How The Brain Perceives Time_ with David Eagleman-এর সম্পূর্ণ প্রতিলিপি

the brain via different channels? And 74 00:04:44.069 --> 00:04:45.750 will the brain figure it out? Because it's all made 75 00:04:45.790 --> 00:04:48.689 of the same currency. It's all the same stuff. And 76 00:04:48.730 --> 00:04:51.250 so it turns out this has a long history. The 77 00:04:51.290 --> 00:04:54.120 first paper on this was in 1969 in the journal Nature. 78 00:04:56.019 --> 00:05:00.300 A scientist named Paul Bakirita put blind people into a 79 00:05:00.439 --> 00:05:05.300 modified dental chair, which had a little grid of solenoids 80 00:05:05.360 --> 00:05:07.620 that poked people in the back. So imagine, let's say, 81 00:05:07.639 --> 00:05:10.629 eight by eight little grid where you feel things poking 82 00:05:10.649 --> 00:05:12.670 you in the back. And he set up a video 83 00:05:12.730 --> 00:05:15.170 camera and whatever the camera was looking at, you would 84 00:05:15.310 --> 00:05:18.470 feel that in your back. So it's like these games 85 00:05:18.490 --> 00:05:20.959 that you do as a kid where you draw something 86 00:05:21.000 --> 00:05:23.100 with your finger on someone's skin and they try to 87 00:05:23.139 --> 00:05:25.839 figure out what it is. It's the same idea. And 88 00:05:26.120 --> 00:05:28.170 he was able to show that blind people get really 89 00:05:28.230 --> 00:05:30.430 good at being able to perceive what's in the world 90 00:05:30.509 --> 00:05:33.110 out there just based on the skin of their back. 91 00:05:34.290 --> 00:05:37.089 And it turns out that the history of this, even 92 00:05:37.209 --> 00:05:40.540 I discovered more recently, it goes back to the 1880s 93 00:05:40.579 --> 00:05:43.180 where people were first trying this sort of thing about 94 00:05:43.279 --> 00:05:47.389 turning light into patterns of vibration on the forehead or something. 95 00:05:48.069 --> 00:05:51.420 So now what we have, is the capacity to really 96 00:05:51.480 --> 00:05:54.819 miniaturize these electronics and make this work. And so one 97 00:05:54.860 --> 00:05:56.379 of the things I've worked on in my lab for 98 00:05:56.420 --> 00:06:01.339 years is converting sound into patterns of vibration on the 99 00:06:01.439 --> 00:06:05.439 skin so that deaf people can hear that way. It's 100 00:06:05.519 --> 00:06:07.600 the same information. It's just getting up to the brain 101 00:06:07.660 --> 00:06:10.160 via an unusual route through the skin. 102 00:06:10.779 --> 00:06:15.160 By the way, in the film Immortal Beloved, which was 103 00:06:15.220 --> 00:06:20.790 basically chronicled Beethoven and in his most productive years, including 104 00:06:20.829 --> 00:06:24.230 his transition to deafness. There's a beautiful scene, which I 105 00:06:24.250 --> 00:06:27.509 didn't fully understand when I first saw it. He's there 106 00:06:27.649 --> 00:06:31.389 alone with his piano in this big open room and 107 00:06:31.589 --> 00:06:35.560 his head is resting on the top of the piano 108 00:06:36.100 --> 00:06:39.399 while he's

banging out these random sounds on the keys. 109 00:06:39.920 --> 00:06:42.720 And we were not explicitly told at this point that 110 00:06:42.740 --> 00:06:44.860 he was deaf. I think if you knew he was, 111 00:06:44.939 --> 00:06:47.680 you would know this, but I didn't. first time seeing 112 00:06:47.720 --> 00:06:53.069 the film. And they're just these very cacophonous notes being 113 00:06:53.149 --> 00:06:56.709 banged out. Again, his head is resting on the top 114 00:06:56.750 --> 00:07:01.889 of the piano. And after 30 seconds of this, out 115 00:07:02.050 --> 00:07:06.810 comes this beautiful music. And then, oh my gosh, he 116 00:07:06.860 --> 00:07:11.399 can't hear it. He's feeling the vibrations into his cranium 117 00:07:12.019 --> 00:07:16.329 through the cavity of the piano itself. And for me, 118 00:07:16.529 --> 00:07:19.290 to this day, it's one of the most poignant cinematic 119 00:07:19.350 --> 00:07:22.930 moments ever. And that's him. I'm just repeating what you're saying. 120 00:07:23.189 --> 00:07:29.180 It's him converting the vibrations, external vibrations into his skin 121 00:07:29.779 --> 00:07:31.379 and getting into his cranium. 122 00:07:31.980 --> 00:07:34.019 There's an old history to this, actually. So people who 123 00:07:34.060 --> 00:07:38.709 are deaf and blind use this method called TADOMA, where 124 00:07:38.750 --> 00:07:42.810 they put their hand on the speaker's face, as in 125 00:07:42.850 --> 00:07:45.250 the person speaking to them, put their hand on their face, 126 00:07:45.610 --> 00:07:47.709 and their hand is covering different parts of them so 127 00:07:47.730 --> 00:07:49.490 they can feel what's going on, the vibrations in the 128 00:07:49.529 --> 00:07:51.889 throat and the muscles of the jaw and so on. 129 00:07:52.389 --> 00:07:56.649 And by pulling all these different pieces of data on 130 00:07:56.689 --> 00:07:59.649 their fingertips, they can figure out exactly what the person 131 00:07:59.709 --> 00:08:00.069 is saying. 132 00:08:00.189 --> 00:08:04.529 Let me ask you. What you just talked about with 133 00:08:04.610 --> 00:08:10.139 the skin makes me think about when blind people read Braille. 134 00:08:11.959 --> 00:08:18.350 That signal, is it still activating in the occipital lobe 135 00:08:18.430 --> 00:08:23.129 and then the occipital lobe actually takes over or takes 136 00:08:23.250 --> 00:08:29.480 part in the sensory of a haptic experience or... Is 137 00:08:29.620 --> 00:08:33.340 it something else where different parts of the brain are 138 00:08:33.379 --> 00:08:38.399 being activated to compensate? What exactly is happening? 139 00:08:38.879 --> 00:08:42.500 OK, lovely question. So let's look at this. So when 140 00:08:42.600 --> 00:08:46.840 you are reading a book and your eyeballs are landing 141 00:08:46.940 --> 00:08:49.759 on the page at different moments, you're seeing these squiggles 142 00:08:49.860 --> 00:08:52.980 on the page. That your brain makes sense of and

143 00:08:53.000 --> 00:08:56.480 you are so over trained on this that you're not 144 00:08:56.519 --> 00:09:00.230 even aware of these squiggles unless you look, for example, 145 00:09:00.269 --> 00:09:02.950 at a foreign alphabet, in which case when you look 146 00:09:02.970 --> 00:09:05.289 at the foreign alphabet, you can't believe how weird these 147 00:09:05.350 --> 00:09:08.009 things are and that anybody could ever see this. Yeah, 148 00:09:08.029 --> 00:09:08.509 it's all squiggles. 149 00:09:08.529 --> 00:09:09.169 It's all squiggles, yeah. 150 00:09:09.350 --> 00:09:11.360 But when it's your own language, you say, my God, 151 00:09:11.379 --> 00:09:14.580 that's the most obvious thing. And all that emerges is 152 00:09:15.139 --> 00:09:17.820 the meaning of the text. And you laugh and you 153 00:09:17.919 --> 00:09:20.919 cry at the trials of the protagonist. 154 00:09:20.980 --> 00:09:21.200 Okay. 155 00:09:21.820 --> 00:09:25.210 Now, when a blind person is reading Braille, they're passing 156 00:09:25.230 --> 00:09:27.629 their fingers over these bumps. As you said, Neil, they're 157 00:09:27.649 --> 00:09:31.070 just each letter. But they're not thinking of it as letters. 158 00:09:31.129 --> 00:09:35.409 As they pass their finger over, they're laughing and crying 159 00:09:35.909 --> 00:09:39.919 because– the meaning emerges. And it's a great example. I'm 160 00:09:40.120 --> 00:09:43.019 glad you brought this up about Braille because it shows 161 00:09:43.080 --> 00:09:48.580 how arbitrary it is. We're using these giant spheres embedded 162 00:09:48.620 --> 00:09:51.450 in our skull to pick up on photons to get 163 00:09:51.500 --> 00:09:53.409 meaning that way, but a blind person gets it through 164 00:09:53.429 --> 00:09:54.549 the fingertips that way. 165 00:09:55.129 --> 00:09:58.850 So let me ask you this. If the brain doesn't care, 166 00:09:58.870 --> 00:10:02.480 I'll say it like that, which way it receives the data, 167 00:10:03.440 --> 00:10:07.110 what does it tell us about our brain's ability to 168 00:10:07.529 --> 00:10:13.009 adapt to this circumstance and our perception in general? 169 00:10:13.750 --> 00:10:16.029 Okay, so actually, let me back up just to one 170 00:10:16.080 --> 00:10:19.980 more issue that Chuck asked, which is this question of 171 00:10:20.720 --> 00:10:23.860 when you're feeling braille with your fingertip, is that going 172 00:10:23.899 --> 00:10:26.059 to the occipital cortex of the back of the brain, 173 00:10:26.080 --> 00:10:28.909 which is normally where we see? The answer is sort of. 174 00:10:29.210 --> 00:10:31.289 What happens when you're using your fingertip is it goes 175 00:10:31.350 --> 00:10:35.950 to the somatosensory cortex because that's where your fingertip directly goes. 176 00:10:36.549 --> 00:10:39.509 But the key is that the brain doesn't let any 177 00:10:39.730 --> 00:10:43.840 land lie fallow. And so if your visual cortex is 178 00:10:44.039 --> 00:10:47.039 not getting used by– there's hundreds of things that could 179 00:10:47.059 --> 00:10:49.220 go wrong with your eyes and your optic nerves or whatever. 180 00:10:49.600 --> 00:10:52.639 If that is no longer getting used, then that territory 181 00:10:52.679 --> 00:10:56.539 gets taken over by the braille reading. And you can 182 00:10:56.590 --> 00:10:59.450 demonstrate this because– well, actually, many ways, even in the 183 00:10:59.490 --> 00:11:02.870 past– You can demonstrate it that if a blind person 184 00:11:02.889 --> 00:11:06.370 who uses Braille gets a stroke in their occipital cortex 185 00:11:06.389 --> 00:11:08.929 at the back of their head, they get worse at reading. 186 00:11:09.330 --> 00:11:12.679 And nowadays, we do it using fMRI, brain imaging, where 187 00:11:12.700 --> 00:11:15.919 we look at what's going on when you're using Braille. 188 00:11:16.080 --> 00:11:18.740 And you see that the visual cortex, what we would 189 00:11:18.759 --> 00:11:20.919 have normally thought of as the visual cortex getting activated. 190 00:11:21.460 --> 00:11:25.750 But it's because the brain doesn't let any territory go 191 00:11:25.789 --> 00:11:29.110 to waste. So if you go deaf, the parts of 192 00:11:29.149 --> 00:11:31.230 your brain that would have taken care of hearing get 193 00:11:31.269 --> 00:11:35.230 taken over. And that's why deaf people are, are really 194 00:11:35.350 --> 00:11:38.549 good at seeing other things. For example, they can see 195 00:11:38.580 --> 00:11:42.559 your accent on your lips as you're moving and talking. And, 196 00:11:42.679 --> 00:11:45.059 and of course, blind people can do all kinds of 197 00:11:45.120 --> 00:11:48.279 extraordinary things because all that territory, the visual cortex has 198 00:11:48.320 --> 00:11:52.100 been taken over. So, you know, they can, hear, you know, 199 00:11:52.340 --> 00:11:57.370 exactly things about your footfall or they can localize things that, 200 00:11:57.429 --> 00:11:58.850 that hearing people can't do so easily. 201 00:11:58.870 --> 00:12:02.139 So, so much so I, I, I actually saw a 202 00:12:02.279 --> 00:12:07.350 piece years ago about a young kid who was blind 203 00:12:07.879 --> 00:12:14.110 and developed echolocation as a means of moving around by 204 00:12:14.590 --> 00:12:19.190 using clicks in his mouth and being able to what 205 00:12:19.309 --> 00:12:23.129 we would call see the room, but of course not 206 00:12:23.309 --> 00:12:25.580 in the sense that we consider sight. 207 00:12:26.009 --> 00:12:26.220 Right. 208 00:12:26.320 --> 00:12:28.240 The young man you're referring to is a kid named 209 00:12:28.320 --> 00:12:33.059 Ben Underwood, who unfortunately passed away a few years later. 210 00:12:33.580 --> 00:12:36.740 But I actually had his mother come in to my 211 00:12:36.799 --> 00:12:39.190 class at Stanford that I teach on brain plasticity to 212 00:12:39.250 --> 00:12:43.129 talk with us about this. What's fascinating, you're exactly right. 213

