Imagine if every night when you dropped off to sleep, you could learn something new. Maybe you need to make sense of a new topic but cannot bear to spend hours reading up on it. No problem – you could try a helpful audiobook or podcast while you sleep!
It would be amazing if we could make our sleep time work twice as hard for us. Sadly, it is almost impossible to learn new information this way. But is there anything we can do to enhance our language learning skills overnight?
In this article, we explore the science around learning a language in our sleep.
Why try to learn while we snooze?
Sleep learning has been a source of fascination for scientists for years. Babies in the womb are capable of recognising words and sounds, so it stands to reason that our restful sleep may have some hidden potential. Making the third of our time that we are asleep more functional could have a huge impact on human productivity, capability and progress.
This is the premise of an episode of the cartoon series Dexter’s Laboratory, where he builds a machine that will help him learn French in his sleep. He wakes up only able to say one thing – ‘omelette du fromage’ – but bizarrely that turns out to be the ideal response to every question he is asked (which is especially surprising, because the correct French for cheese omelette is actually ‘omelette au fromage’!).
This entertaining episode’s theme touches on one of the deepest challenges we face when we learn a new language. It requires a significant commitment of time and energy to develop the language skills that can take us towards fluency, and it is also difficult to find immersive opportunities to practice (which is why group language learning sessions and even overseas travel can be so helpful). If we could find an extra avenue to solidify our learning and reinforce our familiarity with a language, this might have an amazing impact on our ability to learn it in less time.
Is learning as we sleep the answer though? It is such a large part of our lives that it must be important, so perhaps we should exercise caution before we start interfering with our nightly routine…
What happens while we sleep?
We need sleep in order to survive, just like we need food and water. Sleep patterns vary and some people seem to need more sleep than others, but we rely on our sleep for more than just a restful recovery from a hard day’s work.
As we sleep, we move through different stages. First, we enter a lighter sleep as we drift off, which is the start of our non-rapid eye movement (NREM) sleep. There are three stages of NREM sleep, and our sleep deepens as we move through each stage.
The NREM part of our sleep is when we enjoy the deepest sleep – this is the stage in which we store away our long-term memories and release growth hormones to repair our bodies. This seems to be the most crucial stage of sleep – the stage that helps us remain in tip-top mental and physical shape. Can you imagine an Olympic athlete being willing to mess with their NREM sleep?
The next stage, rapid eye movement (REM) sleep, is where we dream – or, at least, we dream our most vivid and memorable dreams. Our arm and leg muscles become temporarily paralysed, which presumably stops us from jumping out of bed if we see something scary in our dreams!
As the night progresses, we cycle through these stages several times, shifting from the three stages of NREM sleep through to REM sleep, and then back again through the cycle. We tend to spend more time in NREM sleep earlier in the night, so the larger portion of dreamlike REM sleep occurs as the night draws to a close. When we wake up in the morning, we hopefully feel rested and ready for the day ahead – perhaps with a few inexplicable dreams to ponder while making breakfast.
How might sleep learning work?
For a long time, the results of sleep learning studies were inconclusive or speculative, but in 2014 Swiss researchers concluded that listening to languages in our sleep can help to boost vocabulary learning.
The participants in the study were better able to recall a set of recently learned words after listening to them again as they slept, but a separate group who had also learned the words while awake did not perform so well.
This suggests that vocabulary can be reinforced and retained more effectively, but it does not conclude that a language can be learned from scratch. So, while this may present a good rationale for listening to some vocab-boosting audio overnight, listening to a podcast in an entirely new language may be a waste of time.
Other studies have shown some correlation between sleep and learning potential, but the jury is still out on whether there is a truly useful scientific approach out there. Further research may unearth more intriguing learning options: only this year, researchers proposed a way to learn words during sleep using a word association technique.
Why sleep learning is not the answer – at least for now
The human brain is incredibly complex, and it is still something that scientists are working hard to understand and make sense of. There are several products and services that make outlandish claims about the potential of sleep-learning, but there are simply too many unknowns to be sure that sleep learning is truly viable.
In the Dexter’s Laboratory cartoon, the main reason that Dexter can only say ‘omelette du fromage’ is because the audio he listens to keeps skipping, repeating this phrase over and over again as he sleeps. Perhaps the phrase became lodged into his brain, stored as a memory through this constant repetition. It certainly failed to teach him, French – he simply learned to repeat the phrase in a form of rote learning.
Who knows what might be happening in our minds while we are listening to a language learning audio in our sleep – or indeed, what might not be happening that should be happening, such as forming new memories and repairing our bodies? We could be reinforcing a few words of vocabulary at the expense of storing our memories of the important events of our lives. We may even damage the way we process emotions (which is thought to happen during REM sleep).
Sleep learning has not been researched fully enough for scientists to offer conclusive advice on learning a language during sleep. Ultimately, sleep-learning is still little more than science fiction – and your precious sleep time is better used for rest, recovery and storing your long-term memories. For now, save your mind’s energy for enthusiastically engaging with learning a language the traditional way!