How your brain's executive function works -- and how to improve it

So I have a confession to make.

I only recently learned how to drive.

And it was really hard.

Now, this wasn't an older brain thing.

Do you remember what it was like
when you first learned how to drive?

When every decision you made
was so conscious and deliberate?

I'd come home from my lessons
completely wiped out mentally.

Now, as a cognitive scientist
I know that this is because I was using

a lot of something
called executive function.

Executive function is our amazing ability
to consciously control our thoughts,

emotions and actions

in order to achieve goals ...

like learning how to drive.

It's what we use when we need
to break away from habit,

inhibit our impulses and plan ahead.

But we can see it most clearly
when things go wrong.

Like, have you ever accidentally
poured orange juice on your cereal?

(Laughter)

Or, ever start scrolling on Facebook

and suddenly realize
you've missed a meeting?

(Laughter)

Or maybe this one's more familiar:

Ever plan to stop at the store
on the way home from work

and then drive all the way home
instead on autopilot?

(Laughter)

These things happen to everyone.

And we usually call it absentmindedness,

but what's really happening

is we're experiencing a lapse
in executive function.

So we use executive function
every day in all aspects of our lives.

And over the past 30 years,

researchers have found
that it predicts all kinds of good things

in childhood and beyond,

like social skills, academic achievement,
mental and physical health,

making money, saving money

and even staying out of jail.

Sounds great, doesn't it?

So it's no surprise

that researchers like me
are so interested in understanding it

and figuring out ways to improve it.

But lately, executive function has become
a huge self-improvement buzzword.

People think you can improve it
through brain-training iPhone apps

and computer games,

or by practicing it in a specific way,
like playing chess.

And researchers are trying
to train it in the lab

in the hopes of improving it
and other things related to it,

like intelligence.

Well, I'm here to tell you

that this way of thinking
about executive function is all wrong.

Brain training won't improve
executive function in a broad sense

because it involves
exercising it in a narrow way,

outside of the real-world contexts
in which we actually use it.

So you can master that executive
function app on your phone,

but that's not going to help you stop
pouring OJ on your Cheeerios twice a week.

(Laughter)

If you really want to improve
your executive function

in a way that matters for your life,

you have to understand
how it's influenced by context.

Let me show you what I mean.

There's a great test
that we use in the lab

to measure executive function
in young children

called the "dimensional change card sort."

In this task, kids have to sort
cards in one way --

like by shape --

over and over until they build up a habit.

And then they're asked to switch

and sort the same cards in another way,

like by color.

Now, really young kids struggle with this.

Three- and four-year-olds will usually
keep sorting the cards in the old way

no matter how many times you remind
them of what they should be doing.

(Video) Woman: If it's blue, put it here.
If it's red, put it here.

Here's a blue one.

OK, so now we're going to play
a different game.

We're not going to play
the color game anymore.

Now we're going to play the shape game,

and in the shape game,

all the stars go here
and all the trucks go here, OK?

Stars go here, trucks go here.

Where do the stars go?

And where do the trucks go?

Excellent.

OK, stars go here, trucks go here.

Here's a truck.

(Laughter)

Stars go here, trucks go here.

Here's a star.

(Laughter)

SB: So it's really compelling,

and it's really obvious when she fails
to use her executive function.

But here's the thing:

we could train her on this task
and others like it

and eventually she'd improve,

but does that mean

that she would've improved
her executive function outside of the lab?

No, because in the real world,
she'll need to use executive function

to do a lot more than switching
between shape and color.

She'll need to switch
from adding to multiplying

or from playing to tidying up

or from thinking about her own feelings
to thinking about her friend.

And success in real-world situations
depends on things

like how motivated you are
and what your peers are doing.

And it also depends
on the strategies that you execute

when you're using executive function
in a particular situation.

So what I'm saying is
that context really matters.

Now let me give you an example
from my research.

I recently brought in a bunch of kids
to do the classic marshmallow test,

which is a measure
of delay of gratification

that also likely requires
a lot of executive function.

So you may have heard about this test,

but basically, kids are given a choice.

They can have one marshmallow right away,

or if they can wait for me
to go to the other room

and get more marshmallows,

they can have two instead.

Now, most kids really want
that second marshmallow,

but the key question is:
How long can they wait?

(Laughter)

Now, I added a twist
to look at the effects of context.

I told each kid that they were in a group,

like the green group,

and I even gave them
a green T-shirt to wear.

And I said, "Your group
waited for two marshmallows,

and this other group, the orange group,

did not."

Or I said the opposite:

"Your group didn't wait
for two marshmallows

and this other group did."

And then I left the kid alone in the room

and I watched on a webcam
to see how long they waited.

(Laughter)

So what I found was that kids who believed

that their group waited
for two marshmallows

were themselves more likely to wait.

So they were influenced by a peer group
that they'd never even met.

(Laughter)

Pretty cool, isn't it?

Well, so with this result
I still didn't know

if they were just copying their group
or if it was something deeper than that.

So I brought in some more kids,

and after the marshmallow test,
I showed them pictures of pairs of kids,

and I told them, "One of these kids
likes to have things right away,

like cookies and stickers.

And the other kid likes to wait

so that they can have
more of these things."

And then I asked them,

"Which one of these two kids
do you like more

and who would you want to play with?"

And what I found was that kids
who believed that their group waited

tended to prefer other kids
who liked to wait for things.

So learning what their group did
made them value waiting more.

And not only that,

these kids likely used executive function

to generate strategies
to help themselves wait,

like sitting on their hands
or turning away from the marshmallow

or singing a song to distract themselves.

(Laughter)

So what this all shows
is just how much context matters.

It's not that these kids
had good executive function or bad,

it's that the context
helped them use it better.

So what does this mean
for you and for your kids?

Well, let's say that you want
to learn Spanish.

You could try changing your context

and surrounding yourself
with other people who also want to learn,

and even better if these are people
that you really like.

That way you'll be more motivated
to use executive function.

Or let's say that you want to help
your child do better on her math homework.

You could teach her strategies
to use executive function

in that particular context,

like putting her phone away
before she starts studying

or planning to reward herself
after studying for an hour.

Now, I don't want to make it sound
like context is everything.

Executive function is really complex,
and it's shaped by numerous factors.

But what I want you to remember

is if you want to improve
your executive function

in some aspect of your life,

don't look for quick fixes.

Think about the context

and how you can make
your goals matter more to you,

and how you can use strategies

to help yourself
in that particular situation.

I think the ancient Greeks said it best
when they said, "Know thyself."

And a key part of this is knowing
how context shapes your behavior

and how you can use that knowledge
to change for the better.

Thank you.

(Applause)