An Alternative to Cramming? Sleep on it!
Imagine a totally hypothetical and unrealistic scenario: It’s 2AM in the morning, and you’re studying for a midterm that’s taking place in six hours. At least, you’re trying to study. The reality is that you can’t seem to retain any information from the page you’ve been staring at for 20 minutes, and you’re fighting back yawns, even though you made sure to have at least three cups of coffee. Wake up, you plead with yourself. There’s just so much more you need to cram into your brain.
At this point, the desperation sinks in. Maybe you resort to chugging one of those caffeinated soft drinks that “gives you wings” but really makes you suffer heart palpitations and subsequent feelings of regret.
Okay, so you really don’t need another blog post reminding you of your awful past (or present…) study habits. After all, everyone has heard it before: Sleep is good for you — and is especially important in the process of learning. Yet, even though students everywhere have heard over and over before that they should “never, ever pull an all-nighter”, it’s evident that few students are actually getting a good night’s sleep.
It may be that students aren’t quite yet convinced by the drawbacks of sleep deprivation to truly alter their sleep habits… which brings us to today’s post. Instead of just listing a slew of reasons for why lack of sleep is bad for you (like the hundreds of other articles you could find on the Internet), we are sharing three powerful experiment conducted by sleep researchers that show powerful links between sleep, learning, and memory.
1. Sleep helps the brain “free up” space to form new memories
In a study from the University of California, Berkeley, researchers found an association between the bursts of brain activity during sleep known as “sleep spindles” and performance in different learning tasks. The study recruited 44 healthy young adults to complete a memorization task at 12pm in which they had to memorize 100 names and faces. They were then tested for how well they could recall this information.
For the second part of the experiment, half the group took a 90-minute nap, during which researchers measured brain wave activity. The other half stayed awake. Six hours later, the participants were once again asked to memorize a different set of 100 names and faces, and tested on their memory.
The results? Those who remained awake throughout the day did significantly worse on the second memory test than they did on the first test. In contrast, those who got some sleep performed about 10% on the second test than the first test. This tells us that a) our ability to learn degrades as the day progresses, and b) sleep provides a significant memory boost.
The brain activity measures revealed that people who had more sleep spindles showed the greatest learning capacity after napping. Researchers believe that when we sleep, these sleep spindles work to transfer fact-based memories from the brain’s hippocampus to the prefrontal cortex in order to “free up” space to take in new information.
“It’s almost like clearing out your informational inbox of your e-mail so you can start to receive new e-mails the next day” — Matt Walker
2. Sleep improves both motor and procedural skills
In another study, participants were taught a basic motor skill task that required them to repeatedly press four numeric keys on a computer keyboard in a certain sequence (e.g. 4–1–3–2–4).
When participants were retested a second time the next morning after a night of sleep, they showed an average of 20% improvement in speed and 39% improvement in accuracy!
3. Sleep strengthens, or “cements” declarative memory
Jenkins and Dallenbach (1924) demonstrated how sleep can protect against forgetting. In their study, students were taught nonsense syllables, then asked to recall as many as they possibly could with every hour. Half the students were asked to recall these syllables throughout the day (“wake group)”), while the other half recalled syllables while sleeping (i.e. they were woken up every hour and tested). Those in the “wake group” gradually forgot the nonsense syllables as the hours passed during the day. The sleep group participants showed signs of forgetting during initial testing sessions; however, their memories began to stabilize and they could no longer forgot the syllables! This study shows how sleep prevents the forgetting of newly learned information; thus, sleep plays a crucial role in helping consolidate memories.
The research findings are clear: Sleep is necessary for processing, integrating, and retaining information. Next time you consider staying up late to study, try hitting the sack instead.