Why does the human brain create false memories?

 
Hot air balloon ride A doctored photo made many people believe they had been on a real hot air balloon ride

Related Stories

Human memory constantly adapts and moulds itself to fit the world. Now an art project hopes to highlight just how fallible our recollections are.

All of us generate false memories and artist AR Hopwood has been "collecting" them.

For the past year he has asked the public to submit anecdotes of fake recollections which he turns into artistic representations.

They have ranged from the belief of eating a live mouse to a memory of being able to fly as a child.

One man who wrote in wrongly believed his girlfriend had a sister who died while at the dentist. So strong was his conviction that he kept all his dentist visits secret.

He wrote: "Over dinner one day she said she was going to the dentist the next week. It all went quiet at the table and my mum said it must be hard for her to visit the dentist after what had happened."

The false memory archive

A selection of anonymous false memories:

I remember biting into a mouse when I was four [and living] in Indonesia in order to make my brother be quiet... A mouse ran by and I bit into it. Blood filled my mouth and ran down my face.

I remembered that I saw a green comet on the sky through the window.

Watching the first Moon landing. I clearly remember it, from inside a playpen. But... I was three, and asleep in another room.

I can remember being able to fly as a small child. For years, in my teens I really struggled to accept that this wasn't a real memory.

This is hardly a rare case. Neuroscientists say that many of our daily memories are falsely reconstructed because our view of the world is constantly changing.

Imagination trick

Subtle cues can easily steer our memories in the wrong direction.

A famous experiment carried out by Elizabeth Loftus in 1994 revealed that she was able to convince a quarter of her participants they were once lost in a shopping centre as a child.

Another similar experiment in 2002 found that half of the participants were tricked into believing they had taken a hot air balloon ride as a child, simply by showing them doctored photographic "evidence".

Lost child in shopping centre Participants readily believed they had once been lost in a shopping centre when presented with "evidence"

This work was carried out by Kimberley Wade at the University of Warwick, UK. For the current project she was asked by Mr Hopwood to take part in a real hot air balloon ride, video and images of which are now exhibited in his show. She says she was very excited to take part.

"I've been studying memory for more than a decade, and I still find it incredible that our imagination can trick us into thinking we've done something we've never really done and lead us to create such compelling, illusory memories," she says.

The reason our memories are so malleable, Kimberley Wade explains, is because there is simply too much information to take in.

"Our perceptual systems aren't built to notice absolutely everything in our environment. We take in information through all our senses but there are gaps," she adds.

"So when we remember an event, what our memory ultimately does is fills in those gaps by thinking about what we know about the world."

Lost keys

For the most part false memories are about everyday situations with no real consequences except the occasional disagreement with a friend or partner about trivial things like who lost the keys, again.

But sometimes, false memories can have more serious ramifications. For example, if an eyewitness testimony in court contributes to a false conviction.

A simple test

  • Say the following words to a friend: bed, rest, awake, tired, dream, wake, snooze, blanket, doze, slumber, snore, nap, peace, yawn and drowsy
  • Later, ask your friend to recall the words they heard
  • How many incorrectly listed sleep as one of the initially given words?

A study found that participants recall the word sleep with about the same probability that they remember other words from the list.

Forensic technology has now led to many such convictions being overturned. The Innocence Project in the US campaigns to overturn eyewitness misidentification and lists all the people who have subsequently been acquitted.

The project reports that there have been 311 post-conviction DNA exonerations in the US, which includes 18 people who were sentenced to death before DNA evidence was able to prove their innocence.

Christopher French of Goldsmiths University in London says there is still a lack of awareness of how unreliable human memory is, especially in the legal system.

"Although this is common knowledge within psychology and widely accepted by anybody who has studied the literature, it's not widely known about in society more generally," he says.

"There are still people who believe memory works like a video camera as well as people who accept the Freudian notion of repression - that when something terrible happens the memory is shoved down into the subconscious."

But the evidence of repressed memories, he adds, is "very thin on the ground".

Hot air balloon ride A psychologist's memory of her hot air balloon ride features in the exhibition

Prof French was also involved in the memory project. He hopes it will create more awareness of the malleability of human memory.

So too does AR Hopwood. He says he was fascinated to learn that people could strongly believe in an entirely imagined event.

"What's interesting is that the submissions become mini-portraits of the person (albeit anonymously) yet the only thing you are finding out about this person is something that didn't actually happen. So there's a lovely paradox there which I'm very drawn to as an artist," he says.

Saving us from the tiger

According to another researcher, the errors the human brain makes can sometimes serve a useful purpose.

Sergio Della Sala, a cognitive neuroscientist at the University of Edinburgh, UK, says it can be thought of in the following way. Imagine you are in the jungle and you see some grass moving. Humans are likely to panic and run away, with the belief that there could be a tiger lurking.

A computer, however, might deduce that 99% of the time, it is simply the wind. If we behaved like the computer, we would be eaten the one time a tiger was present.

"The brain is prepared to make 99 errors to save us from the tiger. That's because the brain is not a computer. It works with irrational assumptions. It's prone to errors and it needs shortcuts," says Prof Della Sala.

False memories are the sign of a healthy brain, he adds. "They are a by-product of a memory system that works well. You can make inferences very fast."

Hot air balloon ride

The False Memory Archive, supported by the Wellcome Trust, opened at The Exchange in Penzance on Saturday 28 September

 

More on This Story

Related Stories

The BBC is not responsible for the content of external Internet sites

Comments

This entry is now closed for comments

Jump to comments pagination
 
  • rate this
    +3

    Comment number 106.

