Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers use new method to probe recollections in memory-impaired patients

05.02.2008
Neuroscientists continue to debate whether or not long-term memory always depends on a region of the brain called the medial temporal lobe, which contains the brain’s memory-processing center, the hippocampus. A new study of brain-damaged patients by researchers at the University of California, San Diego (UCSD) School of Medicine readdresses the issue using a new method to elicit more detailed long-term memories.

The study, led by Larry R. Squire, Ph.D., professor of psychiatry, neurosciences and psychology at UCSD School of Medicine and research career scientist at the San Diego Veterans Affairs Health System, supports the theory that remote, or very long-term, memory remains intact after the medial temporal lobe is damaged. The results will be published in the early on-line edition of Proceedings of the National Academy of Sciences the week of February 4-8.

In 2005, a study led by Squire and published in the journal Neuron, studied the ability of patients with selective brain damage to recall events in their past. The findings strongly suggested that the ability to recollect “remote autobiographic events,” or distant memories, gradually becomes independent of the medial temporal lobe as time passes.

However, proponents of an opposing theory – that retention of distant memories requires the continued involvement of the hippocampus – suggested that these findings were flawed because the measurement techniques used to elicit remote memories weren’t sensitive enough.

The PNAS study looked at the ability of patients with selective brain damage to recall events from their past using a new method, called the Autobiographic Interview, which uses extensive probing to elicit an average of 50 or more details per memory.

“Using this more sensitive testing method, we found that autobiographical recollection was impaired in patients with medial temporal lobe damage when memories were drawn from the recent past, but fully intact when memories came from the remote past,” said Squire.

The new approach used tape-recorded narratives of extended recollections and determined the number of details that patients produced about events from their early lives. The Autobiographical Interview was administered to three patients with limited hippocampal damage, two with large medial temporal lobe lesions and five controls without any brain damage. Participants were asked to provide one memory from each of five time periods: childhood to age 11, teenage years, early adulthood, middle age and the year immediately prior to testing.

“Each of the amnesic patients was able to provide detailed autobiographical memories, with an average of 50 details per memory, from the three most remote time periods that were sampled,” said first author C. Brock Kirwan, Ph.D., postdoctoral fellow in UCSD’s Institute for Neural Computation.

Previous methods looked at a larger number of remote memories, prompting recollection of approximately 20 details per memory. Kirwan theorized that earlier studies elicited fewer details because it is difficult to produce a large number of details when asked about 24 different episodes. “In any case, we have found remote autobiographical memory to be intact after medial temporal lobe damage, whether patients produce memories with more or fewer details,” he said.

The researchers also conclude that impairment to such remote memories that have sometimes been reported using the Autobiographical Interview or other tests is likely due to significant damage outside the medial temporal lobe.

Debra Kain | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Health and Medicine:

nachricht Collagen nanofibrils in mammalian tissues get stronger with exercise
14.12.2018 | University of Illinois College of Engineering

nachricht New discoveries predict ability to forecast dementia from single molecule
12.12.2018 | UT Southwestern Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>