00:12:43.149 --> 00:12:45.289 So Ben makes these clicking sounds and he's getting the 214 00:12:45.330 --> 00:12:48.429 information back. I saw a documentary on him that said 215 00:12:48.629 --> 00:12:50.659 something like, Ben is the only person in the world 216 00:12:50.700 --> 00:12:53.320 that can use echolocation. But it turns out that's not true. 217 00:12:53.899 --> 00:12:57.539 Tens of thousands of blind people use echolocation. And in fact, 218 00:12:57.620 --> 00:13:00.230 the term was coined in a 1930 science paper in 219 00:13:00.450 --> 00:13:08.029 the journal Science. that was called echolocation in bats and 220 00:13:08.049 --> 00:13:10.970 the blind so people use they use either the tapping 221 00:13:10.990 --> 00:13:12.750 of their stick or these clicks with their mouth or 222 00:13:12.789 --> 00:13:15.740 they you know make a sound of some sort or 223 00:13:15.779 --> 00:13:18.440 a snapping sound with their fingers and and they get 224 00:13:18.460 --> 00:13:20.679 the echoes back and they're able to construct it's very 225 00:13:20.860 --> 00:13:23.200 low resolution of course but they're able to construct something 226 00:13:23.259 --> 00:13:26.779 about what's going out there in front of them that's wow. 227 00:13:27.340 --> 00:13:34.500 Nope that's lame ready Do you harbor questions about the universe? 228 00:13:35.879 --> 00:13:42.000 Some long-held bit of cosmic curiosity lingering within you? Or 229 00:13:42.019 --> 00:13:46.669 questions about anything at all? You can become a Patreon 230 00:13:46.730 --> 00:13:51.330 supporter of StarTalk. You have access to our exclusive question 231 00:13:51.370 --> 00:13:54.710 line on our website. Those are where we draw our 232 00:13:54.750 --> 00:13:56.129 questions for our customers. 233 00:13:56.669 --> 00:13:59.509 Some of the most extreme objects in the universe. 234 00:14:00.049 --> 00:14:04.470 StarTalk is a work in progress where we, every month, 235 00:14:04.830 --> 00:14:07.629 come up with some new way, some new idea, some 236 00:14:07.690 --> 00:14:11.399 new understanding of how to bring the universe down to Earth. 237 00:14:12.120 --> 00:14:15.500 We could not do that without your support. Thank you. 238 00:14:16.139 --> 00:14:17.970 And as always, keep looking up. 239 00:14:19.470 --> 00:14:25.169 Why doesn't this land grab of the spheres take place 240 00:14:26.149 --> 00:14:28.700 in someone with a full suite of senses? 241 00:14:29.179 --> 00:14:31.860 The answer is all your senses are in competition with 242 00:14:31.899 --> 00:14:34.639 each other all the time. And the reason all your 243 00:14:34.679 --> 00:14:38.740 senses stay intact is because they're all fighting for it 244 00:14:38.799 --> 00:14:42.269 and they're getting data in there. Now, it depends a 245 00:14:42.289 --> 00:14:44.850 little bit on what is relevant to you as a 246 00:14:47.070 --> 00:14:51.590 If you go into, let's say, perfumery, then your olfactory 247 00:14:51.629 --> 00:14:55.019

cortex dealing with smell is going to enhance and get bigger. 248 00:14:55.100 --> 00:14:57.759 If you are a microscopist who needs to stare at 249 00:14:57.779 --> 00:15:00.200 things all the time, that might be bigger. If you're 250 00:15:00.240 --> 00:15:03.340 a musician who needs to really hear very subtle details 251 00:15:03.379 --> 00:15:06.289 of the music in the orchestra, then that's going to 252 00:15:06.330 --> 00:15:09.149 dominate a bit. But in general, you're getting all of 253 00:15:09.210 --> 00:15:10.169 these senses all the time. 254 00:15:10.190 --> 00:15:11.210 Wow. 255 00:15:11.230 --> 00:15:14.059 Yeah. Now, this led me to a whole new theory 256 00:15:14.080 --> 00:15:16.750 about why we dream. You guys want to hear that? 257 00:15:17.950 --> 00:15:18.750 Oh, okay. 258 00:15:18.809 --> 00:15:19.490 Yeah. Oh, yeah. 259 00:15:19.909 --> 00:15:20.190 Okay. 260 00:15:20.230 --> 00:15:24.009 So, it turns out that because there's this competition with 261 00:15:24.129 --> 00:15:27.529 all the senses going on, one of the new pieces 262 00:15:27.590 --> 00:15:30.379 of data, just let's say 14 years ago that we got, 263 00:15:30.759 --> 00:15:35.340 was that the takeovers can happen pretty rapidly between the senses. So, 264 00:15:35.379 --> 00:15:38.190 for example, if you take people... My colleagues at Harvard 265 00:15:38.230 --> 00:15:41.470 did an experiment where they blindfold people tightly and they 266 00:15:41.509 --> 00:15:43.629 stick them in the scanner and they're measuring things as 267 00:15:43.669 --> 00:15:45.610 they make a sound or they touch them on the hand, 268 00:15:45.669 --> 00:15:48.350 things like that. It turns out that after 60 minutes, 269 00:15:48.389 --> 00:15:52.220 you start to see activity in the occipital lobe, what 270 00:15:52.240 --> 00:15:55.620 we normally think of as the visual cortex. based on 271 00:15:55.960 --> 00:15:59.440 touch or sound, we're seeing activity in the visual cortex 272 00:15:59.519 --> 00:16:01.980 just because the person has been blinded. Normally, if you 273 00:16:02.000 --> 00:16:04.570 touch someone on the hand, you see that activity in 274 00:16:04.590 --> 00:16:07.289 a particular part called the somatosensory cortex. If you play 275 00:16:07.330 --> 00:16:10.070 a sound, you see activity in the auditory cortex. But 276 00:16:10.169 --> 00:16:12.509 now you start to see a little bit of activity 277 00:16:12.970 --> 00:16:16.129 showing up in the visual cortex if you've blinded them 278 00:16:16.190 --> 00:16:19.629 for 60 minutes. And so I was really struck by 279 00:16:20.029 --> 00:16:24.590 how rapidly the takeover starts. And so that's what led 280 00:16:24.649 --> 00:16:27.629 me and my student Don Vaughn to a new hypothesis. 281 00:16:27.960 --> 00:16:30.659 We're on a planet that rotates into darkness for half 282 00:16:30.720 --> 00:16:34.120 the time. And when you're in the dark, you can 283 00:16:34.179 --> 00:16:37.080 still smell and touch and taste

and hear, but you 284 00:16:37.120 --> 00:16:39.860 can't see. And obviously I'm talking about evolutionary time, not 285 00:16:39.899 --> 00:16:43.889 the last nanosecond of electrified existence that we have. And 286 00:16:44.029 --> 00:16:47.409 so that puts the visual system at a real disadvantage. 287 00:16:47.950 --> 00:16:50.559 And when you sleep, If there's a bug crawling on 288 00:16:50.580 --> 00:16:52.519 your skin or a smell, that'll wake you up. You're 289 00:16:52.559 --> 00:16:56.440 still sensing that, but you can't see anything. So the 290 00:16:56.460 --> 00:16:58.580 visual system is at a real disadvantage. And so what 291 00:16:58.620 --> 00:17:02.740 we've realized is dreams are the brain's way of keeping 292 00:17:02.799 --> 00:17:07.799 that territory active. Every 90 minutes, you have this random 293 00:17:08.319 --> 00:17:12.319 burst of activity that just goes blasting into the primary 294 00:17:12.359 --> 00:17:14.980 visual cortex. And that's it. When you dream, you've got 295 00:17:15.000 --> 00:17:19.190 this very ancient circuitry that does nothing but blast random activity. 296 00:17:19.049 --> 00:17:19.349 Into your brain. 297 00:17:19.400 --> 00:17:23.789 Into the primary visual cortex. So that's amazing. 298 00:17:24.069 --> 00:17:28.759 So basically the brain creates its own screensaver to occupy 299 00:17:28.799 --> 00:17:31.000 the real estate from invasion. 300 00:17:31.059 --> 00:17:31.420 Here we go. 301 00:17:31.440 --> 00:17:35.650 We've gone all Game of Thrones. So we've done invasion. 302 00:17:36.460 --> 00:17:37.490 That's actually cool, man. 303 00:17:37.950 --> 00:17:38.150 Yeah. 304 00:17:38.269 --> 00:17:42.410 So the courtesies are always in competition. And when we 305 00:17:42.450 --> 00:17:46.680 go to sleep, is the competition that fierce that this 306 00:17:47.140 --> 00:17:50.799 area of the brain says, hey, you know, it's like 307 00:17:50.839 --> 00:17:53.160 when you work in radio, you can't go on vacation 308 00:17:53.180 --> 00:17:59.150 because when you come back, you don't have a job. No, seriously. 309 00:17:59.390 --> 00:18:01.569 That's the rule in radio. It's like, don't go on 310 00:18:01.589 --> 00:18:04.990 vacation because when you come back, somebody will be behind 311 00:18:05.029 --> 00:18:05.950 that microphone. 312 00:18:06.210 --> 00:18:09.009 Chuck started his career on radio. Yes. 313 00:18:10.289 --> 00:18:10.529 Okay. 314 00:18:11.190 --> 00:18:14.230 So the answer is yes. The competition is very fierce, 315 00:18:14.299 --> 00:18:17.160 but because we live on this planet that has this 316 00:18:17.200 --> 00:18:21.259 rotation only one sense is disadvantaged now if we were 317 00:18:21.299 --> 00:18:25.619 a tidally locked planet or something where we you know 318 00:18:25.640 --> 00:18:30.299 we were always facing the our sun um we would 319 00:18:30.319 --> 00:18:33.420 i think not have dreaming there there would be big 320 00:18:33.480 --> 00:18:35.470 differences in the way that our brains wired up but 321 00:18:35.549 --> 00:18:37.529 but because we're in the situation where you have to 322 00:18:37.569 --> 00:18:41.269 protect it from takeover every single night yep you can't 323 00:18:41.369 --> 00:18:42.930 you can't go on vacation. 324 00:18:42.970 --> 00:18:45.119 Well it's not just whether the sun is set It 325 00:18:45.160 --> 00:18:47.049 is whether your eyes are closed, right? I mean, when 326 00:18:47.069 --> 00:18:50.150 you sleep, whether or not it's day or night, doesn't 327 00:18:50.170 --> 00:18:50.750 that matter too? 328 00:18:51.190 --> 00:18:53.869 So it is the case that currently people have night 329 00:18:53.910 --> 00:18:56.589 shift jobs and whatever. And so things can be different. 330 00:18:56.609 --> 00:18:58.829 But what we're talking about in the development of the 331 00:18:58.869 --> 00:19:02.039 brain is over many hundreds of millions of years. And 332 00:19:02.119 --> 00:19:05.519 so it was when the planet rotates into darkness, that's 333 00:19:05.539 --> 00:19:09.059 when almost all animals sleep. And one of the hypotheses 334 00:19:09.099 --> 00:19:11.619 for why we sleep is just to stay out of trouble. 335 00:19:11.700 --> 00:19:13.680 It's actually easier just to curl up in the corner 336 00:19:13.720 --> 00:19:16.400 of a cave and And shut down and do all 337 00:19:16.440 --> 00:19:19.559 these other things like energy restoration and so on. But 338 00:19:19.700 --> 00:19:22.400 it's both. It's both that it's pitch black outside on 339 00:19:22.779 --> 00:19:26.710 most nights and it's, you know, and you sleep. And 340 00:19:26.809 --> 00:19:30.019 so you need a way of defending that territory. 341 00:19:30.099 --> 00:19:32.700 Yeah. And wouldn't some of that be connected to your 342 00:19:32.779 --> 00:19:38.779 circadian rhythm? Because, for instance, I wake up normally at 343 00:19:38.880 --> 00:19:42.309 first light. And I didn't realize why for the longest time. 344 00:19:42.480 --> 00:19:45.250 I still don't know why. But then I bought a 345 00:19:45.309 --> 00:19:49.009 blackout mask. And so when I wake up, the first 346 00:19:49.029 --> 00:19:52.009 thing I do... I'm wake, right? Like my body's like, 347 00:19:52.069 --> 00:19:53.710 it's time to get up. And I put on the 348 00:19:53.730 --> 00:19:57.089 blackout mask. I go back to sleep with no problem. 349 00:19:57.549 --> 00:19:59.910 And as a matter of fact, That's when I have 350 00:19:59.950 --> 00:20:03.940 to set an alarm because I will sleep much longer 351 00:20:04.359 --> 00:20:08.700 than I would like because it's just black. It's just darkness. 352 00:20:09.400 --> 00:20:11.799 But so it's like almost like even though my eyes 353 00:20:11.859 --> 00:20:15.079 are closed, my body is still able to sense the 354 00:20:15.160 --> 00:20:18.240 light that is coming into the room at first light. 355 00:20:18.619 --> 00:20:21.039 Or maybe maybe this is all just me. I'm really 356

