The linguistic genius of babies | Patricia Kuhl

Summary

In this enlightening talk, the speaker explores the critical period for language acquisition in infants, highlighting how babies are initially 'citizens of the world' capable of discerning all language sounds. The presentation delves into the neurological changes that occur as they become attuned to the specific sounds of their native language, emphasizing the importance of early exposure. It also demonstrates that social interaction is crucial for language learning, as babies exposed to Mandarin during a critical period can acquire it as effectively as native speakers. The speaker concludes by envisioning a future where understanding the child's brain could lead to new interventions for learning difficulties.

Takeaways

• 🧠 The human brain undergoes significant development during infancy, particularly in the area of language acquisition.
• 👀 Babies are born with the ability to discern all the sounds of all languages, a skill that diminishes as they grow older.
• 📉 There is a critical period for language learning, with children showing a sharp decline in their ability to acquire second languages after the age of seven.
• 🌐 Babies are considered 'citizens of the world' in their early months, being able to differentiate sounds from any language.
• 📉 By their first birthday, babies transition from being 'citizens of the world' to being language-bound listeners, influenced by the sounds of their native language.
• 📈 Babies take in language by 'taking statistics' on the speech they hear, which helps them adapt to the language they are exposed to.
• 🗣️ The distribution of sounds in different languages, like English and Japanese, is distinct and affects how babies learn language.
• 🧑‍👧 Interaction with humans, not just exposure to language through screens or audio, is crucial for babies to learn and take in language statistics.
• 🧬 Neuroscience and techniques like magnetoencephalography (MEG) allow researchers to observe the brain's activity in real-time as babies learn.
• 🌟 The study of child brain development is entering a 'golden age,' promising deeper insights into cognitive and emotional growth.
• 🌱 Understanding the critical periods in a child's brain development could lead to brain-based interventions for children with learning difficulties.

Q & A

What is the main focus of the speaker's discussion on the baby's brain?

The speaker focuses on the development of a baby's brain, particularly the critical period for language acquisition and how it changes from being able to discern all sounds of all languages to becoming culture-bound.

What does the speaker refer to as the 'celestial openness' of a child's mind?

The 'celestial openness' refers to the innate ability of children to absorb and learn languages effortlessly, as described by romantic writers and poets, which modern neuroscience is beginning to understand.

Why is it important for the mother in India to speak Koro to her baby?

It is important because to preserve the Koro language, which is spoken by only 800 people in the world, it needs to be passed on to the next generation through speaking to babies, highlighting the critical period for language learning.

What does the slide with the age on the horizontal axis and language acquisition skill on the vertical axis illustrate?

The slide illustrates the critical period for language learning, showing that children are highly skilled at acquiring a second language until the age of seven, after which there is a systematic decline in this ability.

What technique do researchers use to study how babies learn the sounds of their language?

Researchers use a technique where babies are trained to turn their heads when a sound changes, and if they do so correctly, a visual reward is provided, such as a panda bear pounding a drum.

Why are babies described as 'citizens of the world' in terms of their language abilities?

Babies are described as 'citizens of the world' because they can discriminate all the sounds of all languages, regardless of the country or language being tested, unlike adults who are limited to the sounds of their own language.

What happens to babies' language abilities around their first birthday?

Around their first birthday, babies transition from being able to discern all language sounds to becoming more attuned to the sounds of the language they are regularly exposed to, thus becoming culture-bound listeners.

What does the speaker suggest about the importance of statistics in language learning for babies?

The speaker suggests that babies take statistics on the language they hear, meaning they absorb the frequency and patterns of sounds, which influences their developing language abilities and changes their brains accordingly.

How did the speaker's lab test the ability of babies to learn a new language during the critical period?

The lab exposed American babies, who had never heard Mandarin before, to the language during the critical period and compared their performance to babies in Taiwan who had been exposed to Mandarin from birth.

What role does the human interaction play in language learning for babies, according to the speaker's experiments?

Human interaction is crucial for language learning in babies; the experiments showed that exposure to language through television or audio alone did not improve language learning, but interaction with a human being did.

What technology does the speaker mention for observing the brain activity of babies as they learn?

The speaker mentions the use of magnetoencephalography (MEG), a noninvasive and silent technology that can accurately measure the brain's magnetic fields during cognitive processes like language learning.

