Sleep and learning are tightly connected. We could say that sleep helps us learn in two ways – one is before the actual learning. When we are well-rested, our brain is cleared out from sleep-inducing substances, fresh and ready for action. It is then that we are focused, concentrated and likely to absorb new information.
The second way is sleeping after learning. During sleep, new neural links (synapses) are strengthened (or weakened, if we are to forget something) and we ‘rehearse and replay’ scenes, movements, words, or tunes during the night’s rest. After waking up, we can either easily remember what we had previously learned, or we are able to easily continue learning and building our knowledge because the neural pathways were set as a foundation.
How sleep affects learning while we are awake
When we learn new things, we are first presented with information, and then we process it. This new, raw information is in our short-term memory until it’s consolidated (transferred to the long-term memory).
Memory consolidation also means that important bits are remembered and unimportant ones forgotten. Once we’re able to successfully recall the information without any help, the learning process is finished.
Both good night’s sleep and daily naps help with these processes. The sleeping brain is far from being inactive, and although it does rest, it also does a lot of memory processing.
In order to remember things we were presented with, we need to be focused. If we are not, the new stimuli could just go by, without being fully noticed or understood. When there’s no proper input, our brain has nothing or little to process, therefore, the process of learning is undermined in the very beginning.
Being well-rested helps you learn because:
Your attention is excellent. You notice, respond to, and process new information properly. You can easily connect ideas and understand them.
You can solve problems well. When you’re rested, you can find new, creative ways to solve problems.
You have an excellent recall ability. Your mind is quick in thinking, but also in remembering – this means you can easily connect new and old ideas and understand how they are related.
If you are determined to cram as much as possible in one night, remember that there’s sleep debt to be paid – you’ll suffer the consequences for a day or two. During this time, your attention might be impaired. You could also feel strong sleep inertia and daytime sleepiness, so think twice before you pull an all-nighter before an exam.
How learning continues while we sleep
When we sleep, our brain deals with the information we learned that day, and it also ‘replays’ information from before. It seems that all sleep stages (NREM and REM) play a role in the process of learning. However, different stages are responsible for different types of memory consolidation.
Deep sleep (or slow-wave sleep) and REM sleep stages help with your declarative (explicit) memory consolidation. Declarative memory is the memory of how things are named (vocabulary), dates and times of appointments, numerical values, etc. They also deal with procedural memory. This type of memory is about processes of how to do things – how to ride a bike, how to juggle, and so on.
Light sleep stages take over when it comes to motor memory or muscle memory. Motor memory is a type of procedural memory, but the focus is on muscle activity as a response to our mental orders.
Once we fall asleep, those very brain areas that were active while we were learning are reactivated. The information is sifted through so that prioritized pieces are remembered and unimportant pieces are forgotten.
A study showed that those who take a nap after learning new words outperform those who don’t. Sleep will help consolidate memory and after waking up, if we are exposed to new stimuli, what we learned will not deteriorate. Therefore, sleep preserves your hard work from being forgotten.
If you want to rely more on sleep as a learning aid, you should take a quick nap after your learning period, and do some more learning just before sleep.
Sleep deprivation and learning
If we haven’t had enough (or any) sleep, our sleep drive is strong because of the buildup of adenosine – a neurotransmitter which is a product of nerve cell activity. If we don’t sleep, adenosine stays around our nerve cells and prevents us from clear thinking and focusing.
Drowsy drivers sometimes don’t notice obvious things like the red light, or that they are approaching a danger. Or they do, but don’t react. The same thing happens when we try to study without having proper sleep. We could miss important information, just stare at a page, or even go through the entire page without knowing what it was about. Taking a test in a sleep-deprived state not only reduces your chances of remembering, but you might also misread or misunderstand tasks.
Sleep deprivation also impairs motor skills, so if you are playing an instrument or doing sports, you’re more likely to make mistakes or even hurt yourself than actually learn something.
However, it doesn’t mean we’re completely useless when sleep-deprived. If we understand the importance of what we’re learning and have the motivation and determination, our strong will can partially override the negative effects of deprivation, so in this case, learning is still possible.
But when you are tired and don’t like what you’re learning – better leave it for some time when you are well-rested because otherwise, you’ll be wasting your time.
How to make the most of our sleep when we learn or study?
The best thing you can do after learning is to take a nap. Sleep prevents you from being exposed to new information, so there’s nothing to ‘overwrite’ your memories. Also, during sleep, your knowledge is strengthened – especially what you were exposed to just before falling asleep.
While relaxing your body and muscles, before sleep, think about what you had learned. When you feel you’re just about to doze off, wish to dream about that. This is how you give orders to your brain, telling it what to focus on – and it will. You are almost certain to dream your latest lesson, unit or whatever it is that you were learning.
Don’t worry if you don’t recall your dreams – it is scientifically proven that we all dream in all sleep stages, not only in REM sleep. People only recall their dreams if woken from the very dream, but if the sleep cycle is over, we might not be able to remember.
Can I learn new things while I sleep?
Learning something completely new while sleeping is called hypnopaedia. In the 60s and years later, it was extremely popular – people were buying audio materials of motivational and self-improvement messages, languages and playing them while sleeping, believing that they would be able to learn or change themselves effortlessly.
Now we know that there are brainwaves which distort noises occurring while we sleep, so what our brain gets isn’t much information – moreover, if the information isn’t successfully processed in our prefrontal cortex, it can’t be learned from scratch in sleep.
The only type of sleep-learning that was recorded was conditioning – linking smell and simple sound stimuli. A study showed that people can unconsciously acquire reactions. When a sound was played, an unpleasant smell was released, and another sound was paired with a pleasant smell. People were unconsciously sniffing stronger after hearing the second sound (as if to enjoy the smell) and less after the first sound (as if to avoid the smell). This happened during sleep and persisted in wakefulness.
This type of conditional learning can’t be considered ‘real’ learning. We can’t learn a single new word in sleep.
However, we can learn new things while awake and then enforce our knowledge in sleep. For example, we can study German next to a plant which has a distinct smell. When we go to sleep, we can put the plant next to our bed and let the association influence our nightly brain activity. This is not learning from scratch in sleep, though – it’s just ‘reviewing’.
- Schoch S, Cordi M. J, et al. The effect of dream report collection and dream incorporation on memory consolidation during sleep. Journal of Sleep Research. https://www.biorxiv.org/content/early/2018/05/17/323667 Accessed February 5, 2019.
- The Importance of Sleep in Learning. Learning How to Learn: Powerful mental tools to help you master tough subjects. Coursera. https://www.coursera.org/lecture/learning-how-to-learn/the-importance-of-sleep-in-learning-AsWfx Accessed February 5, 2019.
- Rasch B, Born J. About Sleep’s Role in Memory. Physiological reviews. April 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3768102/ Accessed February 5, 2019.
- Sleep, Learning, and Memory. Healthy Sleep. Harvard. http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/learning-memory Accessed February 5, 2019.
- Diekelmann S, Büchel Born J, and Rasch B. Labile or stable: opposing consequences for memory when reactivated during wakefulness and sleep. Nature Neuroscience. January 23, 2011. https://www.ncbi.nlm.nih.gov/pubmed/21258327 Accessed February 5, 2019.
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