Editing Sleep and learning

{{short description|Relationship between sleep and learning in humans}}
{{Use dmy dates|date=October 2018}}
Multiple hypotheses explain the possible connections between '''sleep and learning''' in [[human]]s. Research indicates that sleep does more than allow the brain to rest; it may also aid the consolidation of long-term memories.

REM sleep and slow-wave sleep play different [[sleep and memory|roles in memory consolidation]]. REM is associated with the consolidation of nondeclarative (implicit) memories. An example of a nondeclarative memory would be a task we can do without consciously thinking about, such as riding a bike. Slow-wave, or non-REM (NREM) sleep, consolidates declarative (explicit) memories. These are facts that need to be consciously remembered, such as dates for a history class.<ref>{{cite journal | last1=Wilhelm | first1=I. | last2=Diekelmann | first2=S. | last3=Born | first3=J. | title=Sleep in children improves memory performance on declarative but not procedural tasks | journal=Learning & Memory | publisher=Cold Spring Harbor Laboratory | volume=15 | issue=5 | date=25 April 2008 | issn=1072-0502 | doi=10.1101/lm.803708 | pmid=18441295 | pages=373–377| doi-access=free }}</ref>

==Increased learning==
Popular sayings can reflect the notion that remolded memories produce new creative associations in the morning, and that performance often improves after a time-interval that includes sleep.<ref>{{cite news| last=Neal | first=Rome | title=Sleep On It | website=CBS News | date=21 January 2004 | url=https://www.cbsnews.com/news/sleep-on-it/ | access-date=29 September 2018}}</ref> Current studies demonstrate that a healthy sleep produces a significant [[learning]]-dependent performance boost.<ref>{{cite web | title=The Role of Sleep in Memory, Learning, and Health | website=Therapeutic Literacy Center | date=25 February 2014 | url=https://therapeuticliteracycenter.com/the-role-of-sleep-in-learning-memory-and-health/ | access-date=29 September 2018 |author=Maria Bagby}}</ref><ref>{{cite news |title=To understand the big picture, give it time – and sleep |date=20 April 2007 |url=http://www.eurekalert.org/pub_releases/2007-04/bidm-tut042007.php |work=EurekAlert |access-date=23 April 2007}}</ref> The idea is that sleep helps the brain to edit its memory, looking for important patterns and extracting overarching rules which could be described as 'the gist', and integrating this with existing memory.<ref>{{cite journal | last1=Stickgold | first1=Robert | last2=Walker | first2=Matthew P | title=Sleep-dependent memory triage: evolving generalization through selective processing | journal=Nature Neuroscience | volume=16 | issue=2 | pages=139–145 | date=28 January 2013 | issn=1546-1726 | doi=10.1038/nn.3303 | pmid=23354387 | pmc=5826623 }}</ref>  The 'synaptic scaling' hypothesis suggests that sleep plays an important role in regulating learning that has taken place while awake, enabling more efficient and effective storage in the brain, making better use of space and energy.<ref name="smrv-journal.com">{{cite journal | last1=Tononi | first1=Giulio | last2=Cirelli | first2=Chiara | title=Sleep function and synaptic homeostasis | journal=Sleep Medicine Reviews | volume=10 | issue=1 | date=1 January 2006 | issn=1087-0792 | pmid=16376591 | doi=10.1016/j.smrv.2005.05.002 | pages=49–62 | s2cid=16129740 }}</ref>

Healthy sleep must include the appropriate sequence and proportion of [[NREM]] and [[REM phase]]s, which play different roles in the memory consolidation-optimization process. During a normal night of sleep, a person will alternate between periods of NREM and REM sleep. Each cycle is approximately 90 minutes long, containing a 20-30 minute bout of REM sleep.<ref name="Carlson, N. R. 2010">{{cite book|last=Carlson|first=Neil R.|title=Physiology of Behavior|edition=11th|year=2010|publisher=Allyn & Bacon|location=New York}}</ref> NREM sleep consists of sleep stages 1–4, and is where movement can be observed.  A person can still move their body when they are in NREM sleep. If someone sleeping turns, tosses, or rolls over, this indicates that they are in NREM sleep. REM sleep is characterized by the lack of muscle activity. Physiological studies have shown that aside from the occasional twitch, a person actually becomes paralyzed during REM sleep.<ref name="Carlson, N. R. 2010"/>  In [[motor skill]] learning, an interval of sleep may be critical for the expression of performance gains; without sleep these gains will be delayed.<ref>{{cite journal | last1=Korman | first1=Maria | last2=Raz | first2=Naftali | last3=Flash | first3=Tamar|author3-link=Tamar Flash | last4=Karni | first4=Avi | title=Multiple shifts in the representation of a motor sequence during the acquisition of skilled performance | journal=Proceedings of the National Academy of Sciences | volume=100 | issue=21 | date=14 October 2003 | issn=0027-8424 | pmid=14530407 | doi=10.1073/pnas.2035019100 | pages=12492–12497 |pmc=218785| bibcode=2003PNAS..10012492K | doi-access=free }}</ref>

