --> 00:18:06,400 Speaker 1: versus a tuba, versus a cello versus a flute, the 268 00:18:06,480 --> 00:18:11,159 Speaker 1: timbre of the instrument can trigger very different experiences in 269 00:18:11,240 --> 00:18:15,800 Speaker 1: terms of colors or visualized shapes or whatever. So two 270 00:18:15,840 --> 00:18:19,480 Speaker 1: people might listen to a clarinet playing and that triggers 271 00:18:19,960 --> 00:18:24,320 Speaker 1: different internal experiences. One of them sees it as a flat, 272 00:18:24,400 --> 00:18:28,639 Speaker 1: horizontal shape with spring like protrusions sticking out, and the 273 00:18:28,760 --> 00:18:33,080 Speaker 1: other person sees it as a thick ribbon that's oscillating, 274 00:18:33,600 --> 00:18:37,520 Speaker 1: and so on. For different cinisthetes. And beyond shapes or colors, 275 00:18:37,560 --> 00:18:42,600 Speaker 1: it can trigger other notions as well, like personalities. One 276 00:18:42,640 --> 00:18:47,720 Speaker 1: cinis The reports that the obo is quote profoundly emotional 277 00:18:47,880 --> 00:18:54,520 Speaker 1: and thoughtful, with drawn, introspective, and prone to melancholy, while 278 00:18:54,640 --> 00:19:00,480 Speaker 1: she describes the flute as quote feminine, sweet, innocent, naive 279 00:19:01,280 --> 00:19:04,720 Speaker 1: the personalities of the different instruments. They're not generic, they're 280 00:19:05,080 --> 00:19:09,639 Speaker 1: rich and detailed. The triggered perception can also be a 281 00:19:10,040 --> 00:19:13,639 Speaker 1: physical sensation, like a physical state of your body. For 282 00:19:13,760 --> 00:19:17,560 Speaker 1: one Cyniceitt that I interviewed, different chords make her feel 283 00:19:17,560 --> 00:19:22,240 Speaker 1: like her body is in different positions physically, So when 284 00:19:22,240 --> 00:19:26,200 Speaker 1: she feels one chord, she feels like she's standing upright 285 00:19:26,240 --> 00:19:30,520 Speaker 1: with her feet on the ground, or stepping onto a 286 00:19:30,560 --> 00:19:36,159 Speaker 1: stare or soaring in the sky. She happens to be 287 00:19:36,200 --> 00:19:40,760 Speaker 1: a professional musician, so when she's memorizing a piece of music, 288 00:19:41,200 --> 00:19:45,080 Speaker 1: it's like memorizing a series of dance moves. And there's 289 00:19:45,080 --> 00:19:48,440 Speaker 1: one more form, which is likely the most common, around 290 00:19:48,520 --> 00:19:52,200 Speaker 1: ten percent of the population experience it. It's when people 291 00:19:52,280 --> 00:19:56,000 Speaker 1: perceive sequences like the days of the week or the 292 00:19:56,000 --> 00:19:59,160 Speaker 1: months of the year, as though they have a specific 293 00:19:59,640 --> 00:20:04,359 Speaker 1: space location in relation to their body, like March is 294 00:20:04,400 --> 00:20:06,720 Speaker 1: off here to the left, and April is next to it, 295 00:20:07,160 --> 00:20:09,400 Speaker 1: and May is a little bit higher and off next 296 00:20:09,440 --> 00:20:13,480 Speaker 1: to that. For every month or a weekday or numbered 297 00:20:13,640 --> 00:20:18,120 Speaker 1: things like that, they have a specific spatial location that 298 00:20:18,119 --> 00:20:21,560 Speaker 1: the person can identify where it seems to them that 299 00:20:21,600 --> 00:20:25,360 Speaker 1: the thing exists. It's just self evidently true to them 300 00:20:25,760 --> 00:20:30,120 Speaker 1: that that member of the sequence has that particular spatial location. 301 00:20:30,560 --> 00:20:34,240 Speaker 1: This form of synesthesia is not a hallucination. It's not 302 00:20:34,280 --> 00:20:37,440 Speaker 1: that you actually see April right there visually. 303 00:20:37,800 --> 00:20:39,879 Speaker 2: It's that it's just obviously true to you. 304 00:20:40,200 --> 00:20:44,240 Speaker 1: That April would occupy that spatial location to you. It 305 00:20:44,240 --> 00:20:46,840 Speaker 1: would be like if I asked you to imagine an 306 00:20:46,960 --> 00:20:50,520 Speaker 1: apple five feet in front of you. So you're picturing 307 00:20:50,560 --> 00:20:54,080 Speaker 1: the apple there and it's got a particular spatial location 308 00:20:54,280 --> 00:20:56,760 Speaker 1: with respect to your body, and you can imagine it, 309 00:20:57,040 --> 00:21:00,720 Speaker 1: but you're not actually hallucinating it. But if I ask 310 00:21:00,760 --> 00:21:03,439 Speaker 1: you where that apple is, that's the spatial location that 311 00:21:03,480 --> 00:21:05,679 Speaker 1: it has. A lot of people have this form of 312 00:21:05,720 --> 00:21:10,640 Speaker 1: synesthesia for years, like the year nineteen seventy nine has 313 00:21:10,680 --> 00:21:13,600 Speaker 1: a specific spot in space and relation to your body, 314 00:21:13,920 --> 00:21:17,480 Speaker 1: as does twenty twenty one or twenty fifty seven and 315 00:21:17,600 --> 00:21:22,280 Speaker 1: everything in between, and the years sit on this spatial timeline. 316 00:21:22,800 --> 00:21:26,280 Speaker 1: The timeline isn't necessarily straight. It can curve or take 317 00:21:26,359 --> 00:21:30,359 Speaker 1: sharp turns, and it typically moves with the passing of 318 00:21:30,400 --> 00:21:33,960 Speaker 1: each year. Now, what's interesting is that for many cinisthetes, 319 00:21:34,440 --> 00:21:37,919 Speaker 1: a year in the past moves behind them, say the 320 00:21:38,000 --> 00:21:42,280 Speaker 1: year twenty twenty one. Why because that year has already happened, 321 00:21:42,640 --> 00:21:45,600 Speaker 1: so it moves behind you, while a year like twenty 322 00:21:45,680 --> 00:21:49,439 Speaker 1: forty two is often the distance ahead of you. But 323 00:21:49,560 --> 00:21:53,360 Speaker 1: for other cynisthetes, it's exactly flipped. A year in the 324 00:21:53,440 --> 00:21:57,000 Speaker 1: past is in front of them because they already know 325 00:21:57,040 --> 00:22:00,359 Speaker 1: what happened in twenty twenty one, but year like twenty 326 00:22:00,359 --> 00:22:03,520 Speaker 1: forty two hasn't happened yet, so they don't know anything 327 00:22:03,560 --> 00:22:07,120 Speaker 1: about it. It's as invisible to them as an object 328 00:22:07,119 --> 00:22:10,800 Speaker 1: that is behind them. I'll just note that another research 329 00:22:10,880 --> 00:22:16,199 Speaker 1: group called this form of synesthesia time space synesthesia because 330 00:22:16,240 --> 00:22:18,680 Speaker 1: they looked at things like weekdays and months and years 331 00:22:18,720 --> 00:22:21,359 Speaker 1: and said, hey, those all have something to do with time. 332 00:22:22,000 --> 00:22:24,080 Speaker 1: But I want to emphasize that this is not the 333 00:22:24,119 --> 00:22:29,680 Speaker 1: correct way to understand this, because this same spatialization happens 334 00:22:29,720 --> 00:22:33,359 Speaker 1: with number lines like one, two, three is over here, 335 00:22:33,400 --> 00:22:35,800 Speaker 1: that it takes a right turn here for four through seven, 336 00:22:35,960 --> 00:22:39,200 Speaker 1: then eight, nine, ten climb straight up, then eleven through 337 00:22:39,200 --> 00:22:41,399 Speaker 1: twenty shoot off in a straight line, and then twenty 338 00:22:41,400 --> 00:22:43,960 Speaker 1: one through thirty are stacked above that like that. 339 00:22:43,840 --> 00:22:44,360 Speaker 2: Kind of thing. 340 00:22:45,160 --> 00:22:50,520 Speaker 1: And also we find cinisthetes who have spatialization for the 341 00:22:50,520 --> 00:22:57,200 Speaker 1: Indian caste system, or shoe sizes, or temperatures, or historical 342 00:22:57,240 --> 00:23:01,840 Speaker 1: eras or primetime television line. So it can be anything 343 00:23:01,920 --> 00:23:05,520 Speaker 1: that's a sequence, and it just so happens that time 344 00:23:05,680 --> 00:23:09,880 Speaker 1: is sequential, but it's just a subset of the sequences 345 00:23:09,920 --> 00:23:12,600 Speaker 1: that you might learn in life. And that's why I 346 00:23:12,720 --> 00:23:17,399 Speaker 1: named this spatial sequence synesthesia in the literature, which is 347 00:23:17,440 --> 00:23:19,920 Speaker 1: the name now used in the field. It turns out 348 00:23:20,000 --> 00:23:24,120 Speaker 1: there are many, many forms of synesthesia, and one group 349 00:23:24,160 --> 00:23:27,320 Speaker 1: has estimated that there are one hundred and fifty two 350 00:23:27,400 --> 00:23:31,560 Speaker 1: different forms that have been reported. So anything you can imagine, 351 00:23:31,600 --> 00:23:35,280 Speaker 1: any kind of cross blending between the senses has been 352 00:23:35,400 --> 00:23:37,040 Speaker 1: reported at one point or another. 353 00:23:37,560 --> 00:23:40,399 Speaker 2: Beyond the spatial sequence synesthesia. 354 00:23:40,000 --> 00:23:43,359 Speaker 1: The next most common one seems to be the letters 355 00:23:43,440 --> 00:23:47,280 Speaker 1: or numbers mapping on to colors, or weekdays and months 356 00:23:47,280 --> 00:23:51,200 Speaker 1: to colors, or musical sounds to colors, or smells to colors, 357 00:23:51,280 --> 00:23:55,600 Speaker 1: or taste to colors. Most forms of synesthesia trigger color, 358 00:23:55,960 --> 00:24:02,200 Speaker 1: but we also find triggered tastes, smells, sounds, temperatures, emotions, 359 00:24:02,280 --> 00:24:05,520 Speaker 1: and so on. We find essentially any kind of cross 360 00:24:05,600 --> 00:24:25,760 Speaker 1: sensory blending that you can think of. It appears that 361 00:24:25,800 --> 00:24:30,680 Speaker 1: synesthesia is different for every synesthet Her associations are different 362 00:24:30,680 --> 00:24:33,080 Speaker 1: from hers, are different from hers. So the color that 363 00:24:33,119 --> 00:24:37,520 Speaker 1: gets triggered by the letter J or the number three 364 00:24:37,760 --> 00:24:41,600 Speaker 1: is a different color for everyone. Now why is this. 365 00:24:42,440 --> 00:24:46,159 Speaker 1: It could be that it's just about random wiring in 366 00:24:46,200 --> 00:24:48,879 Speaker 1: the brain, so the particular letter that matches up to 367 00:24:48,920 --> 00:24:53,080 Speaker 1: a particular color is arbitrary. But my colleagues and I 368 00:24:53,080 --> 00:24:57,520 Speaker 1: started to wonder if instead of randomness, it could be 369 00:24:57,560 --> 00:25:02,120 Speaker 1: about something that you imprinted on as a young child. Now, 370 00:25:02,160 --> 00:25:06,240 Speaker 1: this would give essentially the same results as randomness, because 371 00:25:06,560 --> 00:25:10,199 Speaker 1: you might, as a child see an alphabet quilt that 372 00:25:10,240 --> 00:25:13,199 Speaker 1: your mother made, and your mother's choices were just her 373 00:25:13,280 --> 00:25:17,200 Speaker 1: random choice, or an alphabet poster that your teacher made 374 00:25:17,240 --> 00:25:20,359 Speaker 1: at your preschool with some random choice, or some ad 375 00:25:20,400 --> 00:25:24,280 Speaker 1: in a magazine, and the idea is that those particular 376 00:25:24,440 --> 00:25:30,760 Speaker 1: letter color associations stuck for you. For most brains, the 377 00:25:30,800 --> 00:25:34,080 Speaker 1: statistics wash out, which means that one day you see 378 00:25:34,080 --> 00:25:35,760 Speaker 1: an A that's red, and the next day you might 379 00:25:35,800 --> 00:25:37,879 Speaker 1: see an A that's blue, and the next day yellow, 380 00:25:37,920 --> 00:25:41,080 Speaker 1: and so on, and so your brain learns that A 381 00:25:41,520 --> 00:25:45,359 Speaker 1: is not associated with any particular color, but in a 382 00:25:45,520 --> 00:25:50,479 Speaker 1: synesthetes brain, for whatever reason, perhaps the first association that 383 00:25:50,520 --> 00:25:55,520 Speaker 1: they see sticks and doesn't get washed out. Now, how 384 00:25:55,560 --> 00:25:59,880 Speaker 1: could you possibly test for this imprinting given that there's 385 00:25:59,880 --> 00:26:03,480 Speaker 1: no easy way to know what people saw in their childhoods? 386 00:26:04,160 --> 00:26:08,720 Speaker 1: And this is where science comes in. I collected detailed 387 00:26:08,800 --> 00:26:12,760 Speaker 1: colored alphabets from almost seven thousand cynisthetes who had these 388 00:26:12,800 --> 00:26:16,920 Speaker 1: colored alphabets, and with two colleagues at Stanford, we analyzed 389 00:26:17,000 --> 00:26:20,679 Speaker 1: those colors in detail, like person number one has a 390 00:26:20,720 --> 00:26:22,760 Speaker 1: red A and a purple B and a yellow C 391 00:26:23,040 --> 00:26:26,520 Speaker 1: and so on, and the next person has a brown 392 00:26:26,600 --> 00:26:29,520 Speaker 1: A and a crimson B and a gold C and 393 00:26:29,560 --> 00:26:34,160 Speaker 1: so on. So we analyzed this huge pool of cynisthetes 394 00:26:34,840 --> 00:26:38,159 Speaker 1: and we found something amazing. At least six percent of 395 00:26:38,200 --> 00:26:44,320 Speaker 1: the cynisthes had approximately the same colors. A through F 396 00:26:44,640 --> 00:26:51,440 Speaker 1: went red, orange, yellow, green, blue, purple, and then this 397 00:26:51,640 --> 00:26:56,639 Speaker 1: same sequence of colors was repeated G through L, and 398 00:26:56,680 --> 