Sleeping Gives Memory and Learning a Lift

Want to maximize your learning capacity? Get some sleep. That's the takeaway from a study that examined the influence of sleep and time of day on learning and memory. This latest research is another piece of compelling evidence that sleeping helps to strengthen our ability to learn new things, and to convert new learning into longer-term memories.

In this study, 207 students who slept regularly for at least six hours per night were assigned to learn two different sets of word pairs. One set of word pairs were semantically related; the other pairs were made up of unrelated words. The difference is important. The type of learning involved in recalling unrelated word pairs is different than for pairs that are related, and involves forming new associations, essentially creating a relationship in the mind for these words that are otherwise unrelated.

The students were assigned to study the word pairs at one of two times: 9 a.m. or 9 p.m. After an initial study period to learn the two types of word pairs, the students were re-tested after 30 minutes, then again after 12 hours, and a final time after 24 hours. The students who did their learning in the evening went to sleep for their regular nightly rest relatively soon after their initial study period. The daytime learning students, on the other hand, spent a normal day of wakefulness before going to bed as usual that evening.

This allowed researchers to assess the influence of time of day on learning. It also allowed them to examine how the proximity of sleep to learning might have an influence. What did they find?

• Time of day had no effect on performance and initial memory (at the 30 minute test). This was true for both types of word pairs.
• After 12 hours, overall memory was better after a night's sleep than for those who spent the day awake
• After 24 hours, researchers found that students who went to sleep shortly after learning had better memory of what they learned than those who did their learning followed by a day of wakefulness before sleep.
• The different types of word pairs -- and the two types of learning they required -- fared differently depending on sleep. Memory for related word pairs was not affected by how soon sleep followed learning. Memory for the unrelated word pairs -- the kind that required making new associations -- was stronger for students who slept shortly after learning than for those who spent the day awake.
• The deterioration of memory during the wake period was less when students had slept shortly after learning

These results indicate that sleep is most helpful to memory when it happens soon after learning new things. Sleep seems to have a stabilizing effect on newly learned information, rooting it into memories that last and clearing the way for new information to be processed.

This latest research joins a series of recent breakthroughs in the study of sleep and memory.

• In this study, researchers used fruit flies to test the links between sleep and the creation of long-term memories. After breeding fruit flies to sleep on demand, researchers exposed the flies to new information. All of the flies retained their new knowledge for a short period of time, but only the flies that slept after learning appeared to convert their short-term knowledge to long-term memory.
• Another study showed how sounds heard during sleep may help to direct and enhance memory. Participants learned a spatial puzzle that involved moving images to specific places on a computer screen. While doing this, they heard sounds that corresponded to specific images. During sleep, the study subjects were exposed to half of those same sounds. When they performed the puzzle again from memory after sleeping, they were better able to recall the placement of images whose sounds they'd heard during sleep.
• This study showed how naps can boost brainpower. Two groups of young adults learned the same task. One group napped after learning; the other didn't. Six hours after learning the initial task, both groups were asked to learn brand new material. The non-napping group scored lower than they had on their initial learning exercise, while the napping group actually improved their performance compared to their first one.

Sleep doesn't only enhance memory. It also appears to diminish the emotional impact of painful memories. In a study I wrote about recently, two groups were exposed to emotionally charged images. Both groups saw the images twice, in viewings 12 hours apart. One group slept in between viewings and the other did not. Those who slept reported feeling less of an emotional reaction to the images at their second viewing, compared to the group who did not sleep. MRI scans showed decreased activity in the region of the brain that processes emotions for the group who slept.

We're learning more all the time about how sleep helps us learn and retain information, how it clears the mind and prepares us to learn new things, as well as how it may protect us from the emotional pain of difficult memories.

Whether you're prepping for a test, starting a new job, coping with difficult circumstances, or just want to feel more agile of mind, the prescription is the same: Get some sleep!

Sweet Dreams,
Michael J. Breus, PhD
The Sleep Doctor™
www.thesleepdoctor.com

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Everything you do, you do better with a good night's sleep™
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Comments

[Bill Geary]

07:07 PM on 06/07/2012

I'm glad to read scientific information pertaining to the value of sleep. If you are interested, you can read about my severe sleep problems and one change I made which dramatically improved my sleep.
bill - the sleepactivist

http://www.howtosleeptightallnight.com/HowToSleepBetter.aspx

[clusteringideas]

06:56 PM on 06/10/2012

Thank you for this information!

[roscoe301]

09:13 AM on 06/07/2012

I should send these obvious conclusions to every parent in my children's grade school. It amazes me how few kids have regular bedtimes.

[ihatealzheimers]

11:46 PM on 06/06/2012

I can attest to the truth in this information.

Sadly, having sleep apnea makes getting the appropriate amount of sleep impossible. Have had several CPAP machines, different masks and surgery that made my apnea worse - nothing more to try that is affordable "One size fits all" mouth guards are horrific and custom made ones cost $$$ and without insurance, they are not affordable. Wish there were a good answer! I would give almost anything for a good night of sleep.

[JB Dean]

04:45 PM on 06/06/2012

Most of these rather obvious and intuitive insights have been known for centuries. They were known long before there was any academic field called "psychology," with its endless and tedious "studies" and "research."

[abdussamad]

03:37 PM on 06/06/2012

The article is peaking hundred percent true about the advantages of required hours sleep. I have personally experienced this myself. I am working to shifts, both at night and day. The tough working hours, with tough datelines, sometimes cause me to completely forget what i already new, while it affects my physical appearance too. I look quit boring, exhausted, untied and extremely rude. But when I sleep enough, I get to realize that I am quite strong in every term, I take to step in. And this is strongly suggested to get some times to sleep enough.

[yonoton]

01:45 PM on 06/06/2012

Sleep is a left-wing, authoritarian right wing, sensationalist, cannibal conspiracy.

[morefromLA]

10:33 PM on 06/06/2012

Time to take a nap.

[David Hauser]

12:28 PM on 06/06/2012

The doctor says sleep is good. Who knew?

[Helioscopeprime]

11:50 AM on 06/06/2012

This is so important. I have found that sleep is as important as diet in terms of maintaining health, if not more so. I know we are all so busy but if we stopped to cook a meal and went to bed a bit earlier, many of the health problems in this country would solve themselves.

[konspikuous]

10:58 AM on 06/06/2012

"It also appears to diminish the emotional impact of painful memories."

Tell that to the people who experience anxiety attacks in their sleep.

Curious though...what is the explanation for recalling words or sequence of numbers...prior to rest, but well after short-term memory has bumped the recall into long-term memory?

[LEFTisRIGHT ironic]

10:09 AM on 06/06/2012

Thank you Dr.Breus. I'm certainly going to have to move out of my dormitory on my college campus if I'd like to get 6 or more hours of sleep a night. Nothing like a bunch of rowdy kids who are excited to be away from home, and who lack an understanding that school is for an education. LOL

[fumes]

09:43 AM on 06/06/2012

nothing more eville..

than Alarm Clocks

[thecaudills]

09:08 AM on 06/06/2012

The best sleep in the world is when you slide into a dream deeply loving someone.