4
things you can actually learn while you sleep
Make the most of your
sleeping hours.
It turns out there
actually are a few things you can learn - or at least improve your grasp of -
while you snooze. Most of them depend on one thing: sound. Here are some
of the skills you may be able to sharpen in your sleep.
1. Foreign words
In a recent
experiment, scientists had native German speakers start
learning Dutch, beginning with some basic vocab. Then they asked them to go to
sleep.
Unbeknownst to the
dozing Germans, while they slept, the researchers played the sound of some of
those basic words to one group of them. The other group was exposed to no such
sounds. Later on when they were tested on the words, the group that had
listened to them overnight was better able to identify and translate them.
To make sure the
findings were tied to sleep - and not just the result of people hearing the
words - they had another group listen to the words while they did something
else while awake, like walking. The walkers didn't recall the words nearly as
well as the sleepers.
2. Musical skills.
In another study,
researchers taught a group of people to play guitar
melodiesusing a technique borrowed from the video game Guitar Hero. Afterward, all the
volunteers got to nap. When they woke up, they all were asked to play the tune
again.
Unbeknownst to the
sleeping participants, one group was played the same melody they'd just learned
as they slept. The other group was not. The volunteers who'd been played the
sound while they napped - even though they had no memory of it - played the
melody far better than those who didn't hear it as they
snoozed.
3. Where you put
something.
In a 2013 study, researchers
had 60 healthy adults use a computer to place a virtual object in a particular
location on the screen. When they picked a location and placed the object
there, they heard a specific tune. Then, they did two experiments in which they
had the participants nap for 1.5 hours.
During the first nap,
participants dozed as usual, with no sounds playing. During the second
nap, the tune that was played when they were placing the object was played
again - though none of them reported hearing it.
Not surprisingly,
after either nap, people's memories faded. But their memories faded less when
they'd been exposed - even sub- or unconsciously - to the sound that had been
played when they'd placed the item. Interestingly, their memories were sharper
still when they'd been told the virtual object was of 'high value'.
4. How to protect
special memories
Scientists think our
brains use a special tagging system to separate critical memories from
less-important ones. Those the brain flags as 'important' get sent straight to
our long-term memory, while less-important memories are washed away by new
ones. But researchers think there may be a way to hack this system to our
advantage.
In a recent
study, they found that people who listened to a sound they'd
linked with a memory - even an unimportant one - were better able to hold on to
it.
First, they had a
group of volunteers place icons on a computer screen in a specific location.
The computer was programmed to play a specific sound when each object was
placed. Placing a cat icon played a meowing noise; placing a bell icon prompted
a ringing sound. Then, they let participants nap. While one group of them
dozed, the scientists played the sounds of some of the icons. The other group
heard nothing.
People who listened
to any of the sounds were better able to recall all of the objects: One sound
appeared to help trigger multiple memories.
What's happening
while we sleep that's so good for our brains?
Our brain activity
slows down in specific shifts overnight, with some of us spending more time in
a special phase called slow-wave sleep (SWS) than others. But slow-wave
sleep is also the phase of sleep when scientists believe some of our short-term
memories are moved into long-term
storage in our prefrontal cortex.
In some of these
experiments, when researchers were able to study brain wave activity on the
dozing volunteers, they noticed that those who were exposed to sound overnight
- be it the German words played during the first study or the guitar tunes
played as part of the second - also tended to spend more of their sleeping time
in slow-wave sleep.
In other words,
perhaps the more slow-wave sleep we get, the better - both for learning new
skills and preserving important memories.