'Mind-reading' experiment highlights how brain records memories

Mar 12, 2009

It may be possible to "read" a person's memories just by looking at brain activity, according to research carried out by Wellcome Trust scientists. In a study published today in the journal Current Biology, they show that our memories are recorded in regular patterns, a finding which challenges current scientific thinking.

Demis Hassabis and Professor Eleanor Maguire at the Wellcome Trust Centre for at UCL () have previously studied the role of a small area of the brain known as the which is crucial for navigation, recall and imagining future events. Now, the researchers have shown how the hippocampus records memory.

When we move around, nerve cells (neurons) known as "place cells", which are located in the hippocampus, activate to tell us where we are. Hassabis, Maguire and colleagues used an scanner, which measures changes in blood flow within the brain, to examine the activity of these places cells as a volunteer navigated around a . The data were then analysed by a computer algorithm developed by Demis Hassabis.

"We asked whether we could see any interesting patterns in the that could tell us what the participants were thinking, or in this case where they were," explains Professor Maguire, a Wellcome Trust Senior Research Fellow. "Surprisingly, just by looking at the brain data we could predict exactly where they were in the virtual reality environment. In other words, we could 'read' their ."

Earlier studies in rats have shown that spatial memories - how we remember where we are - are recorded in the hippocampus. However, these animal studies, which measured activity at the level of individual or dozens of neurons at most, implied that there was no structure to the way that these memories are recorded. Hassabis and Maguire's work appears to overturn this school of thought.

"fMRI scanners enable us to see the bigger picture of what is happening in people's brains," she says. "By looking at activity over tens of thousands of neurons, we can see that there must be a functional structure - a pattern - to how these memories are encoded. Otherwise, our experiment simply would not have been possible to do."

Professor Maguire believes that this research opens up a range of possibilities of seeing how actual memories are encoded across the neurons, looking beyond spatial memories to more enriched memories of the past or visualisations of the future.

"Understanding how we as humans record our memories is critical to helping us learn how information is processed in the hippocampus and how our memories are eroded by diseases such as Alzheimer's," added Demis Hassabis.

"It's also a small step towards the idea of mind reading, because just by looking at neural activity, we are able to say what someone is thinking."

Professor Maguire led a study a number of years ago which examined the brains of London taxi drivers, who spend years learning "The Knowledge" (the maze of London streets). She showed that in these cabbies, an area to the rear of the hippocampus was enlarged, suggesting that this was the area involved in learning location and direction. In the new study, Hassabis, Maguire and colleagues found that the patterns relating to spatial memory were located in this same area, suggesting that the rear of the hippocampus plays a key role in representing the layout of spatial environments.

More information: Hassabis, D. et al. Decoding neuronal ensembles in the human hippocampus. Current Biology, 12 March 2009.

Source: Wellcome Trust (news : web)

Explore further: 'Chatty' cells help build the brain

add to favorites email to friend print save as pdf

Related Stories

Patients with amnesia 'live in the present'

Jan 16, 2007

Scientists at the Wellcome Trust Centre for Neuroimaging, University College London, have shown that people with damage to the hippocampus, the area of the brain that plays a crucial role in learning and memory, not only ...

Tales of the unexpected: how the brain detects novelty

Nov 28, 2006

When you sit down to watch a DVD of your favourite film, the chances are that you are able to predict the exact sequence of events that is about to unfold. Without our memories we would not only be unable to remember our ...

The 'satellite navigation' in our brains

Sep 11, 2008

Our brains contain their own navigation system much like satellite navigation ("sat-nav"), with in-built maps, grids and compasses, neuroscientist Dr Hugo Spiers told the BA Festival of Science at the University of Liverpool ...

How memories are made, and recalled

Sep 08, 2008

What makes a memory? Single cells in the brain, for one thing. For the first time, scientists at UCLA and the Weizmann Institute of Science in Israel have recorded individual brain cells in the act of calling up a memory, ...

Unlocking the mysteries of memory

Dec 04, 2008

Stop and think for a moment. What do you remember about your breakfast this morning? One part of your brain will recall the smell of coffee brewing, while another will remember your partner's smile while walking out the door. ...

Recommended for you

'Chatty' cells help build the brain

12 hours ago

The cerebral cortex, which controls higher processes such as perception, thought and cognition, is the most complex structure in the mammalian central nervous system. Although much is known about the intricate ...

'Trigger' for stress processes discovered in the brain

Nov 27, 2014

At the Center for Brain Research at the MedUni Vienna an important factor for stress has been identified in collaboration with the Karolinska Institutet in Stockholm (Sweden). This is the protein secretagogin ...

New research supporting stroke rehabilitation

Nov 26, 2014

Using world-leading research methods, the team of Dr David Wright and Prof Paul Holmes, working with Dr Jacqueline Williams from the Victoria University in Melbourne, studied activity in an area of the brain ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.