Children under two years should not be stuck in front of a TV or gadget. At most, children aged two should only be exposed for one hour a day, says the World Health Organisation’s new guidelines on physical activity, sedentary behaviour and sleep for children under the age of five. These guidelines are a rude shock to many parents who feel that some screen time isn’t so bad, provided it’s for educational videos or apps. We chat with clinical neuropsychologist Dr Marieke de Vries about the impact of screen time and gadget use on children’s cognitive development.