Is your memory just an illusion? | Julia Shaw | TEDxPorto

How can you be sure that any particular memory is true? Julia Shaw takes you on an adventure into the weird world of memory hacking. She shows that through a combination of perceptual flaws, brain biases, and social influences, your memories can be easily influenced. Armed with science, she explores how even some of your most cherished and emotional memories might be nothing but fiction.

By the end, she’ll have you wondering whether you actually are who you think you are, or whether your autobiography is just a compelling illusion.

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

I want to take you on an adventure

into the weird world of memory hacking.

What I want you to do
is to rethink memory.

I want you to think about your memories,

rather than as accurate recollections,
permanent records of the past,

instead of that, I want you to think
of your memories as stories.

Stories that you tell yourself
to make sense of your life -

why you're here; who you are -

stories that you tell other people,
part of your tribe,

showing that you're part of the group:

this is who we are.

But before I begin this journey
into memory science

and understanding how easy
it is to distort these stories,

I'm going to tell you a little anecdote.

It starts with my mom
and it ends with my aunt.

So here is the situation:

My mom went to Switzerland.

On this trip to Switzerland,
she went into - well, to get her car,

and she was in a garage underground.

She gets into the
passenger seat of her car.

My father gets into the driver's seat.

They try to exit the garage.

On the way out,

there is a man standing at the exit,
blocking their way out of this garage.

He's clearly not well;

he's talking to himself;

he's disheveled.

And my mom, to try
to get him out of the way,

gets out of the car and says,
"Sir, can you please get out of the way?"

And the man, instead of responding
the way that normal people would,

which is by moving,

he runs at my mom,

pushes her into the car,

and starts punching her.

Now, my dad's response to this
is to drive away -

of course, everyone's in shock -

and they get out of the situation,
and my mom is okay.

But of course, for my mom,

this was an earth-shattering moment.

A stranger randomly attacked her,

this kind of thing had never
happened to her.

So what does she do?

Naturally, she tells her family about it;

she tells her friends about it;

the story is told full of emotion.

Now, a year later,

my aunt is telling the same story

full of emotion,

full of confidence and conviction,

full of details

and claims that she was in the backseat.

Now, that's impossible.

I said this story happened in Switzerland,
and my aunt lives in Germany.

Even when confronted with this fact

that there is no way she could have
possibly been in the back of this car,

she doesn't want to let go of this memory,

because it feels so real.

So how do we find
ourselves in a situation

where we confuse things
that we think we've experienced -

our memories -

with things that we
have actually experienced?

So this is where I'm coming from;

this is where our stories begin.

And so if we rethink our past as a story,

and we think about writing these stories
and who gets to write these stories,

who gets to write into our memory box?

It might be a little more complicated
than we often think.

And ultimately what we find is

that just like my aunt was not actually
the witness of my mom's crime -

as much as she might
identify as this witness;

this may have been an important part
of her personal narrative -

it's not true.

And the same thing goes for you:

that there might be important
moments of your life -

memories of your childhood,
memories of lost loves -

that don't make sense at all.

And so you might not actually be
the person you think you are,

certainly if you're resting
your identity on your memories.

So I want you to dare
to question your memories.

And no memory is off-limits.

Just because it's emotional or complex,
just because it feels real

doesn't necessarily mean that it is.

So question your memories:

"How do I know
that this actually happened?"

Because when you do that,
you dare to question yourself: "Who am I?"

And if you can't trust
your memories,

What then?

And ultimately it leads you
to question your reality.

So let's talk about that.

What is your reality?

So, before we even begin
to talk about distorting memories,

let's talk about where memories begin.

Memories begin at perception.

That doesn't need to be
perception of the real world,

that can be perception,
that can be idea,

that can be something
that we think about -

because we can also remember things
we've thought about or dreams -

but often we talk
about perception in real life.

And of course, here, neuroscience
and people who study psychology,

like myself,

are clear that you have
a unique perceptual filter.

Every one of you
has a different set of eyes,

different set of ears,
different smells.

But that's not where it ends.

You also have a different worldview.