Procedural memories are a form of nondeclarative memory, so they would most benefit from the fast-wave REM sleep.<ref name="Carlson, N. R. 2010"/> In a study,<ref>Walker, M.P. (5 October 2009). *Sleep and Cognition II: Memory (Procedural [Skills]).* Lecture given in Psychology 133 at the University of California, Berkeley, CA.</ref> [[Procedural memory|procedural memories]] have been shown to benefit from sleep.<ref>{{cite journal | last1=Walker | first1=Matthew P. | last2=Brakefield | first2=Tiffany | last3=Morgan | first3=Alexandra | last4=Hobson | first4=J.Allan | last5=Stickgold | first5=Robert | title=Practice with Sleep Makes Perfect | journal=Neuron | publisher=Elsevier BV | volume=35 | issue=1 | year=2002 | issn=0896-6273 | doi=10.1016/s0896-6273(02)00746-8 | pmid=12123620 | pages=205–211| doi-access=free }}</ref>    Subjects were tested using a tapping task, where they used their fingers to tap a specific sequence of numbers on a keyboard, and their performances were measured by accuracy and speed. This finger-tapping task was used to simulate learning a motor skill. The first group was tested, retested 12 hours later while awake, and finally tested another 12 hours later with sleep in between. The other group was tested, retested 12 hours later with sleep in between, and then retested 12 hours later while awake. The results showed that in both groups, there was only a slight improvement after a 12-hour wake session, but a significant increase in performance after each group slept. This study gives evidence that REM sleep is a significant factor in consolidating motor skill procedural memories, therefore sleep deprivation can impair performance on a motor learning task.  This memory decrement results specifically from the loss of stage 2, REM sleep.<ref>{{cite journal | last1=Walker | first1=Matthew P. | last2=Stickgold | first2=Robert | title=Sleep-Dependent Learning and Memory Consolidation | journal=Neuron | publisher=Elsevier BV | volume=44 | issue=1 | year=2004 | issn=0896-6273 | doi=10.1016/j.neuron.2004.08.031 | pages=121–133| pmid=15450165 | doi-access=free }}</ref>

[[Declarative memory]] has also been shown to benefit from sleep, but not in the same way as procedural memory. Declarative memories benefit from the slow-waves nREM sleep.<ref name="Carlson, N. R. 2010"/> A study<ref>Walker, M.P. (7 October 2009). *Sleep and Cognition III: Memory (Declarative [Facts]).* Lecture given in Psychology 133 at the University of California, Berkeley, CA.</ref> was conducted where the subjects learned word pairs, and the results showed that sleep not only prevents the decay of memory, but also actively fixates declarative memories.<ref>{{cite journal | last1=Payne | first1=Jessica D. | last2=Tucker | first2=Matthew A. | last3=Ellenbogen | first3=Jeffrey M. | last4=Wamsley | first4=Erin J. | last5=Walker | first5=Matthew P. | last6=Schacter | first6=Daniel L. | last7=Stickgold | first7=Robert | editor-last=Mazza | editor-first=Marianna | title=Memory for Semantically Related and Unrelated Declarative Information: The Benefit of Sleep, the Cost of Wake | journal=PLOS ONE | publisher=Public Library of Science (PLoS) | volume=7 | issue=3 | date=22 March 2012 | issn=1932-6203 | doi=10.1371/journal.pone.0033079 | page=e33079 | display-authors=5| pmid=22457736 | pmc=3310860| bibcode=2012PLoSO...733079P | doi-access=free }}</ref> Two of the groups learned word pairs, then either slept or stayed awake, and were tested again. The other two groups did the same thing, except they also learned interference pairs right before being retested to try to disrupt the previously learned word pairs. The results showed that sleep was of ''some'' help in retaining the word pair associations, while against the interference pair, sleep helped ''significantly''.

