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 Graphene gives a tremendous boost to future terahertz cameras
16.04.2019 | ICFO-The Institute of Photonic Sciences

nachricht Mount Kilimanjaro: Ecosystems in Global Change
28.03.2019 | Julius-Maximilians-Universität Würzburg

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: Energy-saving new LED phosphor

The human eye is particularly sensitive to green, but less sensitive to blue and red. Chemists led by Hubert Huppertz at the University of Innsbruck have now developed a new red phosphor whose light is well perceived by the eye. This increases the light yield of white LEDs by around one sixth, which can significantly improve the energy efficiency of lighting systems.

Light emitting diodes or LEDs are only able to produce light of a certain colour. However, white light can be created using different colour mixing processes.

Im Focus: Quantum gas turns supersolid

Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.

Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

Proteins stand up to nerve cell regression

24.04.2019 | Life Sciences

New sensor detects rare metals used in smartphones

24.04.2019 | Life Sciences

Controlling instabilities gives closer look at chemistry from hypersonic vehicles

24.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>