You have a completely
different set of memories

that you bring into every situation,

and those matter.

You could even argue
that we're living in a simulation.

Reality as you know it

only exists to you.

And so, from their very inception,
from the very beginning of a memory,

it's already filtered,
it's already tainted.

Let me give you an example

of how perception can filter
how we make decisions

and ultimately how
those memories of our lives,

of things that we think are important,

can change how we make decisions.

So, all right.

This is a study I did with Stephen Porter,
Leanne ten Brinke and Natasha Korva

and published in 2013,

where what we did is
we gave participants a photo.

And we said, alongside this photo,

this person was a murderer.

This person, or at least
is convicted - oh, not convicted -

is a suspect in a murder case.

So this suspect, we give you the case,

we give you pieces of evidence,

11 pieces of evidence
in increasing severity.

Now, what we find is that people,
generally, the more evidence they get,

the more likely they are
to convict someone.

And that makes sense.

But there is one important difference

in terms of how many pieces of evidence
you need to convict someone,

and that has to do with how trustworthy
the picture of the person's face is.

So you look at someone,
and in that moment,

you make a snap decision:

"I trust this person,"
or "I don't trust this person."

And you're basing that decision,

as to whether or not
this person might be capable

of this horrendous crime
that were accusing him of,

just based on your memories.

This is, in general, what society
has bombarded you with:

this is what an offender looks like.

And if a person matches that stereotype
you're more likely to make a bad decision.

And so what we found is that
people who look less trustworthy

need fewer pieces of evidence
to have a juror reach a guilty verdict,

and - and this is what's
most important, I think -

is that when you give
people exonerating evidence,

when you give people
an 11th piece of evidence

that says, actually, the DNA
in this case doesn't match the suspect -

arguably most people would say,
"Oh, that makes sense to them,"

say, "Oh, not guilty," so to exonerate -

what we find is that trustworthy people
are much more likely to be exonerated

than untrustworthy people.

So again, this perception in the moment
is clouding your decision making.

And so you're bringing that to the table.

It's changing your worldview.

So perception influences our memories,

perception influences
how we remember people

and how we interact with them.

And so that can be distorted.

And that can be distorted by things
that we don't even notice.

But before we move on

to the penultimate thing
that I want to talk about,

which is memory hacking -

which is how we can actually,
actively distort people's memories -

let's also talk a bit about the brain.

Because you need to understand
how the brain works

in order to understand
why memories are so flexible, so slippery.

Every day, you wake up a new person.

Now, the reason for that

is that your brain is constantly changing.

From the beginning of this sentence
to the end of this sentence,

your brain looks different.

And that's a good thing

because it means that you're able
to be creative and to learn,

you're able to take on new information
and weave it into your brain

in a way that you can possibly use later.

And so if you understand
that your brain is constantly in motion,

you also understand
that this hugely complex organ ...

if we break it down into a network,

into the network that is the memory,

we see that it's possible
to forget things,

to remember things
and to misremember things.

Now, if you think
about memory as a network,

forgetting is when you cut the connection
between two parts of a memory.

Now, when we talk about memories of
our lives, of autobiographical memories,

what we normally
talk about are things like,

"Oh, I felt this."
" I heard this." " I saw this."

They're called multi-sensory details.

They're complex.

And these multi-sensory details
are actually stored in networks

across the different parts of the brain

that are each responsible
for those sensations,

which is why we can relive,

or feel to relive these
magical times in our lives.

But when we forget, what happens is

that you've cut a connection
between some of these sensations,

some of these details.

And when you misremember
or you have a false memory,

which is what I study,

you reconnect pieces
or connect pieces for the first time

in ways that were never
originally together.

So you might think,
"Oh, I remember that smell,"

but then you have it in the wrong place.

So you've connected things
that aren't supposed to be together.

And that's the basis of memory errors,

is that your flexible brain
is creatively recombining things.

So here we move on to the last part,

which is I think the most exciting,

which is the social influence part:

the idea that your memories
are not just your own,

your memories are
subject to social influence.

So back to the stories.

If you think of your memories,
all of your memories,

as living in a library ...

