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