Science fiction loves sleep-learning. In Aldous Huxley’s Brave New World, a young native Polish boy recites verbatim an English broadcast played to him during his sleep the night before. But can this work? Can we acquire languages in our sleep? Well, you may not realise it, but sleeping is in fact the key to learning anything. But not, unfortunately, the way it works in Sci-fi…
Joe Doucet’s “OneSense” concept “anti-distraction” headphone design. Complete focus on audio would be great for language learning and quite the opposite of sleep-learning!
Sleep is one of the most powerful and underutilised tools in your learning arsenal. Research has shown that sleep is a vital part of the learning process – most importantly in the consolidation of memories. To get the most out of your practice sessions with Kwiziq French, know this: you’ll remember more French by ensuring you get a good night’s sleep afterwards.
In fact, research shows the time of day that you sleep is not that important. What is important is that you don’t deprive yourself of sleep for too long after you’ve learned or practised something.
If you’re short on time to read the whole article, here’s my Kwiziq French Top Tip for this week:
Sleep as soon as you can after learning something
- Especially if it’s completely new to you
- Even a ten-minute nap will help store your new learning
- If you can’t nap during the day, try to learn in the evening so it’s closer to your sleeping hours
- If you miss a night of sleep, you will lose most of what you learned in the previous 24 hours. Sorry.
There’s a ton of research proving the benefits of sleep to learning.
Hypnopædia – does it work?
Back to Brave New World and listening to audio while you sleep. Does it work for language acquisition?
The answer is, I’m afraid, a resounding no.
Research has largely discredited* sleep-learning or “hypnopædia”.
The reason is simple: sleep is already part of the learning process. But it’s the filing of information part, not the inputting of information part.
* In fact, some very primitive animal learning does occur during sleep, such as associating smells with sounds, but higher level learning, such as language skills, requires a conscious, attentive state.
In fact, even “passive listening“, where you are awake and listening to foreign language audio in the background whilst doing other things, is mostly a waste of time – other than for picking up the basic sounds of a language.
As Benny the Irish Polyglot – with more than 9,000 hours of language learning experience – explains:
After sitting my German C2 exam, a few hours of spoken practise [sic] per week gave me 75% in the oral exam, and actively writing several texts for correction gave me 74% in the written exam, both of which I’m very pleased about. But passively hearing over a thousand hours of German radio got me a disappointing 37% in the listening exam.
(emphasis mine)
If you’re tempted to try hypnopaedia or buy a product based on it, don’t waste your time or money – read on:
How Short and Long-Term Memory Works
The exact mechanisms by which the brain stores memories are still the subject of much research and debate. Most psychology-based models about memory are basically just BS in my opinion (that’s Bad Science), but neuroscience’s understanding of memory has made enormous progress in the last few decades, and you can use this understanding of how memory works to accelerate how quickly you acquire French and get the best results from your practice with Kwiziq French Kwizzes (and anything else you use).
During the day, your brain processes vast volumes of information and it all needs sorting, filtering and filing for later retrieval and use – which is essentially what learning is. This sorting and filing process happens during sleep. In fact, it’s very likely to be the reason sleep itself evolved at all. (The only animals that don’t sleep are those that completely lack brains.)
Understanding how we learn and form memories can help set your expectations about learning French (which is good because having the wrong expectations can be very disempowering for students) – and it can inform learning strategies and tactics to make you a much more effective student.
I’m not going to dive too deeply into neuroscience, but let’s have a little toe-dip into that most marvelous of structures currently sitting inside your skull trying to take all of this in…
Short-term memory
Your brain stores different types of information in different ways. Remembering past events (“episodic memory”) is handled differently by your brain to remembering how to ride a bicycle (“procedural memory”). You also have two types of memory that work on different timescales: short- and long-term memory.
Your short-term memory is very small. By contrast, your long-term memory is so large its size is still being debated and may be as much as one exabyte. Tto give you an idea of the sheer size of this, it is estimated that all human texts ever written can be stored in just 5 exabytes.
This might seem surprising given how forgetful we sometimes feel, but forgetting is an entirely different process to remembering – one that is both manageable and preventable if you understand how memory works. We actually need to forget things to function. People who cannot forget (an extremely rare condition known as “hyperthymesia“) are usually dysfunctional, crippled by this inability.
Short-term memory is a process in the brain (as opposed to a structure)
It’s very likely that short-term memories are represented by complex patterns of firing neurons in your brain’s existing structures. The problem is that when you experience new things, the structures required to run those patterns don’t really exist yet. It’s a bit like walking into a field of long grass to make a pattern. The grass bounces back and the pattern is really weak (I’ve used this metaphor before in How to Improve Recall by up to 300%).
Metaphors are great, but it’s really worth actually understanding in more detail what really is going on.
Neurons – the cells that comprise your brain – are fascinating things. Your brain is one of the most complex structures known to humans in the universe (so far, anyway), containing somewhere between 86 and 100 billion neurons. Each neuron has an estimate 7,000 connections (called “synapses”) to other neurons forming a vast information processing network with a hundred trillion synapses.
I’m not going to go into great detail about how neurons and synapses work but this video animation explains them nicely if you want to learn more. (Beware: most animations on Youtube claiming to explain neurotransmission get it wrong. The one I’ve selected for you is quite good though. Electrical currents don’t go up and down a neurons length, for example, as many people believe: it’s more like a Mexican wave of charged ions entering and leave the cell’s walls, but that’s another story.)
So where and how are facts and memories actually stored in this huge neural network?
Your brain isn’t like the internet with each neuron acting as a computer with a hard drive storing stuff. Facts and memories are actually stored as synpaptic structures distributed through many neurons in the brain. When neurons fire (send messages to each other) it’s the firing patterns that represent the thought/fact/memory/sensation. There’s a unique pattern for every thought, feeling, fact or perception you have ever had and ever will have. Thoughts are more like musical melodies that play out as a result of the resonating structures of a fantastically complicated instrument.
The challenge the brain has in learning is this: in order to play new melodies it needs to reshape itself – create new resonating structures and patterns. The existing ones don’t work very well.
This is why short-term memory is both fragile and small. The melodies are quiet and they rapidly fade away because there is no strong resonant structure for them.
Repeating a new fact, sound, sentence, etc works because you force your brain into firing a pattern it hasn’t played before.
If the pattern is entirely new – unrelated to anything played before – your brain may not be able to play it all, which is why you can’t just teach a five year old how to do calculus: you need to build up the that. And it’s why when you hear people speaking a foreign language for the first time ever, you cannot even hear individual words. All you hear is a stream of babble.
This tells us something really useful:
To learn most quickly, build on existing knowledge.
Knowing what you already know is vital to this. (By the way, this is fundamental to how Kwiziq, the technology that powers French-test works – by being test-driven, we know exactly what you know and can build up from that. So, testing yourself constantly is really an amazingly effective way to learn.)
So, how does sleep come into this?
You can’t play an instrument at the same time as re-engineering it.
It’s currently believed (by one model, at least) that when you learn something, you deplete neurotransmitters in your brain in an iconic structure (pattern) that represents the thought/memory/experience. In other words, the shape of what you just tried to learn is carved out like a negative exactly because your brain had difficult playing it. A bit like the after-image you see when you look at the sun.
But it doesn’t last long. A new memory like this will fade completely within 12-16 hours as the neurotransmitter levels are slowly restored. But when you sleep, your brain re-engineers itself to fix this.
If you sleep before these patterns vanish the brain does something amazing. New synapses form where the neurotransmitters are depleted. Existing synapses undergo a process known as up- and down-regulation where receptors for neurotransmitters are removed or added to the cell membrane (the membrane is like a magic liquid wall that can reshape itself and add and remove gateways to let specific things in and out).
Almost certainly a whole bunch of complex structural changes happen that we don’t yet even know about or understand.
The point is, in order to make these changes, and to know which changes to make, the brain must be quiet.
This is sleep.
The more you learn the more you need it. This is why infants need to sleep up to 16 hours a day (they have a lot to learn), why teenagers can sleep eleven hours a day, and why as we age we need less and less sleep: we’ve already learned most of what we’re exposed to. And it’s why learning a new language is one of the best ways to keep an older brain from ageing and protects against neurodegenerative diseases like Alzheimer’s.
Long-term memories are actually physical structures in your brain
New synapses and changed synapses (and even entirely new neurons). This ability for the brain to restructure itself is called neuroplasticity.
These newly created structures match better the firing patterns that your brain initially found difficult to "play" when you were awake. Figuratively speaking, the instrument (ie, your brain) resonates much better now with these melodies and can therefore play them back better and more quickly, and the "music" lasts longer. The new arrangement of neurons and synapses can fire these patterns more strongly.
Long-term memories are permanent structures in your brain. That’s why they are enduring, and your hundred trillion synapses are why you can store such a magnificent amount of them. It can take many nights worth of sleep and repetition of patterns for these resonant structures to be really effective, stable and reliable.
Knowing this, you should not expect of yourself to learn something new in a day, or even overnight.
To really embed something properly can take up to a week
The better you sleep, and the more rehearsing you do of the same subject matter during that time, the more stable those structures will become.
Something almost magical occurs after seven days of practising, rehearsing or testing. Things that we found tricky to recall suddenly are effortless.
And why?
Because you slept properly on it.
Take your first French test and find out your level.
Author info
[Follow on Twitter: @gruffdavies] Despite the very Welsh name, Gruff is actually half French. Nowadays, he's a tech entrepreneur (and some-time novelist) but he used to be a physicist at Imperial College before getting hooked on inventing things. He has a special interest in language learning, speaks five languages to varying degrees of fluency and he often blogs about language learning, science, and technology. As well as co-founding Kwiziq, he is the author the Amazon best-selling SF thriller, The Looking Glass Club and the inventor of the Exertris gaming exercise-bike and Pidgin, a free online tool that makes drawing flow charts and relationship diagrams as quick and easy as describing them in pidgin English.