Devices including TVs, smartphones and tablets could change the brain structures of young children, according to scientists—who fear such technology could affect the development of language and literacy skills.
However, experts stressed the results are preliminary, and parents needn't worry unnecessarily that they have damaged their child's brain by letting them use such gadgets.
For a study published in the journal JAMA Pediatrics, researchers recruited a total of 47 healthy children aged between 3 and 5 years old, who underwent MRI scans to map their brains, and sat language and literacy tests. Of the total, 78 percent of the participants had mothers who were college-educated, meaning they were relatively privileged. Their parents completed a survey on how much their child used devices with screens, as well as the sort of content they interacted with.
Dr. John Hutton, director of the Reading and Literacy Discovery Center at Cincinnati Children's Hospital Medical Center and lead author of the study, told Newsweek the results of the questionnaire were used to generate a score reflecting how well the children adhered to the American Association Pediatrics screen time guidelines. A score of 26 meant none of the advice was followed. Scores ranged from one to 19, with 8.6 being the average. Using a device at mealtime would get one point, for instance, while having a screen in the bedroom would get two points.
The scientists looked at the children's brain wiring, and found differences in the scans of those who scored higher. In the parts of the brain related to language and literacy skills, their white matter integrity—associated with how quickly nerve impulses fire—was lower.
They also had lower expressive language skills, worse emergent literacy skills, and took longer naming objects.
However, the associations were no longer found to be significant when the researchers factored in household income.
On average, the children were introduced to screens at 18 months old and used such devices for 1.5 hours per day. Some 60 percent of the children had their own device, and 41 percent had a T.V. or portable device in their bedroom.
Past studies have shown children under the age of nine spend an average of more than two hours on screened devices outside of school. The American Academy of Pediatrics recommends parents limit the time kids use screens, fearing they may cause issues including sleep problems, and delay the development of language and thinking skills.
Similarly, the World Health Organization warns children aged one shouldn't use screens, and those aged between two and five should use screens for a maximum of one hour per day.
Dr. John Hutton, director of the Reading and Literacy Discovery Center at Cincinnati Children's and lead author of the study, told Newsweek: "This is the first study to document associations between higher screen use and lower measures of brain structure and related skills in preschool-age children."
Hutton stated that although the study's methods mean it can't prove that screens cause negative outcomes, "we believe that an abundance of caution and further research are warranted, to make sure that devices and media are being used in a way that is healthy for kids at different ages and developmental stages."
Further research is needed to discern risks and benefits at different ages, he said.
Experts in the field who did not work on the paper responded cautiously to the findings.
Daniel R. Anderson, Professor Emeritus at the University of Massachusetts Department of Brain and Psychological Sciences, told Newsweek: "The study is provocative, but far from conclusive."
Anderson argued the survey completed by parents is not a good measure of media use in children. It doesn't, for instance, distinguish between preschool educational television and other forms of television, he said.
"Prior research shows better language development if screen media use is predominantly educational, programs such as Sesame Street," said Anderson.
"The best explanation of the findings might well be that children with poorer development in language-related brain areas are more drawn to screen media," argued Anderson.
"In other words, slower language development causes screen media use, perhaps because visual action is more understandable then verbally described actions in books or audio stories," he said.
While the paper is not strong enough to influence how parents allow their kids to use electronic devices, said Anderson, he suggested it is important to remember that young children are known to learn language best when interacting with adults.
Screen time may be cutting into this time, and "that creates the relationship, between screens and language tracts, not the screen itself," he said.
Dorothy Bishop, a professor of developmental neuropsychology at the University of Oxford, said in a statement: "Overall, this is a small study on a sample of preschool children from advantaged backgrounds who show no signs of language or educational difficulties."
"It seems likely that the association with white brain matter connectivity reported here would not replicate if the study were repeated," argued Bishop.
"The study does not provide credible evidence of an adverse effect of screen time on child development, but could serve to stoke anxiety in parents who may worry that they have damaged their child's brain by allowing access to TV, phones or tablets," she said.
Derek Hill, a professor of medical imaging at University College London, said in a statement: "The researchers measured screen time from a recently developed questionnaire answered by parents. This questionnaire may not be very objective or accurate—it might pick up parental worry more than actual time using screens."
He said: "This research is a useful contribution to the debate and should encourage further research."
Compiled by Olalekan Adeleye