April 7, 2025 • 40 mins
Your brain occasionally cooks up falsehoods that you believe entirely, but why does this confabulation happen, and how frequently? What does this tell us about memory, truth-telling, and your life as a story that drifts? And what does this have to do with a paralyzed Supreme Court judge, a blind person who insists she can see, whether Nelson Mandela did or did not die in the 1980s, or whether Curious George had a tail?
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Episode Transcript
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Speaker 1 (00:05):
Why do you brains sometimes make things up entirely? What
does this have to do with Supreme Court Justice William
Douglas sitting in a wheelchair and claiming that he was
just kicking football field goals or a blind person who
insists she can see, And what does any of this
have to do with whether Nelson Mandela did or did
(00:26):
not die in the nineteen eighties, And whether the cartoon
character Curious George had a tale or the exact lines
said in Star Wars or Casablanca, or the spelling of
Oscar Meyer Wieners or the Berenstein Bears, or the narrative
that we tell ourselves about our lives. Welcome to Intercosmos
(00:51):
with me, David Eagleman. I'm a neuroscientist and an author
at Stanford, and in these episodes we sail deeply into
our three pound universe to understand why and how our
lives look the way they do. Today's episode is about confabulation.
(01:18):
That's when the brain makes something up entirely. But it's
different than lying. Lying is purposeful deception. You know the truth,
but you squelch it and make up something in its place.
We all know what lying is, but Confabulation is a
different beast. It's where your brain cooks up something that
(01:39):
is not true, but you believe it entirely. How does
confabulation happen? How frequently does it happen? Is it seen
not just in patience with brain damage? But do we
all do this to some degree? And what does this
tell us about memory and truth telling and the interpretation
of your life as a story that sometimes changes retrospectively.
(02:06):
So to set the table, picture this Alexander, a fifty
eight year old man, sits comfortably in a hospital room,
chatting with a neurologist. Alexander describes his morning in detail,
the breakfast he had, the news that he read, the
friend that he bumped into on his way here. His
voice is confident, the details are specific. But there's a problem.
(02:29):
None of it happened. This man, who's a former school teacher.
He suffered brain damage years ago. His memory is profoundly impaired.
He can't form new memories. Every day is a blank slate,
but he doesn't seem aware of this. Instead, his brain
fills in the gaps, fabricating a seamless believable reality. And
(02:50):
he's not lying, not in the way we usually think
about lying. He fully believes the story he's telling. Why
when the brain is faced with missing in from does
it sometimes just make things up? So let's zoom in
on the issue at the center of all this, which
is our memory systems. We tend to think of memory
as a recording device, something that stores our experiences faithfully
(03:15):
and plays them back on demand.
Speaker 2 (03:17):
But over the past.
Speaker 1 (03:18):
Century, psychology and neuroscience tell us something very different.
Speaker 2 (03:22):
Memory isn't like a video camera.
Speaker 1 (03:25):
It's more like a patchwork quilt stitched together from fragments
of past experience and guesses and expectations. Most of the
time this work's just fine. But when memory fails, maybe
because of injury or aging, the brain doesn't always leave
a void. Sometimes it fills in the blanks, often with
(03:49):
details that are completely false. And that's what confabulation is.
Some forms of it are dramatic, as in cases of
brain injury, which I'll tell you more about, But milder
versions happen to all of us, like when we misremember
childhood events, when we confidently recall things that never happened,
(04:09):
when we rewrite history without realizing it. So in today's episode,
we're going to dive deep into the world of confabulation.
We'll explore cases where brain injury leads to striking, almost
cinematic fabrications, patients who invent entire days and blind people
who insist they can see and split brain patients whose
(04:33):
minds generate explanations out of thin air. And next we'll
turn the lens on ourselves. How often do we confabulate
without realizing it?
Speaker 2 (04:42):
How reliable are our own memories?
Speaker 1 (04:45):
And what does this all tell us about the nature
of reality and history and our sense of self? Okay,
so confabulation is most obvious and most striking in people
who have injuries to their brains. The fabrications the stories
they make up can be detailed and totally convincing, and
(05:07):
they fully believe the stories they tell. Their brains are
damaged in ways that impair memory retrieval, but their brains
just won't admit to the gaps. Instead, they fill those in.
So let's take an example. The neurologist Oliver Sacks described
a patient that he called mister Thompson. Now, mister Thompson
had severe amnesia due to a condition known as Corsicosts syndrome,
(05:32):
which is caused by chronic alcoholism, which leads to a
deficiency an thiamine, which damages particular circuits in the brain. Now,
mister Thompson couldn't form new memories, and yet rather than
expressing confusion or admitting that he couldn't remember, he constantly
invented new realities. Every few minutes, mister Thompson would introduce
(05:53):
himself as someone different, sometimes a shopkeeper, sometimes a businessman,
sometimes a priest. Once someone entered the room, he would
confabulate an entire backstory for them on the spot, convinced
that he had known them for years, and the moment
they left and returned, he had forgotten everything and would
create an entirely new identity for them.
Speaker 2 (06:15):
Why did this happen?
Speaker 1 (06:17):
His brain unable to retrieve the real past improvised. It
was like his mind refused to accept a blank space
where memory should be, so it generated plausible but false alternatives.
And confabulation doesn't just happen in corsicost syndrome. We see
it in many conditions, and each one gives us a
(06:38):
different window into the mind's drive to create coherence. One
extraordinary example comes from people who are blind, but they
don't know it, and they deny it. This condition known
as Anton's syndrome. This happens when damage to the visual
cortex makes a person unable to see, but their.
Speaker 2 (06:58):
Brain still believes they can hand.
Speaker 1 (07:00):
So imagine there's a person named Dina and she has
Anton syndrome, so she's blind. You walk into the room
and you say something like, oh, this is a nice room.
How would you describe this? And Dina will say something like, yeah,
this is nice. The room is bright, there are yellow
curtains over there, there's a red chair in the corner,
(07:21):
even though that's not what the room looks like at all,
and in fact, the room is in total darkness. Anyway,
you might ask her to do something like can you
turn on the lamp, and she'll reach out with total
certainty about where the lamp is, even though there's no
lamp there, and of course she'll fail to reach the
switch that she thinks is there, but rather than acknowledging that,
(07:41):
her brain will generate explanations like, oh, I just miscalculated
the distance. And if you ask her to try again,
she might say, oh, you know, my arm hurts too
much to keep trying again. Dina isn't trying to lie
to you. Her brain believes it it's fabricating reality in
real time to compensate for the missing information, and this
(08:03):
is a fundamental lesson. The brain prioritizes coherence over accuracy. Now,
one interesting feature of confabulations is that they tend to
contain a kernel of truth, so Dina might remember a
room like the one she's describing. One hypothesis about confabulations
(08:24):
is that their memories in the brain, but they're not
built from the right pieces given the situation at hand.
So one way to see this is that a patient
will confabulate if they're asked a question like where are
you right now?
Speaker 2 (08:38):
Or how did you get here?
Speaker 1 (08:40):
But if you ask them something about which they don't
have any pre existing knowledge, like who is Queen schmcgeggy,
they will say that they don't know.
Speaker 2 (08:50):
It's not that.
Speaker 1 (08:50):
They're creating a fictional answer for things out of the blue. Instead,
it's that somehow their confabulated reality is growing.
Speaker 2 (08:58):
From the seeds of memory is that they have had.
Speaker 1 (09:01):
So the hypothesis is that the problem in the network
is that they're not inhibiting irrelevant memories.
Speaker 2 (09:09):
There are some pretty clever ways to.
Speaker 1 (09:10):
Study this, and I'll link these in the show notes,
but the bottom line is that when I ask you
a question about your life right now, your brain kindles
lots and lots of possible pathways, and then certain brain
areas like the orbit or frontal cortex.
Speaker 2 (09:26):
Squelch the activity of most.
