Can sleep make you smarter?

Well, no – not specifically. But it does make your brain work a lot better, especially when it comes to learning new things.

According to a lecturer in neuroscience at the University of Manchester, we should spend about one third of our time asleep because it “is not only critical for staying alert and attentive,” but it effects our ability to memorise information.

Here in the Alumni office, we’re not always getting a full eight-hours of sleep a night either, but if you’re regularly getting less than this, it may be worth spending some time improving your sleep routine in the name of brain power.

Dr Penelope Lewis explains that not only does the number of hours of shut-eye we get a night improve our memories, but the different stages of our sleep actually effect our different types of memory.

But how?

The science bit

When we sleep, our brains carry out a kind of ‘rehearsal’ of what we learned during the day. When we learn something, our brain fires around millions of nerve cells (neurones) in certain patterns, and when we sleep, our brain ‘replays’ these same patterns. This replaying is what reinforces our memories overnight.

But, Lewis explains, it isn’t just any old type of sleep that we need.

The different stages of sleep

Every night your body experiences a ‘sleep cycle’ of five different stages, which repeat throughout the night. One cycle takes about 90-110 minutes.

Stage One – You are on the edge of sleep, where it’s easy to wake up. Ever experienced a jolt like you’re falling when you’re first getting to sleep? That’s this stage.

Stage Two – You are in a light sleep; your heart rate has slowed and your body temperature has fallen.

The next stages are the most important ones for brain power.

Stage Three and Four – You are in a deep sleep, where it’s hard to be woken up, and you would feel disorientated for a few minutes if you did.

How it helps your brain:  This is when your tissues are repaired, energy is restored, and hormones are increased. Research has shown that this restorative stage of sleep plays a vital role in consolidating new information learned during the day – the ‘replaying’ we mentioned earlier that helps you memorise things and transfer information from short term to long term memory.

Stage Five – This is called REM (Rapid Eye Movement) Sleep, where you are more likely to dream. It happens after about the first ninety-minutes of sleep and gets longer and longer each cycle.

How it helps your brain: This is the stage of sleep where your brain behaves more like it’s awake. It experiences high levels of brain waves ‘more typical of high-level active concentration and thinking,’ explains This is where your brain is most active (hence the dreaming) and also when energy is given to your brain and body, which supports your daytime performance when it comes to procedural, spatial and emotional memory.

How can you use this theory to improve your brain power?

Back to Dr Lewis again: “On the face of it, we don’t have much choice about the proportions of the different sleep phases our brain obtains in a typical night. Nor do we choose which memories are replayed and strengthened.”

So that means we can’t actually do anything about it, right?


Strategically planning the time of our naps means you can manipulate what kind of sleep you have, because we get more REM sleep in the morning, and more deep sleep in the afternoons. If you want to memorise facts for a test, or learn a new language, then you can try studying intensely in the afternoon and then taking a nap. If you want to remember something emotional like a wedding, or procedural and spatial like a new dance routine or sport, then do it in the morning and take a nap afterwards.

Of course, the best way to improve the function of your brain is to get to the later stages of sleep every night, by increasing the quality and length of your shut-eye. If you struggle with this, there are a few simple steps you can take.

Simple tips for quality sleep

Have a regular schedule
Avoid caffeine after 2pm
Get blackout curtains, earplugs and a comfortable bed
Make sure your room is cool enough, as your body needs to cool down to reach deep sleep

Sweet dreams.