Brain: memory and multitasking | Adam Gazzaley, MD, PhD | TEDxSanJoseCA

Dr. Adam Gazzaley gives an informative talk on the complexities of our brains. The data presented in the talk is based upon the recent studies in neuroscience with well-known tools, MRI scanner being one of them.
Dr. Gazzaley explains so well and everyone is engaged and able to participate in the live experiment Remember the Face.
The talk touches upon attention, memory, multitasking, unitasking etc.

Dr. Gazzaley is a founder and director of Neuroscape, a neuroscience center devoted to technology development and research.
He was featured in the New York Times, the WSJ, the Times, CNN, and NBC Nightly News.
Dr. Gazzaley has received many awards, including Science Educator Award.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

Thank you. It's quite a privilege
to be here today.

I'm going to start with this picture here
and see if anyone in this room -

let's start with a show of hands -

knows what this picture is depicting.

Does anyone know what this is?

This is the feeling that you have
after you've left the couch

with a clear idea in mind about
what you wanted to get in the kitchen.

(Laughter)

You arrive there, look in the refrigerator
and have no idea what you're doing.

(Laughter)

Has anyone in this room
ever experienced this?

Don't be shy if you have.
You could share with us.

How amazing is that,

that our magnificent brains
could let us down,

that we could know exactly
what we want, one single item,

and just seven seconds later,
we don't remember it.

Clearly, we have the ability to remember
a single item for seven seconds.

How is that possible?

How is it possible
that our brains could fail us

in that very easy task
of just holding one thing in mind?

The brain is the most remarkable
structure we're aware of.

It's capable of incredibly rapid
parallel processing,

allowing us to interpret
complex stimuli in our environment

within a tenth of a second.

Even computers,

which are designed to try to do this,

have an inability to do that.

Plus, we store a massive amount of
information over the course of our lives,

by some estimates,
a billion bits of information -

that's 50,000 times the text
stored in the library of Congress.

Despite living in a rather small space,
the brain is a massive structure,

having approximately
a hundred billion neurons -

that's on the order of stars
in the core of our Milky Way galaxy.

What's even more impressive

is that there are hundreds of trillions
of connections between these neurons,

creating a staggering network
of very, very intricate complexity.

But I don't have to tell you
a lot of cool facts about the brain

for you to realize how amazing it is:

every emotion you feel,
every thought you have,

every sensation you experience,
every move you make,

your very sense of identity -

all emerges from
the function of our brains.

Despite that, the brain
has some very distinct limitations.

I'll be talking about three of them.

The first is attention.

We know, just based on our experience
and now an incredible amount of data,

that we cannot distribute our attention
everywhere, infinitely.

We can selectively focus our attention,
and that's what it's required to do:

that we direct our resources
to what our goals are guiding us towards.

Another limitation is something
known as working memory.

Working memory is online memory,
not long-term memory.

It's the memory you use
to guide your actions;

it happens during a conversation
to carry the thread of what's going on.

It's also the type
of the memory that you use --

in the past, when someone gave you
a phone number instead of send it to you,

you had to hold it in mind
until you got it into the phone.

We know that there are very strict
limits on this capacity,

and they decrease as information
becomes more complex.

Another limitation is speed.

Although, as I described, our brains
and certainly the neurons,

if you look down at a high resolution,
are capable of very rapid processing.

Because our brain functions
as this massive network,

when you have very complex operations,

speed of all these areas communicating
with each other becomes a limitation.

So these three limitations
on our brain's abilities

leads to a sensitivity to interference.

I'm going to describe what that is.

We went and we asked folks
when they had this experience -

and almost everyone describes this;

it increases as you get older,
for those of you that had not noticed -

What happens?

What led you to find your way
to the kitchen with a clear idea in mind

and when you got there
you didn't know what you were doing,

and you could not remember
what you were trying to get?

And people describe in their
best experience what is happening,

and we built a conceptual
framework from this.

And then we study it in our lab,
I'm a neuroscientist,

we use tools to study
how the brain functions,

and how that leads
to higher-order behaviors.