Speaker 1 (09:28):
Of the pathways that aren't relevant in the current circumstances.
But if your orbitor frontal cortex is damaged, it can't
suppress the irrelevant memories, and therefore those can come to
the top.
Speaker 2 (09:41):
Now.
Speaker 1 (09:42):
That might make it sound like this only happens when
there's damage to a particular part of the brain like
the orbit or frontal cortex, but confabulation can also pop
up when people get damaged to bits of their thalamus
or the hypothalamus. Why, all these areas are parts of
a pathway called the circuit of pape, and this whole
circuit is involved for selecting relevant memories versus irrelevant ones.
(10:08):
The key surprising lesson here is that your current situation,
what you're looking at right now, doesn't just trigger a
particular memory, but instead tickles a whole world of possible memories,
which then other parts of the brain go through a
lot of trouble to squish down as they're looking.
Speaker 2 (10:25):
For the right one.
Speaker 1 (10:27):
And if you have less of that squishing, if you
have more noise in the system, then you get a
memory popping up that has nothing to do with your
current situation but feels every bit as real to you
as any other memory. I'll give you another example of confabulation.
In nineteen seventy four, the Supreme Court Justice William Douglas
(10:48):
had a stroke that made him paralyzed on his left
side and confine him to a wheelchair. Now, despite this,
Douglas insisted on being discharged from the hospital, claiming that
he was perfectly fine. He dismissed reports of his paralysis
as a myth, and when he was met with skepticism,
he even invited reporters to join him on a hike,
(11:11):
a suggestion that was widely seen as absurd. He went
so far as to say that he had just been
kicking football field goals with his paralyzed leg. Because of
this detachment from reality, Douglas was ultimately removed from his
position on the Supreme Court. But what he was experiencing
is called a nosagnosia, which is a condition where a
(11:34):
person is completely unaware of their body's impairment. People will
adamantly deny their paralysis, not out of deception, but because
their brain genuinely believes that they can move normally. Douglas
fabricated because of his brain's drive to construct a coherent narrative,
and this is wild to witness. For example, imagine you
(11:57):
meet a person who is paralyzed on one side and
they have a no sagnosia. So you gently ask the
person to put both hands on an imaginary steering wheel
in front of them. So she puts one hand on
the steering wheel, and if you ask her why only
one hand, she will insist that both hands are in place.
Speaker 2 (12:17):
So you might come up with an idea and you ask.
Speaker 1 (12:19):
Her to clap her hands, so she'll just move one hand.
Speaker 2 (12:23):
But she will claim to have clapped.
Speaker 1 (12:26):
If you point out that there was no sound and
you ask her to try again, she might simply refuse
and give an excuse like she just doesn't feel like it.
Speaker 2 (12:35):
This is just like Dina, who lost her vision but still.
Speaker 1 (12:38):
Insists she can see even as she struggles to navigate
the room without bumping into things. Dina might attribute her
difficulties to poor balance or misplaced furniture, rather than acknowledging
her blindness. The key insight about a no sagnosia is
that people like Justice Douglas are not lying. Their brains
(13:00):
are unconsciously generating explanations that maintain a coherent sense of reality,
even when that reality is fundamentally flawed. You can also
(13:28):
seek in fabulation in a very different situation. After a
person has undergone a split brain surgery.
Speaker 2 (13:35):
Okay, so what is that?
Speaker 1 (13:36):
The two hemispheres of the brain are linked by a
super highway of neurons. This is called the corpus colosum.
This is the bridge that connects the two halves of
the brain, and a split brain surgery is when the
super highway gets cut with a scalpel such that the
two halves of the brain, the two hemispheres, are now
operating independently. Usually these work in concert. Now you might
(14:01):
ask why would anyone ever have that surgery. It was
for people with severe epilepsy, where the seizures would spread
from one hemisphere to the other. So the idea was
that by destroying the road between the hemispheres, you disallow
the spread. So neurosurgeons started down this road in the
nineteen sixties, but they stopped once they realized that the
(14:22):
surgeries were revealing something astonishing. So let's say someone has
just had this surgery, and what you do is you
now show a picture, like a snowy scene, but you
place that so only the right hemisphere can see that picture.
And there are several objects laid out on the table.
One of them is, let's say, a snow shovel, and
(14:46):
so the left hand, which is controlled by the right hemisphere,
picks up the snow shovel. But when you verbally ask
the left hemisphere why the hand just chose a snow shovel,
the person will canfabulate. They'll make up a story. They'll say, oh,
my hand picked up that snowshovel because I was recently
(15:07):
doing some gardening and this reminds me of it. So
their left hemisphere has no access to the right hemispher's information,
but rather than admitting confusion, it just makes up a
story to explain the action. I'll put a link about
split brain studies on the show notes. But what this
tells us is that our brain's storytelling function is not
(15:30):
just about narrating past events. It's active even in the
present moment. It shapes our reality as we go. In
all of these cases, from mister Thompson's endless reinventions of
himself to the blind woman who insists she can see,
to the split brain patients who fabricate explanations for their
own actions, the brain is doing what it does best,
(15:53):
creating a cohesive narrative. It just so happens that sometimes
the facts don't cooperate. But these extreme cases lead us
to a bigger question. If confabulation happens in people with
brain damage.
Speaker 2 (16:07):
What about the rest of us.
Speaker 1 (16:09):
How reliable are our everyday memories and how often do
we unknowingly rewrite our past?
Speaker 2 (16:17):
Well?
Speaker 1 (16:17):
We do it far more often than we realize. False
memory doesn't just happen in injured brain. They happen all
the time in all of us. Our memories feel solid
and clear and trustworthy, but in reality they're full of fabrications.
Speaker 2 (16:33):
The normal brain, just like the injured.
Speaker 1 (16:35):
Brain, fills in gaps, and typically we don't notice. So
let's start in the nineteen eighties when Nelson Mandela died
in prison. Millions of people remember hearing about this and
reading the headlines or seeing the news stories, so all
of them were surprised when it was announced in twenty
(16:55):
thirteen that Nelson Mandela had just died out of prison
in his home after having been released in nineteen ninety,
becoming President of South Africa, earning a worldwide reputation. Wait,
what hadn't he passed away three decades before? Weirdly, so
many people had that story wrong.
Speaker 2 (17:15):
They thought he died in the eighties.
Speaker 1 (17:17):
That this is now known in the psychology literature as
the Mandela effect. They truly thought they had heard that
he had died in prison. We've all had the experience
of being convinced that something happened in a certain way,
only to later discover we were completely wrong. But it's
called the Mandela effect when it's not just you, but
thousands or millions of other people come to believe the
(17:40):
same false memory. There are so many examples of this.
Here's one. Everyone seems to remember Darth Vader saying Luke,
I am your father, when in fact that's not the line.
Speaker 2 (17:53):
The line is no, I am your father.
Speaker 1 (17:58):
What where did the luke come from in everyone's memory?
Why do we all misremember that? And how about the
movie Casablanca. Even if you've never seen it, you probably
know the most famous line where Ingrid Bergmann says play
it again, Sam, except that she never says it.
Speaker 2 (18:16):
The line in the movie is play it once, Sam,
for all time's sake. I don't know what you mean.
Miss Elton played them play as time goes by?
Speaker 1 (18:28):
So why does everyone believe that the line was play
it again, Sam? And here's another one. You probably remember
the Disney movie Snow White and the Seven Dwarves when
the Witch says mirror, mirror on the wall, who's the
fairest one of all? So you might be surprised to
know that she actually says.
Speaker 2 (18:47):
Magic mirror on the wall. Who is the fairest one
of all?
Speaker 1 (18:53):
But for some reason everyone started saying mirror mirror, And
that's now how we all misremember. The thing is that
if you had a false memory about what was said
in these movies, that memory felt completely real to you,
as though you had seen that scene. The Mandela effect
tells us that memory is not an accurate recording in
(19:13):
the past, but a flexible process, and often it can
be socially influenced and collectively shaped. And the Mandela effect
applies in all sensory domains.
