What using cellphones before bedtime does to our kids

What using cellphones before bedtime does to our kids – according to science

Cellphones have lots of positive features – they help us keep track of our kids, gives us instant access to a GPS, and let us stay in contact with friends and families. But when it comes to bedtime, they need a little more monitoring. Scrolling through social media, watching a favourite YouTube channel, or texting friends – it all interferes with our children’s sleep. Here’s the science behind why.

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How the sleep-wake cycle works

Our bodies run on regular 24-hour cycles called circadian rhythms that control, amongst other things, the sleep-wake cycle. A huge contributor to the timing of our circadian rhythms is exposure to natural light. Special cells in our eyes called ganglion cells, absorb blue light from the sun and then send signals directly to the circadian region of the brain.

This is why we feel awake when it’s light and start to get tired when it’s dark. It’s a simple yet effective way to regulate an important biological necessity. Which is why throwing artificial light into the mix can get in the way of this.

Phones and sleep delays

Phones and many other devices give off a blue light that mimics sunlight. Using these devices close to bedtime confuses the brain and actually suppresses sleep hormones. This means if our kids are using a phone until bedtime, they might not feel tired for another hour or two.

And it’s not just the light that causes sleep disturbances. A study published in JAMA Pediatrics found that kids knowing they had access to a device while lying in bed is enough to affect their sleep. Many children in the study had a hard time settling down for the night when they knew their device was nearby. They had delayed sleep onsets and shortened sleep times, which made them sleepy the next day. Similar studies have found that internet use and gaming can have these same effects.

Your children without sleep

What happens to kids when they don’t get enough sleep? Many of the same things that happen to adults – only with greater intensity. Their ability to monitor and regulate their emotions goes way down. The emotional centre of their brain becomes overactive and extra sensitive to negative emotions and thoughts. The part of their brain that applies reason to their emotions also gets quiet when they’re tired. That’s why many kids can have emotional outbursts and challenging behaviour after a poor night’s sleep.

Appetites also change. Not sleeping enough causes the body to release more of the hunger hormone ghrelin and less of the hormone leptin, which tells your body when its full. On that note, when someone is running on not enough sleep, the reward centre of the brain gets ‘runner’s highs’ from high-fat and sugar foods. One study found that participants chose foods with 50 percent more sugar and twice the fat when they were sleep deprived.

Limit smartphone use before bed for better sleep

Here’s the good news. Turning off phones and devices two to three hours before bed can keep them from affecting our children’s sleep cycles. Why not give it a go? Making these adjustments with our kids can get our families developing healthy habits that help us all get the rest we need.


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