Hello everyone and welcome back to my Research topic, “How does sleep effect our ability to learn and retain knowledge?”
I would like to start by thanking Lauren Jang, Rhea Manhas, Jessica Scott, and Ivy Hao, for there comments and recommendations, and on that note there should be a survey up at some point (hopefully next 24 hours of this being posted) asking about what time you go to sleep at and other such questions, it would be great if you could go and reply to it. Thank you to Ivy for the idea, and the rest for the other ideas.
For this round (round 2) we will be looking into the following (changes have been highlighted):
- ** Does the time at which we sleep matter? (EX. 9pm to 6am vs. 4pm to 1am) ** This has been moved to the next round as I want to do this one after the survey is done.
- ** Correlation between memory and sleep? Correlations between or attention span and sleep? ** This has been moved to the next round as I want to do this one after the survey is done.
- Habits people have when asleep and why. (Rhea inspired)
- Why do most people use the monophasic sleep cycle? (Jessica inspired)
- "does age affect the amount of sleep needed to learn and retain knowledge to the best of our abilities?" (Lauren inspired)
- Why do we sometimes not remember our dreams? (Lauren inspired)
- Exceptions to the amount of sleep (such as someone needing 6 hours instead of 8 to function at their best), and what is this presumably caused by?
- What is sleep debt, and how does it affect us?
So, to start does age affect the amount of sleep needed to learn and retain knowledge to the best of our abilities?
Yes, it does. The necessary sleep needed (in a monophasic sleep cycle) for an adolescent would be recommended between 9 to 9 and a half hours to be able to function at your best, while for an adult or generally someone who has finished growing they would need 7 to 7 and a half to work at their best. Of course, the actual amount varies from person to person, those numbers are simply an estimate range. Usually/practically most of the time an adult will need less time then an adolescent to function at their best, of course though there are exceptions its best if you try a few different amounts and see what works best for you.
On to the next, what habits do people have when asleep and why?
One example of a habit is grinding your teeth while asleep, and its completely normal, and referred to as bruxism; a problem does arise though when it’s done too often (1). There are a few reasons as to why you could be grinding your teeth, and while it can be caused by stress and anxiety (they more so cause a clenching of the teeth rather then a grinding), its more likely caused by some sort of problem with your teeth (1). Of course, it can also be caused by a sleep disorders, one example would be sleep apnea (sleep apnea is when your breathing is disrupted, while asleep) (1). Of course, if it becomes a problem, your dentist will most likely fit you with a mouth guard to protect your teeth (1). As to why we have these habits, each one has a different reason, but since teeth grinding was mentioned ill explain that one. So, going off the idea that it’s caused by sleep apnea, what happens when your asleep is that the soft tissue in both the mouth and tongue relax, cause you know your asleep now might in keeping them active, and so when this happens they end up blocking the airway, making it difficult to breath/disrupting your breathing, hence sleep apnea (2); the teeth grinding is your body’s solution to sleep apnea, as it was found that one of the factors to deblocking the airway, and bettering your body’s ability to breath was the grinding of the teeth (2), they tested their theory afterwards maybe giving the same people a CPAP machine (it made sure their breathing was kept undisrupted), and ta da the grinding went away as well (2). So, these habits could for one be a simply your body’s reaction to problems it encounters while you are asleep, though there are another 2 types as well one being sleep paralysis (when your brain wakes up and works, and possibly your eyes as well, but your body is still paralysed) and the other being the opposite sleep walking (where the body isn’t paralysed but your asleep), but those are more sleep disorders, rather then habits of the body.
Why do we sometimes remember our dreams and other times not?
So, this question actually interests me quite a bit as, I never remember my dreams except for maybe 1 or 2 every year, but everyone does dream every night, even the people who say they don’t, they just don’t remember; as to why that is there isn’t an exact answer, it more so a theory/idea. So, a study done in 2011 found that in the moments after you wake up the hippocampus (A part of the brain critical to the movement of information from short term memory to long term memory) doesn’t actually wake up till a bit after you (3). See while your asleep the hippocampus takes information from your short-term memory, consolidates it and then sends it to the cortex for long term memory storage (3); the problem is that the cortex must be active for short term memory’s to be able to be kept, so while it is active during the day and most of the night when asleep doing its job, it does eventually go inactive/asleep, and when you wake up it’s a bit slower to wake up, which is why in the morning you might remember the dream for a bit, but a little while later you’ve completely forgotten (3). Now that’s for you remember kind of in the morning but forget, a fleeting dream, but what if you don’t remember anything? That’s a different idea, it differs in that instead of it being that your hippocampus is asleep, its that, your hippocampus is only sending information to the cortex and not receiving (3); so any new memories made (your dreams in other words) by the cortex aren’t sent to the hippocampus to be consolidated and then sent back to the cortex for long-term memory storage, so they are forgotten, and not saved (3). Of course, that begs the obvious question, then how does anyone remember dreams? Well you see their presumption to that comes from a different study that found that when your asleep people that remember their dreams more often usually have a moments during the night where for 2 minutes, they are practically “awake”, but people who remember less are only “awake” for 1 minute on average, so the idea for the moment is that in those 2ish minutes dreams are consolidated and sent to the cortex(3), but of course there’s no way to prove any of this 100%, as we have no way to tell exactly what the brain is doing, we can only guess off of evidence, one example of this is the way we think everyone dreams, which comes from an experiment where they found that if you wake up people, that claim they don’t dream, at the right time they were able to remember their dream(4).