00:26:59,439 Speaker 1: then M through R and so on till the end 399 00:26:59,480 --> 00:27:03,680 Speaker 1: of the alphabet. This was so weird, and even more 400 00:27:03,720 --> 00:27:06,520 Speaker 1: of a clue is that we looked at people's birth 401 00:27:06,600 --> 00:27:09,840 Speaker 1: year and this sequence of colors never came up for 402 00:27:09,960 --> 00:27:13,439 Speaker 1: people who were born before the late nineteen sixties, and 403 00:27:13,480 --> 00:27:16,439 Speaker 1: then the proportion of people started to rise. So for 404 00:27:16,520 --> 00:27:21,560 Speaker 1: cyniesites born between nineteen seventy and nineteen eighty five, fifteen 405 00:27:21,640 --> 00:27:25,480 Speaker 1: percent of them had this same sequence of colors for 406 00:27:25,560 --> 00:27:28,879 Speaker 1: their letters, and then for those born after nineteen ninety 407 00:27:28,920 --> 00:27:33,000 Speaker 1: the proportion decreased again. So what was going on here? 408 00:27:33,720 --> 00:27:37,320 Speaker 1: We figured it out. In nineteen seventy one, a new 409 00:27:37,480 --> 00:27:41,159 Speaker 1: toy started finding its way into homes all over the 410 00:27:41,280 --> 00:27:45,760 Speaker 1: United States. It was the Fisher Price magnet set. This 411 00:27:45,920 --> 00:27:49,280 Speaker 1: was a set of refrigerator magnets that consisted of the 412 00:27:49,400 --> 00:27:52,719 Speaker 1: letters of the alphabet, and each one was colored and 413 00:27:52,760 --> 00:27:56,639 Speaker 1: it cycled through the letters red, orange, yellow, green. 414 00:27:56,480 --> 00:27:57,159 Speaker 2: Blue, purple. 415 00:27:57,600 --> 00:28:01,359 Speaker 1: So for those born in the decade after the magnets existed, 416 00:28:02,000 --> 00:28:06,360 Speaker 1: this color pattern reached fifteen percent. But for those who 417 00:28:06,359 --> 00:28:09,160 Speaker 1: grew up before the magnets existed, not a single one 418 00:28:09,160 --> 00:28:12,960 Speaker 1: of them had this pattern. So for all of these cyinsetes, 419 00:28:13,040 --> 00:28:16,399 Speaker 1: it was about whether they were exposed to these magnets 420 00:28:16,480 --> 00:28:19,239 Speaker 1: as children. Now, I want to be really clear that 421 00:28:19,240 --> 00:28:23,520 Speaker 1: the synesthesia wasn't caused by the Fisher price alphabet set 422 00:28:24,160 --> 00:28:27,399 Speaker 1: because the rest of the population saw it in the 423 00:28:27,440 --> 00:28:31,360 Speaker 1: seventies and eighties, but only three percent of people become cynisthetes. 424 00:28:31,840 --> 00:28:35,600 Speaker 1: It's simply that the sinisthetes who saw it imprinted on it, 425 00:28:35,960 --> 00:28:36,400 Speaker 1: so that. 426 00:28:36,320 --> 00:28:39,800 Speaker 2: To them A always. 427 00:28:38,240 --> 00:28:43,840 Speaker 1: Triggers red, and B orange, and C yellow and so on. 428 00:28:45,000 --> 00:28:48,440 Speaker 1: Synesthesia is something we think of as a different way 429 00:28:48,560 --> 00:28:52,560 Speaker 1: of perceiving the world. It's not a disorder or a disease, 430 00:28:52,920 --> 00:28:56,760 Speaker 1: because there's no disadvantage to it. In fact, in some cases, 431 00:28:57,080 --> 00:29:00,760 Speaker 1: cinisthetes tend to have better memories. So if I were 432 00:29:00,800 --> 00:29:03,600 Speaker 1: to tell you my phone number and you are a sinisthete, 433 00:29:04,120 --> 00:29:07,280 Speaker 1: you might forget some of the digits, but you may think, oh, yeah, 434 00:29:07,280 --> 00:29:10,440 Speaker 1: I remember it had a really nice autumn color pattern 435 00:29:10,520 --> 00:29:14,040 Speaker 1: to it, and so that would help you to reconstruct. 436 00:29:13,280 --> 00:29:14,959 Speaker 2: It later when you're trying to think of it. 437 00:29:15,480 --> 00:29:18,480 Speaker 1: You may have heard the termmneminists spelled with an m 438 00:29:18,840 --> 00:29:23,360 Speaker 1: N like Johnny mnemonic or a mnemonic device. Anyway, aneminist 439 00:29:23,640 --> 00:29:27,280 Speaker 1: is a person with an incredible memory. They can memorize 440 00:29:27,880 --> 00:29:32,160 Speaker 1: long lists of nonsense words, or really long strings of 441 00:29:32,240 --> 00:29:36,360 Speaker 1: numbers or series of locations. It turns out as far 442 00:29:36,400 --> 00:29:38,960 Speaker 1: as I can tell, that every single one of these 443 00:29:39,080 --> 00:29:44,600 Speaker 1: mneminists have synesthesia. They can take something like the digits 444 00:29:44,640 --> 00:29:47,320 Speaker 1: of Pie three point one four one five, nine, two 445 00:29:47,360 --> 00:29:52,400 Speaker 1: sixty five three five, and for thenemenist this may have colors, 446 00:29:52,440 --> 00:29:55,520 Speaker 1: such as the colors helped them to memorize the sequence. 447 00:29:56,160 --> 00:30:00,040 Speaker 1: And more than colors, they may have also textures and 448 00:30:00,120 --> 00:30:05,760 Speaker 1: personalities and genders and sizes, So as they're learning three 449 00:30:05,800 --> 00:30:09,200 Speaker 1: point one four one five, nine two sixty five, there's 450 00:30:09,240 --> 00:30:13,880 Speaker 1: a whole story landscape with a rich texture. So this 451 00:30:14,040 --> 00:30:18,000 Speaker 1: is how they memorize Pie to thousands of digits, while 452 00:30:18,080 --> 00:30:21,240 Speaker 1: for the rest of us who aren't synesthetic, for whom 453 00:30:21,320 --> 00:30:25,760 Speaker 1: all numbers are essentially alike, it's an almost impossible challenge. 454 00:30:25,960 --> 00:30:29,560 Speaker 1: I'll just mention that this advantage of synesthesia can also 455 00:30:29,760 --> 00:30:34,600 Speaker 1: become a confusion in some circumstances. So one synesthete has 456 00:30:34,760 --> 00:30:39,120 Speaker 1: particular colors that he sees for names like Mike and Dan, 457 00:30:39,680 --> 00:30:42,040 Speaker 1: but it turns out that he sometimes runs into trouble 458 00:30:42,080 --> 00:30:45,840 Speaker 1: at cocktail parties because it just so happens that Dave 459 00:30:45,920 --> 00:30:48,920 Speaker 1: and Rob have exactly the same colors for him as 460 00:30:49,080 --> 00:30:52,160 Speaker 1: Mike and Dan. So if your name is Dan, He's 461 00:30:52,200 --> 00:30:54,560 Speaker 1: pretty likely to mess up and call you Rob later 462 00:30:54,600 --> 00:30:58,640 Speaker 1: in the night. It turns out many artists have synesthesia. 