Tablets, mobile phones and other handheld devices are extremely popular among children (and their parents). The former get visual stimulation, while the latter get some peace and quiet. But how does screen use affect a child’s cognitive ability? Well, according to a new study by researchers at Children's Hospital of Eastern Ontario Research Institute, less screen time results in better cognition. Specifically, children aged eight to 11 who used screens for fun for more than two hours every day performed more poorly in cognition tests than their counterparts who got less screen time. Moreover, the researchers found that less screen time, nine to 11 hours of sleep every night and at least one hour of physical activity led to even better results. Nevertheless, less than two hours screen time each day was the factor linked with the best performance results. Speaking about the findings of the study, Dr Jeremy Walsh, from the CHEO Research Institute, said: “Based on our findings, paediatricians, parents, educators, and policymakers should promote limiting recreational screen time and prioritising healthy sleep routines throughout childhood and adolescence.” The study, which looked at data from 4,500 children aged 8-11 from 20 locations across the U.S., is published in The Lancet Child & Adolescent Health journal.