After sleep, there is increased insight.  This is because sleep helps people to reanalyze their memories. The same patterns of brain activity that occur during learning have been found to occur again during sleep, only faster. One way that sleep strengthens memories is by weeding out the less successful connections between neurons in the brain.  This weeding out is essential to prevent overactivity.  The brain compensates for strengthening some synapses (connections) between neurons, by weakening others.  The weakening process occurs mostly during sleep. This weakening during sleep allows for strengthening of other connections while we are awake. Learning is the process of strengthening connections, therefore this process could be a major explanation for the benefits that sleep has on memory.<ref>{{cite book|last=Kalat|first=James W.|title=Biological Psychology|edition=10th|year=2009|publisher=Wadsworth|location=California}}</ref>

Research has shown that taking an afternoon nap increases learning capacity. A study <ref>{{cite journal | last1=Cai | first1=Denise J. | last2=Mednick | first2=Sarnoff A. | last3=Harrison | first3=Elizabeth M. | last4=Kanady | first4=Jennifer C. | last5=Mednick | first5=Sara C. | title=REM, not incubation, improves creativity by priming associative networks | journal=Proceedings of the National Academy of Sciences | volume=106 | issue=25 | date=23 June 2009 | issn=0027-8424 | pmid=19506253 | doi=10.1073/pnas.0900271106 | pages=10130–10134 |pmc=2700890| bibcode=2009PNAS..10610130C | doi-access=free }}</ref> tested two groups of subjects on a nondeclarative memory task. One group engaged in REM sleep, and one group did not (meaning that they engaged in NREM sleep). The investigators found that the subjects who engaged only in NREM sleep did not show much improvement. The subjects who engaged in REM sleep performed significantly better, indicating that REM sleep facilitated the consolidation of nondeclarative memories.<ref name="Carlson, N. R. 2010" />  A more recent study<ref>{{cite journal | last1=Holz | first1=Johannes | last2=Piosczyk | first2=Hannah | last3=Landmann | first3=Nina | last4=Feige | first4=Bernd | last5=Spiegelhalder | first5=Kai | last6=Riemann | first6=Dieter | last7=Nissen | first7=Christoph | last8=Voderholzer | first8=Ulrich | editor-last=Schmidt | editor-first=Ulrike | title=The Timing of Learning before Night-Time Sleep Differentially Affects Declarative and Procedural Long-Term Memory Consolidation in Adolescents | journal=PLOS ONE | publisher=Public Library of Science (PLoS) | volume=7 | issue=7 | date=12 July 2012 | issn=1932-6203 | doi=10.1371/journal.pone.0040963 | pmid=22808287 | pmc=3395672 | page=e40963 | bibcode=2012PLoSO...740963H |display-authors=5| doi-access=free }}</ref> demonstrated that a procedural task was learned and retained better if it was encountered immediately before going to sleep, while a declarative task was learned better in the afternoon.<ref name="smrv-journal.com"/>

==Electrophysiological evidence in rats==

A 2009 study<ref>{{cite journal | last1=Peyrache | first1=Adrien | last2=Khamassi | first2=Mehdi | last3=Benchenane | first3=Karim | last4=Wiener | first4=Sidney I | last5=Battaglia | first5=Francesco P | title=Replay of rule-learning related neural patterns in the prefrontal cortex during sleep | journal=Nature Neuroscience | publisher=Springer Nature | volume=12 | issue=7 | date=31 May 2009 | issn=1097-6256 | doi=10.1038/nn.2337 | pages=919–926|pmid=19483687| s2cid=510348 |url=https://hal.archives-ouvertes.fr/hal-00551868/document}}</ref> based on electrophysiological recordings of large ensembles of isolated cells in the prefrontal cortex of rats revealed that cell assemblies that formed upon learning were more preferentially active during subsequent sleep episodes. More specifically, those replay events were more prominent during [[slow wave sleep]] and were concomitant with hippocampal reactivation events. This study has shown that neuronal patterns in large brain networks are tagged during learning so that they are replayed, and supposedly consolidated, during subsequent sleep. There have been other studies that have shown similar reactivation of learning pattern during motor skill and neuroprosthetic learning.<ref name= "sleep-dependent">{{cite journal | last1=Ramanathan | first1=Dhakshin S. | last2=Gulati | first2=Tanuj | last3=Ganguly | first3=Karunesh | editor-last=Ashe | editor-first=James | title=Sleep-Dependent Reactivation of Ensembles in Motor Cortex Promotes Skill Consolidation | journal=PLOS Biology | publisher=Public Library of Science (PLoS) | volume=13 | issue=9 | date=18 September 2015 | issn=1545-7885 | doi=10.1371/journal.pbio.1002263 | page=e1002263|pmid=26382320|pmc=4575076 | doi-access=free }}</ref><ref name= "reactivation of">{{cite journal | last1=Gulati | first1=Tanuj | last2=Ramanathan | first2=Dhakshin S | last3=Wong | first3=Chelsea C | last4=Ganguly | first4=Karunesh | title=Reactivation of emergent task-related ensembles during slow-wave sleep after neuroprosthetic learning | journal=Nature Neuroscience | publisher=Springer Nature | volume=17 | issue=8 | date=6 July 2014 | issn=1097-6256 | doi=10.1038/nn.3759 | pages=1107–1113|pmc=5568667|pmid=24997761}}</ref> Notably, new evidence is showing that reactivation and rescaling may be co-occurring during sleep.<ref name= "Neural reactivations">{{cite journal | last1=Gulati | first1=Tanuj | last2=Guo | first2=Ling | last3=Ramanathan | first3=Dhakshin S | last4=Bodepudi | first4=Anitha | last5=Ganguly | first5=Karunesh | title=Neural reactivations during sleep determine network credit assignment | journal=Nature Neuroscience | publisher=Springer Nature | volume=20 | issue=9 | date=10 July 2017 | issn=1097-6256 | doi=10.1038/nn.4601 | pages=1277–1284|pmid=28692062|pmc=5808917}}</ref>

==Sleep in relation to school==
Sleep has been directly linked to the grades of students. One in four U.S. high school students admit to falling asleep in class at least once a week.<ref name="SleepDepAbcNews">{{cite news |url=https://abcnews.go.com/US/wireStory?id=1775003 |archive-url=https://web.archive.org/web/20060503132531/https://abcnews.go.com/US/wireStory?id=1775003 |archive-date=3 May 2006 |title=Sleep-Deprived Teens Dozing Off at School |date=28 March 2006 |author=Randolph E. Schmid |website=ABC News }}</ref> Consequently, results have shown that those who sleep less do poorly. In the [[United States]], sleep deprivation is common with students because almost all schools begin early in the morning and many of these students either choose to stay awake late into the night or cannot do otherwise due to [[delayed sleep phase syndrome]].<ref>{{Cite web|url=https://my.clevelandclinic.org/health/diseases/14295-delayed-sleep-phase-syndrome-dsps-in-children-and-adolescents|title=Delayed Sleep Phase Syndrome (DSPS) in Children and Adolescents|website=Cleveland Clinic|language=en|access-date=2019-06-11}}</ref> As a result, students that should be getting between 8.5 and 9.25 hours of sleep are getting only 7 hours.<ref name="SleepDepSchool">{{cite web|url=http://sleepdisorders.about.com/cs/sleepdeprivation/a/backtoschool.htm |archive-url=https://web.archive.org/web/20071117122444/http://sleepdisorders.about.com:80/cs/sleepdeprivation/a/backtoschool.htm |archive-date=17 November 2007 |date=30 November 2003 |title=The Back to School Blues |website=about.com }}</ref> Perhaps because of this sleep deprivation, their grades are lower and their concentration is impaired.<ref>{{cite journal | last1=Roth | first1=Daphne Ari-Even | last2=Kishon-Rabin | first2=Liat | last3=Hildesheimer | first3=Minka | last4=Karni | first4=Avi | title=A latent consolidation phase in auditory identification learning: Time in the awake state is sufficient | journal=Learning & Memory | volume=12 | issue=2 | date=1 February 2005 | issn=1072-0502 | pmid=15805314 | doi=10.1101/87505 | pages=159–164 |pmc=1074334}}</ref>