What broader implications does the speaker foresee for understanding the child's brain development?

The speaker foresees a 'grand and golden age of knowledge' regarding child brain development, where insights gained could lead to brain-based interventions for children with learning difficulties and a deeper understanding of what it means to be human.

Outlines

00:00

🧠 The Wonders of Early Language Acquisition

This paragraph delves into the fascinating world of early childhood language development, emphasizing the critical period for language learning. It highlights the innate ability of babies to discern all sounds of all languages, a skill that diminishes as they approach their first birthday. The speaker discusses the importance of exposure to language during this period, as babies are shown to be remarkably adept at 'taking statistics' on the sounds they hear, thus shaping their linguistic abilities. The paragraph also introduces the idea that this early learning phase could have broader implications for cognitive and social development.

05:02

🌐 The Impact of Bilingualism and Social Interaction on Language Learning

The second paragraph explores the complexities of bilingualism and the role of social interaction in language acquisition. It discusses how bilingual individuals must manage two sets of linguistic statistics and switch between them. The speaker recounts an experiment where American babies were exposed to Mandarin during a critical period, demonstrating that babies can indeed learn a new language's sounds if exposed during this time. However, the study also reveals that social interaction is crucial for this learning process, as babies did not show the same level of learning when exposed to language through television or audio alone. The paragraph concludes with a look at the use of magnetoencephalography to observe the brain's activity during language learning, indicating the importance of social engagement in the development of the 'social brain.'

10:02

🌟 The Future of Understanding Child Brain Development

The final paragraph envisions a future where our understanding of child brain development will be greatly expanded. It speaks to the potential of new technologies and methods to observe and intervene in the learning process, offering insights into the brain's activity during various cognitive tasks. The speaker expresses optimism about the possibility of creating brain-based interventions for children with learning difficulties and emphasizes the profound opportunity to explore the 'celestial openness' of a child's mind, ultimately contributing to a deeper understanding of what it means to be human.

Keywords

💡Neuroscience

Neuroscience is the scientific study of the nervous system, which includes the brain. It is a multidisciplinary field that combines biology, psychology, and other sciences to understand how the nervous system develops, functions, and interacts with the environment. In the video, neuroscience is used to explore the complexities of a child's brain, particularly in the context of language acquisition and the 'rocket science' of what's happening in a baby's mind.

💡Critical Period

A critical period refers to a specific time window in an organism's development when it is particularly receptive to learning certain skills or behaviors. In the context of the video, the critical period for language learning is highlighted, showing how the ability to acquire a second language declines after childhood, with babies and young children being particularly adept at language acquisition.

💡Language Acquisition

Language acquisition is the process by which an individual learns a language. The video emphasizes the extraordinary capabilities of young children to learn languages, noting a systematic decline in language learning abilities after the age of seven, and the importance of early exposure to language for preserving linguistic diversity.

💡Koro

Koro is a newly discovered language spoken by a small community in India. The video uses Koro as an example to illustrate the importance of speaking a language to babies to ensure its survival, highlighting the role of language in cultural preservation and the critical period for language learning.

💡Citizens of the World

In the video, 'citizens of the world' is a metaphor used to describe babies' ability to discriminate all the sounds of all languages, regardless of their cultural or linguistic background. This concept is central to the discussion on the innate language capabilities of infants and how these capabilities change as they grow older.

💡Sound Discrimination

Sound discrimination refers to the ability to differentiate between various sounds, particularly the phonemes of a language. The video script discusses how babies can discriminate all language sounds globally until they are about a year old, after which they become more attuned to the sounds of their native language.

💡Bilingualism

Bilingualism is the ability to speak two languages fluently. The video touches on the topic of bilingualism, suggesting that bilingual individuals must manage two sets of language statistics in their minds and switch between them, which raises questions about the cognitive processes involved in bilingual language acquisition.

💡Mandarin

Mandarin is a language spoken by the largest number of people in the world, primarily in China. In the script, Mandarin is used as an example of a second language that American babies were exposed to during a critical period, demonstrating that babies can take statistical learning from any language they are exposed to.

💡Social Brain

The social brain refers to the aspects of the brain that are involved in social behaviors and interactions. The video emphasizes the importance of human interaction in language learning, stating that babies require social engagement to effectively learn and take statistical information from a language.

💡Magnetoencephalography (MEG)

Magnetoencephalography is a noninvasive neuroimaging technique that measures the magnetic fields produced by electrical activity in the brain. The video describes the use of MEG to observe the brain activity of babies as they learn, providing insights into the neural processes during language acquisition.

💡Brain-Based Interventions

Brain-based interventions are educational or therapeutic strategies that are informed by an understanding of how the brain works. The video concludes with the potential of brain-based interventions to support children who have difficulties with learning, suggesting a future where insights from neuroscience can be applied to improve educational outcomes.

Highlights

Neuroscience reveals the complexity of a baby's brain, comparing it to rocket science.

The 'celestial openness' of a child's mind is illuminated by modern neuroscience.

Language preservation requires speaking to babies, not adults, due to brain development.

There is a critical period for language learning, with a decline in ability post-puberty.

Babies are 'citizens of the world', capable of discriminating all language sounds until a certain age.

Cultural sound discrimination develops in babies before their first birthday.

Babies take linguistic 'statistics' from the languages they hear, influencing their brain development.

Adults are governed by linguistic representations formed early in development, not current statistics.

Bilingual individuals must manage two sets of linguistic statistics.

American babies exposed to Mandarin during the critical period can discriminate Mandarin.

Transcripts

I want you to take a look at this baby.

What you're drawn to are her eyes and the skin you love to touch.

But today I'm going to talk to you about something you can't see.

What's going on up in that little brain of hers.

The modern tools of neuroscience are demonstrating to us

that what's going on up there is nothing short of rocket science.

And what we're learning is going to shed some light

on what the romantic writers and poets described as the "celestial openness"

of the child's mind.

What we see here is a mother in India,

and she's speaking Koro, which is a newly discovered language.

And she's talking to her baby.

What this mother --

and the 800 people who speak Koro in the world --

understands is that, to preserve this language,

they need to speak it to the babies.

And therein lies a critical puzzle.

Why is it that you can't preserve a language

by speaking to you and I, to the adults?

Well, it's got to do with your brain.

What we see here is that language has a critical period for learning.

The way to read this slide is to look at your age on the horizontal axis.

(Laughter)

And you'll see on the vertical your skill at acquiring a second language.

The babies and children are geniuses until they turn seven,

and then there's a systematic decline.

After puberty, we fall off the map.

No scientists dispute this curve,

but laboratories all over the world

are trying to figure out why it works this way.

Work in my lab is focused on the first critical period in development,

and that is the period in which babies

try to master which sounds are used in their language.

We think, by studying how the sounds are learned,

we'll have a model for the rest of language,

and perhaps for critical periods that may exist in childhood

for social, emotional and cognitive development.

So we've been studying the babies

using a technique that we're using all over the world

and the sounds of all languages.

The baby sits on a parent's lap,

and we train them to turn their heads when a sound changes --

like from "ah" to "ee."

If they do so at the appropriate time, the black box lights up

and a panda bear pounds a drum.

A six-monther adores the task.

What have we learned?

Well, babies all over the world

are what I like to describe as "citizens of the world."

They can discriminate all the sounds of all languages,

no matter what country we're testing and what language we're using,

and that's remarkable because you and I can't do that.

We're culture-bound listeners.

We can discriminate the sounds of our own language,

but not those of foreign languages.

So the question arises: When do those citizens of the world

turn into the language-bound listeners that we are?

And the answer: before their first birthdays.

What you see here is performance on that head-turn task

for babies tested in Tokyo and the United States,

here in Seattle,

as they listened to "ra" and "la" --

sounds important to English, but not to Japanese.

So at six to eight months, the babies are totally equivalent.

Two months later, something incredible occurs.

The babies in the United States are getting a lot better,

babies in Japan are getting a lot worse,

but both of those groups of babies are preparing for exactly the language

that they are going to learn.

So the question is: What's happening during this critical two-month period?

This is the critical period for sound development,

but what's going on up there?

So there are two things going on.

The first is that the babies are listening intently to us,

and they're taking statistics as they listen to us talk --

they're taking statistics.

So listen to two mothers speaking motherese --

the universal language we use when we talk to kids --

first in English and then in Japanese.