So we built the framework based on
people's anecdotes and experiences,

and then tried to pursue it empirically
and see if these were really mechanisms

that influence behavior
in the way people experience.

So this is how the framework goes:

we see that there's two types
of interference, generally -

internal interference
and externally induced interference.

We could split those each into different
types of interference based on your goals.

So if the information is totally
irrelevant to you,

we consider it a distraction.

Let's say you're at a restaurant
having a conversation.

If you have any hopes of remembering
the details of that conversation,

you know you're very busy
suppressing the chatter in the room,

maybe the waiter is taking
an order at the next table,

you're just trying to block that out,

it's irrelevant information,

you're trying to suppress it.

That same stimuli can serve

as what we call interruptions,
or multitasking,

when you think maybe you can do
more than one thing at a time.

Maybe you're having that conversation,

but now you're trying to listen

to what the specials are
being announced at the next table.

Or you're on the way
to the refrigerator and a phone rings;

you pick it up, and now you have to
reengage in your initial task.

That's how we split external interference.

This can all happen internally as well.

Some of it is mind wondering:

your thoughts leave your focus
against your will, irrelevantly,

just travel to places that you
did not intend them to.

Or you could be multitasking internally.

Perhaps you're doing it now:

you pay attention to what I'm saying,

you look at the slides, listening to me,

but you might be planning
what to have for lunch later

and who you're going to meet
in the afternoon.

So this constant interference keeps us
from being present, directed on our goals.

So, given those limitations of our brain
and our susceptibility to interference,

what happens when you take your brain
and you expose it to this?

(Laughter)

You're probably all familiar
with most of these things.

The last several decades
have literally seen

an explosion of the diversity
and accessibility of electronic media,

and the devices that deliver it,
many of which are portable.

Probably most of you have a computer
in your pockets right now

that allows you to access
this at any moment.

What's even more profound,
it's not the change in technology,

but historically one media
has replaced other medias.

That's not what's happening now.

Now, data shows,
I'm sure you're all aware of it,

that people are using medias
at the same time.

Approximately 95 percent of people

report using more than one
form of media at a time,

and that activity takes place
almost 30 percent of your days.

Children might probably
have this even more so,

although it's just beginning
to be investigated now.

Almost an obsessive media
multitasking frenzy -

you're almost uncomfortable

when taken away from your ability
to interact with technology in this way.

Before I move forward, I want to say
that I'm a friend of technology,

I'm not anti-technology; I use all these
wonderful toys as well as you do.

Here I am, working on this talk;
I've two large computer monitors,

email on the left side,
cell phone in hand accepting texts,

music playing in the background.

This is how we all interact
with technology, at least to some degree.

Some people have up to six or more forms
of media at any given time.

Another thing that's changed
are expectations.

This constant access to communications,

computers and data has really changed
societal expectations.

Now immediate responsiveness
and continuous productivity are expected.

How many of you are on vacation
and check your email?

A little dark in here, but I just see
a lot of movement out there.

So I'll take that
as a resounding ''yes,'' right.

So we know that our ability to disconnect,

to really be present in what
we're experiencing is decreasing,

even when we're "taking vacations,"

the break from all of this
constant productivity.

So, we should ask the question:
how do we function at all?

Given those limitations
and how we interact with technology,

how are we capable of getting
anything done?

I want to tell you about
the process of cognitive control.

Cognitive control is what allows us
to function at least to some degree

under these circumstances.

How we perceive the world
is not a passive process.

Our environment just
doesn't flood into our brains.

It's sculpted and shaped by our attention.

Two types of attention:

One attention is external,
stimulus-driven attention,

it is the environment imposing
itself upon how you perceive the world.

If there's a flash of light, a loud sound,

even if someone calls your name
quietly behind you,

you pay attention,
you redirect your attention.

Anything that's very salient or novel
demands your attention

and increases your perception of it.

The other type of attention -

the environment coming in
is also known as bottom-up attention.

The other type is internal,
goal-directed attention,

what you're doing now.

