#67 - Blue Screenlight and Bedtime - Part 3
I paused mid-way through an immersive conversation, sat back in my chair, and took in my surroundings.
I was sitting in the cafe section of the conference centre for the 2016 European Sleep Research Society conference in Bologna (that’s in Italy).
All around us were smart looking older men in their suits; lanyards hanging around their necks; deep in conversation with each other. For some reason they were all dressed in black, greys and white.
Across from me sat a young female PhD student - Liese Exelmans - from Leuven in Belgium, dressed in her bright green shirt. I said to her:
“You know what. I bet you if all these sleep experts around us were asked by the media about the link between tech use and sleep, they’d all give the same ‘stock’ answer. They have no clue about what you’ve just told me. They’re stuck in old ideas, yet you’re pushing the envelope!”
(As a sidestep, Doctor Liese Exelmans will be cramming her PhD thesis into a 15-min talk at the WINK Sleep Conference in July).
Two Guys Fishing in the Same Pond
When I started my career as a Lecturer in the mid-2000s, there was barely anyone doing technology and sleep research.
But Prof Jan van den Bulck was one person who stood out.
He proposed a theory known as the Displacement Hypothesis - the idea that people continue their quiet activities beyond their usual bedtime. That is, pre-sleep activities displace sleep. This was a potential reason for technology use affecting sleep.
Over a decade ago, we incorporated Jan van den Bulck’s theory into a comprehensive model for explaining the connection between technology use and sleep (see below).
In the first 2 parts of this blog series, we’ve already examined whether the bluelight from screens makes it difficult to fall asleep. And as you’ve hopefully seen, this is not a reason for technology use affecting sleep.
And we had also tested whether the content embedded within screens is physiologically arousing (eg, increased hear rate) - but we found in a couple of our studies that this did not explain how technology use could affect sleep.
Therefore, what about the Displacement Hypothesis?
Prof Jan van den Bulck talking to the next generation of tech-sleep researchers, Dr Holly Scott, at the 2019 WorldSleep conference.
Enter Artificial Intelligence
Our sleep laboratory experiments investigating screen use before bed were designed to see how alerting the technological activity was. To do this, you need to ensure people switch off their screen at their usual bedtime, and see if they have difficulty falling asleep.
But this isn’t what people usually do in their own home.
So we embarked on two new experiments, with a new protocol as follows:
We ask teens to come and participate in our study, where they get fed pizza, play a new video game, sleep, and get a gift voucher (this has to be one of the easiest research studies to recruit for!).
They get assigned to their own bedroom, and at 8 PM they begin playing the video game. And we say to them “You can play as long as you like, but we’re going to wake you up tomorrow morning at 7 AM and take you to school”.
With infrared cameras, we sit back and watch them for the rest of the night, and note when they turn off the game and attempt sleep.
What did we find?
That us sleep researchers were way behind the tech companies - in this case - game developers.
We found that there is a personality trait called Flow.
When someone is immersed in an activity, where they zone out, and lose track of time, they are in a high state of flow.
And someone stays in the state of flow when there is a balance between the task being just challenging enough, and not too boring.
So in one of our experiments, we tried to bore the teenagers to sleep, by setting the game difficulty level to ‘Easy’.
The problem was there were barely any new games available where the user can set the game difficulty.
The gaming developers had already beaten us to the Flow state.
Dynamic Game Balancing had now been embedded in the majority of games. Its a type of artificial intelligence, where the enemies get easier if the user is having difficulty - yet the enemies get more challenging if the user is getting bored.
Thus, Dynamic Game Balancing ensures the gamer stays in a state of flow.
Bringing ‘Meaning’ to the Tech-Sleep Relationship
In our study, we found that when we set the game difficulty to ‘Easy’ - on average - the teenagers turned off their video game 1.5 hours earlier (compared to the usual ‘Normal’ difficulty.
Let me say it another way.
When teens played the default setting (ie, ‘Normal’ difficulty) they lost 1.5 hours of sleep on a school night.
That’s meaningful!
