2,083
edits
Changes
From Polyphasic Sleep Wiki
Circadian rhythm section add
==Circadian rhythm==
==Circadian rhythm==
The circadian rhythm is the body clock aligned to local solar time by light exposure, among other factors. It produces hormonal effects that changes throughout the day consistently to produce effects on the body. One of the main effects is the secretion of melatonin, the presence of which is essential for entering SWS, and also affects the timing of REM sleep.
After sunset when light levels reduce, the body starts to secrete melatonin to promote sleep. The rising levels of melatonin early in the night allows the body to gain SWS in the first few sleep cycles. In contrast, as melatonin levels drops in the morning, REM becomes the preferred sleep phase to be gained.
[[File:Melanopic.jpg|thumb|Melanopic sensitivity function]]
In modern times with the advent of artificial light, many people's circadian rhythms have been pushed forward (i.e. later). However, this exposure to artificial light sources also compromises people's ability to gain SWS efficiently. The extent to which light influences the circadian rhythm is given by the melanopic sensitivity function, which peaks at ~480nm (blue) and drops off on both sides. To reduce this effect, a [[dark period]] must be employed, during which blue and green lights must not enter the eye. This can be done in many ways, such as with [[red goggles]] or [[screen filters]].
==Minimum sleep threshold==
==Minimum sleep threshold==
|BiphasicX, E1-ext,
|BiphasicX, E1-ext,
Siesta-ext, Segmented-ext
Siesta-ext, Segmented-ext
|7-9
|7-8
|Negligible
|Negligible
|
|
