Welcome to my first round of research on the topic of “How does sleep effect our ability to learn and retain knowledge?”
For this round I will be focusing on the questions:
- Is all sleep the same? What effects how you sleep?
- Does it matter how you sleep? The difference between sleeping all at once (EX.8 hours straight) or splitting it into small periods over 2 hour or 1-hour intervals (EX.20minutes every 2 hours).
- How would different sleeping disorders effect this (EX. Insomnia)?
- Do dreams effect your sleep?
- Why do we need to sleep? What does it do?
So let us start, is all sleep the same and what effects it?
Sleep does not stay the same or constant throughout the entire night, while sleeping we cycle between non-REM sleep and REM sleep. (1) REM stands for rapid eye movement and is usually shorter then non-REM, though your last period of REM sleep can last up to one hour, longer than Non-REM sleep, which is generally somewhere between 15 to 45 minutes. (1) The differences are that during non-REM the body starts to rebuild parts of the body, strengthen the immune system and more; (1) Rem sleep happens only after a cycle of non-REM, in this part of the cycle the heart rate goes and breath quickens, stage where people usually dream as the brain is more active in this time.(1) There are multiple factors that can influence sleep, both inside and outside your body.(2) A few of the factors that effect sleep are, stress, medical conditions (most importantly those that cause discomfort and chronic pain), what we eat and the environment (light, temperature) around us. (2) One of the most important and obvious factors are light, as light first effects our ability to sleep as it makes falling asleep more difficult, and it also changes our internal clock changing what time we prefer going to sleep at. (2)
Does it matter what type of sleep cycle we use?
Yes, though only marginally. Most people use a monophasic sleep cycle where in a 24-hour period we sleep somewhere from 7-10 hours, usually going to sleep at 11PM. (3) Another type of sleep cycle is Byphasic also known as siesta (3,4). A siesta sleep cycle is usually a 5-6-hour sleep during the night with a nap (somewhere from 20 to 90 minutes) later in the day. (3,4) A siesta sleep cycle has been shown to increase (due to the nap in the middle of the day your ability to remain alert, overall productivity (3,4) and Learning ability (4). Another sleep cycle is the everyman sleep cycle, It follows the schedule of a 3.5 hour sleep with 3 twenty minute naps (3,5). This cycle is based off the idea of fighting off points of natural drops in alertness, helping to keep us more focused, at certain parts of the day hence the use of naps (3,5). There are many more sleep cycles though none of the others seem to provide any improvement but rather require an amount of time to adapt to them where you feel groggy and unalert, and once adapted there are no actual advantages in comparison to a monophasic sleep cycle.
Do dreams effect our sleep?
So, most people dream on average about 2 hours a night, and almost always only during REM sleep, and while normally having anxiety dreams (“Anxiety dreams, in their most elementary form, are bad dreams that cause the overwhelming feelings of panic and unease associated with waking anxiety.”(7)) can symbolise stress in the real world, most research suggests that the dreams themselves don’t actually effect your sleep.(6) What you dream of in general do not effect your quality of sleep, but do prove that your brain is properly working and doing its job when you sleep. (8)
Why do we need sleep, what does it do for us, and how do sleep disorders effect it’s ability to properly function?
There is no actual one answer as to why we need sleep, though there are a few theories. Inactivity theory, it’s thought that sleep is a behavioral trait that is meant to protect us from being active when doing so would be more harmful to us then good, for most this would be the night when visibility is limited. Energy conservation theory, the idea behind this one is that we sleep to conserve energy, as when we sleep we use up to 10% less energy than if we were awake. Restorative theory, when we sleep our body does a few things such as synthesis protein, repair tissue, and some things it only does when sleeping such as releasing some hormones, so it’s thought we sleep so that our body may do those things. Brain plasticity theory, is the thought that sleep is directly related to the structure of the brain and any changes to it, so it is thought that we sleep for the benefit of our brain to both correctly grow and be allowed to properly function. (9) As to what it does for us, it does a lot. Starting with the physical aspects, sleep helps with healing and repairing blood vessels and the hear, sleep helps with maintaining the right amount of Ghrelin and Leptin hormones (hungry and full hormones), as well as effecting your blood glucose levels and immune system. It also effects our ability to function during the day, and it has been shown that people who are sleep deficient or sleep less are usually less productive at both work or school, sleep disorders such as insomnia and hypersomnia cause sleep deficiency. (10)
Photos (in order from first to last)
In My next round of research I will be looking into: