Experiment allows scientists to 'read' volunteers' thoughts

Neuroimaging technique gives a new insight into the location and nature of human memory.

Scientists have read the minds of healthy volunteers using a brain scanner to detect what they were thinking. By placing the volunteers in the scanner after they had been shown three film clips, the researchers were able to tell which clip they were recalling.

The advance brings a step closer the prospect of a "thought machine" to detect what a person is thinking from their brain activity pattern. But the technique is still at an early stage of development and its capacity to discriminate between "thoughts" is limited.

Scientists have searched for evidence of memory traces for almost a century. Although their biological existence is accepted, their precise mechanisms, location and nature remain a mystery.

Eleanor Maguire, professor of neuroimaging at University College, London, has previously shown it is possible to tell where a person is standing in a virtual reality room by using a brain scanner to detect the pattern of their thoughts. She has also shown that a small area of the brain at the back of the hippocampus was enlarged in male taxi drivers who had done "The Knowledge" – memorising the maze of London streets. These studies focused on spatial memory, the most basic sort.

The results of the latest study take the research further by showing that episodic memory – of the everyday events that make up the autobiography of our lives – can be tracked in the same way even though they are more complex. They demonstrate that these memories are stable and trigger the same brain activity each time they are recalled, making it possible for them to be identified and correctly interpreted on each occasion.

Professor Maguire said: "We've been able to look at actual memory traces for a specific episodic memory. We found that our memories are definitely represented in the hippocampus. Now we've seen where they are, we have an opportunity to understand how memories are stored and change through time. We are not at the point of being able to put people in a scanner and read their thoughts. But we can predict from their brain activity what they are thinking and remembering. The more we understand about how memories are stored, the more we can understand about how people [with brain injuries] can be rehabilitated."

For the study, 10 volunteers were shown three short film clips, lasting seven seconds each. They showed different actresses performing three tasks – posting a letter, throwing a coffee cup in a bin, and getting on a bike. The volunteers were then placed in a functional magnetic resonance imaging (fMRI) scanner and asked to recall each clip in turn. This was repeated many times and the scans were analysed to detect patterns in the brain activity associated with each clip. In the final stage of the experiment the volunteers were returned to the scanner and asked to recall the clips at random. The researchers found they were able to tell which clip they were thinking about from the pattern of their brain activity.

Although patterns in individual volunteers' brains varied from one another, they showed remarkable similarities in the parts of the hippocampus that were active. The findings are published in Current Biology. "We have documented for the first time that traces of individual rich episodic memories are detectable and distinguishable in the hippocampus. Now that we have shown it is possible to directly access information about individual episodic memories in vivo and noninvasively, this offers new opportunities to examine important properties of episodic memory," the researchers conclude.

Visible recall: How the experiment worked

*Volunteers watched three seven-second film clips of a woman posting a letter, throwing a cup in a bin or getting on a bike, and were asked to recall one of them while in the brain scanner.

*The researchers were able to tell which of the three clips they were recalling by observing their brain activity.

*The brain scan of one volunteer showed where the memories were laid down in the hippocampus – the brightest spots indicate where the memories of the three clips were most distinct from one another.

Start your day with The Independent, sign up for daily news emails
News
people
News
A survey carried out by Sainsbury's Finance found 20% of new university students have never washed their own clothes, while 14% cannot even boil an egg
science...and the results are not as pointless as that sounds
News
politicsIs David Cameron trying to prove he's down with the kids?
News
Dominique Alderweireld, also known as Dodo de Saumure, is the owner of a string of brothels in Belgium
newsPhilip Sweeney gets the inside track on France's trial of the year
PROMOTED VIDEO
News
Cumberbatch was speaking on US television when he made the comment (Getty)
people
Life and Style
tech
Arts and Entertainment
Tom DeLonge, Travis Barker and Mark Hoppus of Blink-182 pictured in 2011.
musicBassist Mark Hoppus and drummer Travis Barker say Tom Delonge is 'disrespectful and ungrateful'
Sport
football
Arts and Entertainment
Olivia Colman and David Tennant star in 'Broadchurch'
tvBroadchurch series 2, episode 4, review - contains spoilers
Sport
cyclingDisgraced cycling star says people will soon forgive his actions
News
Britain's Prince Philip attends a Garden Party at Buckingham Palace in London
people
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Arts and Entertainment
Ed Sheeran will play three sell-out gigs at Wembley Stadium in July
music
News
i100
News
Lena Dunham posing for an official portrait at Sundance 2015
people
Arts and Entertainment
Under the skin: Sarah Kane in May 1998
theatreThe story behind a new season of Sarah Kane plays
Arts and Entertainment
Preening: Johnny Depp in 'Mortdecai'
filmMortdecai becomes actor's fifth consecutive box office bomb
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Project Engineer