Speaker 2 (19:24):
Take your visual memory.
Speaker 1 (19:27):
Tons of people recall the monopoly man as having a monocle,
but he doesn't and he never did. Here's a question,
did the cartoon monkey Curious George have a tail or
not have a tail? Most people remember that he did,
but that's a false memory. If you look at the books,
Curious George has no tail at all. Okay, here's another one.
(19:49):
Think of Pikachu and his tail. He actually does have
a tail. The tail is yellow, but does it have
a black tip? Most people, if you press them on it,
we'll say the tail has a black tip. Even though
his tail is completely yellow, his ears have black tips,
and somehow millions of people misremember it as being on
his tail. And I'll tell you another version of the
(20:11):
Mandela effect that comes about for a slightly different reason.
Think about Oscar Meyer Wieners. You've certainly seen the ads
and maybe even the Oscar Meyer truck driving around. Here's
the question, how is Meyer spelled? The large majority of
people will swear that it is spelled me e y
e r, but in fact it's m a y e r.
(20:36):
But m e y e r is a much more
common spelling, and so we misremember it. And here's another
example of that same thing. You may remember a children's
book series called The Berenstein Bears. Essentially, everyone remembers this
as being spelled barren Stein sti e n, when in
fact the last five letters are stai n. It looks
(21:00):
like Baron stain bears. When this has pointed out to people,
they generally don't believe this until they go and pull
the book off their shelf and take a look.
Speaker 2 (21:10):
I think that both these.
Speaker 1 (21:11):
Examples about Oscar Meyer and Berenstein Bears are interesting because
they're shaped not necessarily by other people's memories, but instead
by your expectations given the particulars of the language. In
other words, some ways of spelling things are so much
more common that you come to believe that's what you
had seen, and like the other versions of the Mandela effect,
(21:33):
you really, really are certain that this is how you
saw it, And when you see the actual thing written down,
it's hard to reconcile the certainty of your memory against
the reality of what is in front of you. Think
about all these examples of the Mandela effect, quiz your
friends on what they believe and remember, and think of
(21:54):
what else you might have misremembered the movies, the characters,
the logos, whatever, and a note at podcasts at Eagleman
dot com to let me know because I can't get
enough of these things. Okay, I think this is one
of the most fascinating ways to study confabulation in the individual.
Healthy mind canfabulations which we normally never notice or gain
(22:16):
an awareness of. And there's a closely related issue about
the way that our knowledge and beliefs can create unconscious
distortions about what details we remember. In episode seventy, I
told you about a nineteen thirty's study on a short
Native American fable called The War of the Ghosts. Participants
(22:38):
read the story and then they wrote down their recollection
of it immediately after, and then again a week after,
and then again three months after. And as people recalled
the story again and again through time, it turned out
they smoothed out the details that were inconsistent with their
own pre existing knowledge and belief systems. As they recalled
(23:01):
the story over and over, it became more consistent with
their worldview. As another example, consider the way we explain
our own decisions. There are a bunch of studies on this,
and essentially, when people are asked why they made a
particular choice, they often canfabulate explanations. Their choices may have
(23:21):
been influenced by subconscious factors they weren't aware of, but
they'll create a convincing story to explain why they did.
Speaker 2 (23:29):
What they did. Why did you pick that car?
Speaker 1 (23:32):
Oh?
Speaker 2 (23:32):
I like the design?
Speaker 1 (23:34):
In reality, they were subtly influenced by an ad they
were exposed to. Why do you believe what you believe?
Because it's logical? In reality? So much of our belief
is shaped by our culture and by our emotions, and
our brains fill in justifications later. Why did you break
up with that person? Well, we just weren't compatible In reality.
(23:57):
Maybe they could have worked harder, but they have restructure
painful memories to make the breakup seem inevitable. In other words,
studies show that with romantic partners, if a relationship goes bad,
we tend to remember the details of that relationship as
more negative than they actually were. If a relationship improves,
then we see it through rose colored glasses and remember
(24:20):
things as better than they were. There's a sense in
which we are always confabulating, turning complex realities into clear stories.
Now all this may seem innocent enough, but in episode nineteen,
I dove deep into why This sort of confabulation matters
so much when it comes to something like eyewitness testimony,
(24:44):
where there's real world consequence. And the issue that comes
up here again is not just about the fragility of memory,
but the way that we feel so certain about whatever
memory gets served up to us, and our memories can
get manipulated by very subtle cues. For example, in one
study by my colleague Elizabeth Loftis, participants watched a video
(25:06):
of a car accident and were asked a question how
fast were the cars going when they hit each other?
Others were asked a slightly different version of the question,
how fast were the cars going when they smashed into
each other. The result was that those who heard smashed
(25:28):
consistently recalled the cars going faster, with some even falsely
remembering broken glass despite the fact that none was shown.
So memory isn't stored like a video. It's actively reshaped
when we recall it, and even a single word can
alter what we remember. And Loftis did other experiments showing
(25:48):
how false memories can be injected. She showed that people
can be led to remember events that never actually happened
simply through suggestion. In one of her Landmark studies. She
successfully implanted false childhood memories by asking participants about events
like the time they were lost in a shopping mall
(26:10):
or the time they went on a hot air balloon ride,
even though these things have never occurred, but they were
described as if they had. Over time, a lot of
the participants not only accepted these fabricated events as real,
but they ended up adding more details into the story
and in the big picture, in the criminal justice system,
it's been shown with hundreds of studies that you can
(26:32):
mislead eyewitnesses by suggestive questioning. You can alter their recollections
of somebody's appearance or what precisely happened during the crime,
and this problem rears its head every day with eyewitness
testimony in the courtroom. The problem is that memory is
notoriously unreliable.
Speaker 2 (26:53):
And I'm not talking.
Speaker 1 (26:53):
About cases where people are intending to deceive, but more
generally about the problem that memory is malleable. Even subtle
suggestions like the wording during a police lineup, can alter
what somebody feels they remember entirely. False details can be inserted,
and once a memory is altered, it feels just as
(27:14):
vivid and true as a genuine memory, and this means
any of us can recall events with absolute confidence.
Speaker 2 (27:22):
While being completely wrong.
Speaker 1 (27:24):
There's this paradox of inaccuracy with high confidence. And the
reason this matters is because eyewitness accounts are very persuasive
in courtrooms, even though the research.
Speaker 2 (27:37):
Shows that they are often fiction.
Speaker 1 (27:39):
So please listen to episode nineteen for a deep dive
on the brain and eyewitness testimony. Zooming back out, why
(28:06):
does the brain can fabulate even in everyday life. Well,
as I said, unlike a camera that passively records everything
it sees, memory is more like a story being rewritten
every time it's told. Each time we recall an event,
our brain pulls together fragments of information and stitches them
together into a coherent narrative. Small gaps get filled in
(28:28):
with assumptions, as we see with the War of the
Ghosts experiment. Details get smoothed over as we see with
the eyewitness experiments. New information can get inserted even if
it wasn't there originally. Over time, the original memory can
be completely rewritten, and once we update a memory, we
forget we ever changed it. The new version feels like
(28:49):
the original. This is why two people who experience the
same event can remember it completely differently. Each person's brain
has reconstructed the experience. It's based on their own biases
and assumptions and emotions. We've seen how confabulation affects history,
like the Mandela effect, how it affects society like Eyewinness testimony,
(29:13):
how it affects your childhood memories. And that leads me
to always wonder about the small confabulations that we tell
ourselves every day. It's hard to know the answer to this,
but how often do you rewrite past decisions, like when
you rationalize some suboptimal decision that you made by convincing
yourself that you always wanted the outcome you got. This
(29:36):
is a post talk confabulation, a way for the brain
to maintain a sense of consistency. How often do we
misremember conversations? You ever had an argument where you and
the other person are one hundred percent certain about what
was said, but your memories completely disagree. I know it's
always tempting to say the other person is the one confabulating,
(29:57):
but my hope is that after listening to this episode,
you might be slightly more willing to revisit this. So
if confabulation happens to all of us, how can we
ever trust our memories? The answer isn't to distrust everything,
but just to develop a tiny bit of skepticism about
the stories our minds tell us. Your memory feels real,
(30:19):
but feeling real doesn't make it true. Okay, so we've
been exploring how memory is a shifting story. But what
does this mean for how we understand ourselves. One thing
that's happened lately in neuroscience is implanting false memories in animals,
let's say rats. So here's how it works. A team
led by Sousumo, Tonogawa and MIT puts a rat in
(30:43):
a box and lets them run around to explore it.