Why do most people use a monophasic sleep cycle?
So, as to this there are a few possible reasons, one being that’s just how people sleep naturally, its also seen in animals (*other sleep cycles are also seen in animals*), though people have also naturally adapted to biphasic sleep cycles (imagine a normal length sleep, with a nap during the day) so that’s debatable (5), to each their own I would say. Another guess as to the reason is that it was shaped from the modern industrial work day (6-8 hour segment per day), as well as the creation of artificial illumination making is more wanting to sleep when they are off for one period preferring to only be up when we have the on, its actually been debated that before the industrial era biphasic sleep cycles and polyphasic sleep cycles were common (5); this would make sense as study’s point that they are more helpful due to the small Naps/breaks which give your brain a chance to clean its memory’s in a way (for more on them view round 1). Me personally id say its simply more effective, as trying to follow a polyphasic sleep cycle wouldn’t work (see SCHOOL), and I can’t really nap during the day unless I’m just dead exhausted (see Grouse 24 hours of winter as an example) so biphasic is also out of the question, its simply more convenient a monophasic sleep cycle.
What is sleep debt and how does it affect us?
Sleep debt could be thought of similar like a credit card debt, imagine that each day you had to pay off a debt to your body for 7-9 hours (paid in sleep), now if you sleep 6 hours only, your now in debt by 1 hour, doing this every day you’d go more and more in debt, the problem with this is that while at first you might have reminders like headaches and such, but after a while those go away (6). Luckily for you though you don’t get charged interest, but it is recommended you deal with it earlier rather then later, simply add a extra hour of sleep to your normal recommended amount for a while and you should be fine, reasons as to why its better dealt with sooner rather then later for one is that it increases your chances of sleep disorders, and sleep deprivation (6). If it worse then just missing a few hours for a week or a month, then it may take a few months instead for the sleep debt to be repaid (6) The other problem with sleep debt is that it doesn’t just cause other problems but also makes it’s own, its been linked to worsening your mood and also negatively impacting you cognitive performance (7). So, if you want to function at your best it might be necessary to not only just get the recommended amount of sleep but also add a few hours to pay off your deb
Cases where people need less sleep then the average to function best.
So, due to the fact that the amount of sleep needed varies from person to person this could just be viewed as variation within our species, but there are special cases of the extreme. One such case of this is when there are mutations to the Dec2 gene in humans (more specifically the transcriptional repressor hDEC2-P385R), as its been found that its directly linked to regulating the sleep length in mammals (8). Which is why its thought that some people’s perfect amount of sleep is more like 4 hours or possibly less, its also these people that the uberman sleep cycle is most useful for. Another possible reason for this difference is your body’s circadian rhythm ( an internal clock, on a 24 hour cycle that switches between you being sleepy and alert, its actually this and the ultradian rhythm that some sleep cycles are based off of), so changes to it can effect how much sleep you would actually need, things that can effect it are well the part of the brain that controls it, the hypothalamus, but so can outside factors such as light (though this is cause they effect the hypothalamus who then effects the circadian rhythm) (9).
- https://www.livescience.com/62...-dreams-quickly.html / https://www.cell.com/neuron/fu...0896-6273(11)00166-8
Photos (in order from first to last):
In My next round of research I will be looking into:
- How are core motor skills effected by sleep? (EX. vision, hearing, ability to process information)
- Would more activity during the day make more sleep necessary?
- Does school effect the amount of time we need to sleep? is it a contributing factor in why adults need 7 hours, but adolescents need 9?
- Are there things we can do to need less sleep? Are there things we do that make us need more sleep?
- The good and bad of having to wake up early.
- Does the time at which we sleep matter? (EX. 9pm to 6am vs. 4pm to 1am)
- Correlation between memory and sleep? Correlations between or attention span and sleep?