Scientists study the effects of tablets on our children

vrijdag, 22 juli 2016 - Categorie: Artikelen

13 juni 2016

Could an iPad hold your baby back? Scientists study the effects of tablets on our children

Olivia Solon reports on the first study into touchscreen tech’s effects on brain development

Jessica’s tiny fingers dart around the iPad, swiping through photos to get to a particularly entertaining video: a 12-second clip of her dancing to Beyoncé’s “Single Ladies”. The 18-month-old taps “play” and emits a squeal of delight.

When Jessica’s mum, Sandy, tries to take away the iPad, there’s a tantrum that threatens to go nuclear: wobbly lip, tears, hands balled into fists and a high-pitched wail. “She does this a lot,” says Sandy. “She seems to prefer the iPad to everything else. Sometimes it’s the only thing that will keep her quiet.”

Technology companies and app developers are throwing their marketing prowess at the problem, slapping words such as “educational” and “e-learning” on their products, often without any scientific basis. But like many parents, Sandy is worried about her child’s obsession with screens. She wants to know which activities are best, and how much time spent on screens is too much.

It’s six years since the launch of the iPad and the birth of tablet computers. These devices are the right size for little hands to handle, and the touchscreens are easy for tiny fingers to manipulate. Plus, there’s so much you can do on these devices: watch videos, play games, draw pictures.

A 2015 study in France found that 58 per cent of under-twos had used a tablet or mobile phone. But the academic research simply hasn’t been able to catch up, which means it’s hard to know the long-term impact on young brains of being exposed to tablets and smartphones.

The concern among some experts is that these devices, if used in particular ways, could be changing children’s brains for the worse – potentially affecting their attention, motor control, language skills and eyesight, especially in under-fives, for whom so much brain development is taking place.

What science says so far

There’s little clarity around the consequences of long-term use of such devices. The American Academy of Pediatrics (AAP) has erred on the side of caution, recommending absolutely no screen time for children under the age of two, and a two-hour daily limit for those older.

“If your child is under two and is exposed to a screen it’s not going to be toxic to their brain: they won’t be turned into idiots,” says Michael Rich, Associate Professor of Pediatrics at Harvard Medical School and an AAP member. “But there are potential downsides… and parents need to make a series of risk–benefit analyses.”

Most child-development experts agree that while passive screen time – such as putting your child in front of a device for a Peppa Pig marathon – might be entertaining, it isn’t going to provide a rich learning experience. If kids are left to play on screens then they are not interacting with the physical world.

There are only so many hours in a day. Under-threes, in particular, need a balance of activities, including instructed play, exploring the natural environment, manipulating physical toys and socialising with other children and grown-ups. The rise in screen use means less of all of these things.

“Parents need to think strategically,” says paediatrician Dimitri Christakis, director of the Centre for Child Health, Behavior and Development at the Seattle Children’s Research Institute. “If your child has 12 hours awake and two of those are spent eating, how do you allocate the rest of the time?”

The problem is that tablets and smartphones make for excellent pacifiers, particularly on long flights and in restaurants. Although helpful in the short term, it’s important for young children to be able to develop internal mechanisms of self-regulation – whether that’s learning without constant rewards or being able to sit patiently without constant digital stimulation.

Christakis says that, anecdotally, he and others are starting to see younger and younger patients using these devices compulsively. “We know there’s such a thing as problematic internet use in older children and adolescents, and it stands to reason that the same would happen with infants,” he says.

The mice experiment

In Seattle’s Centre for Integrative Brain Research, baby mice are exposed to the high-octane soundtrack of Cartoon Network shows accompanied by synchronised flashing lights in red, blue and green, for (like The Powerpuff Girls, pictured) 42 days, six hours every day.

The apparatus has been designed to find out what happens to the rodents’ brains when they are overstimulated by media during a critical window for their development.

The results are startling. “Overstimulating them as babies primes them to become hyperactive for the rest of their life,” said the centre’s director, Professor Nino Ramirez. The overstimulated mice take more risks and find it harder to learn and stay attentive.

They get confused by objects they’ve seen before, for example, and find it more difficult to go through a maze. When given the option to dose themselves with cocaine, these mice were much more prone to addiction than the control group. These behavioural changes are matched by changes in the mice’s brains. The theory is that the same applies to children.

Before we trigger mass panic, it’s important to note that these experiments have drawbacks. The mice are not absorbing content that is meaningful to them, and the lengths of time they are exposed to the media far outweigh what young children experience.