Then the rats come out of the box and they
hang out, relax. And what the researchers now do outside
the box is they reactivate the neurons that encoded the
memory of that box. They do this using optigs, So
they reactivate those neurons, and now they deliver a little
(31:04):
electric shock to the rat's foot. Okay, Now, later they
put the rat back in the box a place where
the rat had never before been harmed, and the rat
freezes in fear, behaving as if it remembered being shocked. There,
even though that had never actually happened. So the scientists
were able to create an entirely false experience, one that
(31:26):
the rat presumably fully believed to be real. Brains don't
store perfect representations of reality, but flexible, rewriteable narratives.
Speaker 2 (31:36):
So will we one.
Speaker 1 (31:36):
Day implant therapeutic memories to help people overcome PTSD? And
how would a technology like that blur the line between
authentic experience and artificial recollection?
Speaker 2 (31:52):
And this, of.
Speaker 1 (31:52):
Course reminds us of the film Total Recall with Arnold Schwarzenegger.
If you haven't seen this movie, the protagonist Dug Quaid
visits a company called Recall that offers to implant vivid,
customized memories of adventures that never happened. So Quaid opts
for the memory of a secret agent mission on Mars,
(32:15):
only to discover that he might actually be a secret
agent whose real memories were erased. This was a very
pioneering story that played with the tension between authentic experience
and synthetic memory.
Speaker 2 (32:29):
If you remember something vividly.
Speaker 1 (32:32):
And emotionally and in detail, doesn't matter whether it actually happened.
The film asks what if your most cherished memories were
never real? And neuroscience replies that, for better or worse,
we're not that far away from creating synthetic memories. And
in any case, you often create them yourself. And I
(32:57):
just want to highlight it's not just that individ jewels
have unreliable memories. Societies do as well. They collectively misremember
their past. Historical confabulation shapes our understanding of events, often
to serve a specific narrative. In episode forty one, I
talked about the former USSR and how they loved to
(33:20):
erase political enemies from photographs. For one example of many,
there's a famous photo which proudly captures Lenin and other
Soviet leaders in Red Square in Moscow in nineteen nineteen.
You can see Lenin and on his left to see
Leon Trotsky, and on Lenin's right is a man named Kamenev,
(33:40):
and there's a Bolshevik leader from Georgia in front of them. Now,
if you look at a release of this photo some
years later, the official Soviet version of the photo, you
see that after Leon Trotsky fell from party favor, he
was airbrushed out of the photo. In the revised photograph,
there's just an empty space where he used to be
(34:01):
and Kommenev on Lenin's right has disappeared as well, and
the bearded Bolshevik leader never existed.
Speaker 2 (34:08):
In the photo either.
Speaker 1 (34:09):
This is essentially the photographic version of confabulation, and this
happens constantly in the retelling of history. As is often said,
history is the pack of lies told by the winner.
And as an apropos side note, it's not at all
clear who first said that quotation. It's commonly associated with
(34:31):
Napoleon or Churchill, but apparently there are versions of this
going back to Herodotus. So nations and cultures are constantly
shaping public memory. History is always being rewritten, and it
works because, just like individuals, societies need a coherent story
(34:52):
when reality is messy. History gets edited, sometimes consciously, sometimes
through the natural distortion of collective memory. So if our
memories are fiction, who are We Just think about the
way that we tell our life stories. We highlight certain events,
(35:13):
we downplay others. We add emotional weight to moments that
might have been minor at the time. We rewrite past
decisions to make them seem more logical. We are, at
least to some extent, unreliable narrators.
Speaker 2 (35:27):
Of our own lives.
Speaker 1 (35:28):
So we can think of identity as a living document
which is constantly being updated. Who you think you are
today is different from who you thought you were ten
years ago. Some of that shift comes from the deposition
of new memories, but some of it comes from the
subtle confabulations that shape our memories. This may not be
(35:51):
a flaw but a feature, because a perfect, unchanging memory
would trap us in the past. Instead, we rewriting our
history in real time to fit the narrative of who
we believe we are. So some argue that confabulation can
be useful, but it also has a dark side, which
(36:12):
is over confidence. Because we don't realize we're confabulating, we
assume our memories are true, and that can lead to
serious problems like false convictions, where innocent people are imprisoned
because if eyewitnesses who believe they are.
Speaker 2 (36:27):
Telling the truth.
Speaker 1 (36:29):
Also a problem with confabulating brains is misinformation. False memories
contribute to conspiracy theories in urban legends and historical distortions
that shape public perception, and confabulation leads all the time
to personal misunderstandings. How many relationships have been damaged because
(36:50):
two people remember an argument differently and each is convinced
that their version is correct. This is why it's always
a good idea to approach your memory with skepticism and humility.
Just because we remember something vividly doesn't necessitate that it's true.
So how do we live with this knowledge? How do
(37:12):
we best navigate the confabulating brain. It doesn't mean we
should distrust all our memories. It just means we should
be more open eyed about the situation. So instead of
saying I remember exactly what happened, try saying this is
how I remember it, But I could be wrong. As
(37:34):
we wrap up today's journey through the confabulations of memory,
let's leave with one thought. Our memories shape our lives,
our identities, and our understanding of the world. But they
aren't perfect records. They are ever changing. They're always evolving,
just like us. The fact is we humans are storytelling creatures.
(37:55):
We don't just experience the world, we organize it into narrative.
In this same way, history can be a story we
tell about the past. Personal identity is a story we
tell about ourselves. We began today's podcast with a simple
but unsettling question, why do brains sometimes make things up?
(38:15):
Along the way we saw that confabulation isn't just a
quirk of the damaged brain. It's a part of how
all brains function. We are all in a sense fiction writers,
Memory is not a recording device. It's a dynamic creative system.
Every time we recall an event, our brains reconstruct it,
(38:35):
sometimes correctly, sometimes with error, and sometimes in ways that
are more than a little fabricated. The strange part is
that we trust our memories with absolute conviction. We trust
them in relationships, we trust them in courtrooms. We trust
them to tell us who we are. But if memories
can change, if our pasts are being subtly rewritten with
(38:59):
each passing year, what does that mean for the sense
of self?
Speaker 2 (39:02):
If we are the sum of our.
Speaker 1 (39:05):
Memories, but those memories are fluid, then how stable is
the person we think we are. We can become too
confident in our false memories. We can rewrite history to
suit our needs, and we can create narratives that justify
our actions, even when those narratives are inaccurate. So the
(39:25):
next time you remember some episode in your life, pause,
take a moment to question it. How do I know
this memory is accurate? Could my brain be filling in
gaps somewhere. Is this a true recollection or has it
been shaped by the stories I've told myself over the years.
Don't distrust every memory. Instead, this is just an invitation
(39:48):
to approach memory with humility, to recognize that what feels
absolutely real might in fact be a creative act.
Speaker 2 (39:58):
Of your brain.
