RxPG News Feed for RxPG News

Medical Research Health Special Topics World
  Home
 
   Health
 Aging
 Asian Health
 Events
 Fitness
 Food & Nutrition
 Happiness
 Men's Health
 Mental Health
 Occupational Health
 Parenting
 Public Health
 Sleep Hygiene
 Women's Health
 
   Healthcare
 Africa
 Australia
 Canada Healthcare
 China Healthcare
 India Healthcare
 New Zealand
 South Africa
 UK
 USA
 World Healthcare
 
   Latest Research
 Aging
 Alternative Medicine
 Anaethesia
 Biochemistry
 Biotechnology
 Cancer
 Cardiology
 Clinical Trials
 Cytology
 Dental
 Dermatology
 Embryology
 Endocrinology
 ENT
 Environment
 Epidemiology
 Gastroenterology
 Genetics
 Gynaecology
 Haematology
 Immunology
 Infectious Diseases
 Medicine
 Metabolism
 Microbiology
 Musculoskeletal
 Nephrology
 Neurosciences
  Brain Diseases
  Demyelinating Diseases
  Headache
  Memory
   Intelligence
  Neurochemistry
  Neurodegenerative Diseases
  Regeneration
  Spinal Cord Diseases
  Stroke
  Taste
  Trigeminal Neuralgia
 Obstetrics
 Ophthalmology
 Orthopedics
 Paediatrics
 Pathology
 Pharmacology
 Physiology
 Physiotherapy
 Psychiatry
 Radiology
 Rheumatology
 Sports Medicine
 Surgery
 Toxicology
 Urology
 
   Medical News
 Awards & Prizes
 Epidemics
 Launch
 Opinion
 Professionals
 
   Special Topics
 Ethics
 Euthanasia
 Evolution
 Feature
 Odd Medical News
 Climate

Last Updated: Oct 11, 2012 - 10:22:56 PM
Research Article
Memory Channel

subscribe to Memory newsletter
Latest Research : Neurosciences : Memory

   EMAIL   |   PRINT
Relational memory requires time and sleep

Apr 21, 2007 - 7:19:27 AM , Reviewed by: Dr. Sanjukta Acharya
"This strongly implies that sleep is actively engaged in the cognitive processing of our memories," notes Ellenbogen. "Knowledge appears to expand both over time and with sleep."

Key Points of this article
This study demonstrates the importance of time and sleep for the processing of information in memory.
 
[RxPG] Memorizing a series of facts is one thing, understanding the big picture is quite another. Now a new study demonstrates that relational memory -- the ability to make logical "big picture" inferences from disparate pieces of information – is dependent on taking a break from studies and learning, and even more important, getting a good night's sleep.

Led by researchers at Beth Israel Deaconess Medical Center (BIDMC) and Brigham and Women's Hospital (BWH), the findings appear on-line in today's Early Edition of the Proceedings of the National Academy of Sciences (PNAS).

"Relational memory is a bit like solving a jigsaw puzzle," explains senior author Matthew Walker, PhD, Director of the Sleep and Neuroimaging Laboratory at BIDMC and Assistant Professor of Psychology at Harvard Medical School (HMS). "It's not enough to have all the puzzle pieces – you also have to understand how they fit together."

Adds lead author Jeffrey Ellenbogen, MD, a postdoctoral fellow at HMS and sleep neurologist at BWH, "People often assume that we know all of what we know because we learned it directly. In fact, that's only partly true. We actually learn individual bits of information and then apply them in novel, flexible ways."

For instance, if a person learns that A is greater than B and B is greater than C, then he or she knows those two facts. But embedded within those is a third fact – A is greater than C – which can be deduced by a process called transitive inference, the type of relational memory that the researchers examined in this study.

Earlier research by Walker and colleagues had shown that sleep actively improves task-oriented "procedural memory" – for example, learning to talk, to coordinate limbs, musicianship, or to play sports. Because relational memory is fundamental to knowledge and learning, Walker and Ellenbogen decided to explore how and when this "inferential" knowledge emerges, hypothesizing that it develops during "off-line" periods and that, like procedural memory, would be enhanced following a period of sleep.

