Changes

<center>For lessons on the [[topic]] of '''''Sleep''''', follow [https://nordan.daynal.org/wiki/index.php?title=Category:Sleep '''''this link'''''].</center>

<center>For lessons on the [[topic]] of '''''Sleep''''', follow [https://nordan.daynal.org/wiki/index.php?title=Category:Sleep '''''this link'''''].</center>

==Anthropology of sleep==

==Anthropology of sleep==

[[Research]] suggests that sleep [[patterns]] vary significantly across [[cultures]].  The most striking [[differences]] are between [[societies]] that have plentiful sources of artificial [[light]] and ones that do not.  The primary difference appears to be that prelight cultures have more broken-up sleep patterns.  For example, people might go to sleep far sooner after the sun sets, but then wake up several times throughout the night, punctuating their sleep with periods of [[wakefulness]], perhaps lasting several hours.  The [[Liminality|boundaries]] between sleeping and waking are blurred in these societies. Some observers believe that nighttime sleep in these societies is most often split into two main periods, the first characterised primarily by deep sleep and the second by [http://en.wikipedia.org/wiki/Sleep#REM_sleep REM sleep]. This [http://en.wikipedia.org/wiki/Segmented_sleep segmented sleep] has led to [[expressions]] such as "first sleep," "watch," and "second sleep," which appear in [[literature]] from preindustrial societies all over the world.

[[Research]] suggests that sleep [[patterns]] vary significantly across [[cultures]].  The most striking [[differences]] are between [[societies]] that have plentiful sources of artificial [[light]] and ones that do not.  The primary difference appears to be that prelight cultures have more broken-up sleep patterns.  For example, people might go to sleep far sooner after the sun sets, but then wake up several times throughout the night, punctuating their sleep with periods of [[wakefulness]], perhaps lasting several hours.  The [[Liminality|boundaries]] between sleeping and waking are blurred in these societies. Some observers believe that nighttime sleep in these societies is most often split into two main periods, the first characterised primarily by deep sleep and the second by [https://en.wikipedia.org/wiki/Sleep#REM_sleep REM sleep]. This [https://en.wikipedia.org/wiki/Segmented_sleep segmented sleep] has led to [[expressions]] such as "first sleep," "watch," and "second sleep," which appear in [[literature]] from preindustrial societies all over the world.

Some societies display a fragmented sleep pattern in which people sleep at all times of the day and night for shorter periods. In many [http://en.wikipedia.org/wiki/Nomadic nomadic] or [http://en.wikipedia.org/wiki/Hunter-gatherer hunter-gatherer] societies, people will sleep on and off throughout the day or night depending on what is happening.  Plentiful artificial [[light]] has been available in the industrialised West since at least the mid-[http://en.wikipedia.org/wiki/19th_century 19th century], and sleep patterns have changed significantly everywhere that lighting has been introduced.  In general, people sleep in a more concentrated burst through the night, going to sleep much later, although this is not always true.

Some societies display a fragmented sleep pattern in which people sleep at all times of the day and night for shorter periods. In many [https://en.wikipedia.org/wiki/Nomadic nomadic] or [https://en.wikipedia.org/wiki/Hunter-gatherer hunter-gatherer] societies, people will sleep on and off throughout the day or night depending on what is happening.  Plentiful artificial [[light]] has been available in the industrialised West since at least the mid-[https://en.wikipedia.org/wiki/19th_century 19th century], and sleep patterns have changed significantly everywhere that lighting has been introduced.  In general, people sleep in a more concentrated burst through the night, going to sleep much later, although this is not always true.

In some [[societies]], people generally sleep with at least one other person (sometimes many) or with [[animals]]. In other cultures, people rarely sleep with anyone but a most [[intimate]] [[relation]], such as a spouse. In almost all societies, sleeping partners are strongly regulated by [[law|social]] [[standards]]. For example, people might only sleep with their immediate [[family]], extended family, spouses, their [[children]], children of a certain age, children of specific [[gender]], [[peers]] of a certain gender, [[friends]], peers of equal social rank, or with no one at all. Sleep may be an actively social [[time]], depending on the sleep groupings, with no constraints on noise or activity.

In some [[societies]], people generally sleep with at least one other person (sometimes many) or with [[animals]]. In other cultures, people rarely sleep with anyone but a most [[intimate]] [[relation]], such as a spouse. In almost all societies, sleeping partners are strongly regulated by [[law|social]] [[standards]]. For example, people might only sleep with their immediate [[family]], extended family, spouses, their [[children]], children of a certain age, children of specific [[gender]], [[peers]] of a certain gender, [[friends]], peers of equal social rank, or with no one at all. Sleep may be an actively social [[time]], depending on the sleep groupings, with no constraints on noise or activity.

==External links==

==External links==

* [http://healthysleep.med.harvard.edu/ Healthy Sleep] from the Division of Sleep Medicine at [http://en.wikipedia.org/wiki/Harvard_Medical_School Harvard Medical School] and [http://en.wikipedia.org/wiki/WGBH-TV WGBH] Educational Foundation

* [https://healthysleep.med.harvard.edu/ Healthy Sleep] from the Division of Sleep Medicine at [https://en.wikipedia.org/wiki/Harvard_Medical_School Harvard Medical School] and [https://en.wikipedia.org/wiki/WGBH-TV WGBH] Educational Foundation

* [http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0060216&ct=1 Is Sleep Essential?] by Chiara Cirelli and Giulio Tononi, from the [[Public Library of Science]] Biology

* [https://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0060216&ct=1 Is Sleep Essential?] by Chiara Cirelli and Giulio Tononi, from the [[Public Library of Science]] Biology

* [http://www.nhlbi.nih.gov/about/ncsdr/index.htm National Center on Sleep Disorders Research]

* [https://www.nhlbi.nih.gov/about/ncsdr/index.htm National Center on Sleep Disorders Research]

[[Category: Biology]]

[[Category: Biology]]