Segmented sleep
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2008-06-20T06:21:18Z
Blueporch
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'''Segmented sleep''', '''divided sleep''', '''bimodal sleep pattern''' and '''interrupted sleep''' are modern Western terms for a [[polyphasic sleep|polyphasic]] or biphasic sleep pattern found in [[medieval Europe|medieval]] and [[Early modern Europe|early modern]] [[Europe]] and many non-industrialised societies today, where the night's sleep is divided by one or more periods of wakefulness. This is particularly common in the winter.<ref>{{cite journal | last = Coturnix | date = 16 October 2006 | title = What is a 'natural' sleep pattern? | journal = A Blog Around the Clock | publisher = ScienceBlogs | url = http://scienceblogs.com/clock/2006/10/what_is_a_natural_sleep_patter.php | format =
| accessdate = 2007-12-29 | quote = Includes image: the original data from Wehr's experiment. }}</ref>
The human [[circadian rhythm]] controls a sleep-wake cycle of wakefulness during the day and sleep at night. Superimposed on this basic rhythm is a secondary one of light sleep in the early afternoon (see [[siesta]]) and quiet wakefulness in the early morning.
The two periods of night sleep were called ''first sleep'' (occasionally ''dead sleep'') and ''second sleep'' (or ''morning sleep'') in medieval [[England]]. First and second sleep are also the terms in the [[Romance languages]], as well as the [[Tiv]] of [[Nigeria]]: In French, the common term was premier sommeil or premier somme; in Italian, primo sonno or primo sono; in Latin, primo somno or comcubia nocte.<ref>A. Roger Ekirch (2005), ''At Day's Close: Night In Times Past'', pp 301-302. ISBN 0-393-05089-0</ref> There is no common word in English for the period of wakefulness between, apart from paraphrases such as ''first waking'' or ''when one wakes from his first sleep'' and the generic ''watch'' (in its old meaning of being awake). In [[French language|French]] an equivalent generic term is ''dorveille'' ("twixt sleep and wake").
This period of wakefulness was often only semi-conscious, as the French term implies. It was highly valued in medieval Europe as a time of quiet and relaxation. [[Peasant]] couples were often too tired after a long day's work to do much more than eat and go to sleep, but they would wake later on to talk and make love.<ref>A. Roger Ekirch (2005), ''At Day's Close: Night In Times Past'', pp 308-310. ISBN 0-393-05089-0</ref> People would also use this time to pray and reflect,<ref>Frances Quarles (London 1644), ''Enchirdion'' ch. 54</ref> and to interpret [[dream]]s, which were more vivid at that hour than upon waking in the morning,<ref>A. Roger Ekirch (2005), ''At Day's Close: Night In Times Past'', pp 311-323. ISBN 0-393-05089-0</ref> and even to visit. This was also a favorite time for authors and poets to write uninterrupted.
There is evidence from [[sleep research]] that this period of nighttime wakefulness, combined with a midday nap, result in greater alertness than a monophasic sleep-wake cycle.{{Fact|date=December 2007}} The brain exhibits high levels of the [[pituitary]] [[hormone]] [[prolactin]] during the period of nighttime wakefulness, which may contribute to the feeling of peace that many people associate with it. It is in many ways similar to the [[hypnagogia|hypnogogic]] and hypnopompic states which occur just before falling asleep and upon waking, respectively.
Because members of modern industrialised societies, with late hours facilitated by [[electric lighting]], no longer have this sleep pattern, they may misinterpret and mistranslate references to it in literature. Common interpretations of the term 'first sleep' are 'beauty sleep' and 'early slumber'. A reference to first sleep in the ''[[Odyssey]]'' was translated as such in the 17th century, but universally mistranslated in the 20th.<ref>A. Roger Ekirch (2005), ''At Day's Close: Night In Times Past'', p 303. ISBN 0-393-05089-0</ref>
The modern assumption that consolidated sleep with no awakenings is the normal and correct way for human adults to sleep, leads many to approach their doctors with complaints of maintenance [[insomnia]] or other [[sleep disorder]]s. Their concerns might best be addressed by assurance that their sleep conforms to historically natural sleep patterns.<ref>{{cite journal
| last = Brown
| first = Walter A., MD | date = 2006-05-26 | title = Acknowledging Preindustrial Patterns of Sleep May Revolutionize Approach to Sleep Dysfunction | journal = Applied Neurology | volume = | issue = | pages = | publisher = CMPMedica | location = | issn = | pmid = | doi = | bibcode = | url = http://appneurology.com/showArticle.jhtml?articleId=188500785 | format = | accessdate = 2008-02-03 | quote = The discoveries of Ekirch and Wehr raise the possibility that segmented sleep is "normal" and, as such, these revelations hold significant implications for both understanding sleep and the treatment of insomnia. }}</ref>
==References==
{{reflist}}
*{{Cite book|chapter=The Watch|title=The Head Trip: Adventures on the Wheel of Consciousness|year=2007|isbn=978-0679314080|first=Jeff|last=Warren}}
*Jean Verdon, ''Night in the Middle Ages'', trans. George Holoch (2002). ISBN 026803656X.
== External links ==
*[http://www.historycooperative.org/journals/ahr/106.2/ah000343.html Sleep We Have Lost: Pre-industrial Slumber in the British Isles]
*[http://www.loc.gov/today/cyberlc/feature_wdesc.php?rec=3730 Library of Congress Webcast - At Day's Close: Night In Times Past]
*[http://www.sciencenews.org/pages/sn_arc99/9_25_99/bob2.htm Slumber's Unexplored Landscape: People in traditional societies sleep in eye-opening ways]
*[http://www.nytimes.com/2006/03/14/health/14beha.html?_r=3&oref=slogin&oref=slogin&oref=slogin New York Times, Richard A. Friedman, M.D., March 14, 2006, Wake Up and Smell the Savanna]
*[http://scienceblogs.com/clock/2006/10/what_is_a_natural_sleep_patter.php Coturnix, ScienceBlogs] Includes image of original data, Wehr's experiment
[[Category:Sleep]]
[[Category:Circadian rhythms]]