Baby-faced research subjects

Some experiments are already being conducted on children. Max, who is 12 months old, is sitting on his mother Helen’s lap in a small, darkened room. On each of Max’s ankles is a smartwatch, one measuring his movements, the other his heart rate. On his head is a rubbery cap covered in electrodes. They are measuring the electrical activity in his brain, to understand whether real and virtual objects trigger different brain responses.

The experiment is part of the Tablet project in the Babylab at Birkbeck, University of London. It’s the first ever scientific study investigating how children aged six months to three years are using touchscreen devices and how this influences their cognitive, brain and social development.

In a second experiment, Max sits in a curtained-off booth facing a screen that displays a 15-minute loop of video that includes trippy abstract animations and sounds, as well as still pictures and videos. He’s mesmerised, and his eyes dart from object to object on the screen. Eye-tracking cameras capture the dance of his gaze, and outside the booth, research fellow Celeste Chung keeps track of how his eye movements match up with the items on screen.

“All the child is doing is looking at the screen, but their gaze behaviour tells us about their learning and anticipations,” says Tim Smith, a cognitive scientist who heads the Babylab. His team is trying to understand how easily Max, and dozens of other babies like him, can focus attention and block out distractions when working on a particular task.

“Some of the parents in our study are reporting three hours of tablet use a day for their children,” says Smith. “That is a large proportion of their waking hours using a screen.”

Devices such as iPads may give lots of stimulation, but they lack the nuanced real-time social feedback that helps develop language, says Smith. Similarly, tablets and phones may make children dexterous at fine-motor control with all the tapping and swiping, but they may have less motivation to get up and explore the world around them.

After around an hour of assessment, Max’s patience for screen-touching, eye-tracking, brain-monitoring and other distractions from his busy schedule of rampaging around and eating bread sticks wanes. He starts to grizzle and wriggle and claw at the EEG cap. These movements corrupt the brain-activity data. “That’s the interesting challenge with infants,” says Smith. “They’re completely non-compliant to instructions.”

Are we being short-sighted?

In California, Maria Liu heads up the Myopia Control Clinic at UC Berkeley’s School of Optometry. She has seen a sharp increase in young children with shortsightedness. “It’s increasing at an alarming rate worldwide and a well-accepted contributing factor is the early introduction of handheld devices to kids.”

In our early years, our eyeballs are very adaptive and plastic, so spending lots of time focusing on objects close-up will make the eyes more likely to be near-sighted. “The eyeball will grow longer to compensate for the prolonged near stress,” Professor Liu says. She does not have any evidence-based recommendations for a time limit on use of devices, but says “frequent breaks from near work” are very important.

Tablets and smartphones are typically viewed much closer to the face than televisions or desktop computers. Although books are also read up close, studies have shown that children tend to hold them further away than they do screens.

The other problematic aspect of screens is that they have been shown to disrupt sleep. The blue light emitted by the super-sharp displays can interfere with our natural body rhythms, preventing melatonin, an important sleep hormone, from being released. This, in turn, can lead to sleep impairments in adults and children alike.

This issue is why the latest version of Apple’s software for iPads and iPhones comes with “Night Shift”, which automatically swaps the blueish light for a warmer hue before bedtime.

What should parents do?

Although we are still in the early days of understanding the impact that mobile computers are having on young children, the key piece of advice from most experts is to make sure that device use is just one part of a rich diet of activities, particularly for under-threes, who seem to struggle to learn from screens.

Interactive, creative touchscreen experiences are preferable to passive TV-like viewing. Parents should also take educational claims from app developers with a hefty pinch of salt. Where possible, a device should be used as a tool to enhance interactions with the child by talking with them about what they are seeing.

But the experts do also acknowledge that parents need time to themselves; helping to distract a child for a short time can be very helpful. For many mothers, this realistic advice will be a relief – they shouldn’t have to feel guilty about giving their child an iPad so they can have some “me time”.

Yet there’s still a lot of snobbery about screen use. “As a mum, I put my 18-month-old in front of a baby poetry video,” says Jenny Radesky, assistant professor of pediatrics at the University of Michigan. “It’s cute and calm and I can wash the dishes or do something that’s a reset for me. That’s a benefit, but it’s something parents need to be very honest about. The video is not educating my 18-month-old. It’s a break for me as a parent.”

This is an edited version of an article that first appeared on and, and is republished here under a Creative Commons licence.

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