The Importance of a Good Night's Sleep

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Sleep allows our brain and body to rest, recover, and prepare itself for the coming day. We spend about a third of our lives asleep. So, what happens when we sleep? And how can we improve it?

Sleep and the brain

During sleep, your brain cycles through four stages:

Stages 1-3 are associated with non-rapid eye movement (NREM) sleep.
Stage 4 is rapid eye movement (REM) sleep.

This cycle (1-4) repeats multiple times, and each stage plays an important role in maintaining overall cognitive performance. While stage 1 and 2 NREM are lighter stages of sleep, these prepare your brain and body for the restorative action of the deeper stages: stage 3 NREM and REM.

Why is sleep so important?

Learning and memory

When we sleep, our brains re-play what happened during the day, sifting through information to select what is important (stored in long-term memory) and what is not (discarded or forgotten). Stage 3 NREM is particularly important for the consolidation of declarative (e.g., facts, places, events) and procedural (e.g., skills, actions) memories. That’s why it’s so important to get a good night’s sleep when you’re revising or learning a new skill.

Mood and emotion

Sleep is also important for emotion processing and regulation. When something happens during the day that triggers high emotion (e.g., anger, sadness, excitement), your brain processes that emotion alongside the memory. Over consecutive nights of emotion processing in REM sleep, your brain removes the emotion from the memory, contextualising the event so that it is properly packaged and stored in your brain. This allows you to remember an event without it triggering the same intense emotions. If you don’t get enough REM sleep, you may feel emotionally reactive (e.g., irritable, sad) which can have a significant effect on your mood and ability to carry out day-to-day tasks.

How to build good sleep hygiene

Good quality sleep is vital for both physical and mental health. It is therefore important to practice good sleep hygiene, tailoring your environment and routine to promote sleep each and every night.

Here are some suggested tips which can be tailored to your circumstances:

1. Keep a regular sleep schedule. Our brains learn from our behaviours and the world around us. When we build good sleep habits, positive behaviours become automatic, allowing you to sleep well consistently.

Wake up at the same time every day, whether it’s a weekday or weekend. Even if you went to bed late, wake up at the same time the next day to reinforce a regular sleep schedule.
Prioritise sleep. Sleep is vital for learning and memory. If you are up late with work or revision, calculate a bedtime that will still give you a reasonable night’s sleep before your wake-up time.
Make gradual changes to your sleep times. Your brain won’t respond well to sudden change, and it will take time to adjust. So, if you want to change your sleep schedule, make small changes of up to an hour or two.

2. Wind down before bed.

Follow a night-time routine.This can include things like washing your face, putting on your pyjamas and brushing your teeth. These activities will tell your brain that you are getting ready to go to sleep.
Do something you enjoy. Allow yourself 30 minutes or so each night to do something that calms/relaxes you e.g., yoga, reading, listening to soft music.
Dim your lights. Bright lights can interfere with your brain’s production of melatonin, a hormone that allows you to sleep.
Turn off your devices. There is significant research, demonstrating that reduced “screen-time” encourages better sleep quality. Turn off your phone, tablet, and/or laptop at least 30-60 minutes before bedtime so that your brain can shut down properly before sleep.
Try relaxation. If you’re worrying about sleep, it may be easier to focus on relaxation. Meditation, deep breathing, and mindfulness can all be helpful for putting you in the right mindset for bed. Worrying about getting to sleep will increase anxiety, making it even harder to sleep.
Don’t toss and turn. If after 20 minutes you are unable to sleep, get up, walk around, stretch, read, or do something else. You don’t want your bed to become associated with restlessness and frustration.

3. Build good daily habits. What we do during the day influences our circadian rhythms which guide our brain’s expectations of behaviour (e.g., eating, waking, sleeping).

Daylight exposure is an important driver of circadian rhythms. When we are exposed to light, our brain signals to cells in our body, preparing it for activity.
Physical activity can make it easier to sleep.
Minimise caffeine in the afternoon-evening as it is a stimulant that will keep you awake!
Try not to eat dinner late, especially big, heavy meals as digestion will interfere with sleep.
Reduce alcohol consumption. It may feel like alcohol facilitates sleep, but this effect often wears off, interfering with important sleep stages.

4. Optimise your environment. Try and create a bedroom environment that facilitates relaxation and is free from distractions.

Use a comfortable mattress and pillow.
Use soft bedding.
Find a comfortable room temperature. Many people find it easier to sleep in a cooler bedroom, cosy under their duvet.
Block out the light with blackout blinds or thick curtains.
Block out noise with earplugs. Or, if you don’t find them comfortable, try a sleep soundtrack such as white noise.

Our January article provides useful tips for building good habits. It can take time, but a good routine can work wonders for your sleep. In turn, improving your cognitive, physical, and emotional wellbeing.

Further information

Podcasts, documentaries, and websites:

Click here to listen to expert sleep physiologist, Stephanie Romiszewski, share advice on how to get a good night’s sleep
Click here to visit Stephanie Romiszewski’s website for information on CBTi, a form of CBT specifically tailored to insomnia
Click here to watch the BBC documentary “How to Sleep Well with Michael Moseley”: