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 Millions through license revenues
27.04.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>