00:20:21.140 --> 00:20:22.140 asking you a question here. 357 00:20:22.950 --> 00:20:23.230 Yeah. 358 00:20:23.849 --> 00:20:28.059 No, that's right. We've traditionally been totally tied to what's 359 00:20:28.099 --> 00:20:30.960 going on with light and darkness in a way that 360 00:20:31.019 --> 00:20:34.220 we've drifted from now because we have artificial light anywhere 361 00:20:34.240 --> 00:20:36.839 we want and that sort of thing. But yes, what 362 00:20:36.859 --> 00:20:39.240 I'm talking about in the brain are these very, very 363 00:20:39.460 --> 00:20:44.329 ancient things. And in fact, this circuitry that causes, these 364 00:20:44.369 --> 00:20:49.109 are called PGO waves, pontine, geniculate, occipital, doesn't matter the details, 365 00:20:49.150 --> 00:20:53.430 but these essentially you find this across all animal species, 366 00:20:53.869 --> 00:20:56.720 all animals dream. As far as we can tell, as 367 00:20:56.740 --> 00:20:58.960 far as we can measure dreamlike activity and so on, 368 00:20:59.579 --> 00:21:03.880 all animals are doing this because it's so fundamental and ancient. 369 00:21:05.200 --> 00:21:06.480 As far as I can tell when I'm looking at 370 00:21:06.529 --> 00:21:09.650 the anatomy, it's like an add-on circuit of, oh, shoot, 371 00:21:09.670 --> 00:21:12.130 we've got this extra problem because of the rotation of 372 00:21:12.150 --> 00:21:14.529 the planet. Let's just go ahead and blast activity in there. 373 00:21:15.269 --> 00:21:17.279 to save this. So one of the things we did 374 00:21:17.690 --> 00:21:21.619 is we measured very carefully across 25 species of primates, 375 00:21:22.339 --> 00:21:26.359 which have different amounts of brain plasticity, how flexible their 376 00:21:26.400 --> 00:21:32.029 brains are. So humans are unbelievably adaptable. We essentially drop 377 00:21:32.069 --> 00:21:35.109 in the world half-baked and we absorb everything around us, 378 00:21:35.170 --> 00:21:37.970 our language, our culture, all the science that's come before us. 379 00:21:38.349 --> 00:21:40.890 We absorb all that and then we springboard off that 380 00:21:40.930 --> 00:21:43.599 to the next level. But even among primates, there are 381 00:21:43.759 --> 00:21:46.259 those that come out that are not particularly flexible. They're 382 00:21:46.279 --> 00:21:49.339 sort of pre-programmed. You can think about it that way. 383 00:21:49.440 --> 00:21:51.740 And so anyway, we looked across all these primate species 384 00:21:51.779 --> 00:21:55.099 with the hypothesis that the more flexible the brain, the 385 00:21:55.140 --> 00:21:59.380 more brain plasticity, the more dreaming will happen every night. 386 00:21:59.420 --> 00:22:02.680 And that's exactly what we find is a significant correlation 387 00:22:03.099 --> 00:22:07.509 where if your brain has more danger of big shifts happening, 388 00:22:08.069 --> 00:22:10.589 more danger of takeover of the occipital cortex, then you 389 00:22:10.630 --> 00:22:11.650 have more dreaming. 390 00:22:12.309 --> 00:22:16.519 But if your hypothesis is accurate as a general statement 391 00:22:16.559 --> 00:22:20.259 about human physiology and our sensory system, it seems to 392 00:22:20.299 --> 00:22:23.160 me you could do this with other senses as well. 393 00:22:23.539 --> 00:22:28.890 So if you plug your ears, denying any auditory signals 394 00:22:29.289 --> 00:22:32.250 from entering your brain, that's a part of your brain 395 00:22:32.269 --> 00:22:35.710 that's now not being used. Would you have more auditory 396 00:22:35.809 --> 00:22:39.049 dreams as opposed to visual ones under those conditions? 397 00:22:39.599 --> 00:22:42.359 So this is exactly what happens when people go into, 398 00:22:42.380 --> 00:22:46.880 let's say, solitary confinement. For example, at Alcatraz, I interviewed 399 00:22:46.940 --> 00:22:49.799 some people who had been in the hole, locked up 400 00:22:49.859 --> 00:22:52.460 in Alcatraz. This is exactly what happens. You have auditory 401 00:22:52.569 --> 00:22:57.890 and visual hallucinations because your brain is fighting back and saying, 402 00:22:57.930 --> 00:23:00.109 wait a minute, I'm used to getting these signals and 403 00:23:00.150 --> 00:23:02.309 now I'm not getting any of this information. So it 404 00:23:02.349 --> 00:23:05.650 starts generating it on its own. I've actually, I've also 405 00:23:05.670 --> 00:23:09.359 hypothesized that Tinnitus, which is ringing in the ears, is 406 00:23:09.400 --> 00:23:13.170 another expression of this, what I call the defensive activation theory, 407 00:23:13.650 --> 00:23:16.329 which is your brain is used to getting all these 408 00:23:16.470 --> 00:23:21.210 frequencies that it's hearing. But when people's, the cells in 409 00:23:21.250 --> 00:23:25.779 their inner ear die off in some range, their brain says, 410 00:23:25.960 --> 00:23:28.539 wait a minute, I'm not hearing that frequency anymore. So 411 00:23:28.579 --> 00:23:31.680 it starts generating it on its own, starts making its 412 00:23:31.819 --> 00:23:33.940 own version of it. And that's what the ringing in 413 00:23:33.960 --> 00:23:34.490 the ears is. 414 00:23:35.309 --> 00:23:35.640 Damn. 415 00:23:36.049 --> 00:23:37.190 That's annoying. 416 00:23:37.410 --> 00:23:38.069 That sucks. 417 00:23:38.109 --> 00:23:38.430 Yeah. 418 00:23:38.450 --> 00:23:42.009 So going back to dreams, David, this is a two-part question. A, 419 00:23:42.529 --> 00:23:46.519 if we do not dream, what is happening there? And B, 420 00:23:46.630 --> 00:23:49.920 why is it we don't always remember our dreams? 421 00:23:50.539 --> 00:23:53.960 So great question. Everybody dreams. And that leads to part B, 422 00:23:53.980 --> 00:23:56.650 which is that often you don't remember your dreams. And 423 00:23:56.690 --> 00:23:58.349 that has a lot to do with when you wake 424 00:23:58.430 --> 00:24:00.609 up during the night. So what happens is you have 425 00:24:00.650 -->

00:24:03.930 different stages of sleep during the night and dreaming happens 426 00:24:04.109 --> 00:24:07.779 at the lightest stage of sleep. And often people will 427 00:24:07.819 --> 00:24:10.200 wake up right at that stage and they'll remember it 428 00:24:10.259 --> 00:24:12.779 just fine. And of course, there are ways to remember 429 00:24:12.799 --> 00:24:14.940 it even better, which is you write it down or 430 00:24:14.980 --> 00:24:16.880 you speak it into your cell phone and then you 431 00:24:16.900 --> 00:24:20.490 can Recall it. But the key is when you are dreaming, 432 00:24:20.609 --> 00:24:23.329 the brain is smart enough to say, hey, I don't 433 00:24:23.349 --> 00:24:26.450 really need this. It's random stuff, which is why it's 434 00:24:26.490 --> 00:24:29.490 not interesting to hear about other people's dreams because it's 435 00:24:29.509 --> 00:24:33.049 just random garbage. I mean, I call it sticking my 436 00:24:33.109 --> 00:24:36.450 head in the night blender. I hate dreaming. It doesn't 437 00:24:36.490 --> 00:24:39.230 interest me at all, the content of it. But let 438 00:24:39.250 --> 00:24:41.670 me say two things. The brain is a storyteller. So 439 00:24:41.690 --> 00:24:45.029 if you blast random activity in there, It's going to 440 00:24:45.549 --> 00:24:48.970 make stories out of it, make narratives. Usually those narratives 441 00:24:49.170 --> 00:24:55.019 follow the connections that are hot from the day. So 442 00:24:55.079 --> 00:24:56.740 things that happen in your day will show up in 443 00:24:56.779 --> 00:25:00.279 your dreams, but there's this very loose association and bizarreness. 444 00:25:00.880 --> 00:25:05.259 and typically magnified emotion too. Anyway, all these things happen 445 00:25:05.299 --> 00:25:07.160 in a dream, but your brain is smart enough to 446 00:25:07.220 --> 00:25:10.200 know that it's not really that useful to remember that. 447 00:25:10.269 --> 00:25:15.130 So your memory systems are mostly shut down during dreaming. 448 00:25:16.059 --> 00:25:18.799 And that's why when you wake up, you might remember 449 00:25:18.839 --> 00:25:22.089 a dream for, let's say, 10 minutes, 15 minutes. You say, 450 00:25:22.420 --> 00:25:25.250 oh my gosh, this happened. My heart's pounding, all this stuff. 451 00:25:25.609 --> 00:25:28.009 But then it kind of goes away. And here's the 452 00:25:28.049 --> 00:25:31.190 really interesting thing. That gives you insight into what it's 453 00:25:31.289 --> 00:25:35.609 like to have, let's say, Alzheimer's disease. Because somebody with 454 00:25:35.710 --> 00:25:40.279 Alzheimer's They have short-term memory. They remember what just happened 455 00:25:40.299 --> 00:25:44.339 a few minutes ago. But after, call it 15 minutes, 456 00:25:44.400 --> 00:25:46.880 it just fades away. So they'll get off the phone. 457 00:25:46.920 --> 00:25:50.400 They'll say, OK, I'll meet you there in a few minutes. 458 00:25:50.460 --> 00:25:53.150 And they hang up the phone. And then it just 459 00:25:53.210 --> 00:25:55.650 fades away the same way that a dream fades away 460 00:25:55.710 --> 00:25:57.809 for you. It's like gossamer that just disappears. 461 00:25:57.829 --> 00:26:01.849 All right, David, you mentioned consciousness. And as you're explaining 462 00:26:01.910 --> 00:26:06.440 these things, It sounds to my mind, which is obviously limited, 463 00:26:06.859 --> 00:26:11.950 that the brain will only manufacture and cement memories during 464 00:26:12.269 --> 00:26:15.700 its conscious state. Because while we're dreaming, we're not quite conscious. 465 00:26:15.759 --> 00:26:18.539 So it doesn't quite imprint and hold on to them. 466 00:26:18.579 --> 00:26:19.480 Is that quite right? 467 00:26:20.200 --> 00:26:22.940 That's generally the case. And by the way, your memory 468 00:26:22.980 --> 00:26:25.829 is terrible. I mean, most things that happen to you, 469 00:26:25.839 --> 00:26:26.720 you don't remember. 470 00:26:26.740 --> 00:26:27.380 You don't remember. 471 00:26:27.400 --> 00:26:28.220 Yeah. 472 00:26:28.779 --> 00:26:31.769 Because memory, it's like a sieve. And that's because most 473 00:26:31.789 --> 00:26:34.910 stuff passing through your system just isn't relevant to you 474 00:26:35.009 --> 00:26:37.910 for whatever your goals are. You don't remember the number 475 00:26:37.930 --> 00:26:40.230 of cracks in the sidewalk or the shirts that people 476 00:26:40.250 --> 00:26:42.930 are wearing or the number of trees. None of that matters, 477 00:26:42.990 --> 00:26:44.349 even though that hit your sensory systems. 478 00:26:44.710 --> 00:26:48.400 Yeah, most of the sensory information we take in is garbage. 479 00:26:49.220 --> 00:26:49.380 Yeah. 480 00:26:49.640 --> 00:26:51.880 But that's our brain editing. Is that not our brain editing? 481 00:26:51.960 --> 00:26:53.960 Is that our brain saying, need it, don't need it, 482 00:26:54.000 --> 00:26:54.829 need it, don't need it? 483 00:26:55.269 --> 00:26:57.869 Nope, it's not. That's an interesting question because it's not 484 00:26:57.890 --> 00:26:59.710 that your brain takes in all this stuff and figures 485 00:26:59.769 --> 00:27:01.069 out what to get rid of. It's that it's not 486 00:27:01.150 --> 00:27:03.009 taking in most everything. 487 00:27:03.170 --> 00:27:03.390 Right. 488 00:27:03.769 --> 00:27:06.930 For example, you've probably seen these things like the invisible 489 00:27:06.990 --> 00:27:08.569 gorilla experiment. Have you seen that? 490 00:27:08.769 --> 00:27:09.670 Yeah. Yeah. 491 00:27:09.769 --> 00:27:11.569 It's brilliant. It's completely brilliant. 492 00:27:12.069 --> 00:27:14.190 But there's a million examples like this. I only mentioned 493 00:27:14.210 --> 00:27:16.170 that one because maybe that's what we all know in common. 494 00:27:16.210 --> 00:27:19.710 But the point is you're watching these people pass the basketball. 495 00:27:19.730 --> 00:27:21.890 The guy in the gorilla costume comes in and

you 496 00:27:21.970 --> 00:27:23.940 just don't see it. It's not that your brain says, oh, 497 00:27:23.950 --> 00:27:25.990 there's a guy in a gorilla, but that's not relevant, blah, blah. 498 00:27:26.289 --> 00:27:30.019 It's that most of the stuff hitting your retinas, you 499 00:27:30.039 --> 00:27:30.539 don't see it. 500 00:27:30.539 --> 00:27:30.990 You don't see. 501 00:27:31.359 --> 00:27:33.859 Just to catch people up on this. So the gorilla experiment, 502 00:27:34.099 --> 00:27:37.140 it's a video and you are tasked as a viewer 503 00:27:37.180 --> 00:27:40.079 of the video to count how many times a basketball 504 00:27:40.099 --> 00:27:43.410 hit changes hands in that video. So you're focusing on 505 00:27:43.430 --> 00:27:46.019 this man. They're like three or four or five people 506 00:27:46.130 --> 00:27:50.180 passing the ball around. Meanwhile, a person in a gorilla 507 00:27:50.240 --> 00:27:54.660 suit enters the scene, looks around and then exits the scene. 508 00:27:55.279 --> 00:27:57.839 And then at the end, they ask you, did you 509 00:27:57.920 --> 00:28:01.849 see the gorilla? And it's like, no, there was no 510 00:28:01.890 --> 00:28:05.089 gorilla there. And then they were showed again. And there 511 00:28:05.109 --> 00:28:08.009 it was the gorilla waves at you. And you just 512 00:28:08.029 --> 00:28:08.809 weren't paying attention. 513 00:28:09.339 --> 00:28:13.849 Is that a result of the fact that we are 514 00:28:14.490 --> 00:28:19.490 focused on something that our brain is trained on? Or 515 00:28:19.990 --> 00:28:23.950 is it because we are literally building what we want 516 00:28:23.990 --> 00:28:27.269 to see in our brain as we look at any scene? 517 00:28:27.869 --> 00:28:32.150 Yes, both. Oh, both. Okay. It's an excellent question. But 518 00:28:32.630 --> 00:28:35.789 here's the thing. The gorilla is hitting your retina. I mean, 519 00:28:36.269 --> 00:28:38.650 all those photons are there. And if you were asking 520 00:28:38.710 --> 00:28:40.990 a different question, like, is there a gorilla in the scene, 521 00:28:41.269 --> 00:28:43.390 then you'd have no problem seeing it there. Even if 522 00:28:43.410 --> 00:28:46.170 your eyes were doing the identical motions and so on. 523 00:28:46.690 --> 00:28:50.990 It's because all we ever do is match our internal model, 524 00:28:51.130 --> 00:28:53.900 all the stuff happening inside the brain, to the little 525 00:28:53.940 --> 00:28:58.319 bits of sensory data that come dribbling in through your eyes, 526 00:28:58.380 --> 00:29:00.799 your ears, your fingertips, so on. You know, your brain 527 00:29:00.839 --> 00:29:04.000 is building a model of the world. And all it's 528 00:29:04.039 --> 00:29:07.740 trying to do is say, hey, is that accurate? And 529 00:29:07.779 --> 00:29:12.359 by the way, you know, you under different circumstances will 530 00:29:12.420 --> 00:29:15.190 rely more on your internal model or more on the 531 00:29:15.250 --> 00:29:17.529 outside world. So if you are in your own home, 532 00:29:17.589 --> 00:29:21.150 you're essentially operating entirely with your internal model about where 533 00:29:21.190 --> 00:29:23.109 things are in the furniture and so on. But if 534 00:29:23.190 --> 00:29:26.170 you go to a new country and you're walking around 535 00:29:26.190 --> 00:29:29.210 the streets, you're having to pay attention more to the outside. 536 00:29:30.109 --> 00:29:32.450 But it's pretty rarely that we do that. Mostly we 537 00:29:32.490 --> 00:29:34.109 fall into routine of various sorts. 538 00:29:34.710 --> 00:29:38.849 And therein is a profound source of bias. in testimony. Yeah. 539 00:29:38.869 --> 00:29:39.049 Yes. 540 00:29:40.099 --> 00:29:42.299 Say eyewitness testimony? Is that what you said? 541 00:29:42.400 --> 00:29:43.470 Yeah. Yeah. 542 00:29:43.750 --> 00:29:47.609 Well, okay. So that involves much more too, because that 543 00:29:47.670 --> 00:29:53.859 involves the fungibility of memory. So you believe that you 544 00:29:53.900 --> 00:29:57.859 saw something. And obviously what happens with eyewitness testimony is 545 00:29:58.140 --> 00:30:00.900 something important and interesting is happening over there. So you 546 00:30:00.940 --> 00:30:05.289 look at what's happening, but it's unbelievable. Memory is not 547 00:30:05.349 --> 00:30:09.740 like a recorder where you're just pulling something back out. Instead, 548 00:30:09.779 --> 00:30:12.799 it's a reconstruction and it's influenced by lots of things, 549 00:30:12.920 --> 00:30:15.940 including what other people tell you. In fact, I'll just 550 00:30:16.000 --> 00:30:18.900 mention really quickly, some colleagues of mine did a great 551 00:30:19.220 --> 00:30:24.130 study on this right after 9-11, 2001. They found a 552 00:30:24.150 --> 00:30:26.589 bunch of New Yorkers who had seen the towers collapse 553 00:30:26.670 --> 00:30:30.309 and they quizzed them on what exactly they saw on 554 00:30:30.329 --> 00:30:32.930 September 11th. And then they were clever enough to also 555 00:30:33.009 --> 00:30:35.849 ask what they saw on September 10th. what they did, 556 00:30:35.910 --> 00:30:37.650 what they ate for lunch on September 10th and so on. 557 00:30:37.970 --> 00:30:40.079 Then they found these people again a month later, three 558 00:30:40.099 --> 00:30:43.660 months later, a year, and they did finally a follow-up 559 00:30:43.660 --> 00:30:47.839 10 years later. And it turns out that Both memories, 560 00:30:47.940 --> 00:30:51.500 both the banal memories from September 10th and the extremely 561 00:30:51.740 --> 00:30:54.819 emotionally intense memories from September 11th, they all drift. They 562 00:30:54.880 --> 00:30:58.869 drift around entirely. And the only thing that stays constant 563 00:30:58.990 --> 00:31:02.230 is the stuff from September 11th that you saw on 564 00:31:02.250 --> 00:31:04.349 the news. Like, okay, there were two planes. They hit 565 00:31:04.369 -->

00:31:07.470 the towers at this time. That stayed constant because there 566 00:31:07.509 --> 00:31:09.930 was a constant external reference that was pinning it down. 567 00:31:10.319 --> 00:31:12.460 But the thing about, oh, I was standing on this 568 00:31:12.579 --> 00:31:14.650 corner and this person was with me and so on. 569 00:31:14.759 --> 00:31:16.039 All that stuff drifts around. 570 00:31:16.880 --> 00:31:17.119 Yeah. 571 00:31:17.460 --> 00:31:19.680 Most people, when they asked him a year later, what 572 00:31:19.720 --> 00:31:23.579 they said was they saw a giant black man fly 573 00:31:23.619 --> 00:31:25.160 into the towers and bring it down. 574 00:31:25.180 --> 00:31:29.500 Oh, was that not it? Yeah. 575 00:31:29.779 --> 00:31:35.259 David, now we're talking about our visual perception and recognition, 576 00:31:35.619 --> 00:31:39.039 but this synesthesia thing where you see a number, but 577 00:31:39.140 --> 00:31:42.240 you visualize it as a color or you have a 578 00:31:42.349 --> 00:31:47.430 word and you taste it. What is our A perception condition. 579 00:31:47.490 --> 00:31:48.210 How is that? 580 00:31:49.170 --> 00:31:49.529 Is this. 581 00:31:50.670 --> 00:31:55.299 Okay, correct me if I'm wrong, please. Is there something 582 00:31:55.339 --> 00:31:57.319 like 20% of the population could be. 583 00:31:57.339 --> 00:31:59.200 That's huge. 584 00:31:59.559 --> 00:32:04.559 Yeah. So is this now an evolutionary upgrade? in how 585 00:32:04.660 --> 00:32:05.680 our mind performs. 586 00:32:06.599 --> 00:32:08.579 Okay, let me correct a couple of things. It's not 587 00:32:08.579 --> 00:32:11.259 20% of the population. Please do. 588 00:32:11.319 --> 00:32:11.539 No. 589 00:32:11.859 --> 00:32:14.900 Probably about 3% of the population has synesthesia. 590 00:32:15.000 --> 00:32:16.819 Not 20, though. Not 20. Sorry. 591 00:32:16.859 --> 00:32:20.720 Thank you for correcting me. Yeah, no problem. There's certainly 592 00:32:20.779 --> 00:32:24.339 no reason to think that it's an evolutionary upgrade as 593 00:32:24.380 --> 00:32:27.200 such or that we're moving that way as a population. 594 00:32:27.900 --> 00:32:28.759 So let me explain. 595 00:32:28.799 --> 00:32:31.869 So what happens in every generation is that mother nature 596 00:32:31.920 --> 00:32:34.549 takes as much play in the wheel as she's able 597 00:32:34.609 --> 00:32:38.289 to with every dimension that she can. She tries people 598 00:32:38.329 --> 00:32:40.450 shorter and taller and wider and this and that, and 599 00:32:40.930 --> 00:32:46.130 she tries everything out, including in the brain. So with synesthesia... 600 00:32:46.210 --> 00:32:50.410 there's essentially just a little bit more crosstalk between neighboring 601 00:32:50.670 --> 00:32:53.730 areas of the brain, sort of more porous borders between 602 00:32:53.750 --> 00:32:56.609 neighboring countries. And so as a result, people have a 603 00:32:56.750 --> 00:33:03.019 slightly different perception. But the reason, so synesthesia is a 604 00:33:03.160 --> 00:33:05.960 really important inroad. I've been studying this for 25 years 605 00:33:06.000 --> 00:33:09.099 in my lab. It's an important inroad into consciousness and 606 00:33:09.160 --> 00:33:13.549 how one tiny tweak, we've been studying the genetics of 607 00:33:13.569 --> 00:33:17.109 synesthesia as well. One tiny genetic tweak leads to a 608 00:33:17.150 --> 00:33:21.589 totally different way of experiencing reality. But it's not like 609 00:33:22.170 --> 00:33:25.400 synesthetic people are, let's say, more creative because if every 610 00:33:25.440 --> 00:33:27.700 time you look at the letter J, you have an 611 00:33:27.740 --> 00:33:30.819 experience of purple and the letter M triggers green and 612 00:33:30.859 --> 00:33:33.009 so on, that doesn't make you more creative. That just 613 00:33:33.049 --> 00:33:34.930 means you think, you know, J is purple and M 614 00:33:34.990 --> 00:33:37.410 is green and so on. So it may be that 615 00:33:37.470 --> 00:33:40.730 synesthetes have a very tiny advantage in some kind of 616 00:33:41.029 --> 00:33:43.670 memory tasks. So if I ask you to remember my 617 00:33:43.750 --> 00:33:46.119 phone number, maybe you'll forget it. But if you're synesthetic, 618 00:33:46.130 --> 00:33:48.519 you'll say, oh, I remember it had this nice autumn 619 00:33:48.599 --> 00:33:51.420 pattern to it. And so then you're able to pull 620 00:33:51.440 --> 00:33:53.779 it up a little bit better. But it's, you know, 621 00:33:53.799 --> 00:33:56.769 especially in modern times, it's not too much of an advantage. 622 00:33:56.809 --> 00:34:01.190 So it's just an alternative perceptual reality. And I've been 623 00:34:01.230 --> 00:34:04.599 studying lots of different versions of this. Just as one example, 624 00:34:04.619 --> 00:34:08.389 have you guys heard of aphantasia and hyperphantasia? You guys 625 00:34:08.409 --> 00:34:08.670 heard of this? 626 00:34:09.480 --> 00:34:09.679 No. 627 00:34:10.300 --> 00:34:12.719 Other than the Disney movie? No. Fantasia. 628 00:34:12.800 --> 00:34:12.900 Okay. 629 00:34:15.059 --> 00:34:18.099 So this is spelled with a PH. So it turns 630 00:34:18.219 --> 00:34:22.260 out that if I ask you to picture something like 631 00:34:22.340 --> 00:34:25.239 an ant crawling on a red and white tablecloth towards 632 00:34:25.320 --> 00:34:29.260 a jar of purple jelly, some of you will see 633 00:34:29.300 --> 00:34:32.159 that clearly like a movie in your head. You can 634 00:34:32.239 --> 00:34:33.030 really picture that. 635 00:34:33.050 --> 00:34:33.309 I just did. 636 00:34:33.949 --> 00:34:37.639 Okay, great. And others of us don't have really any 637 00:34:37.699 --> 00:34:40.619 visual at all. There's just no visual at all. And 638 00:34:40.639 --> 00:34:44.139 the population is spread over the spectrum pretty evenly. So 639 00:34:44.219 --> 00:34:48.079 if you can see, like Chuck apparently did, something super

clearly, 640 00:34:48.139 --> 00:34:49.840 maybe you too, Neil. 641 00:34:49.920 --> 00:34:51.059 Yes. 642 00:34:51.079 --> 00:34:55.780 So that's called hyperphantasia, meaning your imagery or internal imagery 643 00:34:55.840 --> 00:34:58.780 is really clear. I happen to be on the aphantasia 644 00:34:58.880 --> 00:35:01.000 end of the spectrum where I don't really see anything. 645 00:35:01.739 --> 00:35:03.820 It turns out a friend of mine, Ed Catmull, who's 646 00:35:03.840 --> 00:35:05.960 the guy who started Pixar Films, who has all the 647 00:35:06.019 --> 00:35:09.380 patents for ray tracing and all that stuff, he's aphantasic. 648 00:35:09.960 --> 00:35:12.030 He got really interested in this topic some years ago 649 00:35:12.360 --> 00:35:15.909 and tested all the people at Pixar, at his company, 650 00:35:16.309 --> 00:35:18.590 and it turns out that most of his best directors 651 00:35:18.630 --> 00:35:22.110 and animators are aphantasic, meaning they don't picture anything on 652 00:35:22.130 --> 00:35:26.070 the inside. Now, that seems like a big surprise, but. 653 00:35:26.650 --> 00:35:26.849 Yes. 654 00:35:26.949 --> 00:35:31.050 You know, what I've long hypothesized on this issue is 655 00:35:31.090 --> 00:35:34.719 that the aphantasia kids become better artists. 656 00:35:34.840 --> 00:35:35.099 Why? 657 00:35:35.179 --> 00:35:38.659 Because the hyperphantasia kid, you know, the teacher says, draw 658 00:35:38.679 --> 00:35:40.340 a horse when you're in third grade. So you draw 659 00:35:40.360 --> 00:35:41.619 a horse because you think you know what a horse 660 00:35:41.639 --> 00:35:44.280 looks like and you probably do, right? But the aphantasia 661 00:35:44.340 --> 00:35:47.599 kid says, God, I really have to study the model 662 00:35:47.679 --> 00:35:50.659 and look at my page and have a dialogue with 663 00:35:50.739 --> 00:35:53.739 the page, with the pencil. They get better and better 664 00:35:53.880 --> 00:35:56.949 over time at being artists because they really are having 665 00:35:56.969 --> 00:36:00.489 to concentrate on this. What you see when you look 666 00:36:00.510 --> 00:36:03.809 at these artists at Pixar is that they really are 667 00:36:03.849 --> 00:36:07.010 having a dialogue with the page and moving things around 668 00:36:07.050 --> 00:36:07.829 until it looks right. 669 00:36:08.789 --> 00:36:13.489 You're saying a painter, a painter, not a house painter, 670 00:36:13.530 --> 00:36:20.530 but a fine arts painter, if they're aphantasic, they have 671 00:36:20.570 --> 00:36:23.550 to look at They have to look at what it 672 00:36:23.650 --> 00:36:27.130 is they're painting at all times because they can't picture 673 00:36:27.150 --> 00:36:27.750 it in their head. 674 00:36:28.929 --> 00:36:31.929 So that makes sense because that person is going to 675 00:36:31.969 --> 00:36:37.820 be given to hyper-detailed information, whereas a person who can 676 00:36:37.929 --> 00:36:41.760 picture things in their

head will do just that. Because 677 00:36:41.900 --> 00:36:44.139 you've got to think about it. The people at Pixar 678 00:36:44.260 --> 00:36:47.139 are working not with a paint and a brush. They're 679 00:36:47.219 --> 00:36:52.159 actually working with images. computers and numbers and that type 680 00:36:52.199 --> 00:36:55.510 of thing. So, and layering image on top of image 681 00:36:55.610 --> 00:36:57.730 on top of image, that's how they build an image 682 00:36:58.369 --> 00:37:03.690 and they're doing it to match reality. Whereas somebody like Monet, uh, 683 00:37:04.449 --> 00:37:11.400 It's probably just either nearsighted or everything's out of focus. 684 00:37:11.480 --> 00:37:14.889 Everything's out of focus. Or they're just picturing this world 685 00:37:14.969 --> 00:37:17.730 that doesn't exist and then painting from that thing that 686 00:37:17.789 --> 00:37:20.869 they see in their head. OK, so, you know, I mean, 687 00:37:20.889 --> 00:37:24.090 that's just that's that's the impression that I'm getting from that. 688 00:37:24.190 --> 00:37:26.880 I have no empirical evidence of this at all. I'm 689 00:37:26.900 --> 00:37:28.840 just I'm conjecturing right now. 690 00:37:29.199 --> 00:37:30.659 Yeah, I would say a couple. I mean, remember that 691 00:37:30.699 --> 00:37:33.500 Monet and all these guys, they sit in front of 692 00:37:33.519 --> 00:37:36.739 their landscape models and they're painting the Rouen Cathedral and 693 00:37:36.800 --> 00:37:39.559 so on from looking at it. 694 00:37:39.559 --> 00:37:41.159 Oh, that's true. Okay. 695 00:37:41.199 --> 00:37:43.360 The other thing to note is that, of course, Monet, 696 00:37:43.380 --> 00:37:45.409 it wasn't that he was nearsighted. It's that the camera 697 00:37:45.429 --> 00:37:47.769 had been invented and painters were trying to figure out. 698 00:37:47.909 --> 00:37:49.849 Yeah, that's why you have impressionism. 699 00:37:50.110 --> 00:37:51.190 No, absolutely. 700 00:37:51.309 --> 00:37:55.690 That's why you have impressionism because reality had finally been 701 00:37:55.750 --> 00:38:00.429 replicated in a split instant. However, I will say this 702 00:38:00.590 --> 00:38:04.230 as a person, it's very well known by the audience 703 00:38:04.269 --> 00:38:07.840 that I went away and did a week of ayahuasca 704 00:38:08.380 --> 00:38:11.760 and I had an experience where I did something that 705 00:38:11.920 --> 00:38:14.519 most of the people there didn't do, which was I 706 00:38:14.539 --> 00:38:19.210 hallucinated with my eyes open. Where most of the people, 707 00:38:19.690 --> 00:38:23.309 they closed their eyes to see what they were seeing. 708 00:38:23.889 --> 00:38:27.000 We were having the same experience, but differently. The things 709 00:38:27.019 --> 00:38:28.880 that I was seeing was in the room with me 710 00:38:28.940 --> 00:38:32.320 that was, you know, it was really crazy. But, you know, 711 00:38:32.920 --> 00:38:34.659 I'm not sure if that has anything to do with 712 00:38:34.699 --> 00:38:38.110 what you're talking about, aphantasic or hyperphantasic or not. 713 00:38:38.590 --> 00:38:42.769 Well, generally, what's interesting about hallucinations, which are always with 714 00:38:42.789 --> 00:38:46.489 the eyes open, the interesting thing about hallucinations is that 715 00:38:46.829 --> 00:38:50.150 your brain is taking whatever little bits and drabs of 716 00:38:50.190 --> 00:38:53.550 data it has and putting together a story about what's 717 00:38:53.590 --> 00:38:57.820 going on out there. And I mentioned before that all 718 00:38:57.860 --> 00:39:01.059 of this stuff is essentially all of it is internal 719 00:39:01.219 --> 00:39:04.280 activity is how your brain constructs your reality. And you 720 00:39:04.300 --> 00:39:08.969 don't need your eyeballs at all to see because you 721 00:39:08.989 --> 00:39:11.650 do this every night. That's what dreaming is. You're having full, 722 00:39:11.690 --> 00:39:13.929 rich visual experience with your eyes closed because of the 723 00:39:13.989 --> 00:39:18.980 internal activity in your brain, meaning that what you experience 724 00:39:19.039 --> 00:39:22.380 as vision when you're awake is really just awake dreaming. 725 00:39:23.039 --> 00:39:24.639 That's the way to think about vision. 726 00:39:24.659 --> 00:39:24.739 Damn. 727 00:39:25.510 --> 00:39:28.119 And it turns out that your hallucination is just something 728 00:39:28.199 --> 00:39:32.409 in between there. You're a dreamer, Chuck. 729 00:39:33.090 --> 00:39:34.570 I'm a daydreamer. 730 00:39:35.719 --> 00:39:39.119 So David, I have a philosophical question coming to this 731 00:39:39.360 --> 00:39:42.960 as a physicist where I care about what is objectively true. 732 00:39:43.699 --> 00:39:49.500 Things that instruments that can determine about the natural world 733 00:39:49.969 --> 00:39:54.570 That bypass your senses and thereby separate what is objectively 734 00:39:54.610 --> 00:39:58.199 true from what is experienced to be true. But so 735 00:39:58.219 --> 00:40:01.739 my philosophical question is, if the letter M is green 736 00:40:01.800 --> 00:40:06.119 and the letter J is purple to a synesthetic person, 737 00:40:07.340 --> 00:40:12.059 who am I to say that my experience of color 738 00:40:12.519 --> 00:40:16.670 is the correct one and that their experience of color 739 00:40:17.010 --> 00:40:22.699 is crosswired? Who has the access to what is objectively 740 00:40:22.760 --> 00:40:26.030 true in the absence of a third way of verifying? 741 00:40:26.719 --> 00:40:29.070 If we're just humans out there in the Serengeti. 742 00:40:29.670 --> 00:40:33.289 Yeah, a couple layers to this, Neil. So first of all, 743 00:40:33.650 --> 00:40:38.050 what we experience is some sort of reflection of reality 744 00:40:38.530 --> 00:40:41.730 under normal circumstances, unless you're on ayahuasca or have dementia 745 00:40:41.849 --> 00:40:44.550 or a hundred other things where you

can pick up 746 00:40:44.630 --> 00:40:47.309 on the signals incorrectly and get them confused with memories 747 00:40:47.369 --> 00:40:50.869 and so on. But- What has made our species successful 748 00:40:50.929 --> 00:40:54.880 is that we're able to agree, hey, the coffee cup 749 00:40:54.929 --> 00:40:57.559 is over there and the lion is over there and 750 00:40:57.599 --> 00:41:01.219 so on. Now, it turns out, though, that, I mean, 751 00:41:01.340 --> 00:41:04.449 obviously something like color is a construction of the brain. 752 00:41:04.909 --> 00:41:07.349 As you know, all we have is electromagnetic radiation of 753 00:41:07.409 --> 00:41:10.989 different wavelengths. And this, of course, leads to the old 754 00:41:11.070 --> 00:41:13.650 question that we all asked ourselves in college about, you know, 755 00:41:13.989 --> 00:41:15.750 how do I know that what I see is red 756 00:41:15.829 --> 00:41:17.429 is what you see is red and you and you? 757 00:41:17.710 --> 00:41:19.449 And the answer is it may well not be. And 758 00:41:19.469 --> 00:41:21.599 it doesn't matter as long as we can transact and 759 00:41:21.639 --> 00:41:24.000 negotiate in the outside world. And I say, hey, can 760 00:41:24.019 --> 00:41:27.219 you please pass the red thing? Then we're fine. Our 761 00:41:27.260 --> 00:41:30.139 mothers teach us, call that thing red. And so you 762 00:41:30.159 --> 00:41:31.880 call it red. And it doesn't matter if we're seeing 763 00:41:31.900 --> 00:41:33.800 the same thing on the inside. And there's no real 764 00:41:33.860 --> 00:41:37.699 reason to assume that it is the same for us. 765 00:41:38.280 --> 00:41:41.699 But aren't there members of the human species that actually 766 00:41:41.739 --> 00:41:45.559 can see more colors? What have they got? There's two 767 00:41:45.619 --> 00:41:46.219 and four. 768 00:41:46.280 --> 00:41:47.119 Tetrachromatic. 769 00:41:47.539 --> 00:41:48.860 Thank you, tetrachromatic. 770 00:41:49.440 --> 00:41:52.780 So most of us have what's called trichromatic vision because 771 00:41:52.820 --> 00:41:57.170 we have three– types of color photoreceptors in our eyes, 772 00:41:57.230 --> 00:42:01.389 in our retina. But some women, because of a mutation 773 00:42:01.449 --> 00:42:03.010 on the X chromosome where they have two of them, 774 00:42:03.409 --> 00:42:07.420 they end up with four flavors of color photoreceptors and 775 00:42:07.480 --> 00:42:12.760 they see much more color than we do. But it 776 00:42:12.800 --> 00:42:15.280 doesn't make it more real in a sense. Color is 777 00:42:15.320 --> 00:42:19.889 just a way of us tagging something so that we 778 00:42:20.050 --> 00:42:22.789 have an immediate perceptual experience. Instead of me saying, oh, 779 00:42:22.869 --> 00:42:26.679 I think that's 440 over there and that's 770 over there. 780 00:42:26.780 --> 00:42:29.860 It's just color's a way of having an immediate perceptual 781 00:42:29.900 --> 00:42:34.760 experience of the ripe fruit