463 00:30:59,400 --> 00:31:04,840 Speaker 1: Vasili Kandinsky was a music to color cinesthete. So if 464 00:31:04,880 --> 00:31:07,720 Speaker 1: you can picture a Kandinsky painting, you know that he 465 00:31:07,800 --> 00:31:11,360 Speaker 1: has these bold brushstrokes and vibrant colors. He makes these 466 00:31:11,840 --> 00:31:16,000 Speaker 1: abstracts with a sense of movement and energy. Boy, you 467 00:31:16,080 --> 00:31:18,920 Speaker 1: might not know is how he made them. He would 468 00:31:18,920 --> 00:31:22,360 Speaker 1: crank up his phonograph and he would stand in front 469 00:31:22,400 --> 00:31:25,960 Speaker 1: of his canvas and paint the images that came to 470 00:31:26,120 --> 00:31:29,320 Speaker 1: his head from the music that he was hearing. So 471 00:31:29,360 --> 00:31:32,760 Speaker 1: what you see on the canvas are his renditions of 472 00:31:32,800 --> 00:31:39,640 Speaker 1: his synesthetic experience. And many writers are cynisthetes. Vladimir Nabokov, 473 00:31:39,880 --> 00:31:44,960 Speaker 1: who wrote Lolita, was very synesthetic with letters and numbers. 474 00:31:45,000 --> 00:31:49,160 Speaker 1: These would trigger colors for him, and as a young 475 00:31:49,200 --> 00:31:51,520 Speaker 1: man he actually wrote quite a bit of poetry about 476 00:31:51,720 --> 00:31:55,280 Speaker 1: how he saw letters. When he was asked what color 477 00:31:55,320 --> 00:32:00,080 Speaker 1: his own initials were, the Bokhoff answered quote, the D 478 00:32:00,320 --> 00:32:03,520 Speaker 1: is a kind of pale, transparent pink. I think it's 479 00:32:03,600 --> 00:32:07,680 Speaker 1: called technically quartz pink. This is one of the closest 480 00:32:07,720 --> 00:32:10,800 Speaker 1: colors that I can connect with the V, and the N, 481 00:32:11,120 --> 00:32:16,480 Speaker 1: on the other hand, is a grayish yellowish oatmeal color. Interestingly, 482 00:32:16,840 --> 00:32:20,320 Speaker 1: different colors were triggered for him by the same letter 483 00:32:20,440 --> 00:32:25,000 Speaker 1: in different languages, so he said, quote the long A 484 00:32:25,560 --> 00:32:28,960 Speaker 1: of the English alphabet has for me the tint of 485 00:32:29,080 --> 00:32:34,880 Speaker 1: weathered wood, but a French A evokes polished ebony. This 486 00:32:35,080 --> 00:32:41,280 Speaker 1: black group also includes hard G, vulcanized rubber and R, 487 00:32:41,880 --> 00:32:47,680 Speaker 1: a sooty rag being ripped, oatmeal, N noodle, limp L, 488 00:32:48,240 --> 00:32:52,080 Speaker 1: and the ivory backed hand mirror of an O. Take 489 00:32:52,160 --> 00:32:56,000 Speaker 1: care of the whites. I am puzzled by my French on, 490 00:32:56,600 --> 00:33:00,000 Speaker 1: which I see as the brimming tension surface of alcohol 491 00:33:00,200 --> 00:33:05,160 Speaker 1: in a small glass. As a side note, Thebokoff loved butterflies, 492 00:33:05,280 --> 00:33:07,560 Speaker 1: and one of his favorites had yellow wings in a 493 00:33:07,600 --> 00:33:11,640 Speaker 1: black middle. So when yellow black yellow, and that corresponded 494 00:33:11,640 --> 00:33:15,960 Speaker 1: for him to the letters ab a so boom. That 495 00:33:16,040 --> 00:33:19,480 Speaker 1: became the title for his great novel Aida. It was 496 00:33:19,520 --> 00:33:25,160 Speaker 1: his little insider synesthetic joke, and many musicians are synesthetic. 497 00:33:25,840 --> 00:33:30,360 Speaker 1: Take Amy Beach, who was the first successful American female composer. 498 00:33:30,760 --> 00:33:34,959 Speaker 1: Her biographer noted that for her, C was white and 499 00:33:35,200 --> 00:33:38,480 Speaker 1: F sharp was black. And e was yellow and so on. 500 00:33:38,840 --> 00:33:41,840 Speaker 1: Until the end of her life she associated those colors 501 00:33:41,880 --> 00:33:47,520 Speaker 1: with those notes. Or The composer Olivier Mession, he was synesthetic, 502 00:33:47,560 --> 00:33:51,960 Speaker 1: and he described his purpose as quote, painting the visible 503 00:33:52,040 --> 00:33:57,080 Speaker 1: world in sound. He would describe things in his diary like, quote, 504 00:33:57,400 --> 00:34:01,760 Speaker 1: the gentle cascade of blue orange chords. This is the 505 00:34:01,800 --> 00:34:05,560 Speaker 1: way that he would describe particular sequences of music. There 506 00:34:05,600 --> 00:34:11,000 Speaker 1: are lots of musicians with synesthesia. Billy Joel, Duke, Ellington, Torry, 507 00:34:11,120 --> 00:34:17,480 Speaker 1: Amos Grimes. The singer Billy Eilish recently told Rolling Stone quote, 508 00:34:17,880 --> 00:34:20,680 Speaker 1: every person that I know has their own color and 509 00:34:20,840 --> 00:34:24,239 Speaker 1: shape and number in my head, but it's normal to me. 510 00:34:25,040 --> 00:34:28,279 Speaker 1: She says that her brother Phineas is an orange triangle, 511 00:34:28,320 --> 00:34:33,480 Speaker 1: although his name Phineas is dark green. Pharrell Williams also 512 00:34:33,560 --> 00:34:37,319 Speaker 1: has synesthesia. For him, each note has a color, and 513 00:34:37,440 --> 00:34:57,480 Speaker 1: his musical group Nerd named one of their albums Seeing Sounds. 514 00:34:59,239 --> 00:35:02,080 Speaker 1: Now people have speculated, because of this sort of thing, 515 00:35:02,520 --> 00:35:07,719 Speaker 1: that maybe there's an overrepresentation of sinnisthetes in the artistic community. 516 00:35:08,320 --> 00:35:09,799 Speaker 1: But I just want to point out that we don't 517 00:35:09,880 --> 00:35:13,120 Speaker 1: actually know if that's true, because no one's ever gone 518 00:35:13,160 --> 00:35:17,960 Speaker 1: in and tested the community of accountants or deep sea divers. 519 00:35:18,840 --> 00:35:20,360 Speaker 1: All we know is that we can point to a 520 00:35:20,360 --> 00:35:23,360 Speaker 1: lot of artists who are synesthetic, and so we can 521 00:35:23,560 --> 00:35:28,919 Speaker 1: hypothesize that maybe synesthesia provides some pull to those professions. 522 00:35:29,200 --> 00:35:32,520 Speaker 1: In other words, if you have this slightly richer sort 523 00:35:32,560 --> 00:35:37,360 Speaker 1: of perception, then maybe you gravitate towards certain sorts of pursuits. 