To Sleep or to Stay up Studying, That Is the Question

An Independent Project by Monika Nemcova ’19
Part 3 of 4

In my Spanish class, one of the girls summarized the universal student’s dilemma: we can either study, have a social life, or sleep – and as our time is not infinite, we manage to do only two of the three options. Well, most of us do not consider eliminating friends and becoming a hermit a viable life option. And at Andover, studying is really not optional – which leaves sleep as the least important activity. Nights thus become an endless reservoir of time which is spent either by writing that English essay or Snapchating with a well-meaning friend. For my whole year at PA, I have never met someone saying that getting a good night of sleep was their priority. Yet, as I try to argue in my series of posts about the importance of sleep, sleeping well is one of the biggest factors that influence our behavior and our performance in life. In this article, I would like to show you that the distinct choice between studying and sleeping does not exist – as the latter directly enables the former. In order to learn, the brain simply requires sleep.

When thinking about the role of sleep in learning, I remembered my dad’s childhood story that has never ceased to fascinate me. Back in the seventies, the Czech Republic still had a communist government, that made Russian a compulsory subject in all schools (as a nod to the USSR, which backed the regime). My dad, never one for learning languages, hated his Russian lessons with a passion. When he was in sixth grade, his Russian teacher insisted on learning long, lyric poetry by heart as a part of the curriculum. No one expected much of my dad. But he surprised everyone by a fluent recitation. He explained to me that he had found out that if he studied the poem straight before going to sleep, he then slept very poorly but dreamt about the poem. In the morning, he could recall it without problems. In fact, as he was telling me the story, he was still able to recite the poem, thirty years after.

The story of my dad might be an extreme case, but the relationship between dreaming about a task and improvement in that activity has been experimentally established [1]. In 2010, researchers taught two groups of people how to navigate a 3D maze. After the learning session, one of the groups went to sleep and the second one remained awake. In the napping group, the subjects who reported dreaming about things associated with the maze fared significantly better in the re-testing of the navigation. In contrast, no such distinction appeared in the awake group – the performance of the subjects was not affected by thinking about the maze. The researchers were careful not to generalize the findings as direct causation between dream experience and memory consolidation. Instead, they proposed that both the dreaming and the improvement of the task were the results of the processes of “memory reactivation and consolidation in sleep” [1]. So dreaming about the task would be just a side product of an efficiently learning brain.

However, that still does not explain how do these “processes” function, nor, for that matter, why was my dad’s learning technique effective only when he studied directly before going to bed. In order to understand that, we need to know a bit about how learning functions. The neurons in our brains are connected in intricate nets and pathways – one neuron always receives inputs from many others and based on the type and strength of the signal it receives, it either fires as well or stays silent. However, this system is not static. Both external (seeing a member of your tribe get eaten by a tiger because he was too loud) and internal (feeling pain after trying to touch fire) stimuli can affect the strength between the individual neurons. So in my first case, the connection between the neural pathway responsible for being stealthy and the pathway recognizing tiger territories strengthens. In the second case, the pathways for “great things to touch” and “fire” become less connected. It is not that easy but that is the basic principle. When the connection between two neurons strengthens, the neuroscientists say that long-term potentiation (LTP) has occurred. Weakening connection is called depotentiation. The last thing we need to know about learning is that the strengthening of the neural connections can be either short-term or long-term. A new experience evokes a short-term change, which, if it were left so, would disappear after four to six hours [2]. The brain needs to further strengthen the connection to make it last. And that is where sleep comes in.

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Figure 1. The connections and firing patterns of neurons are vital in learning (Retrieved from https://www.thegreatcoursesdaily.com/the-neuron-doctrine/)

Last remainder: LTP and depotentiation are chemical processes and as such depend on the brain’s own levels of chemicals, called neurotransmitters. I talked about neurotransmitters at length last time, so just a quick review relevant to learning. In REM sleep, the most prominent neurotransmitter is acetylcholine and the levels of other chemicals are low (for our context are important norepinephrine and serotonin). In NREM sleep, acetylcholine is low and both norepinephrine and serotonin occur at moderate to low levels. The neurotransmitters occurring in the brain in different sleep phases determine whatever and how the synapses can be strengthened [2].