You're choosing to focus
your cognitive resources

on what you're hearing
and what you're seeing.

This is known as top-down attention,

your goal-directed attention.

All of your interactions
with the environment involve this balance

between these two forms of attention
that are dictating your perception.

And now we know from a lot of research,
a lot of it from our lab also,

is that this influence then goes on
and influences what you remember,

both in the short-term
and in the long-term.

So what happens when all this interference
that we are being exposed to now

exceeds the capabilities
of our cognitive control?

Well, what we now realize is
that there is a broad and deep influence:

safety, family, our social development,
workplace, education.

All of these things are affected.

There's not nearly enough time
in this talk to talk about these

since each one of these can have
their own lecture associated with them,

showing you how broad this issue is.

What I'm going to talk to you
about in detail is cognition,

because this is what we study in our lab,
specifically memory.

There's a really beautiful quote
by Samuel Johnson,

who was a British author in the 1700s.

He wasn't a psychologist,
he wasn't a neuroscientist,

but he was incredibly insightful.

He said something that really showed
a profound awareness,

because there was no data
on this at the time.

What he said is that "the true art
of memory is the art of attention,"

that "no man will read
with much advantage

who is not able, at pleasure,
to evacuate his mind,"

that "if the repositories
of thought are already full,

what can they receive?"

And "if the mind is employed
on the past or the future,

the book will be held
before the eyes in vain."

There's a full career
of research studies here.

We're slowly working our way through these

to show what's going on
in the brain that leads to this,

and how true is this to our behavior.

So, I figured the easiest way to do this

is to have you perform
one of our experiments right now,

so you can get an idea of what we do.

And while we do this,
we'll record brain activities.

You'll do a less demanding
version of this,

where you're not shoved
inside one of our scanners.

What we are going have you do now is
"Remember a face," very simple experiment.

One face will come up,

it comes up pretty quickly,
so be ready for it.

Then around 7 seconds will pass,
there will be an X on the screen,

and you should remember
the face - just one face.

Then another face comes up,
and your job is be to say,

"Yes, that's the face I saw,"
or "No, that's a new face."

O.K.? Ready to give it a shot?

(Audience) No.

No. The answer is no.

If any of you thinking yes,

do not be nervous,

no reason to make a clinic
appointment right now.

It takes practice to get used to this,
people don't always get a 100 percent.

I'm going to have you do another version
of this experiment, it's the same thing -

see a face, after a period of time

another face'll come up
and you'll have to see if it matches.

But in this experiment,
another face will pop up in the middle,

and for that face you'll have to
make a decision: is it a male over 20?

Then you go back to the business
of remembering that first face.

Does that make sense?

(Laughter)

Remember one face and make
a decision on the middle face.

Pretty simple. Give it a shot.

(Audience) Yes.

It was the same face.

So, did this seem a little harder to you?

(Audience) Yes.

It is a little harder.

If you study even healthy 20-30-year-olds,
you see that the performance diminishes

when you introduce that second task,

even though it's not a hard experiment.

Not only that, but if you introduce
a face in the middle

that's totally irrelevant,
your performance also drops -

very subtle, but consistently.

If you happen to be older than 60,

your performance drops
even more from the distraction

and even more so from the interruption.

So we see that there's an exaggerated
effect with age of this impact

that's even there in 20- and 30-year-olds.

We are now looking at how this type
of distraction and interruptions

might affect your long-term memory.

So we did an experiment where we showed
our participants a series of 168 pictures

that had different numbers of objects.

So what you see here are 3 crowns,
4 couches, that's 4 vacuum cleaners -

though they look like Statues of Liberty
every time I look at that slide.

But you see all these pictures,
and then, after an hour,

you go inside our MRI scanner

so we could see what's
happening in your brain,

and you hear these names:

"Crown," and when you hear "Crown,"

you have to press the button
on how many you remember seeing.

Here the correct answer would be 3,
or it might be new,

maybe we never showed that one before.

The interesting thing is that we look
at what happens to your memory

when your eyes are shut,

when they are open
looking at a grey screen,

and when your eyes are open
looking at a busy visual picture.

