A recent study on child brain development and screen time has sparked concerns and discussions.
The study establishes a connection between the extent of screen exposure in young children's lives, their reading and language skills, and the physical development of their brains as observed in MRI scans. Published in JAMA Pediatrics under the title Associations Between Screen-Based Media Use and Brain White Matter Integrity in Preschool-Aged Children, the study sheds light on this correlation.
The MRIs revealed that children aged 3 to 5 who have limited interaction with screens exhibit more pronounced development in the brain's connections responsible for language and literacy. Conversely, children who spend more time with screens display less developed connections between the neurons associated with reading and writing skills. Functional tests supporting these findings were conducted for the children in the study.
"In essence, children with higher screen exposure tend to exhibit lower skills and measures of structural brain development," explained Dr. John Hutton, the lead author of the study and a pediatric researcher at Cincinnati Children's Hospital. "It remains unclear whether screens directly affect this development or if screens displace other activities that are known to be crucial for such development."
Hutton suggested that the decrease in brain development might result from screen time replacing activities like reading and screen-free play, which experts consider essential for child development.
However, experts we consulted were even more cautious in drawing a direct causal link between screen time and underdeveloped brains, whether it is a consequence of screen usage or if other family-related factors play a role. Emily Oster, an economist at Brown University and author of Cribsheet: A data-driven guide to better, more relaxed parenting, highlighted the complexity of drawing definitive conclusions from this study.
"There's a fascination with brain science that revolves around the idea that we can examine the brain's inner workings and discover something crucial," noted Oster. "However, this study cannot conclusively establish whether screen time causes these brain differences or if other family-related factors are involved."
The study itself emphasizes that "further research" is required to comprehend the effects of screen time on the brain development of young children. Experts concur that the study serves as an intriguing starting point for further research in an area that necessitates more investigation. They advise against succumbing to fear and sensationalism.
"This study, being the first to examine brain anatomy differences in young children based on their screen media usage practices, was expected to attract substantial media attention," said Dr. Jenny Radesky, a professor of pediatrics at the University of Michigan who authored the 2016 American Academy of Pediatrics (AAP) digital media guidelines for young children. "Nonetheless, it has numerous limitations, making it a preliminary study that initiates future research and is not evidence of causal relationships."
Accumulating research suggests that excessive screen use may not be ideal for a young child's brain. However, it is important to remember that this single study should not lead parents to fear causing lifelong damage to their children's brains by occasionally using screens, such as showing Sesame Street to keep them engaged while cooking dinner. Here are some key takeaways:
Hutton and his co-authors assessed a child's relationship with screens not just by estimating screen time duration, but by assigning a "ScreenQ score" to each child. This numeric score reflects the extent to which the child's household complies with AAP guidelines based on a survey completed by the parents.
The score includes factors like whether parents adhere to recommended screen time limits for children (no more than 1 hour per day), whether parents engage in digital media consumption alongside their children, and whether screens are present in the bedroom. ScreenQ scores ranged from 1 to 19 (lower scores indicate stronger adherence to guidelines), with a mean score of 8.6.
"Being the first study to examine the correlation between screen time before kindergarten and measures of structural brain development, it offers a fresh perspective on existing guidelines," said Hutton.
However, the author of the AAP guidelines, Dr. Jenny Radesky, expressed reservations about relying on a numeric score to represent a child's relationship with screens.
"It's commendable that the authors are attempting to validate a parent-report measure," Radesky noted. "However, this measure primarily reflects the household's adherence to the guideline. We need more specific measures, which include extensive monitoring and context about when, what, and how screens are used."
ScreenQ, as a measurement, has not been published or scrutinized in a peer-reviewed journal. In an ideal scenario, the assessment of a child's screen time would incorporate more detailed monitoring and context regarding the duration, content, and circumstances of screen usage sessions.
In general, ScreenQ may provide a reasonable measure of how well a family follows AAP guidelines but may not fully reflect a child's relationship with screens.
Imaging trying to persuade a preschooler to remain still inside a loud and intimidating MRI machine. That's the challenge Dr. Hutton and his team faced, and it's impressive that they included 47 children in their study.
Despite this limitation, Emily Oster agreed that this was a valid sample size for the study, with a caveat.
"Drawing extrapolations is always challenging," Oster remarked. "On one hand, convincing children to undergo MRI scans is a daunting task, and the availability of these brain scans is genuinely intriguing. However, when you're exploring the relationship between screen time and outcomes, this sample size is relatively small."
Dr. Radesky presented her perspective more directly.
"This sample of 47 children cannot be considered representative of all children and families in the United States," Radesky emphasized.
Overall, the study revealed a connection between lower ScreenQ scores and stronger reading and language skills, as well as more advanced brain development in areas associated with those skills. Nevertheless, the researchers do not perceive this as definitive proof of a direct causal link.
One of the reasons behind this is the influence of external factors, such as a child's unique personality, socioeconomic background, and other factors, most of which were not considered in the study.
"Each child brings their own set of qualities and characteristics," explained Dr. Radesky.
The study itself demonstrates the possibility that external factors play a role in these outcomes. All researchers we consulted noted that the correlation between literacy skills and ScreenQ scores disappeared when the study adjusted for household income.
"The substantial correlation between household income and these scores implies the presence of larger societal factors," stated Dr. Signe Bray, a researcher of child brain development at the University of Calgary.
Parents understandably seek a definitive scientific guide on the impact of screens on their children. Nevertheless, such a comprehensive guide does not currently exist, which underscores the importance of studies like Dr. Hutton's.
However, this single study, with its small sample size, untested measurement metric, and its inability to establish causation, should not induce fear about children's screen usage. The study's focus on brain imaging may add a sense of urgency and seriousness, but it does not change the message that is already known.
"Parents should be mindful of their children's screen time for various reasons," added Dr. Signe.
Dr. Radesky emphasized, "Parents should not believe that media usage causes damage to the brain. Everything children do influences the brain in some way, either positively or negatively. However, parents should avoid excessive anxiety over every small action they take affecting their child's brain, as this anxiety is a part of intensive parenting that is currently overwhelming parents."