Transcriber: Rhonda Jacobs Reviewer: Eunice Tan
In 1964, Randy Gardner, some college friends
and a university professor, Professor William Dement,
decided to go for the world record of days without sleep.
After day two,
Randy could barely hold his eyes open,
and he couldn’t repeat simple tongue twisters.
His friends were falling asleep leaned up against the wall.
By day three, he was uncoordinated and moody.
By day five, he was hallucinating.
He managed to make it to 11 days and 25 minutes
before he was rushed to the local naval hospital,
where he spent, for the first night,
14 hours asleep,
and spent the majority of that time in deep and dreaming sleep -
these are your restorative sleep states.
Moving on to other research,
Williamson and Feyer show us
that if you spend around 15 to 19 hours deprived of sleep,
you will behave as if your blood alcohol level is 0.05.
That’s drunk.
Your reaction times will be 50 percent slower,
and your accuracy will be abysmal.
If I got you drunk and I gave you your keys,
would you drive home?
At the end of a long shift at work, if I gave you your keys,
would you drive home?
Now, in one of these situations, you’re going to be arrested,
and in the other situation, you’ll be thanked for your time and paid.
The answers to these questions
tell us a lot about how we as a society value sleep,
and as individuals, how we value sleep.
We know from the research
that if you don’t get around 7 to 9 hours on average of sleep per night as an adult,
it’s going to impact your mood, your health,
increase your accident rate,
and it’s less likely that your marriage will work out.
(Laughter)
The relationship between sleep and mental health
is intimately and bidirectionally intertwined.
Traditionally, we thought that if you had sleep symptoms,
it was a symptom of your mental health problem.
However, we now know that poor sleep wreaks absolute havoc
on your neurotransmitters and your stress hormones,
making it really hard for you to think straight
and for you to maintain a good mood.
The stats on sleep and health tell us exactly the same story.
If you have disturbed sleep,
you’re more likely to have a cardiovascular event,
get diabetes, get cancer.
And if you’re an under-sleeper,
that’s a person who sleeps for six hours or less,
or an over-sleeper,
that’s a person who sleeps for 10 hours or more,
you’re at higher risk of all-cause mortality.
We are not going to work ourselves to death;
we’re going to wake ourselves to death.
However, each night all of you hold a key,
a magical pill to help you rewire and heal your brain.
Even Randy Gardner held that key,
because when Randy went to sleep
and he spent the majority of his time in deep and dreaming sleep,
he was healing.
During deep sleep,
you open up your brain’s dedicated waste clearance system -
this is your glymphatic system.
And this system,
made up of all these beautiful little glial cells that kind of look like stars,
pulse with your cardiovascular system at night time.
The point to this system is to wash the metabolites out of your brain
and bring fresh supplies in so that you can work well the next day.
We know that in people where they have disturbed sleep
or their glymphatic system can’t work well
because of cardiovascular problems or older age,
we don’t wash these metabolites out of our brains so well.
They build up in our brain,
and it puts us at a seven to 27 percent higher risk of cognitive dysfunction
and of dementia in later life.
But I say to you
that you are waking yourself to death but you can sleep yourself well.
The other sleep state that Randy spent the majority of his time in
was dreaming sleep.
During the day, you process hundreds of thousands of events
that prime synapses -
those are the connections between your neurons or your nerve cells -
that need further processing.
When you go into dreaming sleep,
your brain processes those primed synapses further,
creating proteins and laying down long-term memories.
The other thing that happens
is that you prune away the synapses that you don’t use very often,
and that makes your brain more effective and more efficient.
So what I want to talk to you about today are three locks on your sleep
and three keys for you to unlock that.
And you can start these changes tonight.
Lock number one:
dirty bedtime habits.
(Laughter)
In the 1890s, there was a Russian behavioral scientist called Pavlov,
and he took some dogs and some bells and some meat.
And every time he’d ring the bell, he would present the dog with some meat,
and that would make the dog salivate.
With enough pairings of the stimulus, which is the bell,
with the reward, the meat,
he could make the dog salivate just by presenting the bell.
You are an animal,
and so you can train yourself behaviorally in this way as well.
With enough presentations - clean presentations -
of the bed with feeling sleepy,
eventually, the bed is enough to make you feel sleepy.
But they need to be clean presentations.
So that brings you to key number one:
Clean your routine.
If you have a clean routine, your body learns.
And your body learns to give you melatonin at night
to make you go to sleep at the same time,
and cortisol in the morning to make you wake up and feel refreshed.
Now, when we're talking about the amount of sleep you get,
we also want quality of sleep.
Keeping that same routine is what gets you that quality.
When you’re creating this clean routine tonight,
I want you to think about ...
babies.
If you want your baby to sleep,
you're going to do the same thing every day by routine.
You’re going to give them a light and fairly satisfying meal,
and then you’re going to give them a shower or a bath
because that’s going to help drop their core body temperature,
which is one of the things we do when we go to sleep.
Then you’re going to read them a book
and take them to a room where it’s dark and comfortable and quiet and cool -
around 19 to 20 degrees Celsius.
