WEBVTT 00:00:16.524 --> 00:00:19.207 I want you to take a look at this baby. 00:00:19.679 --> 00:00:24.475 What you're drawn to are her eyes and the skin you love to touch. 00:00:24.886 --> 00:00:28.026 But today I'm going to talk to you about something you can't see. 00:00:28.050 --> 00:00:30.802 What's going on up in that little brain of hers. 00:00:31.635 --> 00:00:35.556 The modern tools of neuroscience are demonstrating to us 00:00:35.580 --> 00:00:39.475 that what's going on up there is nothing short of rocket science. 00:00:40.236 --> 00:00:43.673 And what we're learning is going to shed some light 00:00:43.697 --> 00:00:49.595 on what the romantic writers and poets described as the "celestial openness" 00:00:49.619 --> 00:00:51.476 of the child's mind. 00:00:52.513 --> 00:00:55.971 What we see here is a mother in India, 00:00:55.995 --> 00:00:59.899 and she's speaking Koro, which is a newly discovered language. 00:01:00.297 --> 00:01:02.104 And she's talking to her baby. 00:01:02.589 --> 00:01:03.745 What this mother -- 00:01:03.769 --> 00:01:06.988 and the 800 people who speak Koro in the world -- 00:01:07.012 --> 00:01:10.222 understands is that, to preserve this language, 00:01:10.246 --> 00:01:12.832 they need to speak it to the babies. 00:01:12.856 --> 00:01:15.731 And therein lies a critical puzzle. 00:01:15.755 --> 00:01:18.005 Why is it that you can't preserve a language 00:01:18.029 --> 00:01:21.264 by speaking to you and I, to the adults? 00:01:21.288 --> 00:01:23.476 Well, it's got to do with your brain. 00:01:24.038 --> 00:01:28.476 What we see here is that language has a critical period for learning. 00:01:28.900 --> 00:01:32.700 The way to read this slide is to look at your age on the horizontal axis. 00:01:32.724 --> 00:01:35.407 (Laughter) 00:01:35.431 --> 00:01:39.070 And you'll see on the vertical your skill at acquiring a second language. 00:01:39.689 --> 00:01:43.548 The babies and children are geniuses until they turn seven, 00:01:43.572 --> 00:01:45.876 and then there's a systematic decline. 00:01:45.900 --> 00:01:48.397 After puberty, we fall off the map. 00:01:48.834 --> 00:01:51.366 No scientists dispute this curve, 00:01:51.390 --> 00:01:53.345 but laboratories all over the world 00:01:53.369 --> 00:01:55.876 are trying to figure out why it works this way. 00:01:56.418 --> 00:02:00.452 Work in my lab is focused on the first critical period in development, 00:02:00.476 --> 00:02:02.321 and that is the period in which babies 00:02:02.345 --> 00:02:05.710 try to master which sounds are used in their language. 00:02:05.734 --> 00:02:08.223 We think, by studying how the sounds are learned, 00:02:08.247 --> 00:02:10.513 we'll have a model for the rest of language, 00:02:10.537 --> 00:02:13.475 and perhaps for critical periods that may exist in childhood 00:02:13.499 --> 00:02:16.362 for social, emotional and cognitive development. 00:02:16.935 --> 00:02:18.876 So we've been studying the babies 00:02:18.900 --> 00:02:21.403 using a technique that we're using all over the world 00:02:21.427 --> 00:02:23.283 and the sounds of all languages. 00:02:23.307 --> 00:02:25.098 The baby sits on a parent's lap, 00:02:25.122 --> 00:02:28.043 and we train them to turn their heads when a sound changes -- 00:02:28.067 --> 00:02:29.525 like from "ah" to "ee." 00:02:29.549 --> 00:02:32.982 If they do so at the appropriate time, the black box lights up 00:02:33.006 --> 00:02:34.990 and a panda bear pounds a drum. 00:02:35.014 --> 00:02:37.432 A six-monther adores the task. 00:02:38.060 --> 00:02:39.221 What have we learned? 00:02:39.245 --> 00:02:41.405 Well, babies all over the world 00:02:41.429 --> 00:02:44.910 are what I like to describe as "citizens of the world." 