against the green leaves instead 782 00:42:34.800 --> 00:42:39.099 of tagging the wavelength in some other way that takes 783 00:42:39.179 --> 00:42:40.360 longer to figure out. 784 00:42:40.880 --> 00:42:44.260 And if there's a subtle color difference between a poisonous 785 00:42:44.300 --> 00:42:46.989 berry and a healthy berry, It'd be nice to be 786 00:42:47.030 --> 00:42:50.510 able to see that color difference if I'm tetra. 787 00:42:51.630 --> 00:42:52.710 Tetrachromatic, yeah. 788 00:42:53.230 --> 00:42:53.989 Tetrachromatic. 789 00:42:54.829 --> 00:42:57.280 Yeah, it would be nice. I don't think we have 790 00:42:57.320 --> 00:43:02.239 enough evidence to know that tetrachromatic women have survived better. 791 00:43:02.719 --> 00:43:05.480 They're very rare, and it comes from mutation. And if 792 00:43:05.539 --> 00:43:08.320 it were such a good mutation, then maybe we would 793 00:43:08.400 --> 00:43:08.809 all have it. 794 00:43:08.820 --> 00:43:15.179 Oh, that makes sense. David, so with our perception of 795 00:43:15.400 --> 00:43:20.239 all different things, i.e. our reality, there's that conversation that 796 00:43:20.280 --> 00:43:24.860 people have about time, where it seems to be stretched 797 00:43:25.059 --> 00:43:27.480 or it's short or whatever it is. And I know 798 00:43:27.519 --> 00:43:31.219 you've conducted a number of experiments, but where is our 799 00:43:31.340 --> 00:43:35.960 perception of time and how do we think it gets stretched? 800 00:43:36.039 --> 00:43:39.400 And a moment in time is a lot longer than 801 00:43:39.429 --> 00:43:41.010 it actually was. 802 00:43:41.639 --> 00:43:43.800 Okay. First, in the answer to where, it's not in 803 00:43:43.940 --> 00:43:47.480 one location of the brain. It's smeared out. And in 804 00:43:47.519 --> 00:43:49.800 a minute, it'll become clear why, which is... Okay. So, 805 00:43:50.059 --> 00:43:54.019 I ended up collecting hundreds of reports from people who 806 00:43:55.530 --> 00:43:57.650 said that time seemed to go in slow motion when 807 00:43:57.670 --> 00:44:01.480 they were in a gunfight or a motorcycle accident or... 808 00:44:02.039 --> 00:44:04.480 You know, their child fell in the lake and they 809 00:44:04.519 --> 00:44:07.730 had to run after them and so on. There's all 810 00:44:07.789 --> 00:44:12.090 kinds of situations that are very dangerous to ourselves or 811 00:44:12.170 --> 00:44:15.349 something we care about where it seems like time runs 812 00:44:15.369 --> 00:44:16.949 in slow motion. And this had happened to me too 813 00:44:16.969 --> 00:44:18.630 when I was a kid and fell off of a roof. 814 00:44:19.010 --> 00:44:21.030 It seemed to take a long time. So I got 815 00:44:21.070 --> 00:44:25.639 really interested in this. And when I became a neuroscientist, 816 00:44:25.860 --> 00:44:28.920 I ran what is the first and only experiment that's 817 00:44:28.960 --> 00:44:32.460 ever been run on this. So I dropped volunteer subjects 818 00:44:32.500 --> 00:44:34.500 from a 150-foot tall tower. 819 00:44:34.519 --> 00:44:36.440 Are you sure they were volunteers, David? 820 00:44:36.519 --> 00:44:37.619 They were. 821 00:44:39.059 --> 00:44:42.260 It took me eight months to get this approved, actually, 822 00:44:42.619 --> 00:44:45.699 by the committee to do the experiment. So I dropped them. 823 00:44:45.860 --> 00:44:48.139 They're caught in a net below going 70 miles an hour. 824 00:44:48.260 --> 00:44:51.969 It's safe, but very, very scary to drop through the 825 00:44:51.989 --> 00:44:53.030 air like that. 826 00:44:53.030 --> 00:44:53.579 70 miles an hour, 7-0. 827 00:44:54.860 --> 00:44:58.710 7-0, exactly. Yeah. And the net has a big slew, 828 00:44:58.750 --> 00:45:01.289 so it slows you down, but it is so scary 829 00:45:01.329 --> 00:45:04.610 falling backwards from that height. So what I did is 830 00:45:04.670 --> 00:45:07.250 I built, my students and I, we built this thing 831 00:45:07.289 --> 00:45:10.070 that goes on the wrist and flashes information at you 832 00:45:10.110 --> 00:45:12.510 at a certain rate. And what we were testing is, 833 00:45:12.969 --> 00:45:15.570 do you actually see in slow motion when you're in 834 00:45:15.590 --> 00:45:19.699 fear for your life? And I'll skip many of the details, 835 00:45:19.900 --> 00:45:23.710 but the punchline, is that you do not, you don't 836 00:45:23.949 --> 00:45:26.500 actually see in slow motion. What happens instead is when 837 00:45:26.539 --> 00:45:29.820 you're in fear for your life, you are writing down 838 00:45:30.019 --> 00:45:32.920 tons of memories so that when you say, what just happened, 839 00:45:32.940 --> 00:45:35.780 what just happened, which is all consciousness is, is probing 840 00:45:35.889 --> 00:45:39.650 on the recent memories, You've got all this memory to 841 00:45:39.690 --> 00:45:41.329 draw on. You say, oh my gosh, this is so 842 00:45:41.349 --> 00:45:43.650 someone in a car accident says, oh yeah, let's see. 843 00:45:43.690 --> 00:45:46.230 I watched the hood crumple and I watched the rear 844 00:45:46.250 --> 00:45:47.989 view mirror fall off. And I was looking at the 845 00:45:48.429 --> 00:45:51.829 expression on the other driver's face. So that must have 846 00:45:51.869 --> 00:45:54.269 taken four or five seconds because I've got all this 847 00:45:54.389 --> 00:45:57.449 memory that I can draw upon, but it's a trick 848 00:45:57.510 --> 00:45:58.050 of memory. 849 00:45:58.389 --> 00:45:59.730 But David, can I give an example? 850 00:45:59.750 --> 00:46:02.309 I'll give you an example. My first experience with this, 851 00:46:02.429 --> 00:46:06.219 which happened in a much safer environment than falling off 852 00:46:06.280 --> 00:46:10.659 a building. I think I've conveyed this story on a 853 00:46:10.699 --> 00:46:15.590 previous episode. When I was 14, maybe 15, I was 854 00:46:15.630 --> 00:46:18.929 driven across the United States nonstop from New York City 855

00:46:19.389 --> 00:46:22.530 to the Mojave Desert. And I'd never been west of 856 00:46:22.670 --> 00:46:27.699 Pennsylvania before. And it was two consecutive days. We never stopped. 857 00:46:27.719 --> 00:46:30.719 Stopped for gas. At the end of those two days. 858 00:46:32.309 --> 00:46:36.369 I felt like I had left New York a week earlier, 859 00:46:37.369 --> 00:46:44.619 not two days earlier. Because my memory had so many 860 00:46:44.780 --> 00:46:49.400 experiences in commensurate with any 48-hour period I had ever 861 00:46:49.480 --> 00:46:53.059 previously lived. And so my brain, trying to make sense 862 00:46:53.119 --> 00:46:55.489 of it, stretched it out. And I said, man, I 863 00:46:55.530 --> 00:46:57.489 must have left New York a week ago. when it 864 00:46:57.510 --> 00:47:01.889 was only 48 hours ago. Is that a similar case here, David? 865 00:47:02.170 --> 00:47:03.750 Except my life was not at risk. 866 00:47:04.820 --> 00:47:08.760 That's exactly right. It turns out that most things you're 867 00:47:08.780 --> 00:47:11.760 not catching at all. We mentioned earlier that memory is 868 00:47:11.820 --> 00:47:15.400 the sieve. And so what happens in an emergency situation 869 00:47:15.519 --> 00:47:18.179 is that that's all memory is for. I mean, memory 870 00:47:18.219 --> 00:47:20.489 is there just so you can write down what happened 871 00:47:20.510 --> 00:47:23.429 when everything hit the fan. So that you can avoid 872 00:47:23.469 --> 00:47:28.409 that situation again, if you live. And so if. 873 00:47:29.409 --> 00:47:32.429 You don't do the experiment again, that's exactly right. 874 00:47:32.510 --> 00:47:35.289 So, so that's when you write everything down and, and, 875 00:47:35.449 --> 00:47:39.409 and your brain doesn't have a way. Look, whenever you're 876 00:47:39.469 --> 00:47:42.309 judging duration, it's just a matter of how much memory 877 00:47:42.329 --> 00:47:44.880 you can pull up. So Neil on your road trip. Yeah. 878 00:47:44.889 --> 00:47:46.900 He just had lots of memory. Let me mention two 879 00:47:46.940 --> 00:47:52.099 things here. One is this is why time seems to 880 00:47:52.179 --> 00:47:55.829 speed up as you grow older. It's because when you're 881 00:47:55.849 --> 00:47:58.469 a kid, everything is novel and you're writing down tons 882 00:47:58.510 --> 00:48:00.429 of memories. And when you get to the end of 883 00:48:00.550 --> 00:48:03.000 a day, you're, There's just a ton of stuff that 884 00:48:03.019 --> 00:48:05.500 when you get to the end of a summertime, you've 885 00:48:05.539 --> 00:48:08.260 gone to camp, you've gone hiking, there's all this new stuff. 886 00:48:08.280 --> 00:48:10.019 It's all new. You've written down tons of stuff. And 887 00:48:10.039 --> 00:48:13.150 when you're asked, what did you do? There's all these landmarks. 888 00:48:13.230 --> 00:48:16.349 But once you're an adult, your internal model of the 889 00:48:16.409 --> 00:48:19.820 world has developed pretty well. And there's not that much 890 00:48:19.880 --> 00:48:23.539 that's really novel. Now, sometimes I hear people say, oh, well, 891 00:48:23.579 --> 00:48:26.059 maybe it has to do with what fraction of your 892 00:48:26.119 --> 00:48:28.320 life something is. You know, now a summertime is only 893 00:48:28.360 --> 00:48:30.530 a small fraction of our life. Whereas when you were 894 00:48:30.550 --> 00:48:32.880 a kid, it was a large fraction. But that's not it, 895 00:48:32.929 --> 00:48:35.969 because you can go on a road trip or, Neil, 896 00:48:36.010 --> 00:48:38.090 if you took, let's say, a trip to the moon now. 897 00:48:38.690 --> 00:48:42.090 That is so novel. And you would write everything down. 898 00:48:42.110 --> 00:48:45.539 And you would come back on a Monday morning and say, 899 00:48:45.659 --> 00:48:47.760 I went to the moon this weekend. And it would 900 00:48:47.780 --> 00:48:49.820 seem like Friday was forever ago. 901 00:48:49.840 --> 00:48:52.239 Right, right. Gotcha. 902 00:48:52.530 --> 00:48:56.929 So, David, go back to the high adrenaline events. Is 903 00:48:56.989 --> 00:49:02.409 it the adrenaline that triggers the amygdala to then dump 904 00:49:02.449 --> 00:49:06.760 this data-rich stuff? messaging into the brain? 905 00:49:07.500 --> 00:49:09.780 It's actually the signals from the amygdala that go tell 906 00:49:09.820 --> 00:49:12.199 the adrenaline to start dumping, which takes care of all 907 00:49:12.219 --> 00:49:12.880 that stuff with your. 908 00:49:12.800 --> 00:49:13.639 Muscles and so on. 909 00:49:14.449 --> 00:49:16.230 But yes, the amygdala, you can think of it as 910 00:49:16.250 --> 00:49:20.500 your emergency control center that says, everybody pay attention to 911 00:49:20.579 --> 00:49:23.199 what is happening right here because normally your brain is 912 00:49:23.239 --> 00:49:26.000 doing 50 million things and you're thinking about what you're 913 00:49:26.019 --> 00:49:27.960 doing tomorrow and the vacation that's coming up and your 914 00:49:28.000 --> 00:49:30.659 grocery list and the call you need to make and whatever. 915 00:49:30.900 --> 00:49:34.969 But when the amygdala kicks into gear, it says everybody 916 00:49:35.030 --> 00:49:37.969 drop that and pay attention over here. And that's why 917 00:49:37.989 --> 00:49:42.239 you're writing stuff down with such– Wow. 918 00:49:42.400 --> 00:49:46.659 That is so cool. That is completely counterintuitive to what 919 00:49:46.719 --> 00:49:47.679 most people might think. 920 00:49:48.909 --> 00:49:50.210 Yeah, but it makes complete sense. 921 00:49:50.309 --> 00:49:52.940 Yeah, it makes great sense. I'm so glad you brought 922 00:49:52.980 --> 00:49:55.739 that up. That's a whole new way of looking at time. 923 00:49:55.980 --> 00:49:57.599 You know, even though we know that time is a 924 00:49:57.639 --> 00:50:02.480 perception to begin with, unless, you know, you're an astrophysicist 925 00:50:02.800 --> 00:50:07.500 and time is an

