#sleep experiment

As voted on on Wednesday, I'll be covering the basics of the circadian rhythm! When I say basics, I mean the basics, this isn't a deep dive by any means and really just scratches the surface of it. Feel free to add anything on or go and research more yourself if you find it interesting. I might do a deep dive once I get more knowledgable on the subject, but for now, this is it!

[My writing will be in blue for ease of recognising what is my writing and what is quoted. Quoted things will have their links attached.]

Dictionary definition: Circadian rhythm (sir-KAY-dee-un RIH-thum). The natural cycle of physical, mental, and behavior changes that the body goes through in a 24-hour cycle.

"Circadian rhythms are the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle. Light and dark have the biggest influence on circadian rhythms, but food intake, stress, physical activity, social environment, and temperature also affect them. Most living things have circadian rhythms, including animals, plants, and microorganisms. In humans, nearly every tissue and organ has its own circadian rhythm, and collectively they are tuned to the daily cycle of day and night.

Circadian rhythms influence important functions in the human body, such as:

Sleep patterns

Hormone release

Appetite and digestion

Temperature" National Institue of General Medical Sciences

Basically, your circadian rhythm is your biological time clock*. Telling your body when to do stuff based on your environmental factors and habits; also called a Zeitgeber (German, literally translating to 'time giver', also translated to 'synchronizer'). A Zeitgeber is anything that resets the bio-time-clock. Most commonly its the sun, but it can really be anything that is consistently reoccuring enough in your scheduele for your body to recognize it as a signal of 24hrs passing. This could be food, excercise, social interactions, etc. Humans are creatures of habit, and our brain reflects that.

*Technically, it's not. I know, sorry. But it is at the same time. The suprachiasmatic nucleus (SCN) is your bio-time-clock; but the SCN is what triggers your circadian rhythm, not just for sleep but for all the other things affected by it; like body temperature, which rises during the day to keep you awake, and drops at night.

My personal favourite experiment / study on the circadian rhythm is the Richardson & Kleitman Mammoth Cave Experiment, 1938.

^^ short video from 1938, subtitles are available.

"Normal sleep--wakefulness cycles operate on a seven day, 24 hour cycle; Kleitman wanted to adjust himself and graduate student Richardson to a six day, 28 hour week."

"Kleitman and Richardson spent 32 days in the cave with a strict schedule of sleeping for 9 hours, working for 10, and 9 hours of leisure time. The absence of light and noise and a constant temperature made for a great experimental environment."

"The goal of their experiment was to determine if humans had an ingrained 24 hour cycle or if we can adjust our circadian rhythm. Measuring changes in body temperature shows a range of 1–2°F change with the highest value in the afternoon and the lowest in the early morning. This curve is not seen in infants, but develops as children adapt to rest-wakefulness cycle of 24 hours."

"It is known that the body temperature curve can be shifted any number of hours, as when a person moves from the United States to China, or it can be completely inverted as when a person regularly stays up at night and sleeps in the day-time [sic]. In either case, however, the duration of the cycle remains unchanged, namely, 24 hours. It is our purpose to find how easy or how difficult it is for a grown up individual to change his body temperature curve from a 24-hour to a 21-hour or 28-hour cycle."

^^ above four (4) paragraphs and video from here

After the experiment concluded, Kleitman wrote and published a study based on their findings called 'Sleep and Wakefulness'.

^^ you can borrow the book for free online, you kind find lots of books / videos / texts / media on here, you just need to sign up <33 (The Internet Archive)

"Nathaniel Kleitman, who died on August 13, 1999 at the age of 104, can be properly described as “the father of modern sleep research”. His claim on this title stems from both his scholarly integration of the work in the field and his own research. His 1939 compendium of prior work on sleep and wakefulness, revised in 1963 (18), includes thoughts on sleep ranging from Aristotle and other ancient thinkers to 20th century pioneers such as Pieron, Hess, Nauta and Kleitman’s contemporaries. The explosive recent growth of the field guarantees that this will be the last such comprehensive, research oriented integration of the literature in sleep research. In the introduction to the 1939 edition, Kleitman apologizes that his reading abilities are “limited to French, German, Italian and Russian” (and English). However, despite this “handicap” he critically integrates 4337 references covering sleep, circadian rhythms, sleep disorders, hibernation and theories of sleep function." - A Tribute to Nathaniel Kleitman

Okay, so not as short as I originally expected, but I could've written more, so yall are lucky I decided to cut it off there. If you have any questions or noticed that I got something wrong, or would ilike to add anything - please feel free!!

I have gotten a lot of what I know of sleep from an amazing amazing book called 'Why We Sleep' - by Matthew Walker. I'm only part way through it but I love it so much, and can definitely see myself buying a copy in the future. Here's a link to his website: https://www.sleepdiplomat.com/ [I only just found his website and omg I didn't know he had a podcast, I know what I'm going to be listening toooo]

Anyway, I hope this has been informative and is a good starter to get you into the science of sleep! I love Hypnos and his realm.. and I hope I can spread further information on him and his domains to others!