REM Sleep

It has been experimentally established that when we learn something new, the proportion of REM in our overall sleep increases. This effect appears only when we actually learn and improve, not just all the time when we try to learn [2]. When we master that task, the amount of REM falls to normal [3]. That alone would be a good indicator that REM sleep somehow contributes to the learning process. However, there is also another proof in favor of that theory – the presence of the before-mentioned neurotransmitter acetylcholine. Acetylcholine makes the synapses (connections between neurons) especially plastic, which allows them to undergo either LTP or depotentiation [2].

LTP occurs when the neuron at the synapse fires in accordance with the general firing pattern of the brain – that EEG diagram pattern which I talked about last time (during REM, the firing pattern looks very much like the pattern of wakefulness). Depotentiation, a process as equally important for learning as LTP, is the result of a neuron firing in-between the pattern seen on the EEG. Also, depotentiation appears only in the absence of both norepinephrine and serotonin – which, again, makes the REM phase of sleep ideal for this process, as the levels of these neurotransmitters are at their lowest during REM [2, 3].

NREM Sleep

We have known for a long time that NREM sleep is also important for memory consolidation – the neurons which fired during the learning process were recorded firing again in the same order, albeit in an accelerated pattern (up to 300x). However, there is one obvious obstacle to proposing that NREM sleep also contributes to LTP – namely the absence of acetylcholine. Without acetylcholine, the short-term LTP potentiation, which happens during REM, cannot be initiated. However, it appears that NREM sleep allows the short-term LTP previously established during the REM phase to be consolidated into the more permanent long-term LTP. In favor of this hypothesis speaks the fact that protein synthesis necessary for long-term LTP notably accelerates during the NREM [2].

In addition, NREM sleep seems to contribute to depotentiation of the unused or even obstructive synapses [2].

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Figure 2. Sleeping properly is key in the learning process (Retrieved from https://www.sciencedaily.com/releases/2018/08/180806104242.htm)

Now we can finally determine the real-life consequences of insufficient sleep. Because the REM phase is the only time when brain has high levels of acetylcholine and simultaneously low levels of other, obstructive neurotransmitters, it is the only time when LTP can be initiated fully. Experiments determined that subjects that were sleep deprived after a learning session showed no performance improvement following day [3]. That is one thing to consider – if we do not get enough REM sleep, learning simply does not occur. Going to sleep might thus be the most effective thing to do before a test, instead of trying to revise the material one more time. Also, subjects allowed to go to sleep immediately after a learning session had especially enhanced performance [3] – which probably explains my childhood mystery concerning my dad’s miraculous technique of poetry memorization. So I hope that the relationship between sleep and learning is less mysterious now (also, do not trust it when someone claims to learn something new while sleeping – it is a myth originating in faulty data analysis during the early twentieth century and as such was debunked in the 50’s [4]). Next time, I would like to focus on circadian rhythms and how do they affect both our sleep and our daily routines.

 

References

[1] Wamsley, E. J., Tucker, M., Payne, J. D., Benavides, J., & Stickgold, R. (2010). Dreaming of a Learning Task is Associated with Enhanced Sleep-Dependent Memory Consolidation. Current Biology, 20(9), 850-855. https://doi.org/10.1016/j.cub.2010.03.027

[2] Poe, G. R., Walsh, C. M., & Bjorness, T. E. (2010). Cognitive Neuroscience of Sleep. Progress in Brain Research, 185, 1-19. https://doi.org/10.1016/B978-0-444-53702-7.00001-4

[3] Maquet, P. (2001). The Role of Sleep in Learning and Memory. Science, 294(5544), 1048-1052. https://doi.org/10.1126/science.1062856

[4] Kang, S. (2018, October 28). Can you learn in your sleep? [Blog post]. Retrieved from Brainy Sundays website: https://scanberlin.com/2018/10/28/can-you-learn-in-your-sleep/

 

The A-MAZE-ing Chicks…

Take On The Labyrinths of Room 103!

GUEST POST BY EMMA BROWN ’19

After a successful relay race last Monday— though some chicks were a tad distractible— Animal Behavior students have spent the past week studying associative learning and spatial cognition. This was achieved through two experiments: teaching our chicks to turn in a circle on command, and determining their learning abilities in the context of navigating a simple Y-maze.

Pictured below is Jan’s chick, Colonel Sanders, who was the only triumphant twirler in our class.

For the second experiment, my group constructed a Y-maze out of shoeboxes wherein one path from the fork would lead to food and freedom, and the other to a dead end. We tested the accuracy of Ferdi, Colonel Sanders, and a third chick over the course of five runs.

