Screen Time Limits Actually Are Important!
Worries around children’s internet access and computer use is not new—but don’t write all of it off as pure technophobia. Since the introduction of personal computers and the internet into homes, parents have had to guide and protect their children in navigating our increasingly digital world. A new study suggests that inappropriate content and toxic social media environments should not be our sole concerns—screen time really might be negatively impacting our kids’ brains.
New research by the Cincinnati Children’s Hospital Medical Center suggests that screen time may be hindering normal brain and language development in children. Participants in the study had decreased brain white matter integrity along with lower scores on language tests.
The brain is made up of white matter and grey matter, and while grey matter has received more attention from neuroscientists because of its relation to important functions like thought and memory, grey matter is only a thin layer of the human brain. If we were to compare the brain to a postal service, while grey matter is a letter that arrives in a mailbox, white matter is the postal worker responsible for delivering it to the correct place in a timely matter. Through a network of neurons, white matter transmits signals between the brain lobes, limbic system, and cerebral cortex. As opposed to grey matter, white matter cells are insulated by myelin sheaths to accelerate the electrical impulses to their destination.
MRIs of participants with higher screen usage were linked to impaired myelin sheath formation, meaning that impulses traveled slower through white matter. This finding was reflected the same participants’ lower scores on language tests. All participants were preschool-aged (between 3-5 years old), during which children often develop more complex communication skills such as asking questions, staying on topic telling a short story, and answering questions about what they’ve been told. At such a crucial time in development for language, excessive television, tablet, and computer time could be inhibiting important functions like word selection, literacy, and language comprehension.
Lead author John Hutton, MD, commented, “While we can't yet determine whether screen time causes these structural changes or implies long-term neurodevelopmental risks, these findings warrant further study to understand what they mean and how to set appropriate limits on technology use.”
The study had only 47 participants, but with continued studies on long-term impact and larger sample sizes, we will continue to learn more about how screen time impacts young brains. Until then, Cincinnati Children’s Hospital recommends following AAP guidelines on screen time and advocating for revised guidelines in schools.
Cincinnati Children's Hospital Medical Center. (2019, November 4). Screen-based media associated with structural differences in brains of young children. ScienceDaily. Retrieved November 5, 2019 from www.sciencedaily.com/releases/2019/11/191104112918.htm
Hutton JS, Dudley J, Horowitz-Kraus T, DeWitt T, Holland SK. Associations Between Screen-Based Media Use and Brain White Matter Integrity in Preschool-Aged Children. JAMA Pediatr. Published online November 04, 2019. doi:10.1001/jamapediatrics.2019.3869
Myelin: MedlinePlus Medical Encyclopedia. (n.d.). Retrieved November 5, 2019, from https://medlineplus.gov/ency/article/002261.htm
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Speech and Language Developmental Milestones. (2018, October 4). Retrieved November 5, 2019, from https://www.nidcd.nih.gov/health/speech-and-language.