Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stages of memory described in new study

09.10.2003


A new study in the Oct. 9 issue of the journal Nature describes three distinct stages in the life of a memory, and helps explain how memories endure – or are forgotten – including the role that sleep plays in safeguarding memories.



"To initiate a memory is almost like creating a word processing file on a computer," explains the study’s first author, Matthew Walker, Ph.D., instructor of psychiatry at Beth Israel Deaconess Medical Center and Harvard Medical School. "Once the file has been created, if you don’t hit the ’save’ button before shutting off the computer it will be lost. Our new research helps explain the process in our brains that enable us to first create the memories and then to stabilize and ’save’ the memories we’ve created." The findings then go on to explain how memories can later be "edited" once they’ve been saved.

Walker, who conducted the research while at the Massachusetts Mental Health Center, and his colleagues focused on "procedural skill memory," the "how" type of memory that enables humans to learn coordination-based skills, such as driving, playing a sport, or learning to play a musical instrument or perform a surgical procedure. "This is the type of memory that we often take for granted," says Walker. "But for stroke patients or other individuals who have suffered neurological damage that has injured their motor skills functioning – including how they speak and how they move – it quickly becomes apparent how critically important this type of memory is to our daily existence." To identify these three stages of memory, the authors instructed a group of individuals (100 young healthy subjects, ages 18 to 27) in several different finger-tapping sequences (for example, 4,1,2,3,4) at various intervals and at various points of the sleep-wake cycle. Their resulting data disclosed several important findings, according to Walker.


"We first discovered that in order for a memory to be stabilized – and therefore become less vulnerable to competing information – it requires somewhere in the region of six waking hours," he explains. "So, this is when your brain is hitting the ’save’ key and putting the file on the ’hard drive,’ but instead of being saved in a matter of seconds like your computer file, a memory needs several hours to be saved."

From there, the researchers went on to discover that the second stage of memory processing occurs during sleep – and that it is "absolutely dependent on sleep in order to occur," according to Walker. Study subjects who were tested 24 hours after their finger-tapping lesson – and following a night’s sleep – were found to have improved or enhanced memory from the previous day. "In keeping with the computer file analogy," says Walker, "this stage of memory would be comparable to an editor coming in and opening a stable but messy file, and reorganizing it, refining it and tightening it up." Furthermore, he explains, this discovery helps strengthen the argument that sleep is beneficial to the learning process. "If you don’t get that full night’s sleep, you may be shortchanging your brain of learning potential," he adds.

The final stage of memory identified by Walker and his colleagues is the "recall phase," which allows a previously stabilized memory to be modified. "What we found was that after the memory had been stabilized [after several waking hours] and enhanced [after a night’s sleep] it once again became pliable so that it could be altered in the context of new ongoing experiences." In other words, although an individual may have learned to play a piano scale, then enhanced the skill after a night of sleep, by way of this third modifying stage of memory he could continue to tweak and refine this new skill.

This last stage may have important clinical implications in the treatment of patients with psychological disorders such as post-traumatic stress disorder (PTSD), says Walker. "In PTSD, individuals have specific memories with specific associations attached to them, which are negative, and thereby causing the disorder," he explains . "What we think behavioral and cognitive therapies do by having patients replay those memories and talk about them is that exact third memory stage. Over time, there may be the chance for these patients to redefine their memories and make them less traumatic."



This study was supported by grants from the National Science Foundation and the National Institute of Mental Health.

Study co-authors include Harvard Medical School researchers Robert Stickgold, PhD, of Beth Israel Deaconess Medical Center, formerly of the Massachusetts Mental Health Center; and J. Allan Hobson, MD, and Tiffany Brafkefield, BA, of the Massachusetts Mental Health Center. Beth Israel Deaconess Medical Center is a major patient care, teaching and research affiliate of Harvard Medical School, ranking third in National Institutes of Health funding among independent hospitals nationwide. The medical center is clinically affiliated with the Joslin Diabetes Center and is a founding member of the Dana-Farber/Harvard Cancer Center. BIDMC is the official hospital of the Boston Red Sox.

Bonnie Prescott | EurekAlert!
Further information:
http://www.bidmc.harvard.edu/

More articles from Studies and Analyses:

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

nachricht Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>