Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lost Connections Amid the Hippocampus: Amnesiac Study Offers Insights into How Working Memory Works

01.06.2006


Memory tests performed with amnesiacs have enabled researchers to refute a long-held belief in an essential difference between long-and short-term memories. In the study, researchers from the University of Pennsylvania determined that the hippocampus -- a seahorse shaped structure in the middle of the brain -- was just as important for retrieving certain types of short-term memories as it is for long-term memories.



Their findings, published in the Journal of Neuroscience, overturn the established view of the hippocampus and offers insight on how the brain forms and recalls memories by piecing together related bits of experiences.

"For over 40 years, the chief paradigm has been that the hippocampus was important for creating long-term memory but not short-term or working memory," said Ingrid Olson, a member of Penn’s Department of Psychology and researcher at Penn’s Center for Cognitive Neuroscience. "However, our data show that one type of working memory, working memory for the relationship between bits of information, is dependent on the hippocampus.


According to Olson, how much time has elapsed or, in other words, the age of the memory -- is less important to the hippocampus than is the requirement to form connections between pieces of information to create a coherent episode of memory.

"I can remember what my keys look like, and I can remember where the coffee table is located, but the critical test of my memory is if I can remember that I left my keys on the coffee table," Olson said.

To study the role of the hippocampus in forming short-term memories, Olson and her colleagues used visual memory tests to study the ability of nine amnesiacs to recall images presented to them on a screen. These subjects all suffered from damage to their hippocampi and related brain structures, and their lives are ruled by the fact that they can no longer form long-term memories, much like characters from the movies "Memento" or "Finding Nemo."

The task required amnesiacs and controls to remember three objects, locations or objects in locations over delays of one or eight seconds. The results show that working memory for objects or locations alone was at normal levels, but that memory for object-location conjunctions was severely impaired at eight-second delays.

"While ’long-term’ memory and ’short-term’ memory have been useful distinctions for us, they may not exist in the same way for the brain," Olson said.

The researchers believe that a more useful distinction would be between feature memory and conjunction memory the ability to remember specific things versus how they are related. In that regard, the hippocampus serves like the brain’s switchboard, piecing individual bits of information together in context.

"The hippocampus is another part of our evolving view of the nature of memories and consciousness," Olson said. "Our memories are not the static, permanent things we would like to think and, even in healthy people, these connections can erode or become muddled, leading to false memories or illnesses like post-traumatic stress disorder."

Contributing authors of this study are Katie Page and Mieke Verfaellie from the Boston VA Healthcare System and Boston University School of Medicine; Katherine Sledge Moore of the University of Michigan; and Anjan Chatterjee of Penn’s School of Medicine.

Funding for their research was provided through grants from the National Institute of Mental Health and the Medical Research Service of the Department of Veterans Affairs.

Greg Lester | EurekAlert!
Further information:
http://www.upenn.edu

More articles from Studies and Analyses:

nachricht Do microplastics harbour additional risks by colonization with harmful bacteria?
05.04.2018 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>