Now, that library sucks.

It's a really bad library.

Why?

Because people can walk into the library;

they can take out the book;
they can rip out pages;

they can cross things out;
they can write over them.

In fact, every single time that you take
a book out of your own library,

you're required to delete the whole thing
and rewrite it from scratch.

And then you put it back in the shelf.

Now, this will also change
depending on who you're talking to.

If you're talking to a friend,
you might change your story a little bit.

You might enhance the parts

that the person is responding to
positively with "uh, yeah."

And you might ignore or delete
the parts where the person's going,

"This isn't very interesting."

So who we're talking to matters.

And if we arrive at my research,
which I'm going to describe now,

which is that I convince people
that they committed crimes

or had other emotional experiences
that never happened.

Things like, you would come into my lab,

and I might convince you
that you were attacked by an animal,

that you lost a large sum of money,

or that you injured yourself.

Alternatively -

because I'm a criminal psychologist -

I'm also interested in trying to convince
you that you committed a crime,

a crime like attacking someone,
attacking someone with a weapon

or stealing something -
all with police contact.

Now, what happens in these situations
is that 70% of the participants

ultimately come to accept
this alternate reality,

as I've suggested it to them,

and they started to tell me -
like my aunt - all about it:

This is why I did it;

here's the situation;

here's who I was fighting.

And the way it works is that I get
participants to come into my lab,

and I tell them - I start with trust -

I tell them, and I say,
"I've contacted your parents" -

these are university students -

"I've contacted your parents,

and they said that six years ago
you attacked someone.

What do you remember?"

And they say, "I have no idea
what you're talking about."

"Okay, do you want to try something?"

If a psychologist asks you
if you want to try something,

be careful.

(Laughter)

And of course, everybody says yes -

"Yes, I want to try this" -
because they think, and this is the key,

they think that I know something about
their lives that they can't remember.

So they need to trust me

and think I actually
have this information.

Then I say, "Okay, let's try this.

Imagine what it could have been like.

Let's try to dig this memory out."

And what we find is

that after repeatedly imagining the event
as it could have been,

three times over three weeks,

people have an increasing difficulty

distinguishing between things
that they just imagined

and things that they experienced.

And now we're back to our flexible brains,

because the reason it's so difficult
to tell the difference

is that actually, in the brain,

imagined experiences
and lived experiences ...

can be identical.

Especially if you get people
to imagine multi-sensory components:

"What did it smell like?"
"What did it feel like?"

Because that's usually what we use
as the marker to distinguish the two.

So what I want is for people to move away

from the idea of truth versus lies,
fact versus fiction,

at least in terms of our memories,

and to embrace that sometimes
things just aren't that black-and-white.

I think this is particularly
important for the legal system.

I work with the courts,
and the military and police,

and I think, especially
in justice settings,

we need to be very careful

not to assume that someone must be lying

just because they're saying something
that's demonstrably untrue.

Because what we might have
instead is a much more gray area

that's somewhere
between this fact and fiction,

lie/false memories,

fiction that's woven into our stories.

So I want to leave you with this.

I want you to be
cautious, curious and kind.

I want you to be cautious.

Think about how you're
remembering things

and things that may have influenced
how you remember.

Was there someone
eagerly watching your memory?

Was there someone giving you feedback,
giving you leading questions?

Was there a therapist
or maybe a police officer

or maybe a teacher or parents
overly zealously asking you questions

and saying, "Oh, no, no,
but don't you remember this?"

Be careful as to where they came from.

Be curious when other people are
remembering things and you think,

"I'm not sure if that's true."

Ask them.

"Do you have any evidence
that this actually happened?"

And be kind.

Just because someone's saying
something clearly untrue,

don't assume that they're lying.

This helps me with my aunt
quite significantly.

(Laughter)

So I want to leave you with the idea

that you are the curator
of your memories.

Only you have control
over who gets to go into the library,

who gets to tear out pages
and scribble over the margins.

So be careful.

Because if you let
too many errors slip in,

you might realize that your memories
are just an illusion.

(Applause)