524 00:35:37,880 --> 00:35:40,520 Speaker 1: By the way, I should note that not every artist 525 00:35:40,520 --> 00:35:45,680 Speaker 1: who does something synesthetic is actually a synisthet The composer 526 00:35:45,800 --> 00:35:50,000 Speaker 1: Scriabin was really interested in the effects of putting sound 527 00:35:50,120 --> 00:35:53,200 Speaker 1: and color together, and he thought that would provide a 528 00:35:53,280 --> 00:35:56,880 Speaker 1: really strong resonance for the listener. So he invented a 529 00:35:57,080 --> 00:36:00,919 Speaker 1: color organ. When you hit the notes, you're not only 530 00:36:00,960 --> 00:36:04,160 Speaker 1: playing the musical sound, but there are spotlights of different 531 00:36:04,200 --> 00:36:07,880 Speaker 1: colors coming out of the top. But Screopin wasn't actually 532 00:36:07,920 --> 00:36:11,680 Speaker 1: a synisthete himself he was just exploring cool things and 533 00:36:11,800 --> 00:36:15,040 Speaker 1: was influenced by the fashions of the art world at 534 00:36:15,040 --> 00:36:17,840 Speaker 1: that moment. So not everyone who does this sort of 535 00:36:17,840 --> 00:36:21,000 Speaker 1: thing is actually a synesthee. And this leads me to 536 00:36:21,040 --> 00:36:25,040 Speaker 1: a really important point. How can you tell if someone 537 00:36:25,560 --> 00:36:30,000 Speaker 1: really is synesthetic? How can you test for this. So 538 00:36:30,040 --> 00:36:32,960 Speaker 1: when someone tells you that they're a synisthete, how could 539 00:36:33,040 --> 00:36:37,720 Speaker 1: you ever know if they're just being artistic or metaphorical 540 00:36:38,040 --> 00:36:41,280 Speaker 1: or poetic, or lying or just trying to get attention. 541 00:36:42,280 --> 00:36:44,960 Speaker 1: So my colleagues and I, over the past fifteen years, 542 00:36:45,000 --> 00:36:48,480 Speaker 1: have developed a whole series of tests where we can 543 00:36:48,560 --> 00:36:54,120 Speaker 1: show when synesthesia is actually a real perceptual experience. And 544 00:36:54,160 --> 00:36:56,719 Speaker 1: I want to tell you how we do that. It 545 00:36:56,800 --> 00:37:01,640 Speaker 1: has everything to do with the consistency of people's perceptions. 546 00:37:02,239 --> 00:37:06,239 Speaker 1: So if you're a cynisthete who sees eight as lavender, 547 00:37:06,560 --> 00:37:09,239 Speaker 1: you're always going to see it as lavender. But if 548 00:37:09,239 --> 00:37:11,400 Speaker 1: I were to ask you to make up some colors 549 00:37:11,480 --> 00:37:14,200 Speaker 1: right now, and then I ask you again a year 550 00:37:14,239 --> 00:37:17,440 Speaker 1: from now, if you're not synesthetic, you're not going to 551 00:37:17,480 --> 00:37:21,399 Speaker 1: be able to get these same color associations. But if 552 00:37:21,440 --> 00:37:26,000 Speaker 1: you are synesthetic, it'll be the same colors. So many 553 00:37:26,080 --> 00:37:29,919 Speaker 1: years ago I launched a website called cinnisthete dot org, 554 00:37:30,520 --> 00:37:33,320 Speaker 1: and it's a battery of tests that are freely available. 555 00:37:33,719 --> 00:37:35,640 Speaker 1: So if you think you might be a synthete, go 556 00:37:35,680 --> 00:37:38,000 Speaker 1: to the site and take the tests. What we can 557 00:37:38,040 --> 00:37:43,000 Speaker 1: do this way is rigorously determine who exactly is synesthetic 558 00:37:43,040 --> 00:37:45,920 Speaker 1: and who's not. Here's the method. It has anything to 559 00:37:46,000 --> 00:37:50,960 Speaker 1: do with internal consistency. So we show you a letter 560 00:37:51,040 --> 00:37:54,560 Speaker 1: of the alphabet at random, say a J, and you 561 00:37:54,640 --> 00:37:58,480 Speaker 1: see a color palette on the screen, and by moving 562 00:37:58,480 --> 00:38:03,200 Speaker 1: a slider around, you can get to any hue, any color, 563 00:38:03,600 --> 00:38:06,680 Speaker 1: and by moving a second slider around, you can specify 564 00:38:07,200 --> 00:38:10,600 Speaker 1: whatever saturation, in other words, how dark or bright it is. 565 00:38:11,560 --> 00:38:13,839 Speaker 1: So you pull the sliders around and you pick the 566 00:38:13,880 --> 00:38:19,000 Speaker 1: color that best matches your synesthetic perception for that letter. 567 00:38:19,239 --> 00:38:21,960 Speaker 1: And this is out of sixteen million different colors that 568 00:38:22,000 --> 00:38:25,279 Speaker 1: can be displayed on a computer screen. And when you 569 00:38:25,360 --> 00:38:28,600 Speaker 1: found the best one, you click submit, and then you 570 00:38:28,640 --> 00:38:32,200 Speaker 1: get the next random letter or number, say the letter 571 00:38:32,400 --> 00:38:35,040 Speaker 1: W or the number three or whatever, and you find 572 00:38:35,080 --> 00:38:39,560 Speaker 1: exactly that color that best matches for that one. And 573 00:38:39,600 --> 00:38:43,160 Speaker 1: the trick is we present you with each letter and 574 00:38:43,239 --> 00:38:51,000 Speaker 1: each number three times, each in random order. So the 575 00:38:51,080 --> 00:38:53,960 Speaker 1: idea is that if you are really a synesthee, you're 576 00:38:53,960 --> 00:38:56,560 Speaker 1: going to land on the same shade of color for 577 00:38:56,640 --> 00:38:59,880 Speaker 1: let's say the letter J every time. And if you're 578 00:39:00,200 --> 00:39:03,239 Speaker 1: a sinisthete, it turns out it's very hard to fake that. 579 00:39:03,760 --> 00:39:07,160 Speaker 1: So when you look at the results for cynisthetes and 580 00:39:07,200 --> 00:39:11,160 Speaker 1: for control subjects who are asked to fake synesthesia, we 581 00:39:11,239 --> 00:39:14,200 Speaker 1: can measure the amount of difference in the colors that 582 00:39:14,239 --> 00:39:17,000 Speaker 1: they chose. And what we see is that for a 583 00:39:17,120 --> 00:39:21,200 Speaker 1: real cinisthete, it's easy. Every time she's presented with the 584 00:39:21,280 --> 00:39:24,759 Speaker 1: letter T, she picks the same color or E, it's 585 00:39:24,800 --> 00:39:27,200 Speaker 1: the same color every time, and so on. Whereas for 586 00:39:27,280 --> 00:39:31,360 Speaker 1: somebody who's asked to use free association or memory or 587 00:39:31,400 --> 00:39:34,960 Speaker 1: whatever but they're not actually synesthetic, it's really difficult to 588 00:39:34,960 --> 00:39:38,200 Speaker 1: get the same colors. It's a very hard test to 589 00:39:38,360 --> 00:39:42,759 Speaker 1: pass to remember what you said fifty seven trials ago 590 00:39:43,120 --> 00:39:46,960 Speaker 1: and find that color again out of sixteen million possible colors. 