And you’re going to repeat this pattern because anyone who’s had a baby
knows that if the baby sleeps well, you sleep well.
So you need to think about yourself in this same way.
If you treat yourself with the routine like you would a baby,
you will also sleep well.
If you take nothing else away from this talk today,
I want you to keep the same wake-up time.
Because the research shows us
that is the critical thing you need to keep exactly the same,
with about a half hour change either side,
to make sure that you sleep well, with good quality.
That takes us to lock number two.
Lock number two is overthinking.
Overthinking is not great for your sleep.
And that’s because of how our brain operates at nighttime.
We are a diurnal species -
that means we’re awake during the day and we’re built to be asleep at nighttime.
So at nighttime, your executive functions -
this is a system in your brain that’s responsible for problem-solving
and for directing your attention -
shut off.
And your default mode network -
this is a network inside of your brain
that’s responsible for things like daydreaming and self-reflection -
that turns on.
With this pattern of turning off and turning on,
unfortunately you cannot trust your thinking at nighttime.
We know that from statistics, we have a much higher risk,
or people who are at risk of engaging in self-harm and suicide behaviors
are going to do it at nighttime.
And one of the contributing factors
is this pattern of things that turn off in our brain and things that turn on.
You cannot trust your thinking at nighttime.
Tell me this:
Has anyone had the experience at nighttime
where you wake up in the middle of the night
with an absolute aha moment?
Yeah? Or thought, Oh my gosh, absolute disaster.
Only to then wake up in the morning and realize it was complete waffle.
Yeah? I think most of us can relate to that experience.
That is you experiencing parts of your brain turning off
and parts of your brain turning on.
So that takes me to key number two.
When you go to bed, put your thinking to bed.
Now, I’m going to say that,
and then there’s going to be a lot of people in the audience
that are thinking, That’s not as easy as you’ve said it to be.
But you will all be familiar
with this non-pharmacological, non-invasive technique
that is actually fabulous for helping you direct your thinking
to where you want it to go,
and that’s called meditation and mindfulness.
Now, this has come out of the realm of the esoteric,
and we now know from research
that if you practice this for 15 minutes a day,
you will get the health benefits
and also you will develop a thing called meta-awareness.
Meta-awareness is the capacity to think about your thinking.
Mindfulness and meditation, if practiced,
it’s a bit like you’re weightlifting for your brain.
Now, you remember I said your executive functions go off
and your default mode network goes on.
If you practice mindfulness and meditation,
you’re able to catch this mind-wandering
and bring your brain back to where you want it to be focusing on.
Mindfulness and meditation are the antithesis
to mind-wandering at nighttime.
So lock number three.
Lock number three is your technology is too smart for your biology.
Now, most of you will have one of these beautiful little devices
in your pocket or your handbag.
A lot of you probably take them to bed with you.
They come in around that kind of shape.
And they allow your boss to come into your bedroom with you at 9:00 at night
and tell you that the Friday deadline that was due for Friday
is now due tonight.
They tell you that your best friend can come into your room at 3 AM in the morning
and say that they’ve made the most amazing cheese toastie.
This is fantastic because it means that we’ve got our friends and our bosses
and everyone’s so available.
It’s not great for your sleep, unfortunately.
There’s two theories on why this might be the case.
The first theory is that the content on these devices
is incredibly stimulating or stressful.
And you’ll remember that I said
that one of the hormones you release to wake up is cortisol.
If you are stimulated or stressed,
one of the hormones that you will release is cortisol.
So, simple. Not great for sleep.
The other reason, and the evidence is a little equivocal for this one,
is that the wavelengths of light on these devices is blue light.
And so that means it’s the same wavelength of light
as you get exposed to during the day.
That light goes in through your eye to your suprachiasmatic nucleus -
there’ll be a test on this at the end -
(Laughter)
and that is your master clock.
The suprachiasmatic nucleus resets your entire body clock
to say it’s daytime.
Again, not so great for sleep.
So that brings us to key number three.
Key number three is at nighttime,
put the tech down and let your biology do its job.
If you want to sleep well,
you need to have good boundaries around your tech use.
And this goes for you and your kids as well.
The research shows us
that if you allow your kids to have free rein on their devices,
they’re going to push their bedtime back,
they’re going to want to wake up earlier in the morning,
and they possibly will have a higher risk of mental health problems as well.
So about two hours before bed, devices need to go away.
And for yourself, be a role model at work.
Call a work work meeting.
Say that you went to a TEDx Talk on sleep health
and you now want to be the sleep health advocate at work.
Make sure that there are work boundaries:
no emails after six, nothing on the weekends.
Be a role model.
Because we know that if you want to work hard,
you need to rest harder.
So that gives us three things for good sleep.
The first is clean your routine.
The second is that overthinking is the enemy for sleep.
Meditate.
And the third is put the tech down and let your biology do its job.
I’ve said to you that we are waking ourselves to death.
But let's all start tonight to sleep ourselves well.
Okay, thank you.
(Applause)