00:02:44.946 --> 00:02:47.874 They can discriminate all the sounds of all languages, 00:02:47.898 --> 00:02:51.130 no matter what country we're testing and what language we're using, 00:02:51.154 --> 00:02:54.149 and that's remarkable because you and I can't do that. 00:02:54.173 --> 00:02:56.144 We're culture-bound listeners. 00:02:56.168 --> 00:02:58.563 We can discriminate the sounds of our own language, 00:02:58.587 --> 00:03:00.434 but not those of foreign languages. 00:03:00.458 --> 00:03:03.625 So the question arises: When do those citizens of the world 00:03:03.649 --> 00:03:06.533 turn into the language-bound listeners that we are? 00:03:06.557 --> 00:03:09.694 And the answer: before their first birthdays. 00:03:09.718 --> 00:03:12.850 What you see here is performance on that head-turn task 00:03:12.874 --> 00:03:15.337 for babies tested in Tokyo and the United States, 00:03:15.361 --> 00:03:16.799 here in Seattle, 00:03:16.823 --> 00:03:18.572 as they listened to "ra" and "la" -- 00:03:18.596 --> 00:03:21.402 sounds important to English, but not to Japanese. 00:03:21.426 --> 00:03:24.804 So at six to eight months, the babies are totally equivalent. 00:03:24.828 --> 00:03:27.382 Two months later, something incredible occurs. 00:03:27.406 --> 00:03:30.086 The babies in the United States are getting a lot better, 00:03:30.110 --> 00:03:32.034 babies in Japan are getting a lot worse, 00:03:32.058 --> 00:03:35.508 but both of those groups of babies are preparing for exactly the language 00:03:35.532 --> 00:03:37.024 that they are going to learn. 00:03:37.048 --> 00:03:41.672 So the question is: What's happening during this critical two-month period? 00:03:41.696 --> 00:03:44.039 This is the critical period for sound development, 00:03:44.063 --> 00:03:45.478 but what's going on up there? 00:03:45.502 --> 00:03:47.481 So there are two things going on. 00:03:47.505 --> 00:03:50.381 The first is that the babies are listening intently to us, 00:03:50.405 --> 00:03:54.138 and they're taking statistics as they listen to us talk -- 00:03:54.162 --> 00:03:56.143 they're taking statistics. 00:03:56.167 --> 00:03:58.706 So listen to two mothers speaking motherese -- 00:03:58.730 --> 00:04:01.772 the universal language we use when we talk to kids -- 00:04:01.796 --> 00:04:04.007 first in English and then in Japanese. 00:04:05.231 --> 00:04:08.670 (Video) Ah, I love your big blue eyes -- 00:04:08.694 --> 00:04:11.500 so pretty and nice. 00:04:11.549 --> 00:04:17.476 (Japanese) 00:04:19.406 --> 00:04:21.319 Patricia Kuhl: So, what I'm telling you 00:04:21.351 --> 00:04:25.046 is that during the production of speech, when babies listen, 00:04:25.443 --> 00:04:30.212 what they're doing is taking statistics on the language that they hear. 00:04:30.953 --> 00:04:33.863 And those distributions grow. 00:04:33.887 --> 00:04:38.260 And what we've learned is that babies are sensitive to the statistics, 00:04:38.284 --> 00:04:42.112 and the statistics of Japanese and English are very, very different. 00:04:42.636 --> 00:04:45.293 English has a lot of Rs and Ls. 00:04:45.317 --> 00:04:47.076 The distribution shows. 00:04:47.100 --> 00:04:49.940 And the distribution of Japanese is totally different, 00:04:49.964 --> 00:04:52.965 where we see a group of intermediate sounds, 00:04:52.989 --> 00:04:55.404 which is known as the Japanese "R." 00:04:55.428 --> 00:04:59.536 So babies absorb the statistics of the language 00:04:59.560 --> 00:05:01.238 and it changes their brains; 00:05:01.262 --> 00:05:03.413 it changes them from the citizens of the world 00:05:03.437 --> 00:05:06.383 to the culture-bound listeners that we are. 00:05:06.407 --> 00:05:10.506 But we as adults are no longer absorbing those statistics. 00:05:10.544 --> 00:05:13.101 We are governed by the representations in memory 00:05:13.125 --> 00:05:15.674 that were formed early in development. 00:05:15.698 --> 00:05:17.476 So what we're seeing here 00:05:17.500 --> 00:05:20.733 is changing our models of what the critical period is about. 00:05:20.757 --> 00:05:23.526 We're arguing from a mathematical standpoint 00:05:23.550 --> 00:05:26.690 that the learning of language material may slow down 00:05:26.714 --> 00:05:29.094 when our distributions stabilize. 00:05:29.118 --> 00:05:31.980 It's raising lots of questions about bilingual people. 00:05:32.418 --> 00:05:36.449 Bilinguals must keep two sets of statistics in mind at once 00:05:36.473 --> 00:05:39.356 and flip between them, one after the other, 00:05:39.380 --> 00:05:41.152 depending on who they're speaking to. 00:05:41.176 --> 00:05:42.330 So we asked ourselves, 00:05:42.354 --> 00:05:45.761 can the babies take statistics on a brand new language? 00:05:45.785 --> 00:05:49.063 And we tested this by exposing American babies 00:05:49.087 --> 00:05:50.776 who'd never heard a second language 00:05:50.800 --> 00:05:53.516 to Mandarin for the first time during the critical period. 00:05:53.540 --> 00:05:57.077 We knew that, when monolinguals were tested in Taipei and Seattle 00:05:57.101 --> 00:05:59.763 on the Mandarin sounds, they showed the same pattern. 00:05:59.787 --> 00:06:02.258 Six to eight months, they're totally equivalent. 00:06:02.282 --> 00:06:04.818 Two months later, something incredible happens. 00:06:04.842 --> 00:06:08.394 But the Taiwanese babies are getting better, not the American babies. 00:06:08.418 --> 00:06:13.300 What we did was expose American babies, during this period, to Mandarin. 00:06:13.324 --> 00:06:16.332 It was like having Mandarin relatives come and visit for a month 00:06:16.356 --> 00:06:20.153 and move into your house and talk to the babies for 12 sessions. 00:06:20.177 --> 00:06:22.383 Here's what it looked like in the laboratory. 00:06:22.407 --> 00:06:27.963 (Mandarin) 00:06:44.162 --> 00:06:46.408 PK: So what have we done to their little brains? 00:06:46.432 --> 00:06:48.476 (Laughter) 00:06:48.900 --> 00:06:51.571 We had to run a control group to make sure 00:06:51.595 --> 00:06:54.807 that coming into the laboratory didn't improve your Mandarin skills. 00:06:54.831 --> 00:06:57.484 So a group of babies came in and listened to English. 00:06:57.508 --> 00:06:58.910 And we can see from the graph 00:06:58.934 --> 00:07:01.517 that exposure to English didn't improve their Mandarin. 00:07:01.541 --> 00:07:05.136 But look at what happened to the babies exposed to Mandarin for 12 sessions. 00:07:05.160 --> 00:07:07.560 They were as good as the babies in Taiwan 00:07:07.584 --> 00:07:10.560 who'd been listening for 10 and a half months. 00:07:10.584 --> 00:07:14.408 What it demonstrated is that babies take statistics on a new language. 00:07:14.432 --> 00:07:17.663 Whatever you put in front of them, they'll take statistics on. 00:07:17.700 --> 00:07:19.290 But we wondered what role 00:07:19.314 --> 00:07:22.973 the human being played in this learning exercise. 00:07:22.998 --> 00:07:27.284 So we ran another group of babies in which the kids got the same dosage, 00:07:27.308 --> 00:07:29.776 the same 12 sessions, but over a television set. 00:07:29.800 --> 00:07:33.461 And another group of babies who had just audio exposure 00:07:33.485 --> 00:07:35.573 and looked at a teddy bear on the screen. 00:07:35.597 --> 00:07:37.776 What did we do to their brains? 00:07:37.800 --> 00:07:41.175 What you see here is the audio result -- 00:07:41.523 --> 00:07:43.261 no learning whatsoever -- 00:07:43.285 --> 00:07:45.043 and the video result -- 00:07:45.836 --> 00:07:47.681 no learning whatsoever. 00:07:47.705 --> 00:07:51.846 It takes a human being for babies to take their statistics. 00:07:52.222 --> 00:07:54.388 The social brain is controlling 00:07:54.412 --> 00:07:56.517 when the babies are taking their statistics. 00:07:56.541 --> 00:08:00.034 We want to get inside the brain and see this thing happening 00:08:00.058 --> 00:08:03.996 as babies are in front of televisions, as opposed to in front of human beings. 00:08:04.020 --> 00:08:08.717 Thankfully, we have a new machine, magnetoencephalography, 00:08:08.741 --> 00:08:10.034 that allows us to do this. 00:08:10.058 --> 00:08:12.643 It looks like a hair dryer from Mars. 00:08:12.667 --> 00:08:17.150 But it's completely safe, completely noninvasive and silent. 00:08:17.204 --> 00:08:18.838 And babies - we're looking at 00:08:18.874 --> 00:08:20.632 millimeter accuracy 00:08:20.657 --> 00:08:23.656 with regard to spatial and millisecond accuracy 00:08:23.681 --> 00:08:26.303 using 306 SQUIDs -- 00:08:26.327 --> 00:08:29.427 these are superconducting quantum interference devices -- 00:08:29.451 --> 00:08:33.082 to pick up the magnetic fields that change as we do our thinking. 00:08:33.349 --> 00:08:38.957 We're the first in the world to record babies in an MEG machine 00:08:38.982 --> 00:08:41.373 while they are learning. 00:08:41.397 --> 00:08:43.076 So this is little Emma. 00:08:43.100 --> 00:08:45.008 She's a six-monther. 00:08:45.032 --> 00:08:48.791 And she's listening to various languages in the earphones. 00:08:48.816 --> 00:08:50.799 You can see, she can move around. 00:08:50.822 --> 00:08:54.592 We're tracking her head with little pellets in a cap, 00:08:54.616 --> 00:08:57.591 so she's free to move completely unconstrained. 00:08:57.615 --> 00:08:59.828 It's a technical tour de force. 00:08:59.852 --> 00:09:01.436 What are we seeing? 00:09:01.460 --> 00:09:03.354 We're seeing the baby brain. 00:09:03.378 --> 00:09:07.652 As the baby hears a word in her language, the auditory areas light up, 00:09:07.888 --> 00:09:12.676 and then subsequently areas surrounding it that we think are related to coherence, 00:09:12.700 --> 00:09:16.676 getting the brain coordinated with its different areas, and causality, 00:09:16.700 --> 00:09:19.676 one brain area causing another to activate. 00:09:20.301 --> 00:09:24.758 We are embarking on a grand and golden age. 00:09:24.799 --> 00:09:27.190 We're going to be able to see a child's brain 00:09:27.214 --> 00:09:31.455 as they experience an emotion, as they learn to speak and read, 00:09:31.479 --> 00:09:34.681 as they solve a math problem, as they have an idea. 00:09:35.015 --> 00:09:38.364 And we're going to be able to invent brain-based interventions 00:09:38.388 --> 00:09:40.658 for children who have difficulty learning. 00:09:41.071 --> 00:09:44.137 Just as the poets and writers described, 00:09:44.161 --> 00:09:48.315 we're going to be able to see, I think, that wondrous openness, 00:09:48.339 --> 00:09:51.763 utter and complete openness, of the mind of a child. 00:09:52.524 --> 00:09:55.200 In investigating the child's brain, 00:09:55.224 --> 00:09:59.220 we're going to uncover deep truths about what it means to be human, 00:09:59.244 --> 00:10:00.399 and in the process, 00:10:00.423 --> 00:10:03.494 we may be able to help keep our own minds open to learning 00:10:03.518 --> 00:10:05.209 for our entire lives. 00:10:05.233 --> 00:10:06.476 Thank you. 00:10:06.500 --> 00:10:09.500 (Applause)