Our data depicted a significant decrease in time taken from Run 1 to Run 2 immediately followed by an outlier increase for all three birds in Run 3. Then, as the timing decreased for all birds aside from Ferdinand (who got distracted) in Runs 4 and 5 respectively, the data appeared to indicate that chicks can retain their learning of a Y-maze for a short amount of time, needing to “re-learn” the route before gaining any form of proficiency.

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Can’t Help Falling In Love With…

The Return of Animal Behavior!

Guest Post By EMMA BROWN ’19

Welcome to Animal Behavior 2018! After the eventful happenings of last Thursday evening, the arrival of baby chicks to dorms and homes was a much-appreciated change of scene. Below is a picture of my chick, Franz Ferdinand, who has a certain fondness for cuddling and attempting to roost in my hair. (Currently, as I type, Ferdi is making his best efforts to turn my attention away from my laptop by means of walking all over the keys.)

This weekend has been devoted to getting our chicks prepared for an obstacle course on Monday. This will test the strength of the filial imprinting process for each chick. At this age, chicks imprint almost immediately. After all, they’re just barely a few days old! As to provide a protective figure for them, it is important to bond with your chick early on. I have been doing this by feeding, cuddling, talking and singing to, and spending as much time with Ferdi as possible. Additionally, as chicks are attracted to the color red, I’ve been wearing solely red shirts for the past few days in true, traitorous Exonian form. (Love knows no bounds.)

Come back next week to see how my Elvis-ballad-loving chick performed for his debut race!

Schooled by the Fish

Animal Behavior Learns about Schooling of Fish

Guest Post by Carley Kukk ’19

This week in Animal behavior we researched the tendency of fish to school. Certain fish school, such as Silver Tail Rasboras, in order to protect themselves against predators. They truly embrace the idea of strength in numbers. In contrast, other fish, like red wag platys, do not school because their slow-moving bodies would not benefit from swimming in groups if a predator came along.

For our lab, Dr. Bailey asked us to come up with a procedure that could identify schooling in fish. My group and I decided to insert a piece of plastic with a hole into a tank with two different amounts of fish on each side. We would time how long it takes for all of the fish to reunite (or swim through the hole and form a school). Our fish, the red wag platys, are non-schoolers, so they didn’t mind the separation from their peers or didn’t reunite.

After we completed our own procedure, Dr. Bailey gave us her own version to test. We drew lines on the outside of the glass fish tank indicating sections 1-4. We separated all of the fish except one into a separate bowl next the side of the tank with a barrier so they couldn’t see the lone fish. After 3 minutes of allowing the lone fish to relax after his separation, we removed the barrier and tracked which section the lone fish remained in. If he was in section 1, closest to the other fish, for the entire 10 minutes, schooling occurred. Yet the red wag platys distributed themselves evenly across the sections, indicating no sign of schooling.

Ultimately, Dr. Bailey’s procedure was more effective in determining whether schooling occurred, yet the lab was extremely interesting and the fish, especially the red wag platys, were/are super cute!

Squirrels and Crayfish!

Animal Behavior Learns About Foraging and Territoriality

Guest Post by Carley Kukk ’19

The last two weeks of animal behavior have been pretty busy with learning about foraging behaviors and territoriality. To explore foraging behaviors, we utilized an abundant resource on campus: squirrels!

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We set up a station next to multiple trees around campus with 4 piles of peanuts. Two piles were 2m from the tree while the others were 6m. One pile at a certain distance had unshelled peanuts and the other shelled. During our double block, we observed squirrel activity. Although we weren’t so lucky in sighting any squirrels (weird, right?), we learned the typical trend for this activity. Unshelled peanuts closer to the tree are a more popular choice because unshelled peanuts require less handling time (aka: less energy) and they are closer to a tree where a squirrel is safe from predators.

In another experiment performed this previous week, we tested the theory that residents are more likely to dominate intruders in a battle over territory. We placed a crayfish (who is extremely territorial) in a tank overnight to establish it’s dominance over the territory.

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The next morning we added an intruder crayfish: one larger and one of the same size. The resident crayfish usually dominated an intruder of the same size, yet was defeated by an intruder of a larger size.

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Like a Chick in a Maze

Animal Behavior Continues Working with Chicks

Guest Post by Carley Kukk ’19

During our last week with the chicks, we focused on teaching them how to get through a maze using associative learning. We constructed a simple Y maze with leftover shoeboxes and placed a small pile of food at the end.

