Patients with amnesia 'live in the present'

January 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 have trouble remembering the past but also in imagining new and future experiences.

Damage to the hippocampus can be caused by a lack of oxygen to the brain, for example during a cardiac arrest, or various other illnesses such as limbic encephalitis or Alzheimer's disease.

It has been known for some time that selective damage to the hippocampus can lead to amnesia, with patients unable to recall past events. However, by asking patients to describe imaginary experiences, the research team led by Dr Eleanor Maguire found that the patients' ability to construct fictitious events was also severely impaired. The research is published today in the Proceedings of the National Academy of Sciences.

The researchers asked the patients to imagine and then describe in detail situations in commonplace settings, such as a beach, pub and forest, as well as potentially plausible future events such as a Christmas party or a future meeting with a friend.

"We found that the role played by the hippocampus in processing memory was far broader than merely reliving past experiences," says Dr Maguire, a Wellcome Trust Senior Research Fellow at UCL. "It also seems to support the ability to imagine any kind of experience including possible future events. In that sense, people with damage to the hippocampus are forced to live in the present."

"Furthermore, the patients reported that they were unable to visualise the whole experience in their mind's eye, seeing instead just a collection of separate images," explains Dr Maguire.

Dr Maguire and her colleagues believe that the findings suggest a common mechanism that might underpin both recalling real memories and how we visualise imaginary and future experiences, with the hippocampus providing the spatial context or environmental setting into which the details of our experiences are bound.

Source: Wellcome Trust

Explore further: Rats 'dream' paths to a brighter future

Related Stories

The most complete review of the peptide behind Alzheimer's

March 30, 2015

The hope is to be able, one day, to fight the pathogenic action of the amyloid-beta protein, whose build-up is associated with Alzheimer's disease. In the meantime, scientists—including a group from the International School ...

Exercise may reduce Alzheimer's disease brain changes

October 4, 2010

(PhysOrg.com) -- Walking, jogging and other forms of regular aerobic exercise may actually ward off the onset of Alzheimer’s disease pathology in the brain, suggests newly published research from Washington University ...

Molecular imaging opens up a vast new world for neuroscience

September 6, 2010

Molecular imaging allows molecules in a living organism to be visualized, and provides a means of observing the distribution and behavior of molecules. One of the most exciting applications of this technology is the ability ...

Recommended for you

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

Quantum Theory May Explain Wishful Thinking

April 14, 2009

(PhysOrg.com) -- Humans don’t always make the most rational decisions. As studies have shown, even when logic and reasoning point in one direction, sometimes we chose the opposite route, motivated by personal bias or simply ...

0 comments

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.