A new study has documented structural differences in the brains of preschool age children related to screen-based media use.
The study, published in JAMA Pediatrics, has demonstrated that children who spend more time looking at screens have lower structural integrity of white matter tracts in parts of the brain that support language and other emergent literacy skills. Other affected skills include imagery and executive function. These children also have lower scores on language and literacy measures.
The Cincinnati Children’s Hospital Medical Center study assessed screen time in line with the American Academy of Pediatrics (AAP) recommendations. These recommendations cover time spent looking at screens, access to screens, content that is viewed, who the children are with while looking at screens and how the children act.
“This study raises questions as to whether at least some aspects of screen-based media use in early childhood may provide sub-optimal stimulation during this rapid, formative state of brain development,” says John Hutton, MD, director of the, Reading & Literacy Discovery Center at Cincinnati Children’s and lead author of the study. “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 AAP recommendations lay out the following:
- For children younger than 18 months, screen media should be avoided altogether, apart from video chatting.
- For children 18 to 24 months of age, parents my begin to introduce digital media with high quality programming, and watch it with their children to help them understand what they are seeing.
- For children between the ages of 2 and 5 years, screen use should be limited to one hour per day of high quality programmes, and parents should view the media with children to help them understand what they are seeing and apply it to the world around them.
- Media free times should be established, such as dinner or while driving, and media free locations should be designated in the home.
Dr. Hutton’s study involved 47 healthy children between the ages of 3 and 5 years old and their parents. The children were asked to complete cognitive tests followed by a diffusion tensor MRI – this provides estimates of white matter integrity in the brain. Parents were given a 15-item screening tool, known as the ScreenQ, which reflects AAP screen-based media recommendations. The scores the ScreenQ reported were then aligned to cognitive test scores and MRI measures, controlling for age, gender, and household income.
Higher ScreenQ scores were closely linked to lower expressive language, the ability to rapidly name objects (processing speed), and emergent literary skills in the child. Higher scores were also associated with lower brain white matter integrity, which can affect organisation and myelination – the process of forming a myelin sheath around a nerve to allow nerve impulses to move more quickly – in tracts involving language, executive function, and other literacy skills.
“Screen-based media use is prevalent and increasing in home, childcare and school settings at ever younger ages,” says Dr. Hutton. “These findings highlight the need to understand effects of screen time on the brain, particularly during stages of dynamic brain development in early childhood, so that providers, policymakers and parents can set healthy limits.”
The study was funded by a Procter Scholar Award from the Cincinnati Children’s Research Foundation. The researchers report no financial relationships of conflicts of interest in regard to the study.
John S. Hutton, Jonathan Dudley, Tzipi Horowitz-Kraus, Tom DeWitt, Scott K. Holland. Associations Between Screen-Based Media Use and Brain White Matter Integrity in Preschool-Aged Children. JAMA Pediatrics, 2019; e193869 DOI: 10.1001/jamapediatrics.2019.3869brain, children, children and screens, screen, screen based media, screens