actual thing that can actually slow 926 00:50:07.539 --> 00:50:12.809 down because of gravity and your proximity to the speed 927 00:50:12.849 --> 00:50:13.150 of light. 928 00:50:13.610 --> 00:50:17.110 It slows down as viewed by others. As viewed by others, correct. 929 00:50:17.150 --> 00:50:18.409 Your only current state is the same. 930 00:50:18.750 --> 00:50:18.929 Right. 931 00:50:18.969 --> 00:50:20.730 Well, this is what I was going to say is 932 00:50:20.789 --> 00:50:24.710 in physics, there's this notion of relativity, but there's a 933 00:50:24.789 --> 00:50:27.829 neural relativity with time also. But it's a very different 934 00:50:27.869 --> 00:50:30.449 sort of thing. But it's this issue of if I'm 935 00:50:30.510 --> 00:50:32.440 in a situation and I'm really scared and you're looking 936 00:50:32.460 --> 00:50:34.719 at the same situation, but you're not scared, we're going 937 00:50:34.739 --> 00:50:36.800 to have a totally different sense of how much time 938 00:50:37.260 --> 00:50:37.960 had passed. 939 00:50:37.980 --> 00:50:38.119 Right. 940 00:50:38.840 --> 00:50:42.300 Wait, say that again. The neural relativity is if we're 941 00:50:42.340 --> 00:50:46.949 both in the same, we're both in one situation and 942 00:50:47.010 --> 00:50:51.030 you're in another situation. I'm scared in mine. You're completely comfortable. 943 00:50:51.230 --> 00:50:51.969 Is that what you're saying? 944 00:50:52.369 --> 00:50:54.309 What I'm saying is we're in the same situation, but 945 00:50:54.369 --> 00:50:57.670 for whatever reason, you've seen this thing before. Oh, okay. 946 00:50:57.690 --> 00:51:00.639 So we're jumping out of a plane and I'm strapped 947 00:51:00.679 --> 00:51:02.900 to you. You've done it a hundred times. It's my 948 00:51:02.940 --> 00:51:03.420 first time. 949 00:51:03.980 --> 00:51:05.300 Exactly right. That's exactly right. 950 00:51:05.340 --> 00:51:06.579 Chuck is screaming the whole way. 951 00:51:09.710 --> 00:51:11.630 Absolutely. My experience of time is. 952 00:51:14.409 --> 00:51:17.010 That's my experience of time. The whole way. 953 00:51:17.480 --> 00:51:20.619 David, we discussed a couple of your experiments, but there 954 00:51:20.679 --> 00:51:23.320 is one that I came across that actually doesn't involve 955 00:51:23.360 --> 00:51:25.659 being pushed off a high tower, jumping out of a plane. 956 00:51:26.239 --> 00:51:28.420 And I think our audience would like to be able 957 00:51:28.460 --> 00:51:30.860 to participate in one of your experiments. Let's see if 958 00:51:30.909 --> 00:51:33.570 I've got this right. It's the looking in the mirror 959 00:51:34.449 --> 00:51:36.380 at your left eye than your right eye. 960 00:51:36.389 --> 00:51:37.150 Yes. 961 00:51:37.170 --> 00:51:37.369 Yes. 962 00:51:37.980 --> 00:51:40.179 Can you break that down and explain? Because our audience 963 00:51:40.199 --> 00:51:42.110 will be able to do this themselves. 964 00:51:42.789 --> 00:51:46.070 Do the following. Stand in front of a mirror and 965 00:51:46.329 --> 00:51:48.269 stand right up close to it, right up against the mirror. 966 00:51:48.389 --> 00:51:50.909 And with both your eyes, you look at your left eye. 967 00:51:51.329 --> 00:51:52.719 Then you look at your right eye. Then you look 968 00:51:52.739 --> 00:51:56.219 at your left eye. Okay. Now watch somebody else do 969 00:51:56.260 --> 00:51:58.280 this also. Watch them look at their left eye and 970 00:51:58.300 --> 00:52:00.099 right eye and so on. When you're watching someone else, 971 00:52:00.139 --> 00:52:02.880 you can see the eyes move. The eyes make these 972 00:52:02.960 --> 00:52:06.909 big jumps. It's called a saccade. And that's when they 973 00:52:07.010 --> 00:52:08.489 shift from looking from one. 974 00:52:08.469 --> 00:52:09.090 Eye to the other. 975 00:52:09.570 --> 00:52:11.869 Okay, easy. But when you look at your own eye, 976 00:52:12.409 --> 00:52:16.510 you never experience that shift, that jump that your eyes make. Instead, 977 00:52:16.550 --> 00:52:19.670 you feel like you're looking at your left eye. Then instantly, 978 00:52:19.690 --> 00:52:22.929 it switches and you're looking at your right eye. Then instantly, 979 00:52:22.969 --> 00:52:23.929 it switches and you're looking at. 980 00:52:23.929 --> 00:52:24.440 Your left eye. 981 00:52:25.239 --> 00:52:27.619 And the question is, what the heck is going on 982 00:52:27.659 --> 00:52:30.800 while your eyes are making this big shift and jumping 983 00:52:30.880 --> 00:52:32.320 from one place to the other? How come you don't 984 00:52:32.340 --> 00:52:35.690 experience that? Well, we have these gaps in time all 985 00:52:35.750 --> 00:52:38.969 the time where you just never experience that. And that's 986 00:52:39.050 --> 00:52:43.050 because all you ever see is your internal model of 987 00:52:43.110 --> 00:52:47.420 the world. And there's all this weird... post-processing that goes on, 988 00:52:47.480 --> 00:52:51.159 like an editing software program. So it just fills in 989 00:52:51.199 --> 00:52:52.889 that gap. So you think you're looking at your left 990 00:52:52.989 --> 00:52:56.110 eye and then you're immediately seeing your right eye. But 991 00:52:57.010 --> 00:53:00.170 what that exposes, that simple experiment, is the degree to 992 00:53:00.210 --> 00:53:05.179 which time isn't experienced exactly as things are happening in 993 00:53:05.199 --> 00:53:05.840 the outside world. 994 00:53:06.719 --> 00:53:12.039 David, I didn't want to learn that. I don't want 995 00:53:12.199 --> 00:53:15.380 any knowledge that my experience is not connected to an 996 00:53:15.420 --> 00:53:19.159 objective reality. So could you take that back? Pretend you 997 00:53:19.199 --> 00:53:20.380 never said that. 998 00:53:20.559 --> 00:53:24.900 I wish I could. Well, I mean, for 25 years, 999 00:53:24.960 --> 00:53:27.599 I've been studying illusions of time. There are actually lots 1000 00:53:27.639 -->

00:53:31.090 and lots of different things about time. You know, not 1001 00:53:31.130 --> 00:53:33.949 only gaps in time and not only things going faster 1002 00:53:33.969 --> 00:53:38.929 and slower, but also something happening before something else. Here, 1003 00:53:38.949 --> 00:53:40.570 I'll just tell you one experiment. I can tell you 1004 00:53:40.590 --> 00:53:42.449 this real fast, which is we have you hit a 1005 00:53:42.489 --> 00:53:44.110 button and that causes a flash of light. So every 1006 00:53:44.130 --> 00:53:45.389 time you hit the button, there's a flash of light. 1007 00:53:45.889 --> 00:53:48.889 Now what we do is we inject a little delay, 1008 00:53:49.389 --> 00:53:52.300 let's say 20 milliseconds. So you hit the button and 1009 00:53:52.320 --> 00:53:54.800 the flashlight happens 20 milliseconds later. And we make this 1010 00:53:54.840 --> 00:53:56.920 delay bigger and bigger each time. And if we do 1011 00:53:56.960 --> 00:54:00.239 that slowly, then you can be hitting the button. There's 1012 00:54:00.280 --> 00:54:04.000 a 200 millisecond delay before the light flashes and your 1013 00:54:04.059 --> 00:54:07.400 brain recalibrates so that it doesn't see the delay happening. 1014 00:54:07.800 --> 00:54:12.119 at all it thinks that it's instant now i remove 1015 00:54:12.179 --> 00:54:14.760 the delay so after you've gotten used to this 200 1016 00:54:14.760 --> 00:54:16.809 millisecond delay i remove it so now you hit the 1017 00:54:16.829 --> 00:54:19.550 button and the light flashes and you say whoa i 1018 00:54:19.570 --> 00:54:21.630 didn't do that it flashed before i hit the button 1019 00:54:22.010 --> 00:54:25.969 what yeah there's an easy reversal of action and effect 1020 00:54:26.050 --> 00:54:29.099 because your brain is recalibrating. 1021 00:54:28.179 --> 00:54:32.489 Yeah recalibrating That's insane. So your brain is a liar. 1022 00:54:32.670 --> 00:54:36.159 It's just a liar all the time. Your brain is 1023 00:54:36.280 --> 00:54:39.139 just foolish. 1024 00:54:40.059 --> 00:54:42.019 It's trying to put together the best story it can. 1025 00:54:42.079 --> 00:54:45.179 And if there's a delay in some system, then it says, oh, 1026 00:54:45.219 --> 00:54:47.079 that's cool. I'll just adjust that. I know I'm the 1027 00:54:47.139 --> 00:54:49.619 one hitting the button. So I'm going to assume there's 1028 00:54:49.639 --> 00:54:51.860 this delay for some other reason. So, the first time 1029 00:54:51.920 --> 00:54:55.019 I saw this, this illusory reversal of action and effect, 1030 00:54:55.639 --> 00:54:59.730 I thought, you know what? That's exactly what happens in schizophrenia. 1031 00:55:00.170 --> 00:55:02.130 Because my participant said, well, I didn't do that. That 1032 00:55:02.170 --> 00:55:04.550 wasn't me. And what happens in schizophrenia is what's called 1033 00:55:04.650 --> 00:55:07.690 credit misattribution, where somebody will do something and say, that 1034 00:55:07.730 --> 00:55:09.590

wasn't me. I wasn't the one who did it. And so, 1035 00:55:09.969 --> 00:55:12.269 that led me down this road that I've been pursuing 1036 00:55:12.309 --> 00:55:15.230 for years, which is that schizophrenia is actually fundamentally a 1037 00:55:15.269 --> 00:55:18.449 disorder of time perception. And that if you're not getting 1038 00:55:18.510 --> 00:55:22.599 your timing signals lined up exactly right, then schizophrenia is 1039 00:55:22.639 --> 00:55:26.440 the obvious thing that happens. For example... You're always talking 1040 00:55:26.480 --> 00:55:29.480 to yourself. You're always generating an internal voice and listening 1041 00:55:29.519 --> 00:55:31.590 to it. But if you get the timing of that 1042 00:55:31.760 --> 00:55:34.150 just slightly wrong so that you think you heard the 1043 00:55:34.170 --> 00:55:37.170 voice before you generated it, that's an auditory hallucination. You 1044 00:55:37.210 --> 00:55:39.630 have to attribute the voice to somebody else. 1045 00:55:39.869 --> 00:55:40.369 Wow. 1046 00:55:40.710 --> 00:55:41.809 And someone is talking to you. 1047 00:55:42.090 --> 00:55:42.369 Yeah. 1048 00:55:42.510 --> 00:55:42.769 Yeah. 1049 00:55:42.909 --> 00:55:45.039 Okay. That's a brilliant take, man. 1050 00:55:45.699 --> 00:55:46.440 Yeah. 1051 00:55:46.480 --> 00:55:49.320 That's a brilliant take. Is there any research going on 1052 00:55:49.480 --> 00:55:54.110 to kind of– sort of re-engineered or sort of back 1053 00:55:54.210 --> 00:55:57.980 engineer a solution to these sort of issues for people 1054 00:55:58.019 --> 00:55:59.900 with mental health problems? Yeah. 1055 00:55:59.920 --> 00:56:01.960 So that's exactly what I'm working on. That's exactly what 1056 00:56:01.980 --> 00:56:04.280 I'm trying to figure out. I mean, here's the dream. 1057 00:56:04.300 --> 00:56:06.739 It'll take me some years before hopefully I get there, 1058 00:56:06.780 --> 00:56:10.010 but the dream is that you take a person suffering 1059 00:56:10.030 --> 00:56:12.530 with schizophrenia and you have them play a video game 1060 00:56:12.969 --> 00:56:16.309 that recalibrates their timing and then their auditory hallucinations go away. 1061 00:56:17.230 --> 00:56:20.219 We'll see. I can't say that works, but I hope so. 1062 00:56:20.239 --> 00:56:21.840 I hope in five years we can get back together 1063 00:56:21.900 --> 00:56:23.320 and celebrate that. 1064 00:56:23.360 --> 00:56:27.159 David, if I'm ever in Palo Alto, I want to 1065 00:56:27.199 --> 00:56:29.360 visit your lab and I want you to do that 1066 00:56:29.519 --> 00:56:33.840 light delay experiment on me because I refuse to believe 1067 00:56:34.460 --> 00:56:39.360 that I would function that way. I'm in denial. I 1068 00:56:41.469 --> 00:56:44.949 would need the experiment. I refuse to believe it. 1069 00:56:45.420 --> 00:56:47.420 It's a super simple experiment. By the way, I presented 1070 00:56:47.460 --> 00:56:50.349 this at a university. And afterwards, a guy came up

