Sleep, studying and Circadian rhythms

Circadiam - sleepThe brain is truly astonishing, if you disagree with that statement it’s just possible you have never heard of circadian rhythms.

Your circadian rhythm is best thought of as a body clock, a 24-hour cycle that tells you when to sleep, get up in the morning and eat. In biological terms the clock is called the suprachiasmatic nucleus or SCN for short. The SCN is a tiny part of the hypothalamus which is situated directly above the pituitary gland in the centre of the brain.



Your body has a clock
Do you wake in the morning naturally or is it the result of a stark shrill from your alarm? If its naturally then this is your internal clock at work. Interestingly it can be pre programmed, you will have done this many time, waking before your alarm goes off for example. We are not talking about 10 minutes before, so accurate is your body clock you can wake 1 minute or even seconds before it is due to go off. Jet lag is an example of what happens when you disrupt the internal clock, your entire body struggles to adapt, affecting your ability to concentrate, eat, rest and sleep.
Interestingly Circadian rhymes exist in all living organisms, including plants. The external stimulus is natural light. However even without light the 24-hour cycle will continue, this has been evidenced by research with people who are totally blind. Although their circadian rhythms are often said to “free run” and extend slightly longer than 24 hours, they continue independent of light.

Why is this important for studying?
One of the reasons for going into so much detail is to illustrate how complex we are as human beings and that what may seem a relatively small change in your behaviour e.g. studying late into the night, can have a significant impact on your ability to function, in this context concentrate and remember.
Pulling an all-nighter to prepare for an exam is a badge of honour that many students will wear with pride. It is perceived as a measure of how committed and mentally tough you are. And on one level the effort and difficulty of the task should be rewarded, but given that examinations are a test of cognitive ability anything that reduces your chances of doing well should be avoided. If Hussain Bolt ran the 100 meters in a record time, having been out on the town the night before, waking up with a hangover and only having two hours sleep he would be a hero. But if he lost, he would be a fool. Why would someone who had invested so much of their time put that at risk?
In simple terms you need to help your brain perform to the best of its abilities.

Circadian rhythms and memory
A little more technical detail to illustrate a simple point, if you don’t follow your natural sleep patterns your ability to memorise and retain information will be affected. Retention appears to hinge on the amount of a neurochemical called GABA which inhibits brain activity. And it is the Circadian clock that moderates the amount of GABA produced. In fact, in an experiment using hamsters where the circadian clock was effectively disabled the hamsters were unable to remember anything.

Mental health types-01There is a far more sinister side to the disruption in your circadian rhythm, ongoing research has identified a direct link with mental health disorders such as depression. This is of particular interest given the rise in reported levels of depression amongst students. One area that is being investigated is screen time be that mobile phones or computers. The artificial blue light emitted from these devices could well be confusing your circadian clock.

Why we sleep is still uncertain but it is believed that deep sleep helps the brain consolidate all the experiences from the day, including what its learned. When you shut down your computer, it may say “do not turn off during this update” – that sounds like  good advice.

And if you would like to find out more

Circadian Rhythm and Your Brain’s Clock

How Your Circadian Rhythm Tunes Your Health


Sleep is for wimps – oh and successful students

Get some sleepAlthough I am sure someone is preparing for an exam this very minute, July/August are the traditional months to take a holiday and get some well earned rest. A holiday can be exactly what you need especially if you have just come to the end of a long period of study followed by in some instances, weeks of exams.

I have to express a personal bias in so much that I believe holidays are essential if you are to be at your best. For me this years holiday has to provide some degree of relaxation after what has been a particularly busy 6 months. I am looking forward to a change of scene, meeting different people and the freedom to wake naturally, feeling rested after a good nights sleep. Holidays are of course very personal and for some an adventure holiday, travelling to new places every day, might be far more desirable.

But one thing that all holidays should provide is the ability to relax and catch up on sleep, even if that means you climb two mountains, swim for three hours before crashing out in a state of satisfied exhaustion on the evening.

Sleep is essential for learning 

Of course sleep is something you should do “properly” every day, it’s just that we don’t. Modern life steals that vital rest time, this is acutely the case when trying to balance both work and study. Studying is often undertaken on an evening and sometimes late into the night as you effectively try to do, too much in too little time.   We now sleep less than we did 50 years ago, it used to be around 8.5 hours, it’s now only 6.5. The sleep should also be of high quality, yet our sleep is interrupted by the lights of mobile phones, and sounds made when texts arrive late into the night. In order to sleep better it is a good idea to avoid light approximately 30 minutes before going to sleep, yet how many read in bed from iPads or equivalent with the bright light emitted from the screen telling your brain to stay awake.

Why sleep is important

We have known that sleep has been important for many years but we didn’t know why, cognitive scientists now have some of the answers. There are three views as to why sleep is beneficial:

One restoration – some of our genes only turn on when we sleep, their role being to make essential repairs.

Two conservation – we sleep to conserve energy, and

Three consolidation – our brain revisit events and experiences, and begins to make sense of them, moving data into long term memory and solving complex problems.

Susanne Diekelmann at the University of Tubingen in Germany says “sleep helps stabilise the memories and integrate them into a network of long-term memory, it 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.”  Bodies need rest – the brain needs sleep Sometimes you may find yourself having to push sleep to one side and in specific situations thats fine.

It’s when lack of sleep becomes the norm that problems arise, the result is greater stress, poor judgement and ineffective learning.   So now the exams are over, take a break, get some quality sleep and try and make a few simple adjustments in you life so that sleep takes more of a priority.

It is a common experience that a problem difficult at night is resolved in the morning after the committee of sleep has worked on it.

John Steinbeck  

Music to help you sleep and two video to watch but not just before you go to sleep

TED neuroscientist Russell foster  explains more about why we sleep  

Arianna Huffington talks about the importance of sleep