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
    +2

    Comment number 46.

    SInce everything we do, hear and see every day is a memory, quite how many gigabytes would you need to hold.
    The trick is to screen out most things as trivial; for example count everything as one or zero, one is of use as a memory so inanimate objects and other peoples tittle tattle should all be classed as zero and discarded as useless information.

  • Comment number 45.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this
    +4

    Comment number 44.

    I create false memories for the blank periods after a major fit.
    Because nobody will believe that I genuinely don't know what the **** happened for up to a week.
    So I make stuff up in self defence and it becomes 'real' (for a given value of).
    Why should I have to do that?

  • rate this
    +8

    Comment number 43.

    I would call some of the examples given misdirection rather than false memory. I do conjuring tricks, based on misdirection, with and for my identical kids: your mind gets so much information that it filters a lot of it out (e.g., that multiple births happen). The older you get, the more you filter, so it's easier to fool adults more than kids - sometimes even after you show how tricks are done!

  • rate this
    -5

    Comment number 42.

    It is because people are taking Drugs all the time.

    Have you not read the other HYS topic of the day?

  • rate this
    -6

    Comment number 41.

    I remember historical facts, ww1, ww2, the moon landings, Kennedy assasination etc, they obviously cant claim i've imagined that,They only can claim things I can't prove, this article based on a study done a few years ago is a pile of crap, and should be looked at again. Yes some people have an over active imagination, but not all, maybe they should be looking at why SOME create false memories.

  • rate this
    +3

    Comment number 40.

    At the age of about four I was living with my Gran for a while, and my mother came to collect me. I can clearly remember floating down the stairs with Gran and Mum watching me through the bannisters. I have to assume that's a false memory, don't I???

  • rate this
    +6

    Comment number 39.

    We need to start screening our politcians for this problem.

  • rate this
    +2

    Comment number 38.

    Here's a few things no one should forget.
    Blair and WMD
    Brown selling off the UK gold reserves at bargain basement prices
    New Labour bankrupting this country.
    Bush conflating Iraq and Bin Laden.
    I'm sure they would all like us to forget and 'remember it differently'
    So don't. Never forget.

    How about some of your lists everyone?

  • rate this
    +9

    Comment number 37.

    Hang on a minute. All the examples in the story are NOT false memories. They are 'opinions' based on what turned out to be unreliable 'evidence'.
    Can you remember EVERYTHING? No. So if I show you 'evidence' of something involving you, you can only conclude that is true and you had forgotten. I am always amazed that convictions can be made on testimony without corroboration.

  • rate this
    +4

    Comment number 36.

    An artificial intelligence 'computer' would look at a 1% chance of being eaten as a totally unacceptable risk and would do a runner too. :)

  • rate this
    +2

    Comment number 35.

    Of course it coyld be that your memories are perfectly correct but past reality has changed

  • rate this
    -1

    Comment number 34.

    I was at Scout camp and there was a spider beneath my skin on my stomach, I squeezed it and it came out alive and ran away, I cannot be certain if this was real or a dream I had.

  • rate this
    0

    Comment number 33.

    Sadly, I have a false memory of total amnesia...

  • rate this
    +1

    Comment number 32.

    @30 thePendantsRevolting

    Good analysis.

    " Photoshopped " memories, as it were.

  • rate this
    +2

    Comment number 31.

    I have a (well, false) memory of our neighbour at the time I was three having a Great Dane dog who had puppies, and vividly remember playing with them- all the senses of touch ect. Years later when my mum asked me what I remembered of where we had lived at that time and there was no Great Dane, or puppies! She did own a Pekingese apparently, but it's strange that I fabricated such an odd memory

  • rate this
    +3

    Comment number 30.

    People tend to belive their memories are solid & fixed like a traditional photograph, actually they're more like a digital image which is reconstructed from bytes on a disc by a not very reliable computer & the reconstruction doesn't always work as it should, the reconstruction can be missing bits or distorted or even have extra bits incorporated from a different image

  • rate this
    +2

    Comment number 29.

    Is this seriously The Matrix?

    If so, why can't I be rich and handsome?

  • rate this
    +30

    Comment number 28.

    I hope they remember this during operation "witch hunt"... sorry, "yew tree". There seem to be an awful lot of people being accussed of things of late. Some will be correct memories, but how many will be influenced into believing something happened by the stories in the papers?

  • rate this
    +1

    Comment number 27.

    When I was younger I would run away to get lost in the shopping centre. When it closed think of all the free toys I would have. They always found me :-(

 

Page 4 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.