£30000 - £40000 per annum: Recruitment Genius: An exciting opportunity has ari...

Recruitment Genius: Project Manager - Civil Engineering

£35000 per annum: Recruitment Genius: The Business: This company is going thro...

Tradewind Recruitment: KS1 & KS2 Teachers Required

Negotiable: Tradewind Recruitment: Tradewind Recruitment are currently working...

Recruitment Genius: Lift Repairs Sales Account Manager

£28000 - £32000 per annum: Recruitment Genius: An exciting new opportunity has...

Day In a Page

Woman who was sent to three Nazi death camps describes how she escaped the gas chamber

Auschwitz liberation 70th anniversary

Woman sent to three Nazi death camps describes surviving gas chamber
DSK, Dodo the Pimp, and the Carlton Hotel

The inside track on France's trial of the year

Dominique Strauss-Kahn, Dodo the Pimp, and the Carlton Hotel:
As provocative now as they ever were

Sarah Kane season

Why her plays are as provocative now as when they were written
Murder of Japanese hostage has grim echoes of a killing in Iraq 11 years ago

Murder of Japanese hostage has grim echoes of another killing

Japanese mood was against what was seen as irresponsible trips to a vicious war zone
Syria crisis: Celebrities call on David Cameron to take more refugees as one young mother tells of torture by Assad regime

Celebrities call on David Cameron to take more Syrian refugees

One young mother tells of torture by Assad regime
The enemy within: People who hear voices in their heads are being encouraged to talk back – with promising results

The enemy within

People who hear voices in their heads are being encouraged to talk back
'In Auschwitz you got used to anything'

'In Auschwitz you got used to anything'

Survivors of the Nazi concentration camp remember its horror, 70 years on
Autumn/winter menswear 2015: The uniforms that make up modern life come to the fore

Autumn/winter menswear 2015

The uniforms that make up modern life come to the fore
'I'm gay, and plan to fight military homophobia'

'I'm gay, and plan to fight military homophobia'

Army general planning to come out
Iraq invasion 2003: The bloody warnings six wise men gave to Tony Blair as he prepared to launch poorly planned campaign

What the six wise men told Tony Blair

Months before the invasion of Iraq in 2003, experts sought to warn the PM about his plans. Here, four of them recall that day
25 years of The Independent on Sunday: The stories, the writers and the changes over the last quarter of a century

25 years of The Independent on Sunday

The stories, the writers and the changes over the last quarter of a century
Homeless Veterans appeal: 'Really caring is a dangerous emotion in this kind of work'

Homeless Veterans appeal

As head of The Soldiers' Charity, Martin Rutledge has to temper compassion with realism. He tells Chris Green how his Army career prepared him
Wu-Tang Clan and The Sexual Objects offer fans a chance to own the only copies of their latest albums

Smash hit go under the hammer

It's nice to pick up a new record once in a while, but the purchasers of two latest releases can go a step further - by buying the only copy
Geeks who rocked the world: Documentary looks back at origins of the computer-games industry

The geeks who rocked the world

A new documentary looks back at origins of the computer-games industry
Belle & Sebastian interview: Stuart Murdoch reveals how the band is taking a new direction

Belle & Sebastian is taking a new direction

Twenty years ago, Belle & Sebastian was a fey indie band from Glasgow. It still is – except today, as prime mover Stuart Murdoch admits, it has a global cult following, from Hollywood to South Korea