The benefits of a bilingual brain - Mia Nacamulli

View full lesson: http://ed.ted.com/lessons/how-speaking-multiple-languages-benefits-the-brain-mia-nacamulli

It’s obvious that knowing more than one language can make certain things easier — like traveling or watching movies without subtitles. But are there other advantages to having a bilingual (or multilingual) brain? Mia Nacamulli details the three types of bilingual brains and shows how knowing more than one language keeps your brain healthy, complex and actively engaged.

Lesson by Mia Nacamulli, animation by TED-Ed.

¿Hablas español? Parlez-vous français?
你会说中文吗？

If you answered, "sí," "oui," or "会"
and you're watching this in English,

chances are you belong to the world's
bilingual and multilingual majority.

And besides having
an easier time traveling

or watching movies without subtitles,

knowing two or more languages
means that your brain

may actually look and work differently
than those of your monolingual friends.

So what does it really
mean to know a language?

Language ability is typically measured
in two active parts, speaking and writing,

and two passive parts,
listening and reading.

While a balanced bilingual has near equal

abilities across the board
in two languages,

most bilinguals around the world
know and use their languages

in varying proportions.

And depending on their situation
and how they acquired each language,

they can be classified into
three general types.

For example, let's take Gabriella,

whose family immigrates to the US
from Peru when she's two-years old.

As a compound bilingual,

Gabriella develops two linguistic
codes simultaneously,

with a single set of concepts,

learning both English and Spanish

as she begins to process
the world around her.

Her teenage brother, on the other hand,
might be a coordinate bilingual,

working with two sets of concepts,

learning English in school,

while continuing to speak Spanish
at home and with friends.

Finally, Gabriella's parents are likely
to be subordinate bilinguals

who learn a secondary language

by filtering it through
their primary language.

Because all types of bilingual people
can become fully proficient in a language

regardless of accent or pronunciation,

the difference may not be apparent
to a casual observer.

But recent advances
in brain imaging technology

have given neurolinguists a glimpse

into how specific aspects of language
learning affect the bilingual brain.

It's well known that the brain's
left hemisphere is more dominant

and analytical in logical processes,

while the right hemisphere is more active
in emotional and social ones,

though this is a matter of degree,
not an absolute split.

The fact that language involves
both types of functions

while lateralization develops
gradually with age,

has lead to the critical
period hypothesis.

According to this theory,

children learn languages more easily

because the plasticity
of their developing brains

lets them use both hemispheres
in language acquisition,

while in most adults, language
is lateralized to one hemisphere,

usually the left.

If this is true, learning a language
in childhood

may give you a more holistic grasp
of its social and emotional contexts.

Conversely, recent research showed

that people who learned
a second language in adulthood

exhibit less emotional bias
and a more rational approach

when confronting problems
in the second language

than in their native one.

But regardless of when you acquire
additional languages,

being multilingual gives your brain
some remarkable advantages.

Some of these are even visible,

such as higher density of the grey matter

that contains most of your brain's
neurons and synapses,

and more activity in certain regions
when engaging a second language.

The heightened workout a bilingual
brain receives throughout its life

can also help delay the onset of diseases,
like Alzheimer's and dementia

by as much as five years.

The idea of major cognitive
benefits to bilingualism

may seem intuitive now,

but it would have surprised
earlier experts.

Before the 1960s, bilingualism
was considered a handicap

that slowed a child's development

by forcing them to spend too much energy
distinguishing between languages,

a view based largely on flawed studies.

And while a more recent study did show

that reaction times and errors increase
for some bilingual students

in cross-language tests,

it also showed that the effort
and attention needed

to switch between languages
triggered more activity in,

and potentially strengthened,
the dorsolateral prefrontal cortex.

This is the part of the brain
that plays a large role

in executive function, problem solving,
switching between tasks,

and focusing while filtering out
irrelevant information.

So, while bilingualism may not
necessarily make you smarter,

it does make your brain more healthy,
complex and actively engaged,

and even if you didn't have
the good fortune

of learning a second language as a child,

it's never too late to do
yourself a favor

and make the linguistic
leap from, "Hello,"

to, "Hola," "Bonjour" or "你好’s"

because when it comes to our brains
a little exercise can go a long way.