591 00:39:47,680 --> 00:39:50,000 Speaker 1: So this turns out to be a powerful way that 592 00:39:50,040 --> 00:39:53,200 Speaker 1: we can distinguish who is a cynisthete and who is not. 593 00:39:54,120 --> 00:39:56,920 Speaker 1: And we actually have several levels of testing to make 594 00:39:56,960 --> 00:40:01,160 Speaker 1: it absolutely impossible to cheat. So, for example, after we've 595 00:40:01,200 --> 00:40:04,120 Speaker 1: collected your colors, we then flash it to you on 596 00:40:04,160 --> 00:40:06,880 Speaker 1: the screen. So let's say it's the letter H. We 597 00:40:06,960 --> 00:40:10,680 Speaker 1: flash an H that's either the color that you've had 598 00:40:10,760 --> 00:40:14,480 Speaker 1: chosen or a different color from somewhere else in your palette, 599 00:40:14,960 --> 00:40:16,640 Speaker 1: and you have to say as quickly as you can 600 00:40:16,719 --> 00:40:20,319 Speaker 1: whether it matches or didn't match your perception. And for 601 00:40:20,480 --> 00:40:25,040 Speaker 1: a real cynisthete, if I'm flashing the orange h they'll say, yeah, 602 00:40:25,080 --> 00:40:27,719 Speaker 1: that match, and if I flash a green age, they'll 603 00:40:27,719 --> 00:40:31,640 Speaker 1: say that doesn't match. But for someone who's just faked 604 00:40:31,680 --> 00:40:35,080 Speaker 1: their way through, it's something they're terrible at, both in 605 00:40:35,160 --> 00:40:39,319 Speaker 1: terms of accuracy and reaction time. So this is how 606 00:40:39,360 --> 00:40:43,000 Speaker 1: we can make sure that we find real cynisthetes. And 607 00:40:43,040 --> 00:40:47,440 Speaker 1: we've translated this battery into many different languages, including Chinese 608 00:40:47,520 --> 00:40:50,719 Speaker 1: and Hebrew as well as a whole bunch of European languages, 609 00:40:51,200 --> 00:40:53,279 Speaker 1: and this way we can find out what's going on 610 00:40:53,800 --> 00:40:56,200 Speaker 1: not only in French and Spanish and German, but also 611 00:40:56,360 --> 00:41:01,520 Speaker 1: in different alphabetic systems like Cyrillic or Hebrew or Chinese. 612 00:41:02,040 --> 00:41:05,520 Speaker 1: Also we can test all sorts of different forms of synesthesia. 613 00:41:05,880 --> 00:41:08,760 Speaker 1: And what we have now are about eighteen different forms 614 00:41:08,840 --> 00:41:13,000 Speaker 1: of tests, like musical notes to color, or instrument tambers 615 00:41:13,040 --> 00:41:15,279 Speaker 1: to color and so on. And it turns out with 616 00:41:15,360 --> 00:41:18,320 Speaker 1: this sort of testing we can finally get the sample 617 00:41:18,440 --> 00:41:21,319 Speaker 1: sizes that we need, because it turns out that all 618 00:41:21,360 --> 00:41:26,160 Speaker 1: the previous literature had a sample size of one. Up 619 00:41:26,239 --> 00:41:29,160 Speaker 1: until the early two thousands, it was all single case 620 00:41:29,200 --> 00:41:32,640 Speaker 1: studies where people said, hey, I met a cinisthet and 621 00:41:32,680 --> 00:41:34,840 Speaker 1: I asked her these questions and here are her answers. 622 00:41:35,280 --> 00:41:38,919 Speaker 1: And then people started publishing papers with a participant group 623 00:41:39,000 --> 00:41:42,040 Speaker 1: size of two or four, and a few papers had 624 00:41:42,080 --> 00:41:45,520 Speaker 1: eight people in them. What we've done now is changed 625 00:41:45,560 --> 00:41:48,719 Speaker 1: the game on that because we have rigorously verified over 626 00:41:48,760 --> 00:41:52,640 Speaker 1: sixty four thousand cinisthetes and we have their data in 627 00:41:52,760 --> 00:41:57,320 Speaker 1: exquisite detail, and this allows us to alter the scientific 628 00:41:57,360 --> 00:42:01,160 Speaker 1: playing field. Now, there were a few papers on synesthesia 629 00:42:01,280 --> 00:42:05,879 Speaker 1: in the eighteen hundreds, but then synesthesia essentially slipped out 630 00:42:05,880 --> 00:42:08,960 Speaker 1: of the scientific spotlight for most of the twentieth century, 631 00:42:09,600 --> 00:42:14,440 Speaker 1: and that was because psychology was dominated by the behaviorist 632 00:42:14,560 --> 00:42:17,400 Speaker 1: school of thought, where the idea was that we're just 633 00:42:17,760 --> 00:42:22,319 Speaker 1: input output reflex machines and it wasn't really appropriate or 634 00:42:22,360 --> 00:42:28,360 Speaker 1: scientific to talk about private subjective experience. So as a result, 635 00:42:28,520 --> 00:42:32,440 Speaker 1: synesthesia fell to the wayside. But fundamentally, if there's one 636 00:42:32,440 --> 00:42:35,279 Speaker 1: thing we know, it's that it feels like something to 637 00:42:35,360 --> 00:42:41,719 Speaker 1: have a brain. We have private subjective experience consciousness, and 638 00:42:41,800 --> 00:42:44,960 Speaker 1: so as this question has become a serious one in 639 00:42:45,000 --> 00:42:49,239 Speaker 1: our field. Synesthesia has risen from the ashes as a 640 00:42:49,440 --> 00:42:55,600 Speaker 1: powerful inroad to understanding consciousness. So what causes synesthesia? My 641 00:42:55,719 --> 00:42:59,040 Speaker 1: colleagues and I have performed brain imaging and what we 642 00:42:59,120 --> 00:43:03,279 Speaker 1: found is that in a cynisthete, neighboring areas of the 643 00:43:03,280 --> 00:43:06,360 Speaker 1: brain have a little bit more cross. 644 00:43:06,000 --> 00:43:06,960 Speaker 2: Talk than normal. 645 00:43:07,600 --> 00:43:09,960 Speaker 1: So regions of the brain that care about letters and 646 00:43:10,040 --> 00:43:13,359 Speaker 1: numbers happen to be close to other regions that care 647 00:43:13,360 --> 00:43:17,439 Speaker 1: about colors, and in a sinisthete, there's a bit more 648 00:43:17,840 --> 00:43:21,440 Speaker 1: cross talk between these areas than in a typical brain. 649 00:43:22,080 --> 00:43:26,160 Speaker 1: So think of it like two neighboring countries with porous borders. 650 00:43:26,680 --> 00:43:29,600 Speaker 1: And some years ago my lab started a long term 651 00:43:29,640 --> 00:43:35,000 Speaker 1: project to find the gene or genes that underlie synesthesia. 652 00:43:35,920 --> 00:43:37,840 Speaker 1: And to my mind, this is the first step in 653 00:43:37,880 --> 00:43:43,080 Speaker 1: a new subfield, which I'm calling perceptual genomics, which just 654 00:43:43,160 --> 00:43:47,799 Speaker 1: means understanding the subtle genetic differences that make you see 655 00:43:47,840 --> 00:43:51,400 Speaker 1: the world differently than I do. As a scientific community, 656 00:43:51,400 --> 00:43:55,800 Speaker 1: we're always looking for the genes for predisposition to diabetes 657 00:43:56,239 --> 00:44:00,320 Speaker 1: or aortic stenosis or Parkinson's, or that make some people 658 00:44:00,400 --> 00:44:04,200 Speaker 1: taller or broader or red haired or whatever. The same 659 00:44:04,320 --> 00:44:07,680 Speaker 1: techniques can be used to find the genes that make 660 00:44:08,160 --> 00:44:12,319 Speaker 1: our realities a little different from one another. Something that 661 00:44:12,400 --> 00:44:14,640 Speaker 1: struck me, as I mentioned earlier, is