Research shows that different remote learning modalities significantly affect nursing students' perceptions of their sleep quality.<ref>{{Cite journal |last1=Smit |first1=Andrea N. |last2=Juda |first2=Myriam |last3=Livingstone |first3=Ashley |last4=U |first4=Stephanie R. |last5=Mistlberger |first5=Ralph E. |date=2021-04-26 |title=Impact of COVID-19 social-distancing on sleep timing and duration during a university semester |journal=PLOS ONE |language=en |volume=16 |issue=4 |pages=e0250793 |doi=10.1371/journal.pone.0250793 |doi-access=free |issn=1932-6203 |pmc=8075219 |pmid=33901264|bibcode=2021PLoSO..1650793S }}</ref><ref name=":0">{{Cite journal |last1=Ngo |first1=Thye Peng |last2=Antisdel |first2=J'Andra L. |last3=Xing |first3=Kuan |last4=Reising |first4=Deanna L. |date=2023 |title=Relationships Between Remote Learning Modalities and Nursing Students' Perceptions of Their Sleep Quality During the COVID-19 Pandemic |journal=Nurse Educator |language=en |volume=48 |issue=2 |pages=E41–E46 |doi=10.1097/NNE.0000000000001320 |issn=1538-9855 |pmc=9936842 |pmid=36730031}}</ref> During the COVID-19 pandemic, a study found that students engaged in asynchronous learning reported better sleep quality compared to those in hybrid or in-person learning environments.<ref name=":0" /> Over half of the nursing students surveyed reported getting less than the recommended 7 hours of sleep per night; however, students who reported more sleep hours also reported better sleep quality.<ref name=":0" />

Given the significant impact of sleep deprivation on academic performance and the differing sleep patterns observed in students, educational institutions have begun to reconsider start times. For instance, a school in [[New Zealand]] changed its start time to 10:30&nbsp;a.m. in 2006, to allow students to keep to a schedule that allowed more sleep. In 2009, Monkseaton High School, in [[North Tyneside]], had 800 pupils aged 13–19 starting lessons at 10&nbsp;a.m. instead of the normal 9&nbsp;a.m. and reported that general absence dropped by 8% and persistent [[absenteeism]] by 27%.<ref name="monkseatonbbc">{{cite news | title=Lie-in for teens yields benefits | work=BBC News | date=22 March 2010 | url=http://news.bbc.co.uk/2/hi/uk_news/education/8579951.stm | access-date=29 September 2018 | first=Margaret |last=Ryan}}</ref> In 2024, some 20 schools in Denmark have pushed back their start times, and there have been positive results.<ref>{{cite news |last1=Min |first1=Roselyne |title=In Denmark, schools are trialling later start times to give teens a sleep boost |url=https://www.euronews.com/health/2024/07/25/in-denmark-schools-are-trialling-later-start-times-to-give-teens-a-sleep-boost |work=euronews |date=2024-07-29}}</ref>

College students represent one of the most sleep-deprived segments of the population.  Only 11% of American college students sleep well, and 40% of students feel well rested only two days per week. About 73% have experienced at least some occasional sleep issues.  This poor sleep is thought to have a severe impact on their ability to learn and remember information because the brain is being deprived of time that it needs to consolidate information which is essential to the learning process.<ref>{{cite web | title=Need Sleep | website=Harvard Sleep and Memory | date=16 December 2008 | url=http://healthysleep.med.harvard.edu/need-sleep/whats-in-it-for-you/memory | access-date=29 September 2018}}</ref>

==See also==
{{col div|colwidth=20em}}
* [[Effects of sleep deprivation on cognitive performance]]
* [[List of thought processes]]
* [[Lucid dream]]
* [[Preconscious]]
* [[Sharp wave–ripple complexes]]
* [[Sleep-learning]]
* [[Unconscious mind]]
{{colend}}
{{Portal bar|Philosophy|Psychology}}

==References==
{{Reflist}}

==External links==
* [http://www.news.wisc.edu/13733 "Study puts us one step closer to understanding the function of sleep"] - from the University of Wisconsin-Madison School of Medicine and Public Health
* [http://www.nature.com/nsu/010426/010426-15.html "To sleep, perchance to learn"] - from ''[[Nature (journal)|Nature]]''
* [http://www.sciencemag.org/cgi/content/full/282/5397/2163 "Birds May Refine Their Songs While Sleeping"] - from ''Science''
* [http://therapeuticliteracycenter.com/the-role-of-sleep-in-learning-memory-and-health/ "Review of Studies showing sleep helps improve memory, learning"] - from Science and Nature

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{{DEFAULTSORT:Sleep And Learning}}
[[Category:Sleep]]
[[Category:Sleep physiology]]
[[Category:Learning]]