    @104
    psychological science doesn't support your assertion.

    I also think your comparison is in error, we don't perform trade skills from recall memory alone. Also trauma adds a great deal of emotional overlay (understandably) to memorising events - a little research will help expand on this.

  • rate this
    +1

    Comment number 105.

    I tend to think really awful or important things that happens to us we are more likely to remember or even blank out, than make up.

  • rate this
    -4

    Comment number 104.

    I would like to dispute the details of this article for two reasons.

    First, a child who is abused for six months and who secretly refreshes the detail of his agony each day for 30 years, is hardly likely to get it wrong.

    Why you ask? Because people who educate themselves in a trade or any other involvement, use the same process and are not in the habit of erroneously remembering that training.

  • rate this
    -2

    Comment number 103.

    70. jgm2
    3 HOURS AGO
    The BBC is the biggest 'false memory' generator on the planet.

    To make this statement you must be loaded with examples. Can you give one?

  • rate this
    +1

    Comment number 102.

    I've long known that my memories are changed by my dreams. So all witness statements should be taken before the witness has slept, otherwise they are completely unreliable.

  • rate this
    -1

    Comment number 101.

    Google Glasses will solve this problem.

  • rate this
    +1

    Comment number 100.

    I think it's easy to confuse memories of things that happened with memories of dreams and fantasies, memories of films, books and music, and even memories of memories. They all give us feelings which become part of us and feed our sense of self. But how to unravel this I have no idea, and I'm not sure that I want to. Maybe I'll ask Flora...

  • rate this
    +1

    Comment number 99.

    My mother recalled individual events in detail into old age. Unfortunately, her memory often re-ordered the events. As a consequence, she would become very angry about something from decades earlier and her explanation would, at first, seem correct ... until we realised her problem.

    In memory, and many other things, little is certain fact; the major part is deduced and filled in by the brain.

  • rate this
    +2

    Comment number 98.

    California years ago had a pre-school child abuse case where many of the children included a story they had been forced to watch bunnies being killed in tunnels. No tunnels existed on the property I I think someone allowed their child to watch Animated Watership Down movie with that scene & that child told the story. I think the conviction was overturned because it was all false memories.

  • rate this
    +2

    Comment number 97.

    It's not what happened, it's what you can make a jury believe happened.

  • rate this
    +3

    Comment number 96.

    A bit like witnessing a car accident, everyone sees it from a different vantage point. Sometimes we see what we want to see.

  • rate this
    +3

    Comment number 95.

    @91. I think your generally right about "devil in the detail". The false memory problem seems to be generated by conflating actuality with impression and the human need for "filling in the details" that are not present.
    We seem to construct a narrative to explain the observation and that's what gets recalled - not the bare facts. Time and repeated telling also seems to "adapt" the memory.

  • rate this
    0

    Comment number 94.

    When you wake up you recall what you dreamt, are you remembering a false memory?

  • rate this
    0

    Comment number 93.

    I remember a government saying they were acting in our interests rather than immigrants', that they'd finished boom and bust, that they would sort out crime rather than punishing victims and rewarding the crims. I also remember the BBC not being left wing multi-failure-culturalled busybodies ... oh well

  • rate this
    -3

    Comment number 92.

    Ive seen this on tv before or something like this any way. But what they did is tricked people and convinced them it had happend which then triggered them to think it must have happend but I think in the back of there minds there thinking it cant have but just saying so, so they dont sound mad lol.big diffs from that then someone making up something to get something or punish someone.

  • rate this
    +1

    Comment number 91.

    I think with regards to false memories the devil is in the detail, not the actual event.
    My mum was on facebook recently and people from her school set up a school reunion page and were reminiscing. Someone mentioned an incident where they all got sent home. However, different people remembered it differently. eg were they in assembly or were they on lunch break, was it a monday or a wednesday etc

  • rate this
    +1

    Comment number 90.

    I think nostalga suffers from this effect quite badly, especially when it comes to sport. You see people in F1 forums saying how much better the races were in the 80s, but rewatch one and half the cars don't finish, with the winner a minute in front.
    Similarly 80s footballers look like they're running through treacle and can barely pass to save their lives. Oh and the hairstyles!

  • rate this
    +2

    Comment number 89.

    Traumatic experience certainly can create false memories: Law Courts in the US and UK (I think/hope ?) are becoming increasingly aware of the problem of false-memory following some high profile trials based on first-person testimony, by perfectly sane victims giving their honest memories, that later proved to be unequivocally wrong.

    It's not wise to accept "eye witness" evidence alone.

  • rate this
    +2

    Comment number 88.

    82.
    Deb

    Maybe so. But do you think the public destruction of the lives of innocent people at the hands of anonymous accusers, some (many? most? who can tell) of whom have leapt on the bandwagon for money or because they like to be the victim is worth it? I find this research very telling - false memories can be so easily created. Especially if these stories about celebs are all over the media.

  • rate this
    +2

    Comment number 87.

    I really enjoyed this article and scrolled down to comments. the first, and only so far, I read was so boring that I wondered if its sheer dullness could be a reason for banning tarangoes. I do hope so. There are always these rather sad characters who live to spoil the enjoyment of others.

 

Page 1 of 6

 

More Science & Environment stories

RSS

Features

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.