Sleep or fail

It's 3 o’clock in the morning and you’re rushing through your lectures notes to prepare for your exam that's in a few hours. You’re desperately trying to focus, but your brain doesn't allow you to do so. You're easily distracted, and you stay stuck on a sentence that you repeat a few times before proceeding. We all had this happen to us at least once. Your brain is craving sleep — it wants to go to bed. What do you do about it? You go to sleep, fall asleep or most often carry on with your studying.

While taking the exam, your memory is very blurry. You cannot remember much of what you learned a few hours ago, and you struggle to solve — what seems to be — complex problems. When you get your grade, you're satisfied. I mean, you studied at the last minute, and you got a B. Worth it! But it doesn't end there. A few months later, you’re sitting in the first lecture of the more advanced classes of your program. The professor is reviewing basic concepts before getting into the course material but you have no idea what the hell he's talking about. You don't remember a single thing.

Use it or lose it

To tell you what's happening in your brain, I need to provide you with some background information on memory. Memory is learning that has persisted through time. It's information that is stored and that can be accessed in two major ways: recognition and recall. Recognition retrieves information based on cues. For example, if I ask you the following: Is Paris the capital of France? You would know right away because of the cues Paris and France. On the other hand, retrieving information without a cue happens through recall. For example, memory is accessed through recall when you’re reminiscing about a vacation.

In the brain, memories are represented by neural connections. When a memory is created, neurons connect. Neurobiologists often use the following famous quote to explain the fundamental mechanism underlying memory: "Use it or lose it." Strengthening a memory requires time and repetition. Without those two key elements, the memory is lost and the connections that make it fade away.

You, who crammed the course material, clearly did not repeat it throughout the semester. You probably went over the material once or twice and will not touch it again until next semester. By then you will have forgotten most of it. Not only that but you were deprived of sleep when you took that exam. Sleep is the single most important thing for memory consolidation. It's during sleep that our memories are put together and the connections that form them are strengthened. And I'm not talking about the four hours of sleep you had before taking the exam. A good night of sleep is necessary for successful memory consolidation. Not only that but sleep also restores our ability to solve complex problems, which decays throughout the day. This will sound unpleasant, but you did all that cramming for nothing. What’s worst is that sleep deprivation increases the risk for mental illness.

A lovely lady that I’ll never forget

This reminds me of a story — no pun intended. On my way to pick up a rented car, while waiting for the bus, a lady asked me to show her directions. "My dear son, does this bus pass this address?" she asks. New to the area myself, I take out my smartphone and look up the address. Then she asks me how old I am and I tell her that I'm 24. And she says, "Oh! That's lovely, you are the same age as my son." She then went on to tell me how her son explained to her how to get to her destination. After a short conversation, we stopped talking. There I stand thinking about my road trip. I was all excited about this trip until a few seconds later.

She asks me again: "My dear son, does this bus pass this address?" I can't describe how I felt at that time. It was the first time I had a discussion with someone that has Alzheimer's disease. On my way back home, I had a gazillion questions rushing through my mind. First, why is she alone? How can she remember that her son showed her the way but not a conversation we had few identical times in a row? I answered this one easily: she probably has some defect in her short-term memory. But then, if she had short-term memory problems, how did her son get the information through while I was helpless? Crazier questions came after. One of them was: does she even have a son? I was shocked!

Memory, Alzheimer’s disease and my research

I study aging and my goal is to increase human lifespan and delay the onset of age-related diseases like Alzheimer’s. I have never met someone with one of these diseases, yet I have been doing research for fours years trying to contribute to a cure for them. That day, that lovely lady made me realize the importance of my research.

You are probably wondering why I am telling you all of this? Well, I care about you and cramming does nothing good to your brain because it’s usually done in a sleep-deprived state. Sleep deprivation leads to poor memory consolidation and a poor ability to solve complex problems. On the long term, this results in poor academic performance and increases the risk for an array of mental disorders. So, until I find a cure to these diseases and a magic pill that will remove the need for sleep, you need to take care of your brain. Jokes aside, if you want to ace the exam and remember concepts for the more advanced courses, you need to practice the material through repetition. It's the only way to remember it.

About the author