And what we found
is that the detailed quality,

your recollection of those details decline

just by having your eyes open
looking at a picture,

which is basically
what you do all day long.

Just that very simple stimulus,

that you have nothing to do
besides remember,

declines just by having your eyes open.

Later, you should do this experiment:

Go up to a significant other
or a friend, look them in the eyes,

and ask them to tell you in detail
what they had for dinner last night.

Almost invariably, what you'll see
is that they look away from you.

What we think is going on
from looking at the brain data

is that people are looking for
a quiet place in their environment

to recreate this memory.

Just looking at your face

is too distracting
to do this at a high level.

(Laughter)

Nothing personal.

We did another experiment,
where it was basically the same,

but now it was done in silence,
or we went into a restaurant

and we taped the normal chatter
that occurs in a restaurant,

and we found the same decline in memory.

The point of this

is not that you should walk around
with blindfolds on and earplugs in.

The point is to show you
how exquisitely sensitive our memory is

even to the normal environmental
stimulation that we cannot escape.

So you can imagine

when you layer upon all the normal
complexity that exists in our environment.

But we do this, the reason
we make such simple experiments

is we're recording brain activity
with these tools:

functional MRI that lets us look at blood
flow correlates of neural activity

and lets us see where in the brain
events are occurring;

as well as EEG, in which we're looking at
electrical signatures of neural activity,

where we can see
when events are occurring.

And we do these tools

to understand what happens in our brain
when we have interference

and how it diminishes our abilities.

I'm just going to summarize this
with a couple of cartoons,

data from our lab and so many labs

to give you the latest understanding
about what's going on.

This is your brain.

The front part is over here on this side,

and what we see is
that the prefrontal cortex -

that's the part of our brain
that makes us most human,

the part that's evolved the most,
the part that develops the latest,

it's the part that's involved
in this cognitive control.

And when you're confronted
with distraction, it acts as a bouncer.

It's saying, "What information
is on the guest list?"

And through its connectivity in a network
with visual parts of the brain,

which are in the back,

it controls what information gets in.

You can see this is
a very busy night club,

but your visual cortex will only fit
six things or even less at a time,

depending on how complicated they are.

When information gets in
that's not on the guest list,

you have a cost - your performance drops.

This is what changes as we get older:

our filter, our ability to block out
information decreases,

and the degree that it decreases
directly correlates

with our inability to remember the things
that we're trying to remember - our goals.

What happens in terms of multitasking?

Once again, the prefrontal
cortex is in charge.

But here it's acting
as a flight controller.

It's determining what information
is the priority right now,

and through its connections
with the back of the brain,

it's making decisions.

So, if you're crazy enough

to be riding a bike through Manhattan
next to a cab, texting,

you have a lot of decisions to make.

So, maybe, the first decision
is to focus on the traffic,

and then you think that it's safe enough
to now continue your text message,

and so you do that.

But what you don't do is this:
you don't split those decisions.

The prefrontal cortex has
what's known as a central bottleneck.

And so what you do is switch.

Your prefrontal cortex
switches between tasks

even though it feels like
you're doing more than one thing.

This is what's led this being referred to
as the myth of multitasking -

that you're not really doing
more than one thing

unless they become very automated,

gum chewing, walking.

Although even those have been found
to have some interference with each other,

believe it or not.

(Laughter)

With each switch, there is a time delay,
and this leads to a cost -

an impact on performance.

You do not do two things
as well as you do one thing

if you switch back and forth between them,
and this gets worse as you get older.

We just had a paper published last week
that shows that as you get older,

this switching, the letting go,

the disengaging and
the reengaging become slower,

and this creates the
interference in your memory.

Why do we do it?

We get the impression,
and we have lots of data now,

that this is negative on our performance.

There is not a lot of data for this,
some of this is anecdotal,

based on my impressions,
but it's a resonable place to start.

Multitasking.

We have this sense it gives flexibility,

fresh perspective, increased variety,

it enables us to use
downtime productively,

but probably the most salient aspect
is that it's just more fun.