that there are 662 00:44:14,640 --> 00:44:19,239 Speaker 1: many different subtypes of synesthesia. Now are these all the 663 00:44:19,320 --> 00:44:23,400 Speaker 1: same thing or different? In other words, are all synesthesias 664 00:44:23,440 --> 00:44:26,760 Speaker 1: due to a single genetic change or are there totally 665 00:44:26,880 --> 00:44:31,839 Speaker 1: separate mechanisms involved? So how could I answer this? We 666 00:44:31,960 --> 00:44:35,239 Speaker 1: tested all these thousands of people on synesthesia, and we 667 00:44:35,480 --> 00:44:39,799 Speaker 1: asked from the data how the different types cluster with 668 00:44:39,840 --> 00:44:43,120 Speaker 1: one another. In other words, if you have colored letters, 669 00:44:43,560 --> 00:44:47,280 Speaker 1: what is the likelihood that you also have instrument tamber 670 00:44:47,320 --> 00:44:51,840 Speaker 1: synesthesia or colored months or colored musical notes or something 671 00:44:51,920 --> 00:44:55,439 Speaker 1: like that. How do these different things clump with each other. 672 00:44:56,480 --> 00:44:59,520 Speaker 1: What we found is that if you have colored letters 673 00:44:59,520 --> 00:45:03,800 Speaker 1: in number, you're really likely to have colored weekdays or months, 674 00:45:04,360 --> 00:45:07,960 Speaker 1: but you're not terribly likely to have other forms of 675 00:45:08,000 --> 00:45:12,239 Speaker 1: synesthesia like vision to sound or taste to touch. And 676 00:45:12,280 --> 00:45:15,120 Speaker 1: what we found is that the different types fall into 677 00:45:15,440 --> 00:45:17,160 Speaker 1: five different clusters. 678 00:45:17,680 --> 00:45:20,279 Speaker 2: If you have touch to color. 679 00:45:20,560 --> 00:45:23,279 Speaker 1: You're not really likely to have sound to touch or 680 00:45:23,360 --> 00:45:26,960 Speaker 1: other types. They fall into these different groups. And if 681 00:45:27,000 --> 00:45:28,880 Speaker 1: you want to know more about this, go to Eagleman 682 00:45:28,960 --> 00:45:33,680 Speaker 1: dot com slash podcast to see our different papers on this. Now, 683 00:45:33,840 --> 00:45:36,200 Speaker 1: this is an important finding that I'm mentioning because it 684 00:45:36,280 --> 00:45:41,360 Speaker 1: suggests that synesthesia is not a single thing genetically, but 685 00:45:41,440 --> 00:45:44,000 Speaker 1: there may be at least five different things that we're 686 00:45:44,000 --> 00:45:48,000 Speaker 1: all putting under the same umbrella. And the reason we 687 00:45:48,080 --> 00:45:50,920 Speaker 1: put them under the same umbrella is simply because they 688 00:45:50,960 --> 00:45:54,719 Speaker 1: have something in common. There's a mixture of the senses, 689 00:45:55,280 --> 00:46:00,080 Speaker 1: but they might actually be underpinned by different genetic bases. 690 00:46:00,120 --> 00:46:02,799 Speaker 1: And this is something I'll talk about in future episodes, 691 00:46:02,840 --> 00:46:05,879 Speaker 1: because we're generally seeing the same thing when we look 692 00:46:05,920 --> 00:46:11,480 Speaker 1: at other things like schizophrenia. People can present clinically very differently, 693 00:46:11,560 --> 00:46:14,560 Speaker 1: but we lump it all under schizophrenia. But I think 694 00:46:14,600 --> 00:46:17,640 Speaker 1: it's likely that in ten years from now, we'll talk 695 00:46:17,680 --> 00:46:21,880 Speaker 1: about multiple types of schizophrenia, and eventually we'll have totally 696 00:46:22,320 --> 00:46:27,200 Speaker 1: new names that identify the different genetic causes that happen 697 00:46:27,280 --> 00:46:31,439 Speaker 1: to give rise to these similar conditions that we stick 698 00:46:31,520 --> 00:46:34,600 Speaker 1: under the same umbrella. So the one that I've been 699 00:46:34,640 --> 00:46:38,920 Speaker 1: concentrating on is the one I call colored sequence synesthesia, 700 00:46:39,520 --> 00:46:42,719 Speaker 1: because as I mentioned, the thing to note is that 701 00:46:43,000 --> 00:46:47,840 Speaker 1: letters and numbers and weekdays and months are all overlearned sequences. 702 00:46:48,480 --> 00:46:52,840 Speaker 1: They're all arbitrary sequences that you memorize when you're about 703 00:46:52,880 --> 00:46:55,480 Speaker 1: four or five years old. And the way I started 704 00:46:55,480 --> 00:46:59,160 Speaker 1: this genetic study was by crashing a wedding and asking 705 00:46:59,200 --> 00:47:02,560 Speaker 1: everyone to spit into spitkits. Now why a wedding, It's 706 00:47:02,600 --> 00:47:07,279 Speaker 1: because the whole family tree of this family with synesthesia 707 00:47:07,440 --> 00:47:10,920 Speaker 1: was there, so I could march through the tree to 708 00:47:10,960 --> 00:47:14,200 Speaker 1: see who has synesthesia and who doesn't, and then do 709 00:47:14,280 --> 00:47:17,919 Speaker 1: what's called a family linkage analysis, which looks at how 710 00:47:17,960 --> 00:47:21,920 Speaker 1: the small genetic changes march through the family tree and 711 00:47:22,000 --> 00:47:25,520 Speaker 1: you find out which tiny changes are tracking with who 712 00:47:25,600 --> 00:47:29,160 Speaker 1: has synesthesia. Now, we're still working on this with lots 713 00:47:29,160 --> 00:47:32,080 Speaker 1: of different families in their trees, and it may well 714 00:47:32,120 --> 00:47:36,279 Speaker 1: be that there are different genetic changes in different families, 715 00:47:36,800 --> 00:47:39,360 Speaker 1: but we're getting closer to identifying at least some of 716 00:47:39,440 --> 00:47:44,040 Speaker 1: the genes involved. Now, this might involve an increased wiring 717 00:47:44,120 --> 00:47:47,680 Speaker 1: in a cineste's brain, or it might involve a slight 718 00:47:48,200 --> 00:47:52,880 Speaker 1: imbalance of the inhibition and excitation in the brain such 719 00:47:52,920 --> 00:47:56,680 Speaker 1: that you have activity in one area that kindles activity 720 00:47:56,719 --> 00:47:59,960 Speaker 1: in the neighboring area. I actually favor the second hypoth 721 00:48:00,239 --> 00:48:06,319 Speaker 1: this because non synesthetes can experience synesthesia with drugs, and 722 00:48:06,400 --> 00:48:10,280 Speaker 1: people can also experience synesthesia sometimes if they're super tired 723 00:48:10,640 --> 00:48:15,239 Speaker 1: and someone slams the door, they'll see colors. Even for synesthetes, 724 00:48:15,320 --> 00:48:19,920 Speaker 1: there synesthesia waxes and wanes a bit. Whether they're stressed 725 00:48:20,000 --> 00:48:24,400 Speaker 1: or fatigued, or on cigarettes or alcohol, or antidepressants or 726 00:48:24,440 --> 00:48:29,359 Speaker 1: anti epileptics. All these things change the quality of their synesthesia. 727 00:48:29,719 --> 00:48:32,600 Speaker 1: And that has the feeling of something to do with 728 00:48:32,719 --> 00:48:36,680 Speaker 1: the chemical balance, not simply the hardwiring. So I think 729 00:48:36,760 --> 00:48:39,920 Speaker 1: that when we find the gene or genes, will be 730 00:48:39,960 --> 00:48:43,600 Speaker 1: able to show that it's something associated with the balance 731 00:48:43,680 --> 00:48:48,000 Speaker 1: between inhibition and excitation in the brain. So what's amazing 732 00:48:48,000 --> 00:48:52,920 Speaker 1: about synesthesia is that what might be a single nucleotide 733 00:48:53,040 --> 00:48:56,600 Speaker 1: change in your genome changes the way that you see 734 00:48:56,640 --> 00:49:00,040 Speaker 1: the world. It changes the way that you experience and 735 00:49:00,080 --> 00:49:03,400 Speaker 1: it's your reality. So this will be the first time 736 00:49:03,560 --> 00:49:06,280 Speaker 1: that we're able to say, if you change this little 737 00:49:06,760 --> 00:49:10,160 Speaker 1: A or C or T or G over here, now 738 00:49:10,320 --> 00:49:14,719 Speaker 1: you are seeing the world differently. Now I want to 739 00:49:14,760 --> 00:49:17,520 Speaker 1: ask you a question. I'm going to play two notes 740 00:49:17,560 --> 00:49:25,080 Speaker 1: on my piano, which one is brighter, which one is bigger. 741 00:49:26,080 --> 00:49:31,200 Speaker 1: I've asked this informally to thousands of nonsynesthes and essentially 742 00:49:31,280 --> 00:49:35,400 Speaker 1: everybody answers that the high note is brighter and the 743 00:49:35,520 --> 00:49:40,040 Speaker 1: low note is larger. And that's strange, right, because all 744 00:49:40,120 --> 00:49:43,359 Speaker 1: I'm doing is playing some notes, and you're mapping that 745 00:49:43,440 --> 00:49:48,160 Speaker 1: sound onto brightness and onto size. So what this suggests 746 00:49:48,239 --> 00:49:52,560 Speaker 1: is that everyone has some cross connectivity in the brain. 747 00:49:53,160 --> 00:49:55,920 Speaker 1: And when you look at the micro anatomy, what you 748 00:49:56,040 --> 00:49:59,400 Speaker 1: find is that there are fibers in the brain carrying 749 00:49:59,520 --> 00:50:03,040 Speaker 1: visual information that go into the auditory part of your brain, 750 00:50:03,120 --> 00:50:07,279 Speaker 1: and there's fibers carrying auditory information that plug straight into 751 00:50:07,320 --> 00:50:11,680 Speaker 1: the visual parts of your brain. So this isn't everybody's brain. 752 00:50:11,800 --> 00:50:15,040 Speaker 1: It turns out there's naturally a lot of mixing of 753 00:50:15,120 --> 00:50:21,319 Speaker 1: the senses, and that's presumably why we all understand expressions 754 00:50:21,320 --> 00:50:24,680 Speaker 1: in the language that cross the senses, like oh, that's 755 00:50:24,760 --> 00:50:29,799 Speaker 1: a loud tie, or that's cool jazz, or she has 756 00:50:29,840 --> 00:50:37,480 Speaker 1: a sweet personality, or that's sharp cheese. Cross sensory expressions 757 00:50:37,880 --> 00:50:40,600 Speaker 1: are all over the language, and they kind of work 758 00:50:40,680 --> 00:50:41,240 Speaker 1: with everybody. 759 00:50:41,320 --> 00:50:43,880 Speaker 2: We all know what it means when. 760 00:50:43,760 --> 00:50:47,040 Speaker 1: You talk about these So this is the sense in 761 00:50:47,080 --> 00:50:51,160 Speaker 1: which we all share something like synesthesia, but we only 762 00:50:51,320 --> 00:50:55,959 Speaker 1: call it synesthesia when it's a cross sensory connection. That's rare, 763 00:50:56,880 --> 00:50:59,880 Speaker 1: And in this way synesthesia can serve as a terrific 764 00:51:00,120 --> 00:51:04,720 Speaker 1: inroad into understanding consciousness, both what people have in common 765 00:51:04,800 --> 00:51:08,680 Speaker 1: and what they experience differently. It illustrates a theme that 766 00:51:08,719 --> 00:51:11,080 Speaker 1: I'm going to come back to a lot in this podcast, 767 00:51:11,360 --> 00:51:15,600 Speaker 1: which is that people can be quite different on the inside. So, 768 00:51:15,640 --> 00:51:19,800 Speaker 1: to wrap up today's episode, reality is not one size 769 00:51:19,840 --> 00:51:22,600 Speaker 1: fits all. Two people can stand right next to each 770 00:51:22,600 --> 00:51:26,640 Speaker 1: other watching the Northern lights, and for one a sound 771 00:51:26,760 --> 00:51:29,960 Speaker 1: is internally triggered by the visuals, and not for the other. 772 00:51:30,560 --> 00:51:35,760 Speaker 1: Two humans watching the same event and having divergent experiences. 773 00:51:37,480 --> 00:51:39,600 Speaker 1: And the important lesson here is that if we're just 774 00:51:39,680 --> 00:51:43,360 Speaker 1: trying to understand our own reality, we're like fish in 775 00:51:43,520 --> 00:51:47,319 Speaker 1: water trying to describe water. It's impossible to describe what 776 00:51:47,520 --> 00:51:51,040 Speaker 1: water is because we've never seen anything other than that. 777 00:51:51,320 --> 00:51:54,279 Speaker 1: But when you see a different way that things can be, 778 00:51:55,400 --> 00:51:59,560 Speaker 1: that gives you a broader platform from which to build theories, 779 00:52:00,200 --> 00:52:02,520 Speaker 1: and that allows us to make progress on one of 780 00:52:02,560 --> 00:52:08,040 Speaker 1: our deepest goals in neuroscience to understand how the microscopic 781 00:52:08,120 --> 00:52:12,759 Speaker 1: activity in these three pounds of wet, gushy alien computational 782 00:52:12,800 --> 00:52:16,920 Speaker 1: material maps onto the world that you see and enjoy 783 00:52:17,000 --> 00:52:21,000 Speaker 1: every day, How it maps onto the view that you're 784 00:52:21,000 --> 00:52:23,920 Speaker 1: looking at right now, or the feel of your clothes 785 00:52:23,960 --> 00:52:27,000 Speaker 1: on your skin, or the sound of my voice in 786 00:52:27,040 --> 00:52:34,000 Speaker 1: your ear. That's all for this week. To find out 787 00:52:34,040 --> 00:52:36,600 Speaker 1: more and to share your thoughts, head over to eagleman 788 00:52:36,680 --> 00:52:40,359 Speaker 1: dot com slash podcasts. If you think you might have 789 00:52:40,400 --> 00:52:43,000 Speaker 1: synesthesia and you want to take the tests, go to 790 00:52:43,120 --> 00:52:51,080 Speaker 1: sinnisthet dot org. Until next time, I'm David Eagleman, and 791 00:52:51,160 --> 00:52:54,160 Speaker 1: this is Inner Cosmos.