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The food acted as a positive reinforcement if the chicks successfully completed the maze. Hopefully, they would later associate the correct end of the maze with the food.

In our experiment, we used 2 chicks to strengthen our data. Each chick surprisingly ran their fastest time through the maze on their first try. This was probably a fluke as later proved in the data where the chicks always explored the other end of the maze before completing it.

Eventually it took around 30 seconds each to complete the maze. There were in total around 7 trials for each chick. They finally began to associate the ending with food and ultimately learned through operate conditioning the correct way to complete our y-maze.

Welcome Back!

Another Year, Another Great Set of Blog Posts!

Welcome back to Andover! I am sure for a lot of you, it has been a great summer, but it is time to get back into the swing of things!

We have a lot of great things planned for you this year! Be sure to check out one (or more!) of our amazing Science classes this year!

If you are enjoying your Science class or have a Science-related independent project and would like to write one (or more!) blog post – let Ms. Andersen know at randersen@andover.edu! It can even count as your work duty… (!!!!!)

Have a great year!

The Herring Are Coming!

Bio100 Visits the Shawsheen River

This year’s Bio100 class had the unique opportunity to visit the Shawsheen River last week and learn a bit about habitat change. Each period piled into a bus and drove down to near Whole Foods in Andover to a bridge overlooking the Shawsheen River.

There, they met Jon Honea, a professor at Emerson College in Boston whose research involves making computer models to see how habitat change effects different communities. In this particular spot, two dams that were built approximately 200 years ago were taken down to allow the migratory fish to return to the area. He is now monitoring the return of the fish that used to be native to this area, namely the River Herring. These fish are silver in color and about a foot long. Mr. Honea and his team are watching the river for about 10 minutes at a time to see how many of these fish are spotted. This data will help to estimate the fish’s spawning population time.

Mr. Honea talked to them a bit about why it is so important for us to repopulate the river with this Herring. They play an important role in the ecosystem as food for many animals. They spawn in fresh water rivers and then move to the ocean to grow up. Mr. Mundra also talked a bit about the two dams that were removed from the area. These dams were preventing the fish from coming back to spawn in the river. These dams were built approximately 200 years ago as a source of energy for the Powder Mills in the area. Mr. Honea also said that the downstream dam was purely ornamental – the owner of the Mills wanted a gurgling sound for his administrative staff to feel comfortable working in the building.

The class then helped Mr. Honea to count the fish in the river. They took some basic data down, the weather and temperature of the air and water, and began to look for the fish. We are looking for the stray fish who are now able to make it upstream, to see how many make it up now that the dams are gone. Unfortunately, in the 10 minutes that we were there, no one saw a fish, but the hope is that within the next three or four years the population will be thriving!

Blue Moon

An introduction to Andover’s new STEM-based Magazine

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The Phillips Academy students have published a new STEM Magazine – Blue Moon – a magazine of student-written research papers and articles.

Blue Moon was created as a platform for STEM research, as a means by which students can exercise the final step of the scientific method: communication. It aims to foster curiosity and cooperation in both its writers and its readers. Bi-annual print publications are made possible by a grant from the Abbot Academy Association, continuing Abbot’s tradition of boldness, innovation, and caring. Issue I of Blue Moon spotlights the diversity of student interest within the sciences, topics ranging from immunotherapy to gender discrimination to prosthetics. (*from the inside cover of Issue I)

We spoke with Amanda Li, ’18 who pioneered this project, which has been about two years in the making, thus far. During her freshman spring, she began to look for a place on campus to share a paper she had written. When she could not find an outlet on campus, she began to formulate the idea of a student scientific publication. 

“Seeing as there wasn’t any such thing yet, I reached out to students from different grades and backgrounds to see if they were interested in a STEM journal. The overwhelming response was yes, so I decided to take some action and hopefully allow other students to share their research and ideas. It also allows new students to start exploring various STEM areas, by allowing them to read about the interests that their peers hold.” -Amanda Li, ’18

img_6869She applied for an Abbot Grant in her lower fall to fund the publication of bi-annual issues. She received full funding and got to work! She gathered editors, graphic designers, and potential writers during her lower spring and summer. They officially started Blue Moon last fall and they have received over 30 articles so far!

“I’m really grateful for the AAA’s support, otherwise I doubt this would be possible. I’m looking forward to start the process of making the next issue!”  -Amanda Li, ’18

If you are interested in learning more or reading the many articles submitted, visit bluemoonjournal.com. They are always looking for submissions and feedback!