We are novelty seeking creatures.

It's a very strong part
of our evolution to seek out new.

It stimulates the dopamine system,
the reward system.

There is no doubt that one chunk of time
in which you're multitasking

has more novelty than the same
period of time in unitasking.

And so we probably seek it out.

There's even been a question that maybe
it's even addicting at a certain level

when you're constantly pressured
to get back into a new task

once you become used to it.

How about distraction?
It's a little more complicated.

Why do people go into noisy coffee shops
to read and to work?

Does anyone do that in this room?

Right, it's very common.

Usually you know
which type of person you are.

So, it's something that's interesting -
all this we're exploring in our lab now

to understand the driving force of this,
and are there possible benefits?

So, what can be done about this?

It's just too dreary
to say all these negative things

and then to walk off the stage.

So, we don't have all the answers,

but I can tell you it seems
there are two paths,

at least to me:

we could change our behavior,
or we could change our brains.

(Laughter)

Not necessarily in this scary way
I'm depicting over here,

but in a positive way.

So, we could change our behavior
because someone forces us to, right?

They say it's too dangerous to talk
on the phone or to text while driving,

so we're not letting you do it anymore;
we give you a ticket if you do that.

But there's other ways
we can change our behavior

on things less dangerous to society.

So we could make decisions.

Just because we have
all these wonderful technologies

doesn't mean we have to use it
all at exactly the same time.

We get to make decisions
based upon what we now understand

about how this interaction
with technology and with ourselves

changes our behavior.

So I'm going to tell you what I do;
I will not tell you what to do.

Since I've researched this,

I felt that I needed to make
some decisions about my own behavior,

and this is what I decided:

When working on something very important,

something that demands high quality,
especially something time sensitive,

I do one thing at a time,
singular attention,

I quit my email - too distracting
with messages coming in -

I turn off my phone,

I close my door, I do one thing,
and I find it quite enjoyable.

I actually had stopped
doing that for quite a while.

But I don't do this all the time.

There is many things in my day
that are very boring,

I know they have to get done,

but I know if I try to do
one thing at a time,

I would never finish it.

So I might set aside three hours
of just intense multitasking;

the more I'm switching, the better;
it just keeps it moving along.

So, it's not a message
that technology is bad, don't do this.

It's just the point
that decisions need to be made

when we interact
and our environment changes.

It's happened many times in the past,

this is just another example that we
have to learn how to deal with better.

Changing our brains.

Our brains are capable
of a tremendous degree of plasticity.

That means it adapts and modifies
to stimuli from the environment.

And we now know that this
is not just when you're a child,

it occurs through your entire life.

We are looking at exercises - there's
a video game that we developed in our lab

to see if we can strengthen
these abilities through practice.

So, in this case, it's a car driving game
and you're interacting with the road,

signs come up, sometimes relevant
and sometimes irrelevant,

and you're pressing buttons,
moving, challenging yourself

in an adaptive way,
in a way that's fun.

What's interesting about this video game -
it was designed to be played in our lab

while recording brain activity
and seeing what's going on in our brain

while you interact with
all this hype of interference.

We have a study going on now
with healthy older adults,

they take home a laptop,

and they play this game at home,
and while they play it,

their behavioral performance data
downloads to their computer

and straight from Dropbox
right into our lab,

almost in real time,
we can get their brain data,

their behavioral data,

while they are playing at home.

Then they come into the lab and we look
what's changed in their brain

to enable them to function
at a higher level,

which is what we're seeing -

brains are capable of plasticity.

We're now looking at wireless
EEG bluetooth headsets

that allow us to have our
older participants put these on at home

and record their brain activity,

so we could move our lab outside
of our laboratory into people's homes

and record what are
the changes in the brain

that lead to this higher
ability with practice.

And then they can come back into the lab,

and we can use fMRI
to look at these changes in networks.

I think it's an exciting time
where we're learning more

about how our brains can adapt to this.

So with that, I want to thank you
for your attention

and, of course, your lack
of attention to other things.

(Applause)