(Video) Ah, I love your big blue eyes --

so pretty and nice.

(Japanese)

Patricia Kuhl: During the production of speech, when babies listen,

what they're doing is taking statistics on the language that they hear.

And those distributions grow.

And what we've learned is that babies are sensitive to the statistics,

and the statistics of Japanese and English are very, very different.

English has a lot of Rs and Ls.

The distribution shows.

And the distribution of Japanese is totally different,

where we see a group of intermediate sounds,

which is known as the Japanese "R."

So babies absorb the statistics of the language

and it changes their brains;

it changes them from the citizens of the world

to the culture-bound listeners that we are.

But we as adults are no longer absorbing those statistics.

We are governed by the representations in memory

that were formed early in development.

So what we're seeing here

is changing our models of what the critical period is about.

We're arguing from a mathematical standpoint

that the learning of language material may slow down

when our distributions stabilize.

It's raising lots of questions about bilingual people.

Bilinguals must keep two sets of statistics in mind at once

and flip between them, one after the other,

depending on who they're speaking to.

So we asked ourselves,

can the babies take statistics on a brand new language?

And we tested this by exposing American babies

who'd never heard a second language

to Mandarin for the first time during the critical period.

We knew that, when monolinguals were tested in Taipei and Seattle

on the Mandarin sounds, they showed the same pattern.

Six to eight months, they're totally equivalent.

Two months later, something incredible happens.

But the Taiwanese babies are getting better, not the American babies.

What we did was expose American babies, during this period, to Mandarin.

It was like having Mandarin relatives come and visit for a month

and move into your house and talk to the babies for 12 sessions.

Here's what it looked like in the laboratory.

(Mandarin)

PK: So what have we done to their little brains?

(Laughter)

We had to run a control group to make sure

that coming into the laboratory didn't improve your Mandarin skills.

So a group of babies came in and listened to English.

And we can see from the graph

that exposure to English didn't improve their Mandarin.

But look at what happened to the babies exposed to Mandarin for 12 sessions.

They were as good as the babies in Taiwan

who'd been listening for 10 and a half months.

What it demonstrated is that babies take statistics on a new language.

Whatever you put in front of them, they'll take statistics on.

But we wondered what role

the human being played in this learning exercise.

So we ran another group of babies in which the kids got the same dosage,

the same 12 sessions, but over a television set.

And another group of babies who had just audio exposure

and looked at a teddy bear on the screen.

What did we do to their brains?

What you see here is the audio result --

no learning whatsoever --

and the video result --

no learning whatsoever.

It takes a human being for babies to take their statistics.

The social brain is controlling

when the babies are taking their statistics.

We want to get inside the brain and see this thing happening

as babies are in front of televisions, as opposed to in front of human beings.

Thankfully, we have a new machine, magnetoencephalography,

that allows us to do this.

It looks like a hair dryer from Mars.

But it's completely safe, completely noninvasive and silent.

We're looking at millimeter accuracy

with regard to spatial and millisecond accuracy

using 306 SQUIDs --

these are superconducting quantum interference devices --

to pick up the magnetic fields that change as we do our thinking.

We're the first in the world to record babies in an MEG machine

while they are learning.

So this is little Emma.

She's a six-monther.

And she's listening to various languages in the earphones that are in her ears.

You can see, she can move around.

We're tracking her head with little pellets in a cap,

so she's free to move completely unconstrained.

It's a technical tour de force.

What are we seeing?

We're seeing the baby brain.

As the baby hears a word in her language, the auditory areas light up,

and then subsequently areas surrounding it that we think are related to coherence,

getting the brain coordinated with its different areas, and causality,

one brain area causing another to activate.

We are embarking on a grand and golden age of knowledge

about child's brain development.

We're going to be able to see a child's brain

as they experience an emotion, as they learn to speak and read,

as they solve a math problem, as they have an idea.

And we're going to be able to invent brain-based interventions

for children who have difficulty learning.

Just as the poets and writers described,

we're going to be able to see, I think, that wondrous openness,

utter and complete openness, of the mind of a child.

In investigating the child's brain,

we're going to uncover deep truths about what it means to be human,

and in the process,

we may be able to help keep our own minds open to learning

for our entire lives.

Thank you.

(Applause)