Screens and their impact on the developing brain
Screen time is involved in many battles in households up and down the country.
How much screen time for children is too much? What effect does screen time have on development? In this article we’ll examine the impact of screens on the brain of growing children.
Screen Use in Children
The present generation has grown up using screens from a very early age. Most children spend their time endlessly scrolling, texting and engrossed in their phones, as well as using computers for schoolwork and watching TV in the evening.
One recent survey of children under 14 found they spent an average of almost three hours and 20 minutes on their phones per day – twice as long as they spent talking to their parents.
Screen Use Affects Brain Development
One ongoing study is looking into the effects of screens on children’s developing brains. It is following over 11,000 children between the nine and ten years old to examine the effects of screens on the physical development of brains as well as emotional health.
Interim results from the study revealed MRI scans showed significant differences in the brains of children who used screens for more than seven hours per day.
Specifically, children spending a lot of time looking at screens had premature thinning of the cortex, which is the wrinkly outermost area of the brain. The cortex processes different types of sensory information. The children’s brains showed changes which would be expected at a much older age. The implications of these are not yet clear.
Even as little as two hours of screen time per day has been shown to lead to lower scores on thinking and language tests.
Although cause and effect have not been established, there’s clearly a link. It’s possible children who have difficulty with certain mental tasks, or those who are genetically prone to the brain changes observed are those who are drawn to screen usage.
Screen Use and Emotions
Screen time has been linked to an increase in depression. Researchers discovered students who restricted social media screen time to less than 30 minutes per day were significantly less lonely and depressed after as little as three weeks. Interestingly, the students who limited their screen time appeared to progressively reduce their anxiety about missing out.
Another study scanned the brains of adolescents as they checked social media and found the reward system of the brain was activated, with the brain chemical dopamine being released. Dopamine is associated with reward, which may be why screen usage can be so pleasurable. This has implications because high dopamine levels can be related to addictive behaviour.
Using screens in the evening is, unsurprisingly, linked to poor sleep. This is because they emit light at the blue end of the spectrum, which boosts alertness. It’s particularly relevant because in the UK, the average child spends one and a half hours looking at a screen before falling asleep.
Screens and Learning
Although screens can be a useful learning tool for children, it’s accepted by experts that children under two years of age don’t learn from a screen in the same way as they do from interacting with a real person. They learn from exploration and need hands-on social interaction with caregivers.
Young children have difficulty transferring learning from digital media to real life. In other words, if they are given a screen which simulates play with building bricks, and are then given the real bricks, they need to learn from the beginning how to use them.
In one small study, toddlers were given a choice of three toys – a plastic guitar, one iPad which passively played musical notes and another which emitted lights, colours and sounds when pressed. The children were far less likely to give the interactive iPad back when asked than they were the other toys. These devices are much more engaging to young children because they reward certain behaviours.
Screen Time Guidance
The World Health Organisation has drawn up a set of screen usage guidelines, which suggest children aged under two should have no screen time at all, but instead be engaged in reading and storytelling with a caregiver. Children’s brains develop rapidly before the age of two years so it’s a critical period for development, and screens may have a greater effect during this time. The guidelines for children aged up to four years are for no more than one hour of screen time daily.
All screen time is not the same, however, with constant social media exposure having different effects to watching TV or doing homework on-line.
Unfortunately our knowledge on the effect of screen time is limited, and information will only be discovered over time as children grow older. Screen time is also connected with sedentary behaviour, less sleep and staying indoors, all of which have effects on healthy brain development, so it makes sense children’s screen time should be limited.