There is a great deal of debate surrounding the issue of young children and “screen time.” It can’t be overlooked that children today are heavily exposed to television, video games, computers and smartphones. And it’s starting younger and younger as the technology evolves. The American Academy of Pediatrics issued guidelines in 1999 that advised no child under the age of 2 should have any screen time, including television. As gadgets like iPads and other tablets came into everyday use, this limit was hard for families to manage. In the fall of 2016, the AAP revised their guidelines, saying that children under 18 months old should still have no screens, except for video chatting, since that can keep working parents connected to their children. In addition, children aged 2-5 are capable of getting some skills from certain apps and computer games, but the pediatricians still believe it should be limited to one hour a day and even then, parents and caregivers should be alongside children as they play.
A new study addressed the issue of the lights and sounds that are often part of screen use. At the Seattle Children’s Research Institute, scientists there recently completed work in lab mice to see how the sensory stimulation of lights and sound, similar to what happens in games, apps and children’s television programs, would affect the brain and possibly behavior. They reported their findings at the November 2016 meeting of the Society for Neuroscience. Their results showed that after being exposed to certain sensory stimuli, the brains of the mice showed “profound” abnormalities and their behavior was significantly changed as well. Most of the mice exhibited behavioral changes that were quite similar to those exhibited in in attention-deficit/hyperactivity disorder.
In terms of stimulation and the brain, the kind of stimulation matters just as much as the amount. There are many developmental toys that have lights and sound and can help the brain develop, but too much or the wrong kind of sensory input has negative consequences in terms of brain development. While it’s difficult to exactly mimic the kind of screen time children get in a lab full of mice, the team decided to use flashing lights and audio from the television shows. For six hours a day, the mice were exposed to a constant stream of stimulation, both visual and audio. The exposure started when the mice were 10 days old and lasted for six weeks. After that, the mouse brains were examined.
Study coauthor Jan-Marino Ramirez stated, “We found dramatic changes everywhere in the brain. Mice that had been stimulated had fewer newborn nerve cells in the hippocampus, a brain structure important for learning and memory, than unstimulated mice.” Behavior was an issue was well. The mice that had been exposed to the lights and noise were distinctly more active than the mice that had not been exposed, they had trouble remembering where their food was, and recognizing objects they had previously encountered. In addition they exhibited risky behaviors, going into open areas in the cages that mice normally would be intimidated by.
It wasn’t the first go round on this kind of research for the team in Seattle. In 2012 they showed similar results in another research study and the most recent work replicates those findings in addition to providing more details about the behavioral changes in the mice exposed to this kind of stimulation. While it remains to be seen if this research translates to human children, it’s important to be aware of what young children are exposed to in terms of sensory stimulation. Check out the video below to learn more
Sources: Science News, Nature.com, Society for Neuroscience, NPR, eNeuro
