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.

voicesGood for Lana Del Rey for helping kill that myth, writes Grace Dent
The University of California study monitored the reaction of 36 dogs
sciencePets' range of emotions revealed
Life and Style
fashion Designs are part of feminist art project by a British student
Arts and Entertainment
The nomination of 'The Wake' by Paul Kingsnorth has caused a stir
Arts and Entertainment
The Tour de France peloton rides over a bridge on the Grinton Moor, Yorkshire, earlier this month
Snoop Dogg pictured at The Hollywood Reporter Nominees' Night in February, 2013
people... says Snoop Dogg
Life and Style
food + drinkZebra meat is exotic and lean - but does it taste good?
Arts and Entertainment
Residents of Derby Road in Southampton oppose filming of Channel 4 documentary Immigration Street in their community
voicesSiobhan Norton on why she eventually changed her mind
ebookA unique anthology of reporting and analysis of a crucial period of history
Scottish singer Susan Boyle will perform at the Commonwealth Games opening ceremony in Glasgow
commonwealth games
Arts and Entertainment
Dwayne 'The Rock' Johnson stars in Hercules
filmReview: The Rock is a muscular Davy Crockett in this preposterous film, says Geoffrey Macnab
Life and Style
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

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

iJobs Job Widget
iJobs General

VB.Net Developer

£35000 - £45000 per annum + competitive: Progressive Recruitment: If you're pa...

SAP Business Consultant (SD, MM and FICO), £55,000, Wakefield

£45000 - £55000 per annum + competitive: Progressive Recruitment: SAP Business...

Java Developer

£40000 - £60000 per annum + competitive: Progressive Recruitment: My client, a...

SAP Functional Consultant (SD, MM and FICO), £45,000 - £55,000.

£45000 - £55000 per annum + Benefits: Progressive Recruitment: SAP Functional ...

Day In a Page

Noel Fielding's 'Luxury Comedy': A land of the outright bizarre

Noel Fielding's 'Luxury Comedy'

A land of the outright bizarre
What are the worst 'Word Crimes'?

What are the worst 'Word Crimes'?

‘Weird Al’ Yankovic's latest video is an ode to good grammar. But what do The Independent’s experts think he’s missed out?
Can Secret Cinema sell 80,000 'Back to the Future' tickets?

The worst kept secret in cinema

A cult movie event aims to immerse audiences of 80,000 in ‘Back to the Future’. But has it lost its magic?
Facebook: The new hatched, matched and dispatched

The new hatched, matched and dispatched

Family events used to be marked in the personal columns. But now Facebook has usurped the ‘Births, Deaths and Marriages’ announcements
Why do we have blood types?

Are you my type?

All of us have one but probably never wondered why. Yet even now, a century after blood types were discovered, it’s a matter of debate what they’re for
Honesty box hotels: You decide how much you pay

Honesty box hotels

Five hotels in Paris now allow guests to pay only what they think their stay was worth. It seems fraught with financial risk, but the honesty policy has its benefit
Commonwealth Games 2014: Why weight of pressure rests easy on Michael Jamieson’s shoulders

Michael Jamieson: Why weight of pressure rests easy on his shoulders

The Scottish swimmer is ready for ‘the biggest race of my life’ at the Commonwealth Games
Some are reformed drug addicts. Some are single mums. All are on benefits. But now these so-called 'scroungers’ are fighting back

The 'scroungers’ fight back

The welfare claimants battling to alter stereotypes
Amazing video shows Nasa 'flame extinguishment experiment' in action

Fireballs in space

Amazing video shows Nasa's 'flame extinguishment experiment' in action
A Bible for billionaires

A Bible for billionaires

Find out why America's richest men are reading John Brookes
Paranoid parenting is on the rise - and our children are suffering because of it

Paranoid parenting is on the rise

And our children are suffering because of it
For sale: Island where the Magna Carta was sealed

Magna Carta Island goes on sale

Yours for a cool £4m
Phone hacking scandal special report: The slide into crime at the 'News of the World'

The hacker's tale: the slide into crime at the 'News of the World'

Glenn Mulcaire was jailed for six months for intercepting phone messages. James Hanning tells his story in a new book. This is an extract
We flinch, but there are degrees of paedophilia

We flinch, but there are degrees of paedophilia

Child abusers are not all the same, yet the idea of treating them differently in relation to the severity of their crimes has somehow become controversial
The truth about conspiracy theories is that some require considering

The truth about conspiracy theories is that some require considering

For instance, did Isis kill the Israeli teenagers to trigger a war, asks Patrick Cockburn