Slip into Sleep Sundays: Sleep Learning

Sleep is known to be crucial for learning and memory formation. What’s more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

We may one day be able to induce brain waves that will enable us to learn in our sleep.

The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

The idea of learning as you sleep was once thought very unlikely, but there are several ways – both low- and hi-tech – to try to help you acquire new skills as you doze. While there is no method that will allow you to acquire a skill completely from scratch while you are unconscious, that doesn’t mean that you still can’t use sleep to boost your memory. During the night, our brain busily processes and consolidates our recollections from the day before, and there could be ways to enhance that process.

Despite being blind and deaf to new information, however, the?sleeping brain is far from idle: it mulls over the day’s experiences, sending memories from the hippocampus – where memories are first thought to form – to regions across the cortex, where they are held in long-term storage. “It helps stabilise the memories and integrate them into a network of long-term memory,” says?Susanne Diekelmann at the University of Tubingen in Germany.

Sleep also helps us to generalise what we’ve learnt, giving us the flexibility to apply the skills to new situations. So although you can’t soak up new material, you might instead be able to cement the facts or skills learned throughout the day.

So far, a few methods have shown promise. The simplest strategy harks back to the research of a 19th Century French nobleman named the Marquis d’Hervey de Saint-Denys. Looking into ways he could direct his dreams, the Marquis found that he could bring back certain memories with relevant smells, tastes or sounds.

Using Your Senses to Aid Memory

While the Marquis simply wanted to seed his slumbers with pleasant and lust-filloed experiences, it now looks like the same approach can also trigger the sleeping brain to replay the learning of skills or facts, reinforcing the memory in the process.

?A look at some of his method of the Marquis reveals something interesting:

·????????Taste

In one experiment, he painted a scantily clad woman while chewing an orris root; when his servant then placed the root in his mouth as he slept, the tart flavour brought back visions of the same beautiful lady in the foyer of a theatre. She was wearing “a costume that would have hardly been acceptable to the theatre committee”, he wrote with delight in his book, Dreams and How to Guide Them.

·????????Sound

On another occasion, he asked the conductor of an orchestra to play certain waltzes whenever he danced with two particularly attractive women. He then rigged up a clock to a music box, so that it played the same tunes during the night, which apparently brought their attractive features to his sleeping mind.

We can see this process every day in our nursery schools – the best way to teach children (and adults too!) is by using music, e.g. nursery rhymes, etc.?You know when a song is a hit when little children are singing it (pay attention to those lyrics!).

Sounds can also help trigger recall, provided they do not wake you up in the process.

In one study,?volunteers found it easier to master a musical game (a little like Guitar Hero) if they heard soft strains of the melody as they slept.

Bjorn Rasch at the University of Zurich found that?the same setup helped Swiss German speakers learning Dutch vocabulary, allowing them to remember about 10% more.

·????????Smell

I know from personal experience how scent can enhance memory – while running a complementary therapy project at a hostel for homeless men, I used essential oils in my treatments – whether delivered physically or in a burner.?I found that using frankincense essential oil – which expands the mind – was triggering depressive moods in the clients.?The scent triggered unpleasant memories related to churches and religion (the majority of the residents were from Ireland).?Awake or asleep, scent reaches from the nasal receptors to the limbic system, where feelings are stored and evoke instant recall.?This part of the brain, also known as the “reptilian brain”, is the instinctual part of us – this is where our survival instincts and emotions sit.

Technology and Brain Wave Research

In the near future, technology may offer further ways of upgrading the brain’s sleep cycles. Memory consolidation is thought to occur during specific, slow, oscillations of electrical activity, so the idea here is to subtly encourage those brain waves without waking the subject.

• Tickling the Brain

In 2004 Jan Born, at the University of Tubingen found that he could help amplify those signals using transcranial direct current stimulation (tDCS), which passes a small electric current across the skull, successfully?improving his subjects’ performance on a verbal memory test.

More recently, he has turned to an even less-invasive form of stimulation, which uses a skullcap of electrodes to measure neural activity,?while headphones deliver sounds that are in sync with the brain waves.

Born used the analogy of a swing to explain: the auditory stimulation is like a tiny push that you might give a child on a swing, so that it gently enhances neural activity that is already present in the brain.

• Game On

If headsets while you sleep don’t appeal, Miriam Reiner at Israel’s Technion Institute of Technology may have a more attractive solution. She hopes to use a form of neurofeedback, which allows subjects to control their neural activity while awake.

The idea is to kick-start memory consolidation straight after learning, which then gives the sleeping brain a head-start as it sets about reorganising the day’s events. “You create a seed that then grows during the night,” says Reiner.?

To test the impact on learning, her subjects first learned a complex sequence of finger movements – a little like learning to play a tune on the piano – before taking 30 minutes of neurofeedback. The benefits were immediate – straight after the training they were about 10% better than the controls, suggesting the computer game really had begun to stabilise their memories as if they were actually asleep.

More importantly, the improvements continued to grow as they were tested throughout the following week, supporting her theory that?neurofeedback could help memories to grow as you sleep.??