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

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

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: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

The RWI/ISL-Container Throughput Index started off well in 2018

22.02.2018 | Business and Finance

FAU researchers demonstrate that an oxygen sensor in the body reduces inflammation

22.02.2018 | Health and Medicine

Histology in 3D: new staining method enables Nano-CT imaging of tissue samples

22.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>