Speaker 1 (40:02):
Go to Eagleman dot com slash podcast for more information
and to find further reading. Send me an email at
podcast at eagleman dot com with questions or discussion or
your examples of the Mandela effect, and check out and
subscribe to Inner Cosmos on YouTube for videos of each
episode and to leave comments. Until next time. I'm David Eagleman,
(40:23):
and this is Inner Cosmos.
Why do you brains sometimes make things up entirely? What
does this have to do with Supreme Court Justice William
Douglas sitting in a wheelchair and claiming that he was
just kicking football field goals or a blind person who
insists she can see, And what does any of this
have to do with whether Nelson Mandela did or did
(00:26):
not die in the nineteen eighties, And whether the cartoon
character Curious George had a tale or the exact lines
said in Star Wars or Casablanca, or the spelling of
Oscar Meyer Wieners or the Berenstein Bears, or the narrative
that we tell ourselves about our lives. Welcome to Intercosmos
(00:51):
with me, David Eagleman. I'm a neuroscientist and an author
at Stanford, and in these episodes we sail deeply into
our three pound universe to understand why and how our
lives look the way they do. Today's episode is about confabulation.
(01:18):
That's when the brain makes something up entirely. But it's
different than lying. Lying is purposeful deception. You know the truth,
but you squelch it and make up something in its place.
We all know what lying is, but Confabulation is a
different beast. It's where your brain cooks up something that
(01:39):
is not true, but you believe it entirely. How does
confabulation happen? How frequently does it happen? Is it seen
not just in patience with brain damage? But do we
all do this to some degree? And what does this
tell us about memory and truth telling and the interpretation
of your life as a story that sometimes changes retrospectively.
(02:06):
So to set the table, picture this Alexander, a fifty
eight year old man, sits comfortably in a hospital room,
chatting with a neurologist. Alexander describes his morning in detail,
the breakfast he had, the news that he read, the
friend that he bumped into on his way here. His
voice is confident, the details are specific. But there's a problem.
(02:29):
None of it happened. This man, who's a former school teacher.
He suffered brain damage years ago. His memory is profoundly impaired.
He can't form new memories. Every day is a blank slate,
but he doesn't seem aware of this. Instead, his brain
fills in the gaps, fabricating a seamless believable reality. And
(02:50):
he's not lying, not in the way we usually think
about lying. He fully believes the story he's telling. Why
when the brain is faced with missing in from does
it sometimes just make things up? So let's zoom in
on the issue at the center of all this, which
is our memory systems. We tend to think of memory
as a recording device, something that stores our experiences faithfully
(03:15):
and plays them back on demand.
Speaker 2 (03:17):
But over the past.
Speaker 1 (03:18):
Century, psychology and neuroscience tell us something very different.
Speaker 2 (03:22):
Memory isn't like a video camera.
Speaker 1 (03:25):
It's more like a patchwork quilt stitched together from fragments
of past experience and guesses and expectations. Most of the
time this work's just fine. But when memory fails, maybe
because of injury or aging, the brain doesn't always leave
a void. Sometimes it fills in the blanks, often with
(03:49):
details that are completely false. And that's what confabulation is.
Some forms of it are dramatic, as in cases of
brain injury, which I'll tell you more about, But milder
versions happen to all of us, like when we misremember
childhood events, when we confidently recall things that never happened,
(04:09):
when we rewrite history without realizing it. So in today's episode,
we're going to dive deep into the world of confabulation.
We'll explore cases where brain injury leads to striking, almost
cinematic fabrications, patients who invent entire days and blind people
who insist they can see and split brain patients whose
(04:33):
minds generate explanations out of thin air. And next we'll
turn the lens on ourselves. How often do we confabulate
without realizing it?
Speaker 2 (04:42):
How reliable are our own memories?
Speaker 1 (04:45):
And what does this all tell us about the nature
of reality and history and our sense of self? Okay,
so confabulation is most obvious and most striking in people
who have injuries to their brains. The fabrications the stories
they make up can be detailed and totally convincing, and
(05:07):
they fully believe the stories they tell. Their brains are
damaged in ways that impair memory retrieval, but their brains
just won't admit to the gaps. Instead, they fill those in.
So let's take an example. The neurologist Oliver Sacks described
a patient that he called mister Thompson. Now, mister Thompson
had severe amnesia due to a condition known as Corsicosts syndrome,
(05:32):
which is caused by chronic alcoholism, which leads to a
deficiency an thiamine, which damages particular circuits in the brain. Now,
mister Thompson couldn't form new memories, and yet rather than
expressing confusion or admitting that he couldn't remember, he constantly
invented new realities. Every few minutes, mister Thompson would introduce
(05:53):
himself as someone different, sometimes a shopkeeper, sometimes a businessman,
sometimes a priest. Once someone entered the room, he would
confabulate an entire backstory for them on the spot, convinced
that he had known them for years, and the moment
they left and returned, he had forgotten everything and would
create an entirely new identity for them.
Speaker 2 (06:15):
Why did this happen?
Speaker 1 (06:17):
His brain unable to retrieve the real past improvised. It
was like his mind refused to accept a blank space
where memory should be, so it generated plausible but false alternatives.
And confabulation doesn't just happen in corsicost syndrome. We see
it in many conditions, and each one gives us a
(06:38):
different window into the mind's drive to create coherence. One
extraordinary example comes from people who are blind, but they
don't know it, and they deny it. This condition known
as Anton's syndrome. This happens when damage to the visual
cortex makes a person unable to see, but their.
Speaker 2 (06:58):
Brain still believes they can hand.
Speaker 1 (07:00):
So imagine there's a person named Dina and she has
Anton syndrome, so she's blind. You walk into the room
and you say something like, oh, this is a nice room.
How would you describe this? And Dina will say something like, yeah,
this is nice. The room is bright, there are yellow
curtains over there, there's a red chair in the corner,
(07:21):
even though that's not what the room looks like at all,
and in fact, the room is in total darkness. Anyway,
you might ask her to do something like can you
turn on the lamp, and she'll reach out with total
certainty about where the lamp is, even though there's no
lamp there, and of course she'll fail to reach the
switch that she thinks is there, but rather than acknowledging that,
(07:41):
her brain will generate explanations like, oh, I just miscalculated
the distance. And if you ask her to try again,
she might say, oh, you know, my arm hurts too
much to keep trying again. Dina isn't trying to lie
to you. Her brain believes it it's fabricating reality in
real time to compensate for the missing information, and this
(08:03):
is a fundamental lesson. The brain prioritizes coherence over accuracy. Now,
one interesting feature of confabulations is that they tend to
contain a kernel of truth, so Dina might remember a
room like the one she's describing. One hypothesis about confabulations
(08:24):
is that their memories in the brain, but they're not
built from the right pieces given the situation at hand.
So one way to see this is that a patient
will confabulate if they're asked a question like where are
you right now?
Speaker 2 (08:38):
Or how did you get here?
Speaker 1 (08:40):
But if you ask them something about which they don't
have any pre existing knowledge, like who is Queen schmcgeggy,
they will say that they don't know.
Speaker 2 (08:50):
It's not that.
Speaker 1 (08:50):
They're creating a fictional answer for things out of the blue. Instead,
it's that somehow their confabulated reality is growing.
Speaker 2 (08:58):
From the seeds of memory is that they have had.
Speaker 1 (09:01):
So the hypothesis is that the problem in the network
is that they're not inhibiting irrelevant memories.
Speaker 2 (09:09):
There are some pretty clever ways to.
Speaker 1 (09:10):
Study this, and I'll link these in the show notes,
but the bottom line is that when I ask you
a question about your life right now, your brain kindles
lots and lots of possible pathways, and then certain brain
areas like the orbit or frontal cortex.
Speaker 2 (09:26):
Squelch the activity of most.
Speaker 1 (09:28):
Of the pathways that aren't relevant in the current circumstances.
But if your orbitor frontal cortex is damaged, it can't
suppress the irrelevant memories, and therefore those can come to
the top.
Speaker 2 (09:41):
Now.
