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 New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

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: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>