So, the researchers tested 56 healthy college students, each of whom was shown five pairs of unfamiliar abstract patterns – colorful oval shapes resembling Faberge' eggs. The students were then told that some of the patterns were "correct" while others were "incorrect," for example, Shape A wins over Shape B, Shape B wins over Shape C, and so on. All of the students learned the individual pairs but were not told that there was a hidden "hierarchy" linking all five of the pairs together.

After a 30-minute study period, the students were separated into three groups to test their understanding of the larger "big picture" relationship between the individual patterns: Group One was tested after a period of 20 minutes; Group Two was tested after a 12-hour period; and Group Three was tested after a 24-hour time span. In addition, approximately half of the students in Group Two slept during the 12-hour period, while the other half remained awake. All of the students in Group Three had a full night's sleep.

The test results showed striking differences among the three groups, especially between the students who had a period of sleep and those who remained awake.

"Group One, the students who were tested soon after their initial learning period, performed the worst," says Walker. "While they were able to learn and recall the component pieces [for example, Shape A is greater than Shape B, Shape B is greater than Shape C] they could not discern the hierarchical relationships between the pieces [Shape A is greater than Shape C] – they couldn't yet see 'the big picture.'"

Groups Two and Three, on the other hand, demonstrated a clear understanding of the interrelationship between the pairs of shapes.

"These individuals were able to make leaps of inferential judgment just by letting the brain have time to unconsciously mull things over," he says. But, perhaps most notable, he adds, when the inferences were particularly difficult, the students who had had periods of sleep in between learning and testing significantly outperformed the other groups.

"This strongly implies that sleep is actively engaged in the cognitive processing of our memories," notes Ellenbogen. "Knowledge appears to expand both over time and with sleep."

Concludes Walker, "These findings point to an important benefit [of sleep] that we had not previously considered. Sleep not only strengthens a person's individual memories, it appears to actually knit them together and help realize how they are associated with one another. And this may, in fact, turn out to be the primary goal of sleep: You go to bed with pieces of the memory puzzle, and awaken with the jigsaw completed."



Funding information and declaration of competing interests: This study was funded by grants from the National Institutes of Health and the American Academy of Sleep Medicine.

Advertise in this space for $10 per month. Contact us today.


Related Memory News
Enriched environment as a child helps reverse memory problem
How brain pacemakers erase diseased messages
Relational memory requires time and sleep
Phase locking of hippocampal interneuron membrane potential
Poor memory could signal heart disease
Memories: It's all in the packaging
Atrial Fibrillation linked to Reduced Cognitive Performance
Human Memory Gene Identified
How the Brain Loses Plasticity of Youth
Apple Juice Inproves Memory By Boosting Acetylcholine Production

Subscribe to Memory Newsletter

Enter your email address:


 About Dr. Sanjukta Acharya
This news story has been reviewed by Dr. Sanjukta Acharya before its publication on RxPG News website. Dr. Sanjukta Acharya, MBBS is the chief editor for RxPG News website. She oversees all the medical news submissions and manages the medicine section of the website. She has a special interest in diabetes and endocrinology.
RxPG News is committed to promotion and implementation of Evidence Based Medical Journalism in all channels of mass media including internet.
 Additional information about the news article
Led by researchers at Beth Israel Deaconess Medical Center (BIDMC) and Brigham and Women's Hospital (BWH), the findings appear on-line in today's Early Edition of the Proceedings of the National Academy of Sciences (PNAS).

The lead author was Jeffrey Ellenbogen, MD, a postdoctoral fellow at HMS and sleep neurologist at BWH. Matthew Walker, PhD, Director of the Sleep and Neuroimaging Laboratory at BIDMC and Assistant Professor of Psychology at Harvard Medical School (HMS)was a senior author.
Study coauthors include BIDMC researchers Peter Hu and Jessica Payne, PhD, and Debra Titone, PhD, of McGill University, Montreal, Canada.

Beth Israel Deaconess Medical Center is a patient care, research and teaching affiliate of Harvard Medical School and ranks third in National Institutes of Health funding among independent hospitals nationwide. BIDMC is clinically affiliated with the Joslin Diabetes Center and is a research partner of the Dana-Farber/Harvard Cancer Center.

 Feedback
For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 
Contact us

RxPG Online

Nerve

 

    Full Text RSS

© All rights reserved by RxPG Medical Solutions Private Limited (India)