Speaker 1 (09:42):
That might make it sound like this only happens when
there's damage to a particular part of the brain like
the orbit or frontal cortex, but confabulation can also pop
up when people get damaged to bits of their thalamus
or the hypothalamus. Why, all these areas are parts of
a pathway called the circuit of pape, and this whole
circuit is involved for selecting relevant memories versus irrelevant ones.
(10:08):
The key surprising lesson here is that your current situation,
what you're looking at right now, doesn't just trigger a
particular memory, but instead tickles a whole world of possible memories,
which then other parts of the brain go through a
lot of trouble to squish down as they're looking.
Speaker 2 (10:25):
For the right one.
Speaker 1 (10:27):
And if you have less of that squishing, if you
have more noise in the system, then you get a
memory popping up that has nothing to do with your
current situation but feels every bit as real to you
as any other memory. I'll give you another example of confabulation.
In nineteen seventy four, the Supreme Court Justice William Douglas
(10:48):
had a stroke that made him paralyzed on his left
side and confine him to a wheelchair. Now, despite this,
Douglas insisted on being discharged from the hospital, claiming that
he was perfectly fine. He dismissed reports of his paralysis
as a myth, and when he was met with skepticism,
he even invited reporters to join him on a hike,
(11:11):
a suggestion that was widely seen as absurd. He went
so far as to say that he had just been
kicking football field goals with his paralyzed leg. Because of
this detachment from reality, Douglas was ultimately removed from his
position on the Supreme Court. But what he was experiencing
is called a nosagnosia, which is a condition where a
(11:34):
person is completely unaware of their body's impairment. People will
adamantly deny their paralysis, not out of deception, but because
their brain genuinely believes that they can move normally. Douglas
fabricated because of his brain's drive to construct a coherent narrative,
and this is wild to witness. For example, imagine you
(11:57):
meet a person who is paralyzed on one side and
they have a no sagnosia. So you gently ask the
person to put both hands on an imaginary steering wheel
in front of them. So she puts one hand on
the steering wheel, and if you ask her why only
one hand, she will insist that both hands are in place.
Speaker 2 (12:17):
So you might come up with an idea and you ask.
Speaker 1 (12:19):
Her to clap her hands, so she'll just move one hand.
Speaker 2 (12:23):
But she will claim to have clapped.
Speaker 1 (12:26):
If you point out that there was no sound and
you ask her to try again, she might simply refuse
and give an excuse like she just doesn't feel like it.
Speaker 2 (12:35):
This is just like Dina, who lost her vision but still.
Speaker 1 (12:38):
Insists she can see even as she struggles to navigate
the room without bumping into things. Dina might attribute her
difficulties to poor balance or misplaced furniture, rather than acknowledging
her blindness. The key insight about a no sagnosia is
that people like Justice Douglas are not lying. Their brains
(13:00):
are unconsciously generating explanations that maintain a coherent sense of reality,
even when that reality is fundamentally flawed. You can also
(13:28):
seek in fabulation in a very different situation. After a
person has undergone a split brain surgery.
Speaker 2 (13:35):
Okay, so what is that?
Speaker 1 (13:36):
The two hemispheres of the brain are linked by a
super highway of neurons. This is called the corpus colosum.
This is the bridge that connects the two halves of
the brain, and a split brain surgery is when the
super highway gets cut with a scalpel such that the
two halves of the brain, the two hemispheres, are now
operating independently. Usually these work in concert. Now you might
(14:01):
ask why would anyone ever have that surgery. It was
for people with severe epilepsy, where the seizures would spread
from one hemisphere to the other. So the idea was
that by destroying the road between the hemispheres, you disallow
the spread. So neurosurgeons started down this road in the
nineteen sixties, but they stopped once they realized that the
(14:22):
surgeries were revealing something astonishing. So let's say someone has
just had this surgery, and what you do is you
now show a picture, like a snowy scene, but you
place that so only the right hemisphere can see that picture.
And there are several objects laid out on the table.
One of them is, let's say, a snow shovel, and
(14:46):
so the left hand, which is controlled by the right hemisphere,
picks up the snow shovel. But when you verbally ask
the left hemisphere why the hand just chose a snow shovel,
the person will canfabulate. They'll make up a story. They'll say, oh,
my hand picked up that snowshovel because I was recently
(15:07):
doing some gardening and this reminds me of it. So
their left hemisphere has no access to the right hemispher's information,
but rather than admitting confusion, it just makes up a
story to explain the action. I'll put a link about
split brain studies on the show notes. But what this
tells us is that our brain's storytelling function is not
(15:30):
just about narrating past events. It's active even in the
present moment. It shapes our reality as we go. In
all of these cases, from mister Thompson's endless reinventions of
himself to the blind woman who insists she can see,
to the split brain patients who fabricate explanations for their
own actions, the brain is doing what it does best,
(15:53):
creating a cohesive narrative. It just so happens that sometimes
the facts don't cooperate. But these extreme cases lead us
to a bigger question. If confabulation happens in people with
brain damage.
Speaker 2 (16:07):
What about the rest of us.
Speaker 1 (16:09):
How reliable are our everyday memories and how often do
we unknowingly rewrite our past?
Speaker 2 (16:17):
Well?
Speaker 1 (16:17):
We do it far more often than we realize. False
memory doesn't just happen in injured brain. They happen all
the time in all of us. Our memories feel solid
and clear and trustworthy, but in reality they're full of fabrications.
Speaker 2 (16:33):
The normal brain, just like the injured.
Speaker 1 (16:35):
Brain, fills in gaps, and typically we don't notice. So
let's start in the nineteen eighties when Nelson Mandela died
in prison. Millions of people remember hearing about this and
reading the headlines or seeing the news stories, so all
of them were surprised when it was announced in twenty
(16:55):
thirteen that Nelson Mandela had just died out of prison
in his home after having been released in nineteen ninety,
becoming President of South Africa, earning a worldwide reputation. Wait,
what hadn't he passed away three decades before? Weirdly, so
many people had that story wrong.
Speaker 2 (17:15):
They thought he died in the eighties.
Speaker 1 (17:17):
That this is now known in the psychology literature as
the Mandela effect. They truly thought they had heard that
he had died in prison. We've all had the experience
of being convinced that something happened in a certain way,
only to later discover we were completely wrong. But it's
called the Mandela effect when it's not just you, but
thousands or millions of other people come to believe the
(17:40):
same false memory. There are so many examples of this.
Here's one. Everyone seems to remember Darth Vader saying Luke,
I am your father, when in fact that's not the line.
Speaker 2 (17:53):
The line is no, I am your father.
Speaker 1 (17:58):
What where did the luke come from in everyone's memory?
Why do we all misremember that? And how about the
movie Casablanca. Even if you've never seen it, you probably
know the most famous line where Ingrid Bergmann says play
it again, Sam, except that she never says it.
Speaker 2 (18:16):
The line in the movie is play it once, Sam,
for all time's sake. I don't know what you mean.
Miss Elton played them play as time goes by?
Speaker 1 (18:28):
So why does everyone believe that the line was play
it again, Sam? And here's another one. You probably remember
the Disney movie Snow White and the Seven Dwarves when
the Witch says mirror, mirror on the wall, who's the
fairest one of all? So you might be surprised to
know that she actually says.
Speaker 2 (18:47):
Magic mirror on the wall. Who is the fairest one
of all?
Speaker 1 (18:53):
But for some reason everyone started saying mirror mirror, And
that's now how we all misremember. The thing is that
if you had a false memory about what was said
in these movies, that memory felt completely real to you,
as though you had seen that scene. The Mandela effect
tells us that memory is not an accurate recording in
(19:13):
the past, but a flexible process, and often it can
be socially influenced and collectively shaped. And the Mandela effect
applies in all sensory domains.
Speaker 2 (19:24):
Take your visual memory.