Compare losing 90 minutes of sleep (due to Flow) vs several minutes of lost sleep (due to a Bright Screen).
And now think about how many times you encounter a social media post that claims the blue screenlight affects sleep vs what tech companies are doing to vulnerable people.
The Social Dilemma
Tech companies want their users to continue using their product for as long as possible.
We discovered this in 2016 - but you can discover so much more for yourself.
If you have Netflix, there is a documentary called The Social Dilemma.
It describes how popular tech companies - Facebook, Instagram, Youtube, etc - are successfully controlling … You.
If I had to set homework for this week, I’d ask you to watch the first 10 minutes and see what you think (and don’t multitask at the same time!).
What About The Title of this Blog?
After researching this area of technology use and sleep, my current opinion is the following:
There is reliable evidence that the bright screens (which contain blue light) not only suppress melatonin, but also increase pre-sleep alertness (eg, self-reported alertness, EEG, cognitive performance; Cajochen et al., 2011; Heath et al., 2014; van der Lely et al., 2015).
If people attempt sleep at a time when they should, they will not have difficulty falling asleep.
But, because of their increased alertness + the fact that tech companies are controlling users (to a lesser or more extent), then people are using technology when they should be attempting sleep.
If the blue screenlight has anything to do with sleep, it’s likely it plays 1/3rd of the role - by pushing away ‘sleepiness’. But the research findings are suggesting the biggest influence is when a vulnerable person (with certain personality traits, like Flow) falls victim to the greedy intentions of tech companies (eg, continuing to ‘use’ for hours when they should be sleeping).
Thus, Jan van den Bulck’s theory from the mid-2000s was correct.
A theory that superseded the commercial release of touchscreens, the prevalent use of screens in bed (and home WiFi), the use of blue-blocking apps and glasses - yet around the time that game developers began implementing flow into their products.
What Should We Recommend to People?
World Sleep Day occurred this week (March 19th).
I took this opportunity to sit back and do nothing. That’s because there are now so many people promoting the importance of sleep. The word is definitely getting out there!
Or is it ? …
A simple Google search shows even some big guns are still suggesting to not use screens in the our before ‘bed’.
As a clinical sleep researcher, I know how tricky it is to change people’s sleep behaviours. For example, it took us several years before we managed to change teenagers’ sleep behaviours with our School Education Program.
You see, just saying something once is likely not enough to change someone’s behaviour. Remember the homework I set for you this week? Are you going to be one of the ones who does it?
Well, here’s a list of things NOT to say:
Remove all devices from the bedroom
Do not use technology in the hour before bed.
It’s interesting that I’m seeing Suggestion 1 less and less these days. I think people realise technology is here to stay.
So here we can borrow from the addiction field, and aim our suggestions at ‘harm minimisation’.
People can use technology in the hour before. And whilst a bright screen doesn’t make it harder to fall asleep, they can dim the brightness to a comfortable level.
But the key thing is that people put their screen down when it’s time to sleep.
This can be an alarm on the phone. Some apps, including social media apps, do have a function to warn you when it’s time to sleep. There are even apps and functions that turn your screen to greyscale (which makes it hard to see those red notifications).
And whilst we have found playing videogames ‘in the hour before bed’ does not make it significantly more difficult to fall asleep, we recommend watching TV, reading, or listening to music.
It’s what we’ve called a ‘Bedtime Menu’.
As Jan van den Bulck has said, as long as the activities are structured, sleep may be protected.
What Was That Conversation in Bologna About?
Liese and her PhD supervisor - Prof Jan van den Bulck - had independently figured out “one size does not fit all” when it came to the technology use and sleep link.
Whilst we were exploring certain personality traits - like Flow - Liese was exploring other traits.
What were they? Well like I mentioned above, we’re incredibly fortunate that she’s going to cram her PhD into a 15-min talk at our WINK Sleep Conference this July.
Do you wanna be one of those people wearing black, grey and white at a conference? Or do you wanna sit down for a coffee with her and see how she pushed the envelope?
Prof Michael Gradisar