1071 00:56:50.389 --> 00:56:51.989 to me and he said, you know, this explains something, 1072 00:56:52.030 --> 00:56:54.289 which is we just got a new telephone system installed. 1073 00:56:54.889 --> 00:56:56.469 It turns out, by the way, this is something that 1074 00:56:56.530 --> 00:56:58.369 I had studied also. It turns out when you hit 1075 00:56:58.389 --> 00:57:00.690 a key on the keyboard, there's like a hundred millisecond 1076 00:57:00.710 --> 00:57:03.840 delay before the letter shows up on your screen. So anyway, 1077 00:57:03.900 --> 00:57:07.079 he said, look, I'd be typing in my computer and 1078 00:57:07.119 --> 00:57:09.519 then I go to my phone and type in a number. 1079 00:57:10.659 --> 00:57:13.150 It turns out on a telephone, there's essentially no delay, 1080 00:57:13.250 --> 00:57:15.670 especially on these new telephones that he just got installed. 1081 00:57:16.250 --> 00:57:18.590 So what happened is when he dialed the last number, 1082 00:57:18.650 --> 00:57:22.010 he had the impression that the phone started ringing before 1083 00:57:22.090 --> 00:57:25.519 he hit the last number because his brain got used 1084 00:57:25.579 --> 00:57:28.179 to the delay on the keyboard. So now when he 1085 00:57:28.219 --> 00:57:31.360 went to the telephone, which had no delay, he had 1086 00:57:31.400 --> 00:57:33.780 this illusion of the reversal of action in effect. 1087 00:57:34.510 --> 00:57:37.389 I'm going to naively declare that I'm not susceptible to that. 1088 00:57:38.130 --> 00:57:42.190 That's how much I believe my own objective reality. And 1089 00:57:42.409 --> 00:57:45.210 so I have to prove it. I'm going to find you. 1090 00:57:45.829 --> 00:57:48.320 I'm so glad that we have this recorded. We'll have 1091 00:57:48.340 --> 00:57:50.139 to hold it out when I show you this. 1092 00:57:51.000 --> 00:57:53.400 I'm going to find you. Neil sounds like somebody on 1093 00:57:53.420 --> 00:58:00.670 the internet telling him about vaccines right now. Right. 1094 00:58:00.710 --> 00:58:03.230 You've got a good brain, Neil, but it's like everybody else's. 1095 00:58:03.800 --> 00:58:07.920 So David, earlier you mentioned certain evidence of consciousness, some 1096 00:58:08.059 --> 00:58:11.460 functions of the brain. There's no end of books on 1097 00:58:11.500 --> 00:58:17.000 a shelf written by people in your world who declare 1098 00:58:17.239 --> 00:58:22.820 that they have explained consciousness. And as an academic, evidence 1099 00:58:22.900 --> 00:58:26.530 that people don't know anything about a subject is brought 1100 00:58:26.610 --> 00:58:28.949 forth by the fact that people keep writing books on 1101 00:58:28.969 --> 00:58:32.369 that subject. That's the evidence that is not fully explained. 1102 00:58:32.650 --> 00:58:35.489 Because if it were explained, people would stop writing books 1103 00:58:35.889 --> 00:58:40.809 because it would be explained. So where do you feel 1104 00:58:40.989 --> 00:58:45.730 about this? And is consciousness even something that needs an explanation? 1105 00:58:45.750 --> 00:58:49.690 Or is it just some emergent property of having neural activity? 1106 00:58:50.409 --> 00:58:56.559 It definitely needs explanation because consciousness– is you know our 1107 00:58:57.059 --> 00:59:02.380 subjective impression of having this world and and the pain 1108 00:59:02.460 --> 00:59:05.349 and the beauty and the the agony and the ecstasy 1109 00:59:05.590 --> 00:59:07.809 all of that internally that i am a self and 1110 00:59:07.829 --> 00:59:11.809 all that that is my conscious experience But Somehow, when 1111 00:59:11.829 --> 00:59:13.889 we look at the brain and the body, it's just 1112 00:59:13.929 --> 00:59:17.969 a bunch of cells. It's cells doing very cool neural networks, 1113 00:59:18.030 --> 00:59:20.860 the original neural networks, and there's chemicals, and there's all 1114 00:59:20.880 --> 00:59:23.039 kinds of stuff going on. But fundamentally, it's a wet 1115 00:59:23.079 --> 00:59:27.400 biological machine. And when we look at other sophisticated machines 1116 00:59:27.440 --> 00:59:30.679 like the laptop on my table here, that's also made 1117 00:59:30.739 --> 00:59:32.530 up of lots of pieces and parts, but we don't 1118 00:59:32.590 --> 00:59:37.170 suspect that it's having internal experience. And so it is 1119 00:59:37.230 --> 00:59:39.750 a real question. I would say it's the deepest mystery 1120 00:59:39.789 --> 00:59:42.409 that we have in neuroscience is why does it feel 1121 00:59:42.449 --> 00:59:45.360 like something to have all these pieces and parts going? 1122 00:59:45.570 --> 00:59:47.840 And by the way, it's very easy for conscious experience 1123 00:59:48.280 --> 00:59:52.000 to change. So when people put alcohol in their system 1124 00:59:52.420 --> 00:59:57.409 or drugs of various sorts or– You know, all that 1125 00:59:57.610 --> 00:59:59.690 changes their conscious experience. If you hit your head and 1126 00:59:59.730 --> 01:00:02.510 go into a coma, your conscious experience just went away. 1127 01:00:02.550 --> 01:00:04.530 Even though the rest of your body is fine and working, 1128 01:00:04.889 --> 01:00:09.360 your consciousness has gone away. Anyway, somehow we think it's 1129 01:00:09.389 --> 01:00:14.019 an emergent property of the algorithms that are being run here, 1130 01:00:14.579 --> 01:00:17.500 but it wouldn't be sufficient to just end there because 1131 01:00:17.539 --> 01:00:20.239 we don't know why that happens. Part of the reason... 1132 01:00:20.849 --> 01:00:23.030 that this is so important to answer this question. We 1133 01:00:23.070 --> 01:00:25.409 have a new reason why this is important is because 1134 01:00:25.469 --> 01:00:28.650 now we're dealing with this new world of AI and 1135 01:00:28.829 --> 01:00:31.489 we're asking the question, how would we know if an 1136 01:00:31.639 --> 01:00:34.599 LLM were conscious or the next, you know, a large 1137 01:00:34.659 -->

01:00:38.159 world model becomes conscious because then you don't want to 1138 01:00:38.219 --> 01:00:40.739 turn off the computer. Does that count as murder? All 1139 01:00:40.780 --> 01:00:43.659 kinds of, all kinds of new questions that crop up 1140 01:00:43.699 --> 01:00:47.460 with this. And that's why we're trying to understand why 1141 01:00:47.480 --> 01:00:47.980 that happens. 1142 01:00:48.619 --> 01:00:51.170 By the way, In the film, I didn't read the 1143 01:00:51.190 --> 01:00:55.239 original story, forgive me. But so in the movie, I, Robot, 1144 01:00:55.400 --> 01:00:57.420 the original story by Isaac Asimov. 1145 01:00:57.460 --> 01:00:58.300 Isaac Asimov. 1146 01:00:58.539 --> 01:01:02.199 Yeah, there are these decommissioned robots and they're put in 1147 01:01:02.239 --> 01:01:06.880 this truck and you go inside the truck and the 1148 01:01:06.980 --> 01:01:12.469 robots tended to mingle with each other rather than just 1149 01:01:12.570 --> 01:01:16.949 stay where you put them. They've been decommissioned. So there's no... 1150 01:01:17.050 --> 01:01:17.610 There's nothing. 1151 01:01:19.179 --> 01:01:22.929 Actively programmed going on in them. And that was explained 1152 01:01:23.429 --> 01:01:26.869 by the fact that the software, since it was always 1153 01:01:26.929 --> 01:01:32.210 just simply updated and not reprogrammed from scratch, there were 1154 01:01:32.250 --> 01:01:41.179 these lingering software pathways within them that were long gone 1155 01:01:41.420 --> 01:01:44.559 out of the needs of later functioning, but were still 1156 01:01:44.599 --> 01:01:47.760 there operating. And when I heard that and I learned that, 1157 01:01:48.340 --> 01:01:51.820 All I could think of was evolutionarily, we have so 1158 01:01:51.940 --> 01:01:55.260 much baggage of what it is to be alive, just 1159 01:01:55.360 --> 01:02:02.559 leftover from millions of years that maybe this leftover wiring 1160 01:02:03.219 --> 01:02:09.530 that no one wants in our daily existence still operates 1161 01:02:09.650 --> 01:02:13.650 in our own sense of self without us even trying 1162 01:02:13.690 --> 01:02:14.389 to make that happen. 1163 01:02:14.949 --> 01:02:18.690 Yeah, that's certainly a possibility. One issue, though, is that 1164 01:02:18.730 --> 01:02:22.550 consciousness does seem to be useful because it's what allows 1165 01:02:22.590 --> 01:02:25.090 you to have a high-level operating system and say, look, 1166 01:02:25.530 --> 01:02:29.010 I'm made of 30 trillion trillion cells, but I need 1167 01:02:29.030 --> 01:02:31.510 to know whether I'm going left or right around that tree. 1168 01:02:31.590 --> 01:02:33.719 And so I'm going to make a decision that takes 1169 01:02:33.780 --> 01:02:37.039 care of all these systems and all this stuff and 1170 01:02:37.480 --> 01:02:42.380 coordinates as one being. And by laying down memory and saying, oh, 1171 01:02:42.400 --> 01:02:45.559 that memory happened to me as an individual. And that's 1172 01:02:45.699 --> 01:02:48.019 therefore why I can predict that I should do this 1173 01:02:48.079 --> 01:02:50.219 in the future and so on. You get a lot 1174 01:02:50.260 --> 01:02:52.539 more use out of the whole system this way. And 1175 01:02:52.599 --> 01:02:55.920 so consciousness appears to be very useful. And it has 1176 01:02:55.980 --> 01:02:59.699 allowed us as a species to coordinate and cooperate to 1177 01:02:59.780 --> 01:03:04.909 build relationships. whole civilizations. So, you know, it's more than 1178 01:03:04.929 --> 01:03:07.710 an evolutionary piece of baggage that we'd want to get 1179 01:03:07.849 --> 01:03:10.849 rid of, like the appendix. It's something that's really useful. 1180 01:03:10.969 --> 01:03:14.449 Well, call me when you figured it out. And then 1181 01:03:14.510 --> 01:03:17.610 we could ignore all subsequent books written on that subject. 1182 01:03:19.949 --> 01:03:20.610 I'll let you know. 1183 01:03:21.489 --> 01:03:24.690 Yeah, I think that's all the time we have. Damn. 1184 01:03:24.869 --> 01:03:25.849 Fascinating stuff. 1185 01:03:26.219 --> 01:03:29.159 Great. Thanks, guys. Great to talk with y'all. 1186 01:03:29.539 --> 01:03:32.800 All right, David, a delight to have you on StarTalk. 1187 01:03:33.300 --> 01:03:35.380 And stop wasting time talking to us. Get back to 1188 01:03:35.400 --> 01:03:39.719 the lab and figure out our inner cosmos. 1189 01:03:40.099 --> 01:03:42.619 Go scare the crap out of more people. 1190 01:03:43.059 --> 01:03:43.559 Right away. 1191 01:03:44.039 --> 01:03:46.039 All right, take care, y'all. Great to see you. 1192 01:03:46.619 --> 01:03:52.219 This has been another installment of StarTalk Special Edition. It 1193 01:03:52.260 --> 01:03:55.360 was all about the inner cosmos. Chuck, always good to 1194 01:03:55.380 --> 01:03:55.760 have you, man. 1195 01:03:56.159 --> 01:03:57.079 Always a pleasure. 1196 01:03:57.480 --> 01:03:57.900 And Gary. 1197 01:03:58.059 --> 01:03:59.050 Great show. Loved it. 1198 01:03:59.369 --> 01:04:03.139 All right. This is Neil deGrasse Tyson, your personal astrophysicist. 1199 01:04:03.360 --> 01:04:05.110 As always, keep looking up.