Speaker 1 (19:27):
Tons of people recall the monopoly man as having a monocle,
but he doesn't and he never did. Here's a question,
did the cartoon monkey Curious George have a tail or
not have a tail? Most people remember that he did,
but that's a false memory. If you look at the books,
Curious George has no tail at all. Okay, here's another one.
(19:49):
Think of Pikachu and his tail. He actually does have
a tail. The tail is yellow, but does it have
a black tip? Most people, if you press them on it,
we'll say the tail has a black tip. Even though
his tail is completely yellow, his ears have black tips,
and somehow millions of people misremember it as being on
his tail. And I'll tell you another version of the
(20:11):
Mandela effect that comes about for a slightly different reason.
Think about Oscar Meyer Wieners. You've certainly seen the ads
and maybe even the Oscar Meyer truck driving around. Here's
the question, how is Meyer spelled? The large majority of
people will swear that it is spelled me e y
e r, but in fact it's m a y e r.
(20:36):
But m e y e r is a much more
common spelling, and so we misremember it. And here's another
example of that same thing. You may remember a children's
book series called The Berenstein Bears. Essentially, everyone remembers this
as being spelled barren Stein sti e n, when in
fact the last five letters are stai n. It looks
(21:00):
like Baron stain bears. When this has pointed out to people,
they generally don't believe this until they go and pull
the book off their shelf and take a look.
Speaker 2 (21:10):
I think that both these.
Speaker 1 (21:11):
Examples about Oscar Meyer and Berenstein Bears are interesting because
they're shaped not necessarily by other people's memories, but instead
by your expectations given the particulars of the language. In
other words, some ways of spelling things are so much
more common that you come to believe that's what you
had seen, and like the other versions of the Mandela effect,
(21:33):
you really, really are certain that this is how you
saw it, And when you see the actual thing written down,
it's hard to reconcile the certainty of your memory against
the reality of what is in front of you. Think
about all these examples of the Mandela effect, quiz your
friends on what they believe and remember, and think of
(21:54):
what else you might have misremembered the movies, the characters,
the logos, whatever, and a note at podcasts at Eagleman
dot com to let me know because I can't get
enough of these things. Okay, I think this is one
of the most fascinating ways to study confabulation in the individual.
Healthy mind canfabulations which we normally never notice or gain
(22:16):
an awareness of. And there's a closely related issue about
the way that our knowledge and beliefs can create unconscious
distortions about what details we remember. In episode seventy, I
told you about a nineteen thirty's study on a short
Native American fable called The War of the Ghosts. Participants
(22:38):
read the story and then they wrote down their recollection
of it immediately after, and then again a week after,
and then again three months after. And as people recalled
the story again and again through time, it turned out
they smoothed out the details that were inconsistent with their
own pre existing knowledge and belief systems. As they recalled
(23:01):
the story over and over, it became more consistent with
their worldview. As another example, consider the way we explain
our own decisions. There are a bunch of studies on this,
and essentially, when people are asked why they made a
particular choice, they often canfabulate explanations. Their choices may have
(23:21):
been influenced by subconscious factors they weren't aware of, but
they'll create a convincing story to explain why they did.
Speaker 2 (23:29):
What they did. Why did you pick that car?
Speaker 1 (23:32):
Oh?
Speaker 2 (23:32):
I like the design?
Speaker 1 (23:34):
In reality, they were subtly influenced by an ad they
were exposed to. Why do you believe what you believe?
Because it's logical? In reality? So much of our belief
is shaped by our culture and by our emotions, and
our brains fill in justifications later. Why did you break
up with that person? Well, we just weren't compatible In reality.
(23:57):
Maybe they could have worked harder, but they have restructure
painful memories to make the breakup seem inevitable. In other words,
studies show that with romantic partners, if a relationship goes bad,
we tend to remember the details of that relationship as
more negative than they actually were. If a relationship improves,
then we see it through rose colored glasses and remember
(24:20):
things as better than they were. There's a sense in
which we are always confabulating, turning complex realities into clear stories.
Now all this may seem innocent enough, but in episode nineteen,
I dove deep into why This sort of confabulation matters
so much when it comes to something like eyewitness testimony,
(24:44):
where there's real world consequence. And the issue that comes
up here again is not just about the fragility of memory,
but the way that we feel so certain about whatever
memory gets served up to us, and our memories can
get manipulated by very subtle cues. For example, in one
study by my colleague Elizabeth Loftis, participants watched a video
(25:06):
of a car accident and were asked a question how
fast were the cars going when they hit each other?
Others were asked a slightly different version of the question,
how fast were the cars going when they smashed into
each other. The result was that those who heard smashed
(25:28):
consistently recalled the cars going faster, with some even falsely
remembering broken glass despite the fact that none was shown.
So memory isn't stored like a video. It's actively reshaped
when we recall it, and even a single word can
alter what we remember. And Loftis did other experiments showing
(25:48):
how false memories can be injected. She showed that people
can be led to remember events that never actually happened
simply through suggestion. In one of her Landmark studies. She
successfully implanted false childhood memories by asking participants about events
like the time they were lost in a shopping mall
(26:10):
or the time they went on a hot air balloon ride,
even though these things have never occurred, but they were
described as if they had. Over time, a lot of
the participants not only accepted these fabricated events as real,
but they ended up adding more details into the story
and in the big picture, in the criminal justice system,
it's been shown with hundreds of studies that you can
(26:32):
mislead eyewitnesses by suggestive questioning. You can alter their recollections
of somebody's appearance or what precisely happened during the crime,
and this problem rears its head every day with eyewitness
testimony in the courtroom. The problem is that memory is
notoriously unreliable.
Speaker 2 (26:53):
And I'm not talking.
Speaker 1 (26:53):
About cases where people are intending to deceive, but more
generally about the problem that memory is malleable. Even subtle
suggestions like the wording during a police lineup, can alter
what somebody feels they remember entirely. False details can be inserted,
and once a memory is altered, it feels just as
(27:14):
vivid and true as a genuine memory, and this means
any of us can recall events with absolute confidence.
Speaker 2 (27:22):
While being completely wrong.
Speaker 1 (27:24):
There's this paradox of inaccuracy with high confidence. And the
reason this matters is because eyewitness accounts are very persuasive
in courtrooms, even though the research.
Speaker 2 (27:37):
Shows that they are often fiction.
Speaker 1 (27:39):
So please listen to episode nineteen for a deep dive
on the brain and eyewitness testimony. Zooming back out, why
(28:06):
does the brain can fabulate even in everyday life. Well,
as I said, unlike a camera that passively records everything
it sees, memory is more like a story being rewritten
every time it's told. Each time we recall an event,
our brain pulls together fragments of information and stitches them
together into a coherent narrative. Small gaps get filled in
(28:28):
with assumptions, as we see with the War of the
Ghosts experiment. Details get smoothed over as we see with
the eyewitness experiments. New information can get inserted even if
it wasn't there originally. Over time, the original memory can
be completely rewritten, and once we update a memory, we
forget we ever changed it. The new version feels like
(28:49):
the original. This is why two people who experience the
same event can remember it completely differently. Each person's brain
has reconstructed the experience. It's based on their own biases
and assumptions and emotions. We've seen how confabulation affects history,
like the Mandela effect, how it affects society like Eyewinness testimony,
(29:13):
how it affects your childhood memories. And that leads me
to always wonder about the small confabulations that we tell
ourselves every day. It's hard to know the answer to this,
but how often do you rewrite past decisions, like when
you rationalize some suboptimal decision that you made by convincing
yourself that you always wanted the outcome you got. This
(29:36):
is a post talk confabulation, a way for the brain
to maintain a sense of consistency. How often do we
misremember conversations? You ever had an argument where you and
the other person are one hundred percent certain about what
was said, but your memories completely disagree. I know it's
always tempting to say the other person is the one confabulating,
(29:57):
but my hope is that after listening to this episode,
you might be slightly more willing to revisit this. So
if confabulation happens to all of us, how can we
ever trust our memories? The answer isn't to distrust everything,
but just to develop a tiny bit of skepticism about
the stories our minds tell us. Your memory feels real,
(30:19):
but feeling real doesn't make it true. Okay, so we've
been exploring how memory is a shifting story. But what
does this mean for how we understand ourselves. One thing
that's happened lately in neuroscience is implanting false memories in animals,
let's say rats. So here's how it works. A team
led by Sousumo, Tonogawa and MIT puts a rat in
(30:43):
a box and lets them run around to explore it.
Then the rats come out of the box and they
hang out, relax. And what the researchers now do outside
the box is they reactivate the neurons that encoded the
memory of that box. They do this using optigs, So
they reactivate those neurons, and now they deliver a little
(31:04):
electric shock to the rat's foot. Okay, Now, later they
put the rat back in the box a place where
the rat had never before been harmed, and the rat
freezes in fear, behaving as if it remembered being shocked. There,
even though that had never actually happened. So the scientists
were able to create an entirely false experience, one that
(31:26):
the rat presumably fully believed to be real. Brains don't
store perfect representations of reality, but flexible, rewriteable narratives.
Speaker 2 (31:36):
So will we one.
Speaker 1 (31:36):
Day implant therapeutic memories to help people overcome PTSD? And
how would a technology like that blur the line between
authentic experience and artificial recollection?
Speaker 2 (31:52):
And this, of.
Speaker 1 (31:52):
Course reminds us of the film Total Recall with Arnold Schwarzenegger.
If you haven't seen this movie, the protagonist Dug Quaid
visits a company called Recall that offers to implant vivid,
customized memories of adventures that never happened. So Quaid opts
for the memory of a secret agent mission on Mars,
(32:15):
only to discover that he might actually be a secret
agent whose real memories were erased. This was a very
pioneering story that played with the tension between authentic experience
and synthetic memory.
Speaker 2 (32:29):
If you remember something vividly.
Speaker 1 (32:32):
And emotionally and in detail, doesn't matter whether it actually happened.
The film asks what if your most cherished memories were
never real? And neuroscience replies that, for better or worse,
we're not that far away from creating synthetic memories. And
in any case, you often create them yourself. And I
(32:57):
just want to highlight it's not just that individ jewels
have unreliable memories. Societies do as well. They collectively misremember
their past. Historical confabulation shapes our understanding of events, often
to serve a specific narrative. In episode forty one, I
talked about the former USSR and how they loved to
(33:20):
erase political enemies from photographs. For one example of many,
there's a famous photo which proudly captures Lenin and other
Soviet leaders in Red Square in Moscow in nineteen nineteen.
You can see Lenin and on his left to see
Leon Trotsky, and on Lenin's right is a man named Kamenev,
(33:40):
and there's a Bolshevik leader from Georgia in front of them. Now,
if you look at a release of this photo some
years later, the official Soviet version of the photo, you
see that after Leon Trotsky fell from party favor, he
was airbrushed out of the photo. In the revised photograph,
there's just an empty space where he used to be
(34:01):
and Kommenev on Lenin's right has disappeared as well, and
the bearded Bolshevik leader never existed.
Speaker 2 (34:08):
In the photo either.
Speaker 1 (34:09):
This is essentially the photographic version of confabulation, and this
happens constantly in the retelling of history. As is often said,
history is the pack of lies told by the winner.
And as an apropos side note, it's not at all
clear who first said that quotation. It's commonly associated with
(34:31):
Napoleon or Churchill, but apparently there are versions of this
going back to Herodotus. So nations and cultures are constantly
shaping public memory. History is always being rewritten, and it
works because, just like individuals, societies need a coherent story
(34:52):
when reality is messy. History gets edited, sometimes consciously, sometimes
through the natural distortion of collective memory. So if our
memories are fiction, who are We Just think about the
way that we tell our life stories. We highlight certain events,
(35:13):
we downplay others. We add emotional weight to moments that
might have been minor at the time. We rewrite past
decisions to make them seem more logical. We are, at
least to some extent, unreliable narrators.
Speaker 2 (35:27):
Of our own lives.
Speaker 1 (35:28):
So we can think of identity as a living document
which is constantly being updated. Who you think you are
today is different from who you thought you were ten
years ago. Some of that shift comes from the deposition
of new memories, but some of it comes from the
subtle confabulations that shape our memories. This may not be
(35:51):
a flaw but a feature, because a perfect, unchanging memory
would trap us in the past. Instead, we rewriting our
history in real time to fit the narrative of who
we believe we are. So some argue that confabulation can
be useful, but it also has a dark side, which
(36:12):
is over confidence. Because we don't realize we're confabulating, we
assume our memories are true, and that can lead to
serious problems like false convictions, where innocent people are imprisoned
because if eyewitnesses who believe they are.
Speaker 2 (36:27):
Telling the truth.
Speaker 1 (36:29):
Also a problem with confabulating brains is misinformation. False memories
contribute to conspiracy theories in urban legends and historical distortions
that shape public perception, and confabulation leads all the time
to personal misunderstandings. How many relationships have been damaged because
(36:50):
two people remember an argument differently and each is convinced
that their version is correct. This is why it's always
a good idea to approach your memory with skepticism and humility.
Just because we remember something vividly doesn't necessitate that it's true.
So how do we live with this knowledge? How do
(37:12):
we best navigate the confabulating brain. It doesn't mean we
should distrust all our memories. It just means we should
be more open eyed about the situation. So instead of
saying I remember exactly what happened, try saying this is
how I remember it, But I could be wrong. As
(37:34):
we wrap up today's journey through the confabulations of memory,
let's leave with one thought. Our memories shape our lives,
our identities, and our understanding of the world. But they
aren't perfect records. They are ever changing. They're always evolving,
just like us. The fact is we humans are storytelling creatures.
(37:55):
We don't just experience the world, we organize it into narrative.
In this same way, history can be a story we
tell about the past. Personal identity is a story we
tell about ourselves. We began today's podcast with a simple
but unsettling question, why do brains sometimes make things up?
(38:15):
Along the way we saw that confabulation isn't just a
quirk of the damaged brain. It's a part of how
all brains function. We are all in a sense fiction writers,
Memory is not a recording device. It's a dynamic creative system.
Every time we recall an event, our brains reconstruct it,
(38:35):
sometimes correctly, sometimes with error, and sometimes in ways that
are more than a little fabricated. The strange part is
that we trust our memories with absolute conviction. We trust
them in relationships, we trust them in courtrooms. We trust
them to tell us who we are. But if memories
can change, if our pasts are being subtly rewritten with
(38:59):
each passing year, what does that mean for the sense
of self?
Speaker 2 (39:02):
If we are the sum of our.
Speaker 1 (39:05):
Memories, but those memories are fluid, then how stable is
the person we think we are. We can become too
confident in our false memories. We can rewrite history to
suit our needs, and we can create narratives that justify
our actions, even when those narratives are inaccurate. So the
(39:25):
next time you remember some episode in your life, pause,
take a moment to question it. How do I know
this memory is accurate? Could my brain be filling in
gaps somewhere. Is this a true recollection or has it
been shaped by the stories I've told myself over the years.
Don't distrust every memory. Instead, this is just an invitation
(39:48):
to approach memory with humility, to recognize that what feels
absolutely real might in fact be a creative act.
Speaker 2 (39:58):
Of your brain.
Speaker 1 (40:02):
Go to Eagleman dot com slash podcast for more information
and to find further reading. Send me an email at
podcast at eagleman dot com with questions or discussion or
your examples of the Mandela effect, and check out and
subscribe to Inner Cosmos on YouTube for videos of each
episode and to leave comments. Until next time. I'm David Eagleman,
(40:23